CA2233937A1 - In a fingerprint recognizing apparatus detector for recognizing the living character of a finger - Google Patents
In a fingerprint recognizing apparatus detector for recognizing the living character of a finger Download PDFInfo
- Publication number
- CA2233937A1 CA2233937A1 CA002233937A CA2233937A CA2233937A1 CA 2233937 A1 CA2233937 A1 CA 2233937A1 CA 002233937 A CA002233937 A CA 002233937A CA 2233937 A CA2233937 A CA 2233937A CA 2233937 A1 CA2233937 A1 CA 2233937A1
- Authority
- CA
- Canada
- Prior art keywords
- detector
- electrode system
- electrode
- finger
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/117—Identification of persons
- A61B5/1171—Identification of persons based on the shapes or appearances of their bodies or parts thereof
- A61B5/1172—Identification of persons based on the shapes or appearances of their bodies or parts thereof using fingerprinting
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
- G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
- G06V40/12—Fingerprints or palmprints
- G06V40/13—Sensors therefor
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06V—IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING
- G06V40/00—Recognition of biometric, human-related or animal-related patterns in image or video data
- G06V40/10—Human or animal bodies, e.g. vehicle occupants or pedestrians; Body parts, e.g. hands
- G06V40/12—Fingerprints or palmprints
- G06V40/1382—Detecting the live character of the finger, i.e. distinguishing from a fake or cadaver finger
- G06V40/1394—Detecting the live character of the finger, i.e. distinguishing from a fake or cadaver finger using acquisition arrangements
Abstract
Detector for recognizing the living character of a finger which is arranged in a fingerprint recognizing apparatus and the detector is in contact with a print area (2) of the living finger constituting a print forming element (1) and the apparatus comprises for the examination of the print area (2) a print detector (5) which has a print imaging surface (4) partially covered by the print area (2). The detector comprises an electrode system (3) made of an electrically conductive material and sensing the presence of the print forming element (1), and an electrical evaluation unit coupled through electrical contacts (10) to the electrode system (3), the unit senses the change in state in the electrode system (3) caused by the proximity of the print forming element (1). The electrode system (3) is arranged on a portion of the print detector (5) covered by the print area (2) and it is coupled to the print imaging surface (4).
Description
W O 97/14111 PCT~HU96/00056 In a Fingerprint Recognizing Apparatus Detector for Recognizing the Living Character of a Finger The invention relates to a detector for recogni7in~ the living character of a S finger which is arranged in a fingerprint recogni7ing apparatus. The detector is in contact with a print area of the living finger that constitutes a print forming element~
and for the ex~min~tion of the print area the apparatus comprises a print detector which has a print im~ginSJ surface partially covered by the print area, and the detector comprises an electrode system made of an electrically conductive material 10 which senses the presence of the print forming element. The detector further comprises an elec~ical evaluation unit coupled through electrical contacts to the electrode system, the unit senses the change in state in the electrode system caused by the proximity of the print forming element.
The identification of individuals on the basis of fingerprint recognition has 15 become recently a widely used technique. In case of conventional fing~lL)linlanalysis using a painted paper as well as in case of opto-electric fmgerprint recog~ution systems the fingerprints are obtained when the tip of a finger is pressed against a surface. The modern opto-electric fingerprint recognition can take place under human supervision (e.g. when the fingerprint is entered in the criminal ~0 record) or without any supervision (e.g. in case of access control systems).
In case of fingerprint recognition without human supervision the fingerprint reading apparatus can be deceived by using a plastic imprint copy made from the finger of the person to be identified, thus a false access cannot be excluded.
Therefore in case of protection or security systems as well as in systems perrnitting ~5 access to computer systems and in case of any similar application in addition to the fingerprint recognition it is also of vital importance whether the print has been taken from a living finger or from a copy. It is also important that the detection of the living character of the finger be fast and reliable.
There are known methods for detecting the living character of a finger. In the 30 EP 0194783 A~ the optical spectral reflection coefficient of the finger is measured ~ CA 02233937 1998-04-02 . . ~ ', ' ', ~ , , , ' ' . ' ', ' AMEND~D S~EEl' at two wavelengths. The measurement of the reflection coefficient takes place at the two free sides of the finger pressed to the fing~ t recogni~ing a~a~us. The quotient of the t~vo reflection coefficients varies during the pl~cemPnt of the finger to the print area from a position where the tip of the finger just touches the surface 5 till the fully pressed state. The detection of the living character of the finger is based on the detected çh~npes of the quotient of the reflection coefficient. The drawback of this technique lies in that if a thin, transparent copy made by a thin film is placed on a living finger of another person, the change of the quotient of the reflection coefficient will be char~ctP~.~tic to a living finger, and a false detection is obtainecl ~ 10 Such a system is used in the personal identification a~alalus m~.mlf~ctllred by the co,..~ Biometrics Technology as reported in "The Biometrics Report, ISBN
190018009, 1995. page 69".
In the Japanese patent publication 05309082 an example can be found wherein the me~sllrements are based on the electrical resistance as one property of the print 15 formin~ element. In this technique an electrode is provided which contacts the surface of the finger just below the first joint i.e. which is outside the area from where the fing~ ~ is taken. The electrode is used to detect the electncal resi~t~nce of the living inger. The resi~t~nce value depends on the humidity of the finger, and if this resi.et~nce falls in a pre~ e~l range, the living character will 20 be established. This identification is not reliable either, since the detection takes place at a location which differs from the location from where the fingel~ is taken. If a thin copy is placed between the finger tip and a print area, the con~ctc can still engage the living finger.
Fig. 34 of the EP 0 359 554 A2 shows an electrical system which also utilizes 25 the difference in the reci~nce value of a living finger and of a replica, ~,vherein the area used for (3ele....;l~ the resi~t~nce value falls in the field from where the fingerprint is taken. The cited publication describes this technic~l solution as one where the electrode pattems used for ~lP,t~nninin~ the resi~nc-e value may disturb the image of the finge,~ . Further~nore it has been analysed that in such a system 30 the allowable re~i~t~nce value must be very large, however, then the difference , CA 02233937 1998-04-02 7 , ~ 7 ~. AMENDED SHEEt between the re~iet~nce value of the finger and the replica will become smaller, thus the security of such a system can be insufficient.
It can be understood from the above described known methods that they are ina~io~l;ate for the reliable detection whether the living finger belongs to the5 authorized person or not.
The object of the invention is to provide a detection system which can detect the living character of a finger and which associated with a fing~ int recogni7ing a~a~ s and excludes false identification if the person is diLCel'cn~ from the one whose fingel~ t serves as a basis for recognition.
This object can be achieved by a detection system, wherein the recognition of the living character of a finger is flet~ ed by the evaluation of the electncal si~als of an electrode system arranged within the print area of a print im~in,~
sllrf~ce7 and it takes place ~imnlt~neously with the recognition of the fing~
wherein the electrode system is designed in such a way that the two ~imnlt~neous15 mç~lrements cannot disturb one another.
