1. Field of the Invention
The present invention is directed to the field of access control and remote identity verification, in particular, utilizing biometric technology.
2. Related Art
Access control systems are used to limit access to selected individuals.
Some of these systems use biometric technologies to determine whether access for an individual will be granted or denied. A biometric is a unique, measurable characteristic or trait of a human being for automatically recognizing or verifying identity. For instance, fingerprint biometrics are largely regarded as an accurate method of biometric identification and verification. See, e.g., Roethenbaugh, G. Ed., Biometrics Explained (International Computer Security Association: Carlisle, Pa. 1998), pages 1-34, which is herein incorporated by reference in its entirety. Access control units (ACUs) may be placed locally to perform a biometric analysis on the individual, and determine whether access will be granted or denied. As the number of people needing access to facilities grows, so must be any database holding their biometric information. Eventually, this will become a prohibitive aspect of access control because of the cost, both in equipment and updating time, required to maintain an ever increasing amount of stored biometric data.
What is needed is a system utilizing a device that stores data for an unlimited number of enrollees allowing easy scalability. Also, a system is needed that utilizes a device that allows for easy updating of stored biometric information to keep all information current for all enrollees.
Embodiments of the present invention provide a system including an enrollment system that controls storing of biometric data. The system further includes an access control system that reads the stored biometric data, an extracting system coupled to the access control system that extracts live biometric data, and a matching system coupled to the access control system that compares the stored biometric data to the live read biometric data to generate a matching result that is transmitted to the access control system. The system further includes an accessed system coupled to the access control system into which admittance is either allowed or denied based on the matching result. The system may also include a threshold controller that determines and generates a threshold value to be used during extracting, matching, or both. Using the threshold value increases the number of enrollees successfully managed by an access control system, and reduces the number of false rejections of entry. Thresholds can also provide more data with which to make an access control decision rather than mere presentation of a biometric input. These thresholds are individualized and help to make a more informed security decision that, among other things, reduces the rejection of more difficult to read fingerprints.
Other embodiments of the present invention provide a method including the step of enrolling enrollees and storing their biometric data. The method further includes the steps of performing a live read of one of the enrollees using a reader in an access control system, extracting live biometric data during the live read in an extracting system, and comparing the extracted live biometric data with the stored biometric data in a matching system and outputting a matching result. The method further includes the step of performing access control based on the matching result. The method also includes the steps of determining and generating a threshold value to be used during extracting, matching, or both.
According to a further feature, processing is distributed across a networked system. In one embodiment, extraction is carried out remotely over a network. In another embodiment, matching is carried out remotely over a network. In this way, an access control reader or panel need not perform extraction and matching, which reduces processing requirements at the access control reader or panel. Processing of extraction and matching is more efficiently managed at the remote sites, for example different extraction or matching algorithms, or changes thereto, can be more easily implemented.
Further, the system is more scalable as additional, cheaper access control readers and panels utilizing biometric data can be easily added.
According to a further feature, in one embodiment the access control system is easily installed as an upgrade to an existing Wiegand panel through the use of a live access control reader, which acts as an interface to a Wiegand panel.
Some advantages of the system and method may be that they provide an access control system and method that utilizes a device allowing for data to be stored for an unlimited number of enrollees allowing easy scalability. Also, a system and method are provided that utilize a device requiring little, if any, updating time to keep current stored biometric information for all enrollees.
Further embodiments, features, and advantages of the present inventions, as well as the structure and operation of the various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.
The accompanying drawings, which are incorporated herein and form a 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 pertinent art to make and use the invention.
The present invention will now be described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
Overview and Terminology
Some embodiments of the present invention are directed to systems and methods that perform access control and mobile identity verification, including examples utilizing a handheld device, with a memory that stores at least biometric data, such as minutia. The handheld device may also store other data, such as a threshold value and Wiegand data. The data may be stored in a memory, a magnetic strip, a machine-readable code, a bar code, or in all of these devices associated with the handheld device. The handheld device may be a SmartCard or the like.
