Patent Grant
7997687
The following Australian provisional patent applications are hereby incorporated by cross-reference. For the purposes of location and identification, US patents/patent applications identified by their US patent/patent application serial numbers are listed alongside the Australian applications from which the US patents/patent applications claim the right of priority.
Not applicable.
The present invention relates to the field of fluid ejection and, in particular, discloses a fluid ejection chip.
Many different types of printing mechanisms have been invented, a large number of which are presently in use. The known forms of printers have a variety of methods for marking the print media with a relevant marking media. Commonly used forms of printing include offset printing, laser printing and copying devices, dot matrix type impact printers, thermal paper printers, film recorders, thermal wax printers, dye sublimation printers and ink jet printers both of the drop on demand and continuous flow type. Each type of printer has its own advantages and problems when considering cost, speed, quality, reliability, simplicity of construction and operation etc.
In recent years the field of ink jet printing, wherein each individual pixel of ink is derived from one or more ink nozzles, has become increasingly popular primarily due to its inexpensive and versatile nature.
Many different techniques of ink jet printing have been invented. For a survey of the field, reference is made to an article by J Moore, “Non-Impact Printing: Introduction and Historical Perspective”, Output Hard Copy Devices, Editors R Dubeck and S Sherr, pages 207-220 (1988).
Ink Jet printers themselves come in many different forms. The utilization of a continuous stream of ink in ink jet printing appears to date back to at least 1929 wherein U.S. Pat. No. 1,941,001 by Hansell discloses a simple form of continuous stream electro-static ink jet printing.
U.S. Pat. No. 3,596,275 by Sweet also discloses a process of a continuous ink jet printing including a step wherein the ink jet stream is modulated by a high frequency electro-static field so as to cause drop separation. This technique is still utilized by several manufacturers including Elmjet and Scitex (see also U.S. Pat. No. 3,373,437 by Sweet et al).
Piezoelectric ink jet printers are also one form of commonly utilized ink jet printing device. Piezoelectric systems are disclosed by Kyser et. al. in U.S. Pat. No. 3,946,398 (1970) which utilizes a diaphragm mode of operation, by Zolten in U.S. Pat. No. 3,683,212 (1970) which discloses a squeeze mode form of operation of a piezoelectric crystal, Stemme in U.S. Pat. No. 3,747,120 (1972) which discloses a bend mode of piezoelectric operation, Howkins in U.S. Pat. No. 4,459,601 which discloses a piezoelectric push mode actuation of the ink jet stream and Fischbeck in U.S. Pat. No. 4,584,590 which discloses a shear mode type of piezoelectric transducer element.
Recently, thermal ink jet printing has become an extremely popular form of ink jet printing. The ink jet printing techniques include those disclosed by Endo et al in GB 2007162 (1979) and Vaught et al in U.S. Pat. No. 4,490,728. Both the aforementioned references disclose ink jet printing techniques which rely on the activation of an electrothermal actuator which results in the creation of a bubble in a constricted space, such as a nozzle, which thereby causes the ejection of ink from an aperture connected to the confined space onto a relevant print media. Manufacturers such as Canon and Hewlett Packard manufacture printing devices utilizing the electro-thermal actuator.
As can be seen from the foregoing, many different types of printing technologies are available. Ideally, a printing technology should have a number of desirable attributes. These include inexpensive construction and operation, high-speed operation, safe and continuous long-term operation etc. Each technology may have its own advantages and disadvantages in the areas of cost, speed, quality, reliability, power usage, simplicity of construction and operation, durability and consumables.
Applicant has developed a substantial amount of technology in the field of micro-electromechanical inkjet printing. The parent application is indeed directed to a particular aspect in this field. In this application, the Applicant has applied the technology to the more general field of fluid ejection.
In accordance with a first aspect of the present invention, there is provided a nozzle arrangement for an ink jet printhead, the arrangement comprising a nozzle chamber defined in a wafer substrate for the storage of ink to be ejected; an ink ejection port having a rim formed on one wall of the chamber; and a series of actuators attached to the wafer substrate, and forming a portion of the wall of the nozzle chamber adjacent the rim, the actuator paddles further being actuated in unison so as to eject ink from the nozzle chamber via the ink ejection nozzle.