The detector according to the invention is defined in the attached cl2~ims.
An electrode system ~1~cigned according to the invention does not disturb or limit the fingt;l~ recognition process and enables the me~...elllent of one or more properties or the ~~h~nges of these pr~,~lies of a living finger at the same time 20 as the recognition of the fingel~l~t takes place. Such ~r()~ lies can be e.g.:
- electrical ~l~clLies (dielectric con~t~nt impedance, etc.) - biophysical p~ Lies (points of acupuncture, reflex points, etc.) - bioch~nic~l ~r~lies (pEI, sllrf~ce humidity, etc.).
An increased re1i~bility can be provided by combining several kinds of 25 detection e.g. by using me~llrements taken from dil~e~t sllrf~ce areas and/or using an electrode system with combined p;.llf...~ and/or me~ one or more properties or the variation of these properties, wherein mllltiple conditions can be defined for the ~lele~ ion of the living character of the finger.
. CA 02233937 1998-04-02 ~ ! ~ 7 oO~ " o o 1 ~ " ~ ~ 1 AM~NDE~ S~EE~
, The invention will now be described in connection with preferable embo~lim~nt.~ thereof, in w~ich reference will be made to the accom~ ~ng drawings. In the drawings:
Fig. 1 shows the basic arrangement of a ~lP,tector usable for ~imlllt~neous detection of the living character of a finger and of the finge~ LI itself;
Fig. 2 shows an embodiment of an electrode system which has a design other than using thin layers, wherein the electric cormections can be seen;
Fig. 3 shows an electrode system covered partially with an in~ ~ing thin , . - layer;
Fig. 4 shows an electrode systern covered by a glass plate;
Fig. 5.shows an embodiment of a pattern of a single element electrode system used preferably for me~ellrin~ the dielectnc ct~n~t~nt;
Fig. 6 shows a further pattern of a ~ingle element electrode system used ~l~,r~.ably for me~.~-rin~ the electrical impe ance of the print forming element;
Fig. 7 shows the pattern of an electrode system with three elements used ~r~bly for the si~ lL~Ileous m~ lrement of dielectric constant and electrical imre~l~nce; and Fig. 8 shows a mnltirle el~m~nt electrode system and its pattern made from an electricaUy con~ ve and light transpa~ent m~t~i~l for the .c;...--l~(\çQus m.o~ elllent of dielec~ric con.~nt and electrical impe~l~nce.
The basic operational principles of the ~lstect~r for reco ni7inp the living character of a finger will now be descnbed in connection with Fig. 1. In this Fig. 1 a 25 print forming element 1 e.g. a living finger gets in cont~ct with electrode system 3 of a t1etector along a print area 2 when pressed to the sllrf~ce of the ~l~,tector. The electrode syste_ 3 is arranged on a pnnt im~ng s~ ce 4 ~l.?cigned p~er~lably as a planar surface of a print d~ctor 5.
W O 97/14111 PCTm U96/00056 The material of the print detector 5 is preferably optical glass or a transparent plastic material. When the fingerprint is imaged by means of opto-elech-ical im~7,~inf~, the image of the fingerprint will be created primarily on the print im~ging surface 4, and this image will be converted into an electrical signal sequence by 5 means of a two-dimensional detector system (being preferably a CCD detector).
When the im.qgin~ takes place by means of a total reflection method, ill~min~ting light beams 6 and image forming light beams 7 are used. When the image folming is based on light diffraction, free path should be provided to ill..min~1~n~, light beams 8 and image forming (back-scattered) light bearns 9. The role of these light beams 8 10 and 9 can be interchanged.
In Fig. 1 the electrode system 3 together with lead out contacts are desi~ned asa thin layer electrode. The lead out contacts form additional parts of the elech-ode.
The material of the electrode has a good electrical conductivity and preferably it is transparent at the waveleng~s of the ill7~min~hng light beams 6 or 8. Respective15 electrical cormections are coupled to the lead out contacts. The elechical connections can be made e.g. by metal wires. The wires can be contacted in a reliable manner e.g. by means of an ultrasonic thermal binding to the thin layer, by electrically conductive paints or by means of an epoxy-based adhesive filled with a plurality of tiny gold particles.
~0The literature describes several examples for m~king thin layers which are electrically conductive and at the same time light transparent. Such technologies include e.g. the use of chemicals, vacuum sputtering, vacuum evaporation or plasma techniques~ and the structure of the electrode system 3 can be made by the conventional use of masks. The material of the layer can be e.g. the mixture of ~5 indium-dioxide (In~03) and tin-oxide (Sn~O) refened often to as ITO layer. Further layers like pure tin-oxide layers and mixtures including aluminurn-zinc-oxides (Al~ZnO~) are also used. Such layers are not only electrically conductive and light ~ transparent but they have the required resistance against mechanical and thermal loads. The typical thickness of thin layers falls in the range of ~0 to 100 llm and 30 their specific electrical resistance is in the range of R2 = ~50 to lOOO ohm!- and CA 02233937 l998-04-02 W O 97/14111 PCT/~U96/00056 they have a sufficiently high light hransparency (practically close to 95 %). When such layers are used, the full print area ~ can be imaged, since the presence of the thin layer cannot change the contrast of the detected image in any of the cited image detection methods using either total reflection or light diffraction. The conhrast of 5 the image of the fingerprint is typically 50-80 % and relative to this amount the additional contrast modulation of 5 % caused by the presence of the transparent thin layer is negligibly small.
The electrode system 3 of the detector can also be realized by using a thin layer which is not light transparent or which has only a limited transparency. Such 10 thin layers are e.g. the thin metal layers made typically by gold, aluminum, chrome and similar metals. Such less light hransparent layers are cheaper, however. their significant drawback lies in that the print surface sections covered by their shucture cannot be imaged, thus such sections cannot take part in the identification of the fingerprint.
Fig. ~ shows an embodiment of the electrode system 3 together with elechical contacts 10 made without using thin layer technique. In this embodiment the pattern of the electrode system 3 is constituted by the fiber ends 1~ of electlically conductive wires 11 embedded in the material of the print detector 5. The conductive wires 11 constitute at the same time the lead out wires. The electrically ~0 conductive wires 11 can be made either by thin metal wires or by glass fibers doped by metal ions. In the last mentioned alternative the additional advantages of light transparency will be obtained. In connection with Fig. '~ it should be noted that when the print im~ging surface 4 is made (by means of grinding or polishing) theelectrode system 3 constituted by the ~lber ends 1~ will forrn part of the printim~ing surface 4.