One example of biometric data that may need the threshold value is a value indicative of a fingerprint image capture quality of an individual. For example, a low value can indicate a relative poor image capture quality, while a high value can indicate a relative high capture quality. Low threshold values may be appropriate for individuals with difficult to read fingerprints, such as those with dry fingers, missing or damaged fingers, or birth defects. High threshold values may be appropriate for individuals with easy to read fingerprints, such as those with oily fingers or with complete fingertips having a number of distinct minutiae. In some embodiments of the invention, threshold values can be numeric values or categorical values (such as good, average, poor). These threshold values can be used in a variety of ways in the systems of the present invention to accommodate an even greater range of biometric objects successfully managed by the system. The threshold value is used during extracting, matching, or both, to most accurately determine the identity and characteristics of an individual wanting access to an accessed system or being questioned by law enforcement in the field.
An object as used throughout the specification may be a physical part of an individual, such as an eye, a finger, a limb, etc. An accessed system as used through the specification may be any known system that requires some limitation to entry, which can be a computer, electrical or mechanical equipment, a room, a hallway, a building, a section of a compound, etc. An enrollee as used throughout the specification may be any individual, whether within a business setting, public setting, or otherwise. As mere examples, an enrollee may be an employee of a company, a person receiving governmental assistance, a prisoner, or a person at a traffic stop. Matching used throughout the specification relates to matching either 1:1 to determine if the individual matches with whom he/she says he/she is or 1:m, where m= all the enrollees, to determine if an individual is an enrollee at all.
Overall Access Control and Remote Verification System
With reference to
Enrolling System
Now turning to
Through use of this handheld device 206 the need for a large database is virtually eliminated because biometric and other personal data can be stored on the handheld device 206. There would also be no need to update a central database, just the hand held device 206 memory, which ensures more accurate information is timely maintained. The use of the handheld device 206 is most effective for systems that have a large and continuously growing enrollee list.
In embodiments where the biometric reader 200 reads and extracts fingerprints, the biometric reader 200 may be coupled between an electronic fingerprint template (EFT) file 208 and an EFT service 210. The EFT file 208 converts read fingerprint data into a predetermined form and transmits the data to the EFT Service 210, which may be the Federal Bureau of Investigations (FBI), other federal, state, or local authorities, private entities, or the like. This data is then used by the EFT Service 210 to run background checks on possible enrollees.
In still other embodiments the enrolling system 102 may include a threshold controller 212 coupled between the biometric reader 200, the handheld device controller 204 and/or the database 202, and an input system 214. According to one feature, threshold values associated with each biometric input are assigned and stored during enrollment in an enrolling system. In this way, the assignment and storage of correct or suitable thresholds can be obtained during enrollment. This may have advantages in many practical situations where more experienced personnel are available at enrollment to monitor threshold value assignment and storage. Also, the presentation of biometric input at enrollment may often occur in a setting where more time is available for ensuring proper threshold values are assigned and quality biometric data, such as fingerprint data, are captured. Details of the threshold controller 212 are described below with reference to
Mobile Verification System
Now turning to
According to one embodiment, the reader 300 is a handheld, mobile device. This is helpful in allowing capture of biometric data at different locations. Individuals can be checked during spot checks, mobile or roving checks, and in other ways to provide additional security in support of access control systems. This is especially helpful in applications such as airport security, where spot checks need to be performed on a tarmac or runway, in a terminal, etc. Other applications that require mobile verifications also benefit from the mobile reader 300. Wireless links can also be used to transfer data from the mobile reader 300 to the verification system 302.