The actuators can include a surface which bends inwards away from the center of the nozzle chamber upon actuation. The actuators are preferably actuated by means of a thermal actuator device. The thermal actuator device may comprise a conductive resistive heating element encased within a material having a high coefficient of thermal expansion. The element can be serpentine to allow for substantially unhindered expansion of the material. The actuators are preferably arranged radially around the nozzle rim.
The actuators can form a membrane between the nozzle chamber and an external atmosphere of the arrangement and the actuators bend away from the external atmosphere to cause an increase in pressure within the nozzle chamber thereby initiating a consequential ejection of ink from the nozzle chamber. The actuators can bend away from a central axis of the nozzle chamber.
The nozzle arrangement can be formed on the wafer substrate utilizing micro-electro mechanical techniques and further can comprise an ink supply channel in communication with the nozzle chamber. The ink supply channel may be etched through the wafer. The nozzle arrangement may include a series of struts which support the nozzle rim.
The arrangement can be formed adjacent to neighbouring arrangements so as to form a pagewidth printhead.
In this application, the invention extends to a fluid ejection chip that comprises
a substrate; and
a plurality of nozzle arrangements positioned on the substrate, each nozzle arrangement comprising
Each nozzle arrangement may include a plurality of actuators, each actuator including an actuating portion and a paddle positioned on the actuating portion, the actuating portion being anchored to the substrate and being displaceable on receipt of an electrical signal to displace the paddle, in turn, the paddles and the wall being substantially coplanar and the actuating portions being configured so that, upon receipt of said electrical signal, the actuating portions displace the paddles into the nozzle chamber to reduce a volume of the nozzle chamber, thereby ejecting fluid from the fluid ejection port.
A periphery of each paddle may be shaped to define a fluidic seal when the nozzle chamber is filled with fluid.
Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
a) and
In the following description, reference is made to the ejection of ink for application to ink jet printing. However, it will readily be appreciated that the present application can be applied to any situation where fluid ejection is required.
In the preferred embodiment, ink is ejected out of a nozzle chamber via an ink ejection port using a series of radially positioned thermal actuator devices that are arranged about the ink ejection port and are activated to pressurize the ink within the nozzle chamber thereby causing the ejection of ink through the ejection port.
Turning now to
A top of the nozzle arrangement 1 includes a series of radially positioned actuators 8, 9. These actuators comprise a polytetrafluoroethylene (PTFE) layer and an internal serpentine copper core 17. Upon heating of the copper core 17, the surrounding PTFE expands rapidly resulting in a generally downward movement of the actuators 8, 9. Hence, when it is desired to eject ink from the ink ejection port 4, a current is passed through the actuators 8, 9 which results in them bending generally downwards as illustrated in
The actuators 8, 9 are activated only briefly and subsequently deactivated. Consequently, the situation is as illustrated in
a) and 4(b) illustrate the principle of operation of the thermal actuator. The thermal actuator is preferably constructed from a material 14 having a high coefficient of thermal expansion. Embedded within the material 14 are a series of heater elements 15 which can be a series of conductive elements designed to carry a current. The conductive elements 15 are heated by passing a current through the elements 15 with the heating resulting in a general increase in temperature in the area around the heating elements 15. The position of the elements 15 is such that uneven heating of the material 14 occurs. The uneven increase in temperature causes a corresponding uneven expansion of the material 14. Hence, as illustrated in
In
Turning now to
As shown initially in
The first step, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
In
In this manner, large pagewidth printheads can be fabricated so as to provide for a drop-on-demand ink ejection mechanism.
One form of detailed manufacturing process which can be used to fabricate monolithic ink jet printheads operating in accordance with the principles taught by the present embodiment can proceed utilizing the following steps:
1. Using a double-sided polished wafer 60, complete a 0.5 micron, one poly, 2 metal CMOS process 61. This step is shown in
2. Etch the CMOS oxide layers down to silicon or second level metal using Mask 1. This mask defines the nozzle cavity and the edge of the chips. This step is shown in
3. Deposit a thin layer (not shown) of a hydrophilic polymer, and treat the surface of this polymer for PTFE adherence.
4. Deposit 1.5 microns of polytetrafluoroethylene (PTFE) 62.
5. Etch the PTFE and CMOS oxide layers to second level metal using Mask 2. This mask defines the contact vias for the heater electrodes. This step is shown in
6. Deposit and pattern 0.5 microns of gold 63 using a lift-off process using Mask 3. This mask defines the heater pattern. This step is shown in