In the embodiment shown in Fig. 3 the print forming element 1 is partially or completely insulated from the electrode system 3 by means of an inteImediate electrically insulating thin layer 13, and the degree of insulation depends on the material property to be detennined. If the insulating thin layer completely co~ers the 30 electrode system 13, the print forming element 1 will reach the close pro,Yimity of , O 97/14111 PCT~U96/00056 the electrode system 3. The close proximity means that the print formin~ element 1 will be in the electric field of the electrode system 3. In case of thin lavers the corresponding distance is not more than a few micrometers, and the penetration is apparent. The required limit of proximity de~ends on the pattern of the electrode system, and in case of predetermined patterns several times 100 ,um can be sufficient. The electrically insulating electrode system 3 is an important requirement when the measured material property is constituted by the dielectric constant.
The preparation of thin insulating layers is known from the state of alt. Such layers are made typically by silicon-dioxide by vacuum deposition technique.
Figure 4 shows a further embodiment for electrically insulating the electrode system 3. The print im~g~ing, surface that canies the electrode system 3 is covered by an insulating cover sheet in such a way that the sheet is coupled to the print im~g,ino surface 4 by means of an optical adhesive. Such optical adhesive materials are known in the art and they are transparent and have optical refraction indices close to that of glass, therefore they cannot cause undesired light reflections, i.e. a correct optical coupling is provided thereby. The presence of such a light transparent covering layer 15 will not prevent the illl-min~ino light beams 6 and 8 from reaching the print detector S and from im~"ing the fingerprint. Obviously in that case the role of the print im~ging surface 4 will be played by the surface of the electrically insulating cover sheet 14 that contacts the print forming element 1.
Fig. 5 shows the pattems of an element of the electrode system 3 used for measuring the dielectric constant. The pattern together with the lead out conductors is completely insulated from the print forrning element 1 along the full surface of the electrically insulating thin layer 13. The pattern itself is a version of a so-called interdigital electrode 16 optimized for measuring the dielectric constant. The interdigital electrode 16 comprises a pair of oppositely arranged "comb" pattems.
Such an electrode type is known for uses of other objectives and principles e._. in the field of acoustic filters with surface waves. The typical si~e data of the electrode pattern used for measuring dielectric constant are: the line width of the comb lies between 5-100 ~Lm and the spacing between the lines is between 5-100 ,um. By CA 02233937 l998-04-02 W O 97/14111 PCT~U96/00056 means of the interdigital electrode 16 it is possible to determine the dependence of the dielectric constant from the frequency. The size data of the pattern of the comb can vary according to the frequency range used. In practice the e~mining frequency range is between 0.1 and ~00 kHz. In this frequency range the dielectric constant of living tissues largely differ from that of commercially available plastics (Hedvig P.: r Applied Polymer Analysis and Characterization, Vol. II, Chapter 5., Hauser Publisher, Munich, 199'~). The typical relative dielectric constant value of living body tissues is between about 60 and 90, while in case of plastics this value isbetween about S and 30. The difference is sufficiently large for the distinction of living tissues from plastics.
Fig. 6 shows the pattern of an element of the electrode system 3 used for determining the electrical impedance. The paKern represents the so-called doubledot electrode 17 as optimized for electrical impedance measurements. The typicalsize of the sensor dots is berween about 0.1 and 1 mm, and the spacing between the dots is 1 to 5 mm. The dots of the measurement dot electrode 17 are in electrical contact with print forming element 1, because respective open windows are made at the dot locations on the insulating thin layer 13 that covers the pattern, while the lead out conductors of the dots are electrically insulated from the print forming element ~.
'~O Fig. 7 shows an electrode system 3 comprising three elements. Two of the elements constitute respective interdigital electrodes 16 while the third one is a double dot electrode 17. The size of the patterns of the two interdigital electrode elements can be different depending on the frequency range of the dielectric constant measurement. The use of multiple frequency ranges further increases thereliability of identifying living fingers. On the electrically insulating thin layer 13 that covers the electrode system 3 a window is provided for enabling impedance measurement as shown in Fig. 6.
Fig. 8 shows a preferable embodiment of the detector according to the invention that uses multiple element electrode system 3. The double dot electrode elements of the electrode system 3 are arranged within the print area ~ about 3 to _9_ 5 rnm from the contour line, while the interdigital electrode element 16 is ananged in the central portion of ~e print area. In this exemplaly arrangement the print area ~ is sufficiently covered by elements of the electrode system, and it can be prevented that a false copy that covers only a poltion of the plint area could cause 5 an erroneous personal identification. Naturally, the number of elements in theelectrode system 3 can be increased and several other patterns and arrangements can be made within the scope of the present invention.
The electrical contacts 10 of the elements of the electrode system 3 are connected to the inputs of an electrical evaluating unit 18. This unit 18 can 10 determine not only the static values of certain material properties of the plint forming element 1 but also for detelmining the valiation of such material propelties as a function of time. The measuring of such changes should be carTied out preferably during the time between the print forming element 1 touches the printim~gin~ surface 4 until it will be pressed thereto. The typical value of this time is 1~ between about 0.~ and 0.6 sec.
The electrical evaluation unit 1~ generates an enable signal for the fingerprintidentification or it provides data for the central processor unit of the fingerprint identifying apparatus and this unit enables the identification by analyzing the data obtained. Such an electric evaluation unit can be designed in several ways as it is ~0 obvious for those f~mili~r with the measurement technique using micro controllers.
-
and for the ex~min~tion of the print area the apparatus comprises a print detector which has a print im~ginSJ surface partially covered by the print area, and the detector comprises an electrode system made of an electrically conductive material 10 which senses the presence of the print forming element. The detector further comprises an elec~ical evaluation unit coupled through electrical contacts to the electrode system, the unit senses the change in state in the electrode system caused by the proximity of the print forming element.
The identification of individuals on the basis of fingerprint recognition has 15 become recently a widely used technique. In case of conventional fing~lL)linlanalysis using a painted paper as well as in case of opto-electric fmgerprint recog~ution systems the fingerprints are obtained when the tip of a finger is pressed against a surface. The modern opto-electric fingerprint recognition can take place under human supervision (e.g. when the fingerprint is entered in the criminal ~0 record) or without any supervision (e.g. in case of access control systems).
In case of fingerprint recognition without human supervision the fingerprint reading apparatus can be deceived by using a plastic imprint copy made from the finger of the person to be identified, thus a false access cannot be excluded.
Therefore in case of protection or security systems as well as in systems perrnitting ~5 access to computer systems and in case of any similar application in addition to the fingerprint recognition it is also of vital importance whether the print has been taken from a living finger or from a copy. It is also important that the detection of the living character of the finger be fast and reliable.