Access Control Apparatus
Access Control Reader
In this arrangement, the live access control reader 400 both reads live biometric data and accesses stored biometric data to be used during an access control operation described in more detail below. Also, in some embodiments an additional level of security can be provided because multiple factors (a live biometric and an input) may be used in access control. This architecture provides significant installation advantages for incorporating aspects of the system 100 into existing stand-alone access control systems having Wiegand panels. For instance, one or more live access control readers 400 can be coupled to one or more existing Wiegand panels 402. This allows existing stand-alone Wiegand access control systems to be easily upgraded to a more secure, scalable, network-based access control system 100 of the present invention.
As also seen in
Access Control Panel
Turning now to
In this arrangement, the access control panel 500 reads live biometric data and accesses stored biometric data to be used during an access control operation described in more detail below. As described with respect to
Network Extraction or Matching Systems
As shown in
Similar advantages are provided in a feature where matching processing is carried out by a remote matching system 110 (FIG. 7). In this way, processing work is distributed across the system 100. Hence, the access control system 104, access control reader 400, and access control panel 500 need not carry out matching. This reduces the processing requirement at the access control reader 400 or panel 500. Further, because matching is handled at a remote site accessed over the network 114, the system 100 can more easily scale to accommodate more access control readers 400 and/or panels 500 and more enrollees. Different types of matching, changes in matching algorithms, or moving processing power to support matching need only be provided in the matching system 110 rather than individual access control readers 400 or individual access control panels 500.
As seen in
Example Access Control and Remote Verification System
Shown in
In this example, one embodiment of reading the SmartCard 801 may be to use a remote verification system including a mobile reader 812 that reads both a code 814 on the SmartCard 810 and a live fingerprint of an individual to perform matching in the verification system 816. The reader 812 may be manufactured by Cross Match Technologies, Inc. and the verification system may be a computer either linked or unlinked to a network, such as one found in a law enforcement vehicle.
Other embodiments used to read and utilize information on the SmartCard 810 are an access control reader (ACR) 818 environment and an access control panel (ACP) 820 environment. Either of these access control systems can be used to control access to a door 822, either via a Wiegand panel 824 or directly. As shown, both the ACR 818 and the ACP 820 can access the SmartCard 810 to send extracting parameters to an extracting service 826. Also, both the ACR 818 and ACP 820 can access the SmartCard to send stored biometric data and matching parameters, along with the live read biometric data read by a live biometric reader (not shown), to a matching service 828. In some embodiments, based on a result from the matching service 828, the ACR 818 sends Wiegand signal to the Wiegand panel 824 to control opening of the door 822 via a relay signal from the Wiegand panel 824. In other embodiments, based on a result from the matching service 828, the ACP 820 sends a relay signal to the door 822 to control its opening.
Threshold Value System
Referencing
As discussed above, one example of biometric data that may need the threshold value is a value indicative of a fingerprint image capture quality of an individual. For example, a low value can indicate a relative poor image capture quality, while a high value can indicate a relative high capture quality. Low threshold values may be appropriate for individuals with difficult to read fingerprints, such as those with dry fingers, missing or damaged fingers, or birth defects. High threshold values may be appropriate for individuals with easy to read fingerprints, such as those with oily fingers or with complete fingertips having a number of distinct minutiae. In embodiments of the invention, threshold values can be numeric values or categorical values (such as good, average, poor). These threshold values can be used in a variety of ways in the system 100 to accommodate an even greater range of biometric objects successfully managed by the system 100. A threshold value may be a required value or parameter generated from input criteria based on biometric data read and extracted by an extracting system 108 during an enrolling process. The threshold value is used during extracting, matching, or both, to most accurately determine the identity and characteristics of an individual wanting access to an accessed system 112 or being questioned by law enforcement in the field.
Overall Operation
An overall operation 1000 of the system 100 is shown in FIG. 10. In step 1002 an individual enrolls in the enrolling system 102 by having their biometric and other data read, extracted, accessed, and stored. A live read of biometric data is taken of an individual in step 1004 when they wish to access an accessed system 112. The live read biometric data is extracted by the extracting system 108 at step 1008. A matching operation is performed by the matching system 110 at step 1008 to compare at least the stored biometric data and the live read biometric data. Based on an output from the matching system 110 generated at step 1008, access to an accessed system 112 is controlled by the access control system 104 at step 1010.