7. Deposit 1.5 microns of PTFE 64.
8. Etch 1 micron of PTFE using Mask 4. This mask defines the nozzle rim 65 and the rim at the edge 66 of the nozzle chamber. This step is shown in
9. Etch both layers of PTFE and the thin hydrophilic layer down to silicon using Mask 5. This mask defines a gap 67 at inner edges of the actuators, and the edge of the chips. It also forms the mask for a subsequent crystallographic etch. This step is shown in
10. Crystallographically etch the exposed silicon using KOH. This etch stops on <111> crystallographic planes 68, forming an inverted square pyramid with sidewall angles of 54.74 degrees. This step is shown in
11. Back-etch through the silicon wafer (with, for example, an ASE Advanced Silicon Etcher from Surface Technology Systems) using Mask 6. This mask defines the ink inlets 69 which are etched through the wafer. The wafer is also diced by this etch. This step is shown in
12. Mount the printheads in their packaging, which may be a molded plastic former incorporating ink channels which supply the appropriate color ink to the ink inlets 69 at the back of the wafer.
13. Connect the printheads to their interconnect systems. For a low profile connection with minimum disruption of airflow, TAB may be used. Wire bonding may also be used if the printer is to be operated with sufficient clearance to the paper.
14. Fill the completed print heads with ink 70 and test them. A filled nozzle is shown in
The presently disclosed ink jet printing technology is potentially suited to a wide range of printing systems including: color and monochrome office printers, short run digital printers, high speed digital printers, offset press supplemental printers, low cost scanning printers high speed pagewidth printers, notebook computers with inbuilt pagewidth printers, portable color and monochrome printers, color and monochrome copiers, color and monochrome facsimile machines, combined printer, facsimile and copying machines, label printers, large format plotters, photograph copiers, printers for digital photographic “minilabs”, video printers, PHOTO CD (PHOTO CD is a registered trade mark of the Eastman Kodak Company) printers, portable printers for PDAs, wallpaper printers, indoor sign printers, billboard printers, fabric printers, camera printers and fault tolerant commercial printer arrays.
It would be appreciated by a person skilled in the art that numerous variations and/or modifications may be made to the present invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects to be illustrative and not restrictive.
Ink Jet Technologies
The embodiments of the invention use an ink jet printer type device. Of course many different devices could be used. However, presently popular ink jet printing technologies are unlikely to be suitable.
The most significant problem with thermal ink jet is power consumption. This is approximately 100 times that required for high speed, and stems from the energy-inefficient means of drop ejection. This involves the rapid boiling of water to produce a vapor bubble which expels the ink. Water has a very high heat capacity, and must be superheated in thermal ink jet applications. This leads to an efficiency of around 0.02%, from electricity input to drop momentum (and increased surface area) out.
The most significant problem with piezoelectric ink jet is size and cost. Piezoelectric crystals have a very small deflection at reasonable drive voltages, and therefore require a large area for each nozzle. Also, each piezoelectric actuator must be connected to its drive circuit on a separate substrate. This is not a significant problem at the current limit of around 300 nozzles per printhead, but is a major impediment to the fabrication of pagewidth printheads with 19,200 nozzles.
Ideally, the ink jet technologies used meet the stringent requirements of in-camera digital color printing and other high quality, high speed, low cost printing applications. To meet the requirements of digital photography, new ink jet technologies have been created. The target features include:
low power (less than 10 Watts)
High-resolution capability (1,600 dpi or more)
photographic quality output
low manufacturing cost
small size (pagewidth times minimum cross section)
high speed (<2 seconds per page).
All of these features can be met or exceeded by the ink jet systems described below with differing levels of difficulty. Forty-five different ink jet technologies have been developed by the Assignee to give a wide range of choices for high volume manufacture. These technologies form part of separate applications assigned to the present Assignee as set out in the table below under the heading Cross References to Related Applications.
The ink jet designs shown here are suitable for a wide range of digital printing systems, from battery powered one-time use digital cameras, through to desktop and network printers, and through to commercial printing systems.
For ease of manufacture using standard process equipment, the printhead is designed to be a monolithic 0.5-micron CMOS chip with MEMS post processing. For color photographic applications, the printhead is 100 mm long, with a width which depends upon the ink jet type. The smallest printhead designed is IJ38, which is 0.35 mm wide, giving a chip area of 35 square mm. The printheads each contain 19,200 nozzles plus data and control circuitry.