There are known methods for detecting the living character of a finger. In the 30 EP 0194783 A~ the optical spectral reflection coefficient of the finger is measured ~ CA 02233937 1998-04-02 . . ~ ', ' ', ~ , , , ' ' . ' ', ' AMEND~D S~EEl' at two wavelengths. The measurement of the reflection coefficient takes place at the two free sides of the finger pressed to the fing~ t recogni~ing a~a~us. The quotient of the t~vo reflection coefficients varies during the pl~cemPnt of the finger to the print area from a position where the tip of the finger just touches the surface 5 till the fully pressed state. The detection of the living character of the finger is based on the detected çh~npes of the quotient of the reflection coefficient. The drawback of this technique lies in that if a thin, transparent copy made by a thin film is placed on a living finger of another person, the change of the quotient of the reflection coefficient will be char~ctP~.~tic to a living finger, and a false detection is obtainecl ~ 10 Such a system is used in the personal identification a~alalus m~.mlf~ctllred by the co,..~ Biometrics Technology as reported in "The Biometrics Report, ISBN
190018009, 1995. page 69".
In the Japanese patent publication 05309082 an example can be found wherein the me~sllrements are based on the electrical resistance as one property of the print 15 formin~ element. In this technique an electrode is provided which contacts the surface of the finger just below the first joint i.e. which is outside the area from where the fing~ ~ is taken. The electrode is used to detect the electncal resi~t~nce of the living inger. The resi~t~nce value depends on the humidity of the finger, and if this resi.et~nce falls in a pre~ e~l range, the living character will 20 be established. This identification is not reliable either, since the detection takes place at a location which differs from the location from where the fingel~ is taken. If a thin copy is placed between the finger tip and a print area, the con~ctc can still engage the living finger.
Fig. 34 of the EP 0 359 554 A2 shows an electrical system which also utilizes 25 the difference in the reci~nce value of a living finger and of a replica, ~,vherein the area used for (3ele....;l~ the resi~t~nce value falls in the field from where the fingerprint is taken. The cited publication describes this technic~l solution as one where the electrode pattems used for ~lP,t~nninin~ the resi~nc-e value may disturb the image of the finge,~ . Further~nore it has been analysed that in such a system 30 the allowable re~i~t~nce value must be very large, however, then the difference , CA 02233937 1998-04-02 7 , ~ 7 ~. AMENDED SHEEt between the re~iet~nce value of the finger and the replica will become smaller, thus the security of such a system can be insufficient.
It can be understood from the above described known methods that they are ina~io~l;ate for the reliable detection whether the living finger belongs to the5 authorized person or not.
The object of the invention is to provide a detection system which can detect the living character of a finger and which associated with a fing~ int recogni7ing a~a~ s and excludes false identification if the person is diLCel'cn~ from the one whose fingel~ t serves as a basis for recognition.
This object can be achieved by a detection system, wherein the recognition of the living character of a finger is flet~ ed by the evaluation of the electncal si~als of an electrode system arranged within the print area of a print im~in,~
sllrf~ce7 and it takes place ~imnlt~neously with the recognition of the fing~
wherein the electrode system is designed in such a way that the two ~imnlt~neous15 mç~lrements cannot disturb one another.
The detector according to the invention is defined in the attached cl2~ims.
An electrode system ~1~cigned according to the invention does not disturb or limit the fingt;l~ recognition process and enables the me~...elllent of one or more properties or the ~~h~nges of these pr~,~lies of a living finger at the same time 20 as the recognition of the fingel~l~t takes place. Such ~r()~ lies can be e.g.:
- electrical ~l~clLies (dielectric con~t~nt impedance, etc.) - biophysical p~ Lies (points of acupuncture, reflex points, etc.) - bioch~nic~l ~r~lies (pEI, sllrf~ce humidity, etc.).
An increased re1i~bility can be provided by combining several kinds of 25 detection e.g. by using me~llrements taken from dil~e~t sllrf~ce areas and/or using an electrode system with combined p;.llf...~ and/or me~ one or more properties or the variation of these properties, wherein mllltiple conditions can be defined for the ~lele~ ion of the living character of the finger.
. CA 02233937 1998-04-02 ~ ! ~ 7 oO~ " o o 1 ~ " ~ ~ 1 AM~NDE~ S~EE~
, The invention will now be described in connection with preferable embo~lim~nt.~ thereof, in w~ich reference will be made to the accom~ ~ng drawings. In the drawings:
Fig. 1 shows the basic arrangement of a ~lP,tector usable for ~imlllt~neous detection of the living character of a finger and of the finge~ LI itself;
Fig. 2 shows an embodiment of an electrode system which has a design other than using thin layers, wherein the electric cormections can be seen;
Fig. 3 shows an electrode system covered partially with an in~ ~ing thin , . - layer;
Fig. 4 shows an electrode systern covered by a glass plate;
Fig. 5.shows an embodiment of a pattern of a single element electrode system used preferably for me~ellrin~ the dielectnc ct~n~t~nt;
Fig. 6 shows a further pattern of a ~ingle element electrode system used ~l~,r~.ably for me~.~-rin~ the electrical impe ance of the print forming element;
Fig. 7 shows the pattern of an electrode system with three elements used ~r~bly for the si~ lL~Ileous m~ lrement of dielectric constant and electrical imre~l~nce; and Fig. 8 shows a mnltirle el~m~nt electrode system and its pattern made from an electricaUy con~ ve and light transpa~ent m~t~i~l for the .c;...--l~(\çQus m.o~ elllent of dielec~ric con.~nt and electrical impe~l~nce.
The basic operational principles of the ~lstect~r for reco ni7inp the living character of a finger will now be descnbed in connection with Fig. 1. In this Fig. 1 a 25 print forming element 1 e.g. a living finger gets in cont~ct with electrode system 3 of a t1etector along a print area 2 when pressed to the sllrf~ce of the ~l~,tector. The electrode syste_ 3 is arranged on a pnnt im~ng s~ ce 4 ~l.?cigned p~er~lably as a planar surface of a print d~ctor 5.
W O 97/14111 PCTm U96/00056 The material of the print detector 5 is preferably optical glass or a transparent plastic material. When the fingerprint is imaged by means of opto-elech-ical im~7,~inf~, the image of the fingerprint will be created primarily on the print im~ging surface 4, and this image will be converted into an electrical signal sequence by 5 means of a two-dimensional detector system (being preferably a CCD detector).
When the im.qgin~ takes place by means of a total reflection method, ill~min~ting light beams 6 and image forming light beams 7 are used. When the image folming is based on light diffraction, free path should be provided to ill..min~1~n~, light beams 8 and image forming (back-scattered) light bearns 9. The role of these light beams 8 10 and 9 can be interchanged.
In Fig. 1 the electrode system 3 together with lead out contacts are desi~ned asa thin layer electrode. The lead out contacts form additional parts of the elech-ode.
The material of the electrode has a good electrical conductivity and preferably it is transparent at the waveleng~s of the ill7~min~hng light beams 6 or 8. Respective15 electrical cormections are coupled to the lead out contacts. The elechical connections can be made e.g. by metal wires. The wires can be contacted in a reliable manner e.g. by means of an ultrasonic thermal binding to the thin layer, by electrically conductive paints or by means of an epoxy-based adhesive filled with a plurality of tiny gold particles.