Enrolling Operation
The details of the enrolling operation 1002 performed by the enrolling system 108 according to embodiments of the present invention are shown in FIG. 11. The biometric reader 200 at step 1102 reads an individual's biometric data. In some embodiments, a threshold operation is performed at step 1104 by a threshold controller 212 and a threshold value is stored at step 1106. In other embodiments, the enrolling operation 1002 moves from step 1102 to step 1108, during which EFT data generated by the EFT file 208, which is based on the read biometric data, is transmitted to an EFT service 210. Information is received from the EFT service 210 at step 1110. Based on this information, a determination is made whether an enrollee is acceptable at step 1112. If no, the enrollee is rejected at step 1114, and their information is stored in a memory in the database 202 at step 1116. If yes, their biometric and other information is stored in a memory of a database 202 at step 1118, in a memory of a handheld device 206 at step 1120, or both. Following this, the enrolling operation 1002 returns to step 1102 and waits for more enrollees.
Remote Verification Operation
A mobile verification operation 1200 performed by the mobile verification system 106 is shown in
This roving or mobile verification operation 1200 can be used to supplement the security provided by the system 100.
Access Control Operation
Extracting, Matching, and Controlling Operations
Referencing
The extraction parameter step 1306 and the matching parameter step 1312 are performed along with an operation 1400 shown in FIG. 14. Some of the parameters are determined by reading the handheld device 206 or receiving information from the input device 406, 506, or 906 at step 1402. Depending on the embodiment, values for threshold and other parameters are determined by the access control system 104 at step 1404. After receiving the request for extraction parameters at step 1306, the extraction parameters are transmitted at step 1406. Also, after receiving the requests for matching parameters at step 1312, the matching parameters are transmitted at step 1408.
Access Control Reader Operation
After performing the operations shown in
Access Control Panel Operation
Similar to the operation shown in
Threshold Value Operation
A threshold value determination and generation operation 1104, and how the generated threshold value is utilized, are shown in more detail in
As seen in
As seen in
The score values are a correlation between the live extracted biometric data and the stored biometric data based on the threshold value. For example, scores may range from 0 to 1000, where 500 is an acceptable score for an average individual as being a positive match, and anything below is not a positive match. The threshold value may adjust the acceptable score for a below average person to 300 in order for a match to be positive, while the threshold value may adjust the acceptable score for an above average person to 900 in order for a match to be positive. Thus, in this way each individual's biometric data is taken into consideration when determining what score is needed to allow then entry into an accessed system.
Remote Management Operation
Turning now to
With reference to
In these embodiments utilizing a system administrator 118, small organizations that need external support for their access control or large organizations that need a central or remote station for their access control can utilize a network, such as the Intranet or the Internet, as part of their access control system 100. For a small company, this helps reduce some costs involved in installing and maintaining an access control system. While in large companies this gives central station information about every single thing requiring access control in a company, such that problems can be detected and resolved timely.
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 apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, 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.