Ink is supplied to the back of the printhead by injection molded plastic ink channels. The molding requires 50 micron features, which can be created using a lithographically micromachined insert in a standard injection molding tool. Ink flows through holes etched through the wafer to the nozzle chambers fabricated on the front surface of the wafer. The printhead is connected to the camera circuitry by tape automated bonding.
Tables of Drop-on-Demand Ink Jets
Eleven important characteristics of the fundamental operation of individual ink jet nozzles have been identified. These characteristics are largely orthogonal, and so can be elucidated as an eleven dimensional matrix. Most of the eleven axes of this matrix include entries developed by the present assignee.
The following tables form the axes of an eleven dimensional table of ink jet types.
Actuator mechanism (18 types)
Basic operation mode (7 types)
Auxiliary mechanism (8 types)
Actuator amplification or modification method (17 types)
Actuator motion (19 types)
Nozzle refill method (4 types)
Method of restricting back-flow through inlet (10 types)
Nozzle clearing method (9 types)
Nozzle plate construction (9 types)
Drop ejection direction (5 types)
Ink type (7 types)
The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of ink jet nozzle. While not all of the possible combinations result in a viable ink jet technology, many million configurations are viable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain ink jet types have been investigated in detail. These are designated IJ01 to IJ45 above which matches the docket numbers in the table under the heading Cross References to Related Applications.
Other ink jet configurations can readily be derived from these forty-five examples by substituting alternative configurations along one or more of the 11 axes. Most of the IJ01 to IJ45 examples can be made into ink jet printheads with characteristics superior to any currently available ink jet technology.
Where there are prior art examples known to the inventor, one or more of these examples are listed in the examples column of the tables below. The IJ01 to IJ45 series are also listed in the examples column. In some cases, print technology may be listed more than once in a table, where it shares characteristics with more than one entry.
Suitable applications for the ink jet technologies include: Home printers, Office network printers, Short run digital printers, Commercial print systems, Fabric printers, Pocket printers, Internet WWW printers, Video printers, Medical imaging, Wide format printers, Notebook PC printers, Fax machines, Industrial printing systems, Photocopiers, Photographic minilabs etc.
The information associated with the aforementioned 11 dimensional matrix is set out in the following tables.
| Number | Date | Country | Kind |
|---|---|---|---|
| PP3987 | Jun 1998 | AU | national |