~0The literature describes several examples for m~king thin layers which are electrically conductive and at the same time light transparent. Such technologies include e.g. the use of chemicals, vacuum sputtering, vacuum evaporation or plasma techniques~ and the structure of the electrode system 3 can be made by the conventional use of masks. The material of the layer can be e.g. the mixture of ~5 indium-dioxide (In~03) and tin-oxide (Sn~O) refened often to as ITO layer. Further layers like pure tin-oxide layers and mixtures including aluminurn-zinc-oxides (Al~ZnO~) are also used. Such layers are not only electrically conductive and light ~ transparent but they have the required resistance against mechanical and thermal loads. The typical thickness of thin layers falls in the range of ~0 to 100 llm and 30 their specific electrical resistance is in the range of R2 = ~50 to lOOO ohm!- and CA 02233937 l998-04-02 W O 97/14111 PCT/~U96/00056 they have a sufficiently high light hransparency (practically close to 95 %). When such layers are used, the full print area ~ can be imaged, since the presence of the thin layer cannot change the contrast of the detected image in any of the cited image detection methods using either total reflection or light diffraction. The conhrast of 5 the image of the fingerprint is typically 50-80 % and relative to this amount the additional contrast modulation of 5 % caused by the presence of the transparent thin layer is negligibly small.
The electrode system 3 of the detector can also be realized by using a thin layer which is not light transparent or which has only a limited transparency. Such 10 thin layers are e.g. the thin metal layers made typically by gold, aluminum, chrome and similar metals. Such less light hransparent layers are cheaper, however. their significant drawback lies in that the print surface sections covered by their shucture cannot be imaged, thus such sections cannot take part in the identification of the fingerprint.
Fig. ~ shows an embodiment of the electrode system 3 together with elechical contacts 10 made without using thin layer technique. In this embodiment the pattern of the electrode system 3 is constituted by the fiber ends 1~ of electlically conductive wires 11 embedded in the material of the print detector 5. The conductive wires 11 constitute at the same time the lead out wires. The electrically ~0 conductive wires 11 can be made either by thin metal wires or by glass fibers doped by metal ions. In the last mentioned alternative the additional advantages of light transparency will be obtained. In connection with Fig. '~ it should be noted that when the print im~ging surface 4 is made (by means of grinding or polishing) theelectrode system 3 constituted by the ~lber ends 1~ will forrn part of the printim~ing surface 4.
In the embodiment shown in Fig. 3 the print forming element 1 is partially or completely insulated from the electrode system 3 by means of an inteImediate electrically insulating thin layer 13, and the degree of insulation depends on the material property to be detennined. If the insulating thin layer completely co~ers the 30 electrode system 13, the print forming element 1 will reach the close pro,Yimity of , O 97/14111 PCT~U96/00056 the electrode system 3. The close proximity means that the print formin~ element 1 will be in the electric field of the electrode system 3. In case of thin lavers the corresponding distance is not more than a few micrometers, and the penetration is apparent. The required limit of proximity de~ends on the pattern of the electrode system, and in case of predetermined patterns several times 100 ,um can be sufficient. The electrically insulating electrode system 3 is an important requirement when the measured material property is constituted by the dielectric constant.
The preparation of thin insulating layers is known from the state of alt. Such layers are made typically by silicon-dioxide by vacuum deposition technique.
Figure 4 shows a further embodiment for electrically insulating the electrode system 3. The print im~g~ing, surface that canies the electrode system 3 is covered by an insulating cover sheet in such a way that the sheet is coupled to the print im~g,ino surface 4 by means of an optical adhesive. Such optical adhesive materials are known in the art and they are transparent and have optical refraction indices close to that of glass, therefore they cannot cause undesired light reflections, i.e. a correct optical coupling is provided thereby. The presence of such a light transparent covering layer 15 will not prevent the illl-min~ino light beams 6 and 8 from reaching the print detector S and from im~"ing the fingerprint. Obviously in that case the role of the print im~ging surface 4 will be played by the surface of the electrically insulating cover sheet 14 that contacts the print forming element 1.
Fig. 5 shows the pattems of an element of the electrode system 3 used for measuring the dielectric constant. The pattern together with the lead out conductors is completely insulated from the print forrning element 1 along the full surface of the electrically insulating thin layer 13. The pattern itself is a version of a so-called interdigital electrode 16 optimized for measuring the dielectric constant. The interdigital electrode 16 comprises a pair of oppositely arranged "comb" pattems.
Such an electrode type is known for uses of other objectives and principles e._. in the field of acoustic filters with surface waves. The typical si~e data of the electrode pattern used for measuring dielectric constant are: the line width of the comb lies between 5-100 ~Lm and the spacing between the lines is between 5-100 ,um. By CA 02233937 l998-04-02 W O 97/14111 PCT~U96/00056 means of the interdigital electrode 16 it is possible to determine the dependence of the dielectric constant from the frequency. The size data of the pattern of the comb can vary according to the frequency range used. In practice the e~mining frequency range is between 0.1 and ~00 kHz. In this frequency range the dielectric constant of living tissues largely differ from that of commercially available plastics (Hedvig P.: r Applied Polymer Analysis and Characterization, Vol. II, Chapter 5., Hauser Publisher, Munich, 199'~). The typical relative dielectric constant value of living body tissues is between about 60 and 90, while in case of plastics this value isbetween about S and 30. The difference is sufficiently large for the distinction of living tissues from plastics.
Fig. 6 shows the pattern of an element of the electrode system 3 used for determining the electrical impedance. The paKern represents the so-called doubledot electrode 17 as optimized for electrical impedance measurements. The typicalsize of the sensor dots is berween about 0.1 and 1 mm, and the spacing between the dots is 1 to 5 mm. The dots of the measurement dot electrode 17 are in electrical contact with print forming element 1, because respective open windows are made at the dot locations on the insulating thin layer 13 that covers the pattern, while the lead out conductors of the dots are electrically insulated from the print forming element ~.
'~O Fig. 7 shows an electrode system 3 comprising three elements. Two of the elements constitute respective interdigital electrodes 16 while the third one is a double dot electrode 17. The size of the patterns of the two interdigital electrode elements can be different depending on the frequency range of the dielectric constant measurement. The use of multiple frequency ranges further increases thereliability of identifying living fingers. On the electrically insulating thin layer 13 that covers the electrode system 3 a window is provided for enabling impedance measurement as shown in Fig. 6.
Fig. 8 shows a preferable embodiment of the detector according to the invention that uses multiple element electrode system 3. The double dot electrode elements of the electrode system 3 are arranged within the print area ~ about 3 to _9_ 5 rnm from the contour line, while the interdigital electrode element 16 is ananged in the central portion of ~e print area. In this exemplaly arrangement the print area ~ is sufficiently covered by elements of the electrode system, and it can be prevented that a false copy that covers only a poltion of the plint area could cause 5 an erroneous personal identification. Naturally, the number of elements in theelectrode system 3 can be increased and several other patterns and arrangements can be made within the scope of the present invention.