Number | Name | Date | Kind |
---|---|---|---|
2500017 | Altman | Mar 1950 | A |
3200701 | White | Aug 1965 | A |
3475588 | McMaster | Oct 1969 | A |
3482498 | Becker | Dec 1969 | A |
3495259 | Rocholl et al. | Feb 1970 | A |
3527535 | Monroe | Sep 1970 | A |
3540025 | Levin et al. | Nov 1970 | A |
3617120 | Roka | Nov 1971 | A |
3699519 | Campbell | Oct 1972 | A |
3906520 | Phillips | Sep 1975 | A |
3947128 | Weinberger et al. | Mar 1976 | A |
3968476 | McMahon | Jul 1976 | A |
3975711 | McMahon | Aug 1976 | A |
4032975 | Malueg et al. | Jun 1977 | A |
4063226 | Kozma et al. | Dec 1977 | A |
4120585 | DePalma et al. | Oct 1978 | A |
4152056 | Fowler | May 1979 | A |
4209481 | Kashiro et al. | Jun 1980 | A |
4210899 | Swonger et al. | Jul 1980 | A |
4253086 | Szwarcbier | Feb 1981 | A |
4322163 | Schiller | Mar 1982 | A |
4414684 | Blonder | Nov 1983 | A |
4537484 | Fowler et al. | Aug 1985 | A |
4544267 | Schiller | Oct 1985 | A |
4553837 | Marcus | Nov 1985 | A |
4601195 | Garritano | Jul 1986 | A |
4669487 | Frieling | Jun 1987 | A |
4681435 | Kubota et al. | Jul 1987 | A |
4684802 | Hakenewerth et al. | Aug 1987 | A |
4701772 | Anderson et al. | Oct 1987 | A |
4783823 | Tasaki et al. | Nov 1988 | A |
4784484 | Jensen | Nov 1988 | A |
4792226 | Fishbine et al. | Dec 1988 | A |
4811414 | Fishbine et al. | Mar 1989 | A |
4876726 | Capello et al. | Oct 1989 | A |
4896363 | Taylor et al. | Jan 1990 | A |
4905293 | Asai et al. | Feb 1990 | A |
4924085 | Kato et al. | May 1990 | A |
4933976 | Fishbine et al. | Jun 1990 | A |
4942482 | Kakinuma et al. | Jul 1990 | A |
4946276 | Chilcott | Aug 1990 | A |
4995086 | Lilley et al. | Feb 1991 | A |
5054090 | Knight et al. | Oct 1991 | A |
5067162 | Driscoll, Jr. et al. | Nov 1991 | A |
5067749 | Land | Nov 1991 | A |
5131038 | Puhl et al. | Jul 1992 | A |
5146102 | Higuchi et al. | Sep 1992 | A |
5157497 | Topper et al. | Oct 1992 | A |
5185673 | Sobol | Feb 1993 | A |
5187747 | Capello et al. | Feb 1993 | A |
5210588 | Lee | May 1993 | A |
5222152 | Fishbine et al. | Jun 1993 | A |
5222153 | Beiswenger | Jun 1993 | A |
5230025 | Fishbine et al. | Jul 1993 | A |
5233404 | Lougheed et al. | Aug 1993 | A |
5249370 | Stanger et al. | Oct 1993 | A |
5253085 | Maruo et al. | Oct 1993 | A |
5261266 | Lorenz et al. | Nov 1993 | A |
5285293 | Webb et al. | Feb 1994 | A |
5291318 | Genovese | Mar 1994 | A |
D348445 | Fishbine et al. | Jul 1994 | S |
5351127 | King et al. | Sep 1994 | A |
D351144 | Fishbine et al. | Oct 1994 | S |
5363318 | McCauley | Nov 1994 | A |
5384621 | Hatch et al. | Jan 1995 | A |
5412463 | Sibbald et al. | May 1995 | A |
5416573 | Sartor, Jr. | May 1995 | A |
5448649 | Chen et al. | Sep 1995 | A |