This application is a continuation of U.S. application Ser. No. 12/422,936 filed Apr. 13, 2009, now issued U.S. Pat. No. 7,708,386, which is a continuation of U.S. application Ser. No. 11/706,379 filed Feb. 15, 2007, now issued U.S. Pat. No. 7,520,593, which is a continuation application of U.S. application Ser. No. 11/026,136 filed Jan. 3, 2005, now issued U.S. Pat. No. 7,188,933, which is a continuation application of U.S. application Ser. No. 10/309,036 filed Dec. 4, 2002, now issued U.S. Pat. No. 7,284,833, which is a Continuation Application of U.S. application Ser. No. 09/855,093 filed May 14, 2001, now issued U.S. Pat. No. 6,505,912, which is a Continuation Application of U.S. application Ser. No. 09/112,806 filed Jul. 10, 1998, now issued U.S. Pat. No. 6,247,790 all of which are herein incorporated by reference.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4423401 | Mueller | Dec 1983 | A |
| 4480259 | Kruger et al. | Oct 1984 | A |
| 4553393 | Ruoff | Nov 1985 | A |
| 4672398 | Kuwabara et al. | Jun 1987 | A |
| 4737802 | Mielke | Apr 1988 | A |
| 4855567 | Mueller | Aug 1989 | A |
| 4864824 | Gabriel et al. | Sep 1989 | A |
| 5029805 | Albarda et al. | Jul 1991 | A |
| 5113204 | Miyazawa et al. | May 1992 | A |
| 5258774 | Rogers | Nov 1993 | A |
| 5387314 | Baughman et al. | Feb 1995 | A |
| 5666141 | Matoba et al. | Sep 1997 | A |
| 5697144 | Mitani et al. | Dec 1997 | A |
| 5719604 | Inui et al. | Feb 1998 | A |
| 5812159 | Anagnostopoulos et al. | Sep 1998 | A |
| 5828394 | Khuri-Yakub et al. | Oct 1998 | A |
| 5896155 | Lebens et al. | Apr 1999 | A |
| 6007187 | Kashino et al. | Dec 1999 | A |
| 6019457 | Silverbrook | Feb 2000 | A |
| 6074043 | Ahn | Jun 2000 | A |
| 6151049 | Karita et al. | Nov 2000 | A |
| 6174050 | Kashino et al. | Jan 2001 | B1 |
| 6188415 | Silverbrook | Feb 2001 | B1 |
| 6213589 | Silverbrook | Apr 2001 | B1 |
| 6247790 | Silverbrook et al. | Jun 2001 | B1 |
| 6283582 | Silverbrook | Sep 2001 | B1 |
| 6416167 | Silverbrook | Jul 2002 | B1 |
| 6505912 | Silverbrook et al. | Jan 2003 | B2 |
| 6561627 | Jarrold et al. | May 2003 | B2 |
| 6644786 | Lebens | Nov 2003 | B1 |
| 6669332 | Silverbrook | Dec 2003 | B2 |
| 6682174 | Silverbrook | Jan 2004 | B2 |
| 6685303 | Trauernicht et al. | Feb 2004 | B1 |
| 6866369 | Silverbrook | Mar 2005 | B2 |
| 6874866 | Silverbrook | Apr 2005 | B2 |
| 6880918 | Silverbrook | Apr 2005 | B2 |
| 6886917 | Silverbrook et al. | May 2005 | B2 |
| 6969153 | Silverbrook et al. | Nov 2005 | B2 |
| 6979075 | Silverbrook et al. | Dec 2005 | B2 |
| 7077508 | Silverbrook | Jul 2006 | B2 |
| 7134740 | Silverbrook | Nov 2006 | B2 |
| 7134745 | Silverbrook | Nov 2006 | B2 |
| 7156494 | Silverbrook et al. | Jan 2007 | B2 |
| 7156495 | Silverbrook et al. | Jan 2007 | B2 |
| 7182436 | Silverbrook et al. | Feb 2007 | B2 |
| 7188933 | Silverbrook et al. | Mar 2007 | B2 |
| 7195339 | Silverbrook | Mar 2007 | B2 |
| 7264335 | Silverbrook et al. | Sep 2007 | B2 |
| 7284838 | Silverbrook et al. | Oct 2007 | B2 |
| 7287834 | Silverbrook | Oct 2007 | B2 |
| 7322679 | Silverbrook | Jan 2008 | B2 |
| 7347536 | Silverbrook et al. | Mar 2008 | B2 |
| 7364271 | Silverbrook | Apr 2008 | B2 |
| 7401902 | Silverbrook | Jul 2008 | B2 |
| 7438391 | Silverbrook et al. | Oct 2008 | B2 |
| 7465023 | Silverbrook | Dec 2008 | B2 |
| 7465029 | Silverbrook et al. | Dec 2008 | B2 |
| 7465030 | Silverbrook | Dec 2008 | B2 |
| 7467855 | Silverbrook | Dec 2008 | B2 |
| 7470003 | Silverbrook | Dec 2008 | B2 |
| 7506969 | Silverbrook | Mar 2009 | B2 |
| 7517057 | Silverbrook | Apr 2009 | B2 |
| 7520593 | Silverbrook et al. | Apr 2009 | B2 |
| 7520594 | Silverbrook | Apr 2009 | B2 |
| 7533967 | Silverbrook et al. | May 2009 | B2 |
| 7537301 | Silverbrook | May 2009 | B2 |
| 7549731 | Silverbrook | Jun 2009 | B2 |