The electrical contacts 10 of the elements of the electrode system 3 are connected to the inputs of an electrical evaluating unit 18. This unit 18 can 10 determine not only the static values of certain material properties of the plint forming element 1 but also for detelmining the valiation of such material propelties as a function of time. The measuring of such changes should be carTied out preferably during the time between the print forming element 1 touches the printim~gin~ surface 4 until it will be pressed thereto. The typical value of this time is 1~ between about 0.~ and 0.6 sec.
The electrical evaluation unit 1~ generates an enable signal for the fingerprintidentification or it provides data for the central processor unit of the fingerprint identifying apparatus and this unit enables the identification by analyzing the data obtained. Such an electric evaluation unit can be designed in several ways as it is ~0 obvious for those f~mili~r with the measurement technique using micro controllers.
-
Claims
1. Detector for recognizing the living character of a finger which is arranged in a fingerprint recognizing apparatus and the detector is in contact with a print area (2) of the living finger constituting a print forming element (1) and the apparatus comprises for the examination of said print area (2) a print detector (5) which has a print imaging surface (4) partially covered by said print area (2), said detector comprises an electrode system (3) made of an electrically conductive material, said electrode system (3) is arranged on a portion of said print detector (5) covered by said print area (2) and being coupled to said print imaging surface (4), and an electrical evaluation unit (18) coupled through electrical contacts (10) to the electrode system (3), said unit (18) sensing the change in state in the electrode system (3) caused by the proximity of the print forming element (1), characterized in that said print imaging surface (4) is constituted by an electrically non-conductive and light transparent material at least on portions not including exceptional areas defined by predetermined electrodes of said electrode system (3) and by the close vicinity region of said electrodes, wherein the total surface of said exceptional areas is substantially smaller than the total surface of said non-conductive portions.2. The detector as claimed in claim 1, characterized in that said non-conductivematerial being a separate layer (13,14).
3. The detector as claimed in claim 2, characterized in that the electrode system (3) is covered by an electrically insulating, light transparent cover sheet (14) which forms said layer, and a separate thin light transparent insulating layer (15) is arranged on the inner side of said cover sheet (14) for providing an optical coupling.
4. The detector as claimed in claim 2, characterized in that said electrode system (3) is designed for determining dielectric constant and being constituted by interdigital electrodes (16) covered completely by said insulating layer (13).
5. The detector as claimed in claim 2, characterized in that said electrode system (3) is designed for determining electrical impedance and constituted by at least one double dot electrode (17), and said electrically insulating layer (13)leaving said double dot electrode (17) and the close vicinity region thereof uncovered while covering the lead out contacts of the electrode (17).
6. The detector as claimed in claim 1, characterized in that the electrode system (3) comprises a plurality of identical elements and said elements being arranged in a non-overlapping manner for identifying different portions of the print forming element (1).
7. The detector as claimed in claim 1, characterized in that the electrode system (3) comprises fiber ends (12) of electrically conductive wires (11) embedded in the non-conductive material of said print detector (5) and said fiber ends (12) forming part of said print imaging surface (4), wherein the remaining portion of said print imaging surface (4) constituting said non-conductive portion.
8. The detector as claimed in claim 7, characterized in that said electrically conductive wires (11) being metal wires or glass fibers doped by metal ions.
9. The detector as claimed in claim 1, characterized in that the electrode system (3) comprises a plurality of different elements for determining differentmaterial properties of the print forming element (1) or the change of such properties as a function of time.
3. The detector as claimed in claim 2, characterized in that the electrode system (3) is covered by an electrically insulating, light transparent cover sheet (14) which forms said layer, and a separate thin light transparent insulating layer (15) is arranged on the inner side of said cover sheet (14) for providing an optical coupling.
4. The detector as claimed in claim 2, characterized in that said electrode system (3) is designed for determining dielectric constant and being constituted by interdigital electrodes (16) covered completely by said insulating layer (13).
5. The detector as claimed in claim 2, characterized in that said electrode system (3) is designed for determining electrical impedance and constituted by at least one double dot electrode (17), and said electrically insulating layer (13)leaving said double dot electrode (17) and the close vicinity region thereof uncovered while covering the lead out contacts of the electrode (17).
6. The detector as claimed in claim 1, characterized in that the electrode system (3) comprises a plurality of identical elements and said elements being arranged in a non-overlapping manner for identifying different portions of the print forming element (1).
7. The detector as claimed in claim 1, characterized in that the electrode system (3) comprises fiber ends (12) of electrically conductive wires (11) embedded in the non-conductive material of said print detector (5) and said fiber ends (12) forming part of said print imaging surface (4), wherein the remaining portion of said print imaging surface (4) constituting said non-conductive portion.
8. The detector as claimed in claim 7, characterized in that said electrically conductive wires (11) being metal wires or glass fibers doped by metal ions.