5467403 | Fishbine et al. | Nov 1995 | A |
5469506 | Berson et al. | Nov 1995 | A |
5471240 | Prager et al. | Nov 1995 | A |
5473144 | Mathurin, Jr. | Dec 1995 | A |
5483601 | Faulkner | Jan 1996 | A |
5509083 | Abtahi et al. | Apr 1996 | A |
5517528 | Johnson | May 1996 | A |
5528355 | Maase et al. | Jun 1996 | A |
5548394 | Giles et al. | Aug 1996 | A |
5591949 | Bernstein | Jan 1997 | A |
5596454 | Hebert | Jan 1997 | A |
5598474 | Johnson | Jan 1997 | A |
5613014 | Eshera et al. | Mar 1997 | A |
5615277 | Hoffman | Mar 1997 | A |
5625448 | Ranalli et al. | Apr 1997 | A |
5640422 | Johnson | Jun 1997 | A |
5649128 | Hartley | Jul 1997 | A |
5650842 | Maase et al. | Jul 1997 | A |
5661451 | Pollag | Aug 1997 | A |
5680205 | Borza | Oct 1997 | A |
5689529 | Johnson | Nov 1997 | A |
5717777 | Wong et al. | Feb 1998 | A |
5729334 | Van Ruyven | Mar 1998 | A |
5736734 | Marcus et al. | Apr 1998 | A |
5745046 | Itsumi et al. | Apr 1998 | A |
5745684 | Oskouy et al. | Apr 1998 | A |
5748766 | Maase et al. | May 1998 | A |
5748768 | Sivers et al. | May 1998 | A |
5755748 | Borza | May 1998 | A |
5757278 | Itsumi | May 1998 | A |
5767989 | Sakaguchi | Jun 1998 | A |
5778089 | Borza | Jul 1998 | A |
5781647 | Fishbine et al. | Jul 1998 | A |
5793218 | Oster et al. | Aug 1998 | A |
5801681 | Sayag | Sep 1998 | A |
5805777 | Kuchta | Sep 1998 | A |
5809172 | Melen | Sep 1998 | A |
5812067 | Bergholz et al. | Sep 1998 | A |
5815252 | Price-Francis | Sep 1998 | A |
5818956 | Tuli | Oct 1998 | A |
5822445 | Wong | Oct 1998 | A |
5825005 | Behnke | Oct 1998 | A |
5825474 | Maase | Oct 1998 | A |
5828773 | Setlak et al. | Oct 1998 | A |
5832244 | Jolley et al. | Nov 1998 | A |
5832464 | Houvener et al. | Nov 1998 | A |
5848231 | Teitelbaum et al. | Dec 1998 | A |
5855433 | Velho et al. | Jan 1999 | A |
5859420 | Borza | Jan 1999 | A |
5859710 | Hannah | Jan 1999 | A |
5862247 | Fisun et al. | Jan 1999 | A |
5867802 | Borza | Feb 1999 | A |
5869822 | Meadows, II et al. | Feb 1999 | A |
5872834 | Teitelbaum | Feb 1999 | A |
5892599 | Bahuguna | Apr 1999 | A |
5900993 | Betensky | May 1999 | A |
5907627 | Borza | May 1999 | A |
5920384 | Borza | Jul 1999 | A |
5920640 | Salatino et al. | Jul 1999 | A |
5920642 | Merjanian | Jul 1999 | A |
5928347 | Jones | Jul 1999 | A |
5942761 | Tuli | Aug 1999 | A |
5946135 | Auerswald et al. | Aug 1999 | A |
5960100 | Hargrove | Sep 1999 | A |
5973731 | Schwab | Oct 1999 | A |
5974162 | Metz et al. | Oct 1999 | A |
5987155 | Dunn et al. | Nov 1999 | A |
5991467 | Kamiko | Nov 1999 | A |
5995014 | DiMaria | Nov 1999 | A |
5999307 | Whitehead et al. | Dec 1999 | A |
6016476 | Maes et al. | Jan 2000 | A |
6018739 | McCoy et al. | Jan 2000 | A |
