FINGERPRINT IDENTIFICATION SYSTEM AND METHOD

• US 3,781,855 A
• Filed: 03/13/1970
• Issued: 12/25/1973
• Est. Priority Date: 03/13/1970
• Status: Expired due to Term

• Current Assignee: Donald E. Killen
• Original Assignee: Donald E. Killen
• Inventors: Killen, Donald E.
• Primary Examiner(s): Robinson, Thomas A.
• Application Number:
  US05/019,327
• Time in Patent Office: 1,383 Days
• Field of Search: 324/65R,65M,71R 340/146.3E,166,407,146.3R,149 73/104,105,150 128/2.1R,2.1A,DIG.4
• US Class Current: 382/126
• CPC Class Codes: A61B 5/1172 using fingerprinting
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing

Abstract

The specification discloses a matrix sensing device for sensing the pattern of the skin of a finger for comparison with measurements previously obtained and stored in a storage device for identification purposes. The matrix sensing device comprises a plurality of electrical conductance sensing means located in rows and columns in a planar surface for contacting the skin of a finger. Selection means is provided for sequentially selecting each sensing means row by row for sequentially measuring the electrical conductance of the skin at a plurality of points in an orderly fashion. Initially, in a first cycle, the conductance is sequentially measured and an average value obtained. Subsequently, in a second cycle, each measurement obtained is compared to the average value. From the resulting measurements there is derived a signal image of the pattern of the skin of the finger for use for identification purposes.

Claims

1. A matrix device for measuring an electrical property of the skin of a body member for identification purposes comprising:

a plurality of spaced sensing means located in a grid pattern forming rows and columns of sensing means, said plurality of sensing means being located in a planar surface for engaging said skin for electrical resistance measuring purposes, each sensing means comprising a pair of spaced first and second contacts electrically isolated from each other in the plane of said surface for sensing for said electrical property of the skin dependent at least in part upon the amount of contact of the skin with each pair of said contacts, a first set of electrical conducting means located in rows and electrically isolated from each other, each row of electrical conducting means of said first set electrically connecting together a row of said first contacts, and a second set of electrical conducting means located in columns and electrically isolated from each other and from said electrical conducting means of said first set, each column of electrical conducting means of said second set electrically connecting together a column of said second contacts.

2. A method of electrically scanning the surface pattern of a portion of the skin tissue of a body member of a human being such as a fingerprint to produce an electrical signal image of said pattern comprising:

sensing for an electrical parameter representative of a surface feature of said skin pattern at a plurality of different points on the surface of the skin of said body member;

producing electrical signals representative of said electrical parameters sensed between selected ones of said plurality of different points on said surface of said skin of said body member; and

deriving an electrical signal image of said surface pattern of said skin from said electrical signals.

3. A method in accordance with claim