9. The detector as claimed in claim 1, characterized in that the electrode system (3) comprises a plurality of different elements for determining differentmaterial properties of the print forming element (1) or the change of such properties as a function of time.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| HU9502937A HU214533B (en) | 1995-10-06 | 1995-10-06 | Detector for identifying living character of a finger |
| HUP9502937 | 1995-10-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2233937A1 true CA2233937A1 (en) | 1997-04-17 |
Family
ID=10987276
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002233937A Abandoned CA2233937A1 (en) | 1995-10-06 | 1996-10-04 | In a fingerprint recognizing apparatus detector for recognizing the living character of a finger |
Country Status (15)
| Country | Link |
|---|---|
| US (1) | US6175641B1 (en) |
| EP (1) | EP0853795B1 (en) |
| JP (1) | JPH11513516A (en) |
| CN (1) | CN1201541A (en) |
| AT (1) | ATE222660T1 (en) |
| AU (1) | AU7141796A (en) |
| CA (1) | CA2233937A1 (en) |
| CZ (1) | CZ99198A3 (en) |
| DE (1) | DE69623125T2 (en) |
| DK (1) | DK0853795T3 (en) |
| EA (1) | EA199800362A1 (en) |
| ES (1) | ES2181911T3 (en) |
| HU (1) | HU214533B (en) |
| PT (1) | PT853795E (en) |
| WO (1) | WO1997014111A1 (en) |
Families Citing this family (46)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6310683B1 (en) * | 1997-08-05 | 2001-10-30 | Casio Computer Co., Ltd. | Apparatus for reading fingerprint |
| US6784413B2 (en) | 1998-03-12 | 2004-08-31 | Casio Computer Co., Ltd. | Reading apparatus for reading fingerprint |
| JP3898330B2 (en) * | 1998-03-12 | 2007-03-28 | カシオ計算機株式会社 | Reader |
| DE19830830C2 (en) * | 1998-07-09 | 2000-11-23 | Siemens Ag | Process for the live detection of human skin |
| AU5393999A (en) * | 1998-08-06 | 2000-02-28 | Secugen Corporation | A compact optical fingerprint capturing and recognition system |
| US6411726B1 (en) * | 1998-10-08 | 2002-06-25 | Durel Corporation | Fingerprint detector using an EL lamp |
| US6381347B1 (en) | 1998-11-12 | 2002-04-30 | Secugen | High contrast, low distortion optical acquistion system for image capturing |
| WO2000060530A1 (en) * | 1999-04-05 | 2000-10-12 | Ethentica, Inc. | Planar optical image sensor and system for generating an electronic image of a relief object for fingerprint reading |
| US6324020B1 (en) | 1999-08-04 | 2001-11-27 | Secugen Corporation | Method and apparatus for reduction of trapezoidal distortion and improvement of image sharpness in an optical image capturing system |
| AU2001232162A1 (en) * | 2000-02-25 | 2001-09-03 | Sensirion Ag | Sensor and sigma-delta converter |
| US6292576B1 (en) * | 2000-02-29 | 2001-09-18 | Digital Persona, Inc. | Method and apparatus for distinguishing a human finger from a reproduction of a fingerprint |
| US6956608B1 (en) | 2000-08-11 | 2005-10-18 | Identix Incorporated | Fingerprint imaging device including an optical plate having microreflectors |
| US20020131624A1 (en) * | 2000-08-11 | 2002-09-19 | Yury Shapiro | Fingerprint imaging device with fake finger detection |
| US6501284B1 (en) * | 2000-08-28 | 2002-12-31 | Stmicroelectronics, Inc. | Capacitive finger detection for fingerprint sensor |
| KR20020028754A (en) * | 2001-05-04 | 2002-04-17 | 안준영 | LCD panel also functioning as fingerprint acquisition |
| DE10126839A1 (en) * | 2001-06-01 | 2002-12-19 | Infineon Technologies Ag | Fingerprint sensor for personal identification incorporates electrostatic discharge protection and verification that applied finger is living tissue |
| KR100432490B1 (en) * | 2001-09-17 | 2004-05-22 | (주)니트 젠 | Optical fingerprint acquisition apparatus |
| JP2003111749A (en) * | 2001-10-09 | 2003-04-15 | Bmf:Kk | Device for discriminating human |
| KR20030066920A (en) * | 2002-02-06 | 2003-08-14 | (주)니트 젠 | Apparatus and method for distinguishing live fingerprint |
| NO321659B1 (en) * | 2002-05-14 | 2006-06-19 | Idex Asa | Volume specific characterization of human skin by electrical immitance |
| JP2005536792A (en) * | 2002-08-21 | 2005-12-02 | セキユジエン・コーポレイシヨン | TFT detection device with improved imaging surface |
| NO20025803D0 (en) | 2002-12-03 | 2002-12-03 | Idex Asa | Live finger |
| FR2849244B1 (en) * | 2002-12-20 | 2006-03-10 | Sagem | METHOD FOR DETERMINING THE LIVING CHARACTER OF A CARRIER COMPONENT OF A DIGITAL IMPRINT |
| FR2849246B1 (en) * | 2002-12-20 | 2006-03-10 | Sagem | METHOD FOR DETERMINING THE LIVING CHARACTER OF A CARRIER COMPONENT OF A DIGITAL IMPRINT |
| EP1679036B1 (en) * | 2003-08-15 | 2013-02-27 | Nippon Telegraph And Telephone Corporation | Organism recognition system |
| JP2005233688A (en) * | 2004-02-17 | 2005-09-02 | Seiko Epson Corp | Capacitance detection device, fingerprint sensor, biometrics authentication device, and search method for capacitance detection condition |
| FR2872318B1 (en) * | 2004-06-23 | 2006-09-22 | Sagem | OPTICAL BIOMETRIC CAPTURE DEVICE BY CONTACT AND INSTALLATION USING SUCH A DEVICE |
| RU2286599C2 (en) * | 2004-09-22 | 2006-10-27 | ОАО "Центральный научно-исследовательский институт "Электрон" | Method for biometric identification |
| CA2742379A1 (en) * | 2008-11-03 | 2010-05-06 | Cross Match Technologies, Inc. | Apparatus and method for the identification of fake fingerprints |
| WO2011143279A1 (en) | 2010-05-11 | 2011-11-17 | Ultra-Scan Corporation | Reflex longitudinal imaging using through sensor insonification |
| EP2710582A4 (en) * | 2011-05-17 | 2014-12-31 | Cross Match Technologies Inc | Fingerprint sensors |
| WO2013071311A1 (en) | 2011-11-11 | 2013-05-16 | Cross Match Technologies, Inc. | Ambient light rejection for non-imaging contact sensors |
| KR101981730B1 (en) | 2011-11-12 | 2019-05-23 | 크로스 매치 테크놀로지스, 인크. | Ambient light illumination for non-imaging contact sensors |
| CN105981049A (en) * | 2014-02-25 | 2016-09-28 | Hid环球公司 | Bioimpedance spoof detection |
| CA2946668C (en) | 2014-04-23 | 2020-11-17 | Novomatic Ag | Arrangement and method for identifying fingerprints |
| CN106156698A (en) * | 2015-03-30 | 2016-11-23 | 联想(北京)有限公司 | A kind of information processing method and electronic equipment |
| EP3109793B1 (en) | 2015-06-22 | 2020-07-22 | Nxp B.V. | Fingerprint sensing system |
| CN106250857A (en) * | 2016-08-04 | 2016-12-21 | 深圳先进技术研究院 | A kind of identity recognition device and method |
| CN106618570B (en) * | 2017-01-22 | 2019-08-20 | 深圳先进技术研究院 | A kind of skin biochemical indicator detection method and system based on biological dielectric spectra |
| US11531756B1 (en) | 2017-03-20 | 2022-12-20 | Hid Global Corporation | Apparatus for directing presentation attack detection in biometric scanners |
| US10810405B2 (en) * | 2017-08-09 | 2020-10-20 | Qatar University | Biometric liveness detection through biocompatible capacitive sensor |