| 7556351 | Silverbrook | Jul 2009 | B2 |
| 7556355 | Silverbrook | Jul 2009 | B2 |
| 7556356 | Silverbrook | Jul 2009 | B1 |
| 7562967 | Silverbrook et al. | Jul 2009 | B2 |
| 7566114 | Silverbrook | Jul 2009 | B2 |
| 7568790 | Silverbrook et al. | Aug 2009 | B2 |
| 7568791 | Silverbrook | Aug 2009 | B2 |
| 7604323 | Silverbrook et al. | Oct 2009 | B2 |
| 7611227 | Silverbrook | Nov 2009 | B2 |
| 7628471 | Silverbrook | Dec 2009 | B2 |
| 7637594 | Silverbrook et al. | Dec 2009 | B2 |
| 7641314 | Silverbrook | Jan 2010 | B2 |
| 7641315 | Silverbrook | Jan 2010 | B2 |
| 7669973 | Silverbrook et al. | Mar 2010 | B2 |
| 7708386 | Silverbrook et al. | May 2010 | B2 |
| 7758161 | Silverbrook et al. | Jul 2010 | B2 |
| 7780269 | Silverbrook | Aug 2010 | B2 |
| 7802871 | Silverbrook | Sep 2010 | B2 |
| 20080316269 | Silverbrook et al. | Dec 2008 | A1 |
| Number | Date | Country |
|---|---|---|
| 1648322 | Mar 1971 | DE |
| 2905063 | Aug 1980 | DE |
| 3245283 | Jun 1984 | DE |
| 3430155 | Feb 1986 | DE |
| 3716996 | Dec 1988 | DE |
| 3934280 | Apr 1990 | DE |
| 4328433 | Mar 1995 | DE |
| 19516997 | Nov 1995 | DE |
| 19517969 | Nov 1995 | DE |
| 19532913 | Mar 1996 | DE |
| 19623620 | Dec 1996 | DE |
| 19639717 | Apr 1997 | DE |
| 0092229 | Oct 1983 | EP |
| 0398031 | Nov 1990 | EP |
| 0416540 | Mar 1991 | EP |
| 0427291 | May 1991 | EP |
| 0431338 | Jun 1991 | EP |
| 0478956 | Apr 1992 | EP |
| 0506232 | Sep 1992 | EP |
| 0510648 | Oct 1992 | EP |
| 0627314 | Dec 1994 | EP |
| 0634273 | Jan 1995 | EP |
| 0713774 | May 1996 | EP |
| 0737580 | Oct 1996 | EP |
| 0750993 | Jan 1997 | EP |
| 0882590 | Dec 1998 | EP |
| 2231076 | Dec 1974 | FR |
| 792145 | Mar 1958 | GB |
| 1428239 | Mar 1976 | GB |
| 2262152 | Jun 1993 | GB |
| 58-112747 | Jul 1983 | JP |
| 58-116165 | Jul 1983 | JP |
| 61-025849 | Feb 1986 | JP |
| 61-268453 | Nov 1986 | JP |
| 62-094347 | Apr 1987 | JP |
| 01-105746 | Apr 1989 | JP |
| 01-115639 | May 1989 | JP |
| 01-128839 | May 1989 | JP |
| 01-257058 | Oct 1989 | JP |
| 01-306254 | Dec 1989 | JP |
| 02-030543 | Jan 1990 | JP |
| 02-050841 | Feb 1990 | JP |
| 02-092643 | Apr 1990 | JP |
| 02-108544 | Apr 1990 | JP |
| 02-158348 | Jun 1990 | JP |
| 02-162049 | Jun 1990 | JP |
| 02-265752 | Oct 1990 | JP |
| 03-065348 | Mar 1991 | JP |
| 03-112662 | May 1991 | JP |
| 03-180350 | Aug 1991 | JP |
| 04-001051 | Jan 1992 | JP |
| 04-001051 | Jan 1992 | JP |
| 04-118241 | Apr 1992 | JP |
| 04-126255 | Apr 1992 | JP |
| 04-141429 | May 1992 | JP |
| 04-353458 | Dec 1992 | JP |
| 04-368851 | Dec 1992 | JP |
| 05-284765 | Oct 1993 | JP |
| 05-318724 | Dec 1993 | JP |
| 06-091865 | Apr 1994 | JP |
| 06-091866 | Apr 1994 | JP |
| 07-314665 | Dec 1995 | JP |
| 08-142323 | Jun 1996 | JP |
| 08-336965 | Dec 1996 | JP |
| WO 9418010 | Aug 1994 | WO |
| WO 9712689 | Apr 1997 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20100207997 A1 | Aug 2010 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12422936 | Apr 2009 | US |
| Child | 12772825 | US | |
| Parent | 11706379 | Feb 2007 | US |
| Child | 12422936 | US | |
| Parent | 11026136 | Jan 2005 | US |
| Child | 11706379 | US | |
| Parent | 10309036 | Dec 2002 | US |
| Child | 11026136 | US | |
| Parent | 09855093 | May 2001 | US |
| Child | 10309036 | US | |
| Parent | 09112806 | Jul 1998 | US |
| Child | 09855093 | US |