6023522 | Draganoff et al. | Feb 2000 | A |
6038332 | Fishbine et al. | Mar 2000 | A |
6041372 | Hart et al. | Mar 2000 | A |
6055071 | Kuwata et al. | Apr 2000 | A |
6064398 | Ellenby et al. | May 2000 | A |
6064753 | Bolle et al. | May 2000 | A |
6064779 | Neukermans et al. | May 2000 | A |
6072891 | Hamid et al. | Jun 2000 | A |
6075876 | Draganoff | Jun 2000 | A |
6078265 | Bonder et al. | Jun 2000 | A |
6088585 | Schmitt et al. | Jul 2000 | A |
6097873 | Filas et al. | Aug 2000 | A |
6104809 | Berson et al. | Aug 2000 | A |
6115484 | Bowker et al. | Sep 2000 | A |
6122394 | Neukermans et al. | Sep 2000 | A |
6140939 | Flick | Oct 2000 | A |
6144408 | MacLean | Nov 2000 | A |
6150665 | Suga | Nov 2000 | A |
6154285 | Teng et al. | Nov 2000 | A |
6162486 | Samouilhan et al. | Dec 2000 | A |
6166787 | Akins et al. | Dec 2000 | A |
6178255 | Scott et al. | Jan 2001 | B1 |
6182221 | Hsu et al. | Jan 2001 | B1 |
6195447 | Ross | Feb 2001 | B1 |
6198836 | Hauke | Mar 2001 | B1 |
6204331 | Sullivan et al. | Mar 2001 | B1 |
6259108 | Antonelli et al. | Jul 2001 | B1 |
6272562 | Scott et al. | Aug 2001 | B1 |
6281931 | Tsao et al. | Aug 2001 | B1 |
6311272 | Gressel | Oct 2001 | B1 |
6327047 | Motamed | Dec 2001 | B1 |
6347163 | Roustaei | Feb 2002 | B1 |
6394356 | Zagami | May 2002 | B1 |
6424249 | Houvener | Jul 2002 | B1 |
6687829 | Miyamoto et al. | Feb 2004 | B1 |
6758394 | Maskatiya et al. | Jul 2004 | B1 |
6819219 | Bolle et al. | Nov 2004 | B1 |
20020030668 | Hoshino et al. | Mar 2002 | A1 |
20030025599 | Monroe | Feb 2003 | A1 |
Number | Date | Country |
---|---|---|
0 101 772 | Mar 1984 | EP |
0 308 162 | Mar 1989 | EP |
0 308 162 | Mar 1989 | EP |
0 379 333 | Jul 1990 | EP |
0 623 890 | Nov 1994 | EP |
0 623 890 | Nov 1994 | EP |
0 653 882 | May 1995 | EP |
0 379 333 | Jul 1995 | EP |
0 889 432 | Jan 1999 | EP |
0 889 432 | Jan 1999 | EP |
0 905 646 | Mar 1999 | EP |
0 785 750 | Jun 1999 | EP |
0 924 656 | Jun 1999 | EP |
2 089 545 | Jun 1982 | GB |
2 313 441 | Nov 1997 | GB |
62-212892 | Sep 1987 | JP |
1-205392 | Aug 1989 | JP |
3-161884 | Jul 1991 | JP |
3-194674 | Aug 1991 | JP |
3-194675 | Aug 1991 | JP |
11-225272 | Aug 1999 | JP |
11-289421 | Oct 1999 | JP |
WO 8702491 | Apr 1987 | WO |
WO 9003620 | Apr 1990 | WO |
WO 9211608 | Jul 1992 | WO |
WO 9422371 | Oct 1994 | WO |
WO 9422371 | Oct 1994 | WO |
WO 9617480 | Jun 1996 | WO |
WO 9617480 | Jun 1996 | WO |
WO 9729477 | Aug 1997 | WO |
WO 9741528 | Nov 1997 | WO |
WO 9809246 | Mar 1998 | WO |
WO 9812670 | Mar 1998 | WO |
WO 9912123 | Mar 1999 | WO |
WO 9926187 | May 1999 | WO |
WO 9940535 | Aug 1999 | WO |
Number | Date | Country | |
---|---|---|---|
20030197593 A1 | Oct 2003 | US |