| CA2992333C (en) * | 2018-01-19 | 2020-06-02 | Nymi Inc. | User access authorization system and method, and physiological user sensor and authentication device therefor |
| CN110543864A (en) * | 2018-11-30 | 2019-12-06 | 神盾股份有限公司 | Sensor and fake finger identification method |
| US11451536B2 (en) | 2019-10-25 | 2022-09-20 | Nymi Inc. | User state monitoring system and method using motion, and a user access authorization system and method employing same |
| FR3103934B1 (en) * | 2019-11-29 | 2022-11-18 | Idemia Identity & Security France | Impedance sensing fingerprint sensor |
| US11605255B2 (en) | 2020-05-14 | 2023-03-14 | Nymi Inc. | User activity-related monitoring system and method, and a user access authorization system and method employing same |
Family Cites Families (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3622989A (en) * | 1969-11-28 | 1971-11-23 | Carter Craft Inc | Fingerprint identification |
| US3781855A (en) * | 1970-03-13 | 1973-12-25 | Identification Systems Inc | Fingerprint identification system and method |
| US3639905A (en) * | 1970-11-27 | 1972-02-01 | Omron Tateisi Electronics Co | Credit card system having means for sensing if object is living |
| US4210899A (en) * | 1975-06-23 | 1980-07-01 | Fingermatrix, Inc. | Fingerprint-based access control and identification apparatus |
| US4353056A (en) * | 1980-06-05 | 1982-10-05 | Siemens Corporation | Capacitive fingerprint sensor |
| DK155242C (en) * | 1985-05-02 | 1989-07-31 | Jydsk Telefon As | METHOD AND APPARATUS FOR AUTOMATIC DETECTION OF FINGERPRINT |
| JPH01180685A (en) * | 1988-01-12 | 1989-07-18 | Nec Corp | Fingerprint picture input device |
| JPH021243A (en) * | 1988-06-08 | 1990-01-05 | Nec Corp | Method and apparatus for detecting forged fingerprint |
| JPH0823885B2 (en) * | 1988-09-16 | 1996-03-06 | 富士通株式会社 | Biological detection device and fingerprint collation system using the device |
| DE68919394T2 (en) * | 1988-09-16 | 1995-03-30 | Fujitsu Ltd | System for detecting a biological object and fingerprint comparison system using this system. |
| US5095278A (en) * | 1988-11-21 | 1992-03-10 | Ta Instruments, Inc. | Planar interdigitated dielectric sensor |
| JP2708051B2 (en) * | 1989-08-31 | 1998-02-04 | 富士通株式会社 | Fingerprint image input device |
| JP3060656B2 (en) * | 1990-11-26 | 2000-07-10 | セイコーエプソン株式会社 | Liquid crystal display device |
| FR2674051A1 (en) * | 1991-03-14 | 1992-09-18 | Gemplus Card Int | Device for identifying a person, especially by fingerprint detection |
| US5623552A (en) * | 1994-01-21 | 1997-04-22 | Cardguard International, Inc. | Self-authenticating identification card with fingerprint identification |
| US5419826A (en) * | 1994-03-25 | 1995-05-30 | The United States Of America As Represented By The Secretary Of The Navy | Ion-selective reference probe |
| JP2937046B2 (en) * | 1994-12-26 | 1999-08-23 | 日本電気株式会社 | Fingerprint image input device |
| JP3418479B2 (en) * | 1995-05-11 | 2003-06-23 | 日本電信電話株式会社 | Fingerprint input device |
| US5629764A (en) * | 1995-07-07 | 1997-05-13 | Advanced Precision Technology, Inc. | Prism fingerprint sensor using a holographic optical element |
-
1995
- 1995-10-06 HU HU9502937A patent/HU214533B/en not_active IP Right Cessation
-
1996
- 1996-10-04 AU AU71417/96A patent/AU7141796A/en not_active Abandoned
- 1996-10-04 JP JP9514845A patent/JPH11513516A/en active Pending
- 1996-10-04 WO PCT/HU1996/000056 patent/WO1997014111A1/en active IP Right Grant
- 1996-10-04 CN CN96198122A patent/CN1201541A/en active Pending
- 1996-10-04 ES ES96932745T patent/ES2181911T3/en not_active Expired - Lifetime
- 1996-10-04 EP EP96932745A patent/EP0853795B1/en not_active Expired - Lifetime
- 1996-10-04 CA CA002233937A patent/CA2233937A1/en not_active Abandoned
- 1996-10-04 PT PT96932745T patent/PT853795E/en unknown
- 1996-10-04 US US09/051,154 patent/US6175641B1/en not_active Expired - Fee Related
- 1996-10-04 EA EA199800362A patent/EA199800362A1/en unknown
- 1996-10-04 CZ CZ98991A patent/CZ99198A3/en unknown
- 1996-10-04 DE DE69623125T patent/DE69623125T2/en not_active Expired - Fee Related
- 1996-10-04 AT AT96932745T patent/ATE222660T1/en not_active IP Right Cessation
- 1996-10-04 DK DK96932745T patent/DK0853795T3/en active
Also Published As
| Publication number | Publication date |
|---|---|
| HUT76403A (en) | 1997-08-28 |
| CN1201541A (en) | 1998-12-09 |
| JPH11513516A (en) | 1999-11-16 |
| WO1997014111A1 (en) | 1997-04-17 |
| HU9502937D0 (en) | 1995-12-28 |
| DK0853795T3 (en) | 2002-12-02 |
| EP0853795A1 (en) | 1998-07-22 |
| HU214533B (en) | 1998-03-30 |
| CZ99198A3 (en) | 1998-11-11 |
| ES2181911T3 (en) | 2003-03-01 |
| US6175641B1 (en) | 2001-01-16 |
| ATE222660T1 (en) | 2002-09-15 |
| PT853795E (en) | 2003-01-31 |
| DE69623125T2 (en) | 2003-11-06 |
| AU7141796A (en) | 1997-04-30 |
| EP0853795B1 (en) | 2002-08-21 |
| EA199800362A1 (en) | 1998-10-29 |
| DE69623125D1 (en) | 2002-09-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2233937A1 (en) | In a fingerprint recognizing apparatus detector for recognizing the living character of a finger | |
| US5757278A (en) | Personal verification system | |
| JP4528130B2 (en) | Live finger detection by complex impedance four-point measurement | |
| EP0983572B1 (en) | Fingerprint sensor including an anisotropic dielectric coating and associated methods | |
| EP0372748B1 (en) | Fingerprint-detecting device | |
| US5953441A (en) | Fingerprint sensor having spoof reduction features and related methods | |
| US5903225A (en) | Access control system including fingerprint sensor enrollment and associated methods | |
| US5920640A (en) | Fingerprint sensor and token reader and associated methods | |
| US6052475A (en) | Fingerprint detector using ridge resistance sensing array | |
| US20100113952A1 (en) | Apparatus and method for the identification of fake fingerprints | |
| KR100603917B1 (en) | Irradiated images described by electrical contact | |
| KR20010012633A (en) | Fingerprint sensor having filtering and power conserving features and related methods | |
| US20060159314A1 (en) | Method of dertermining the living character of an bearing carrying a fingerprint | |
| JPH0387981A (en) | Fingerprint image input device | |
| US11328536B2 (en) | Fingerprint sensor with impedance detection | |
| JP3190356B2 (en) | Personal ID identification method and ID identification device | |
| JPH02144685A (en) | Organism identifying device | |
| KR20010105969A (en) | A finger-pattern cognition device using the piezoresistive type sensor and thereof method | |
| JPH10293015A (en) | Optical detection device | |
| JPS61283994A (en) | Private collation method and apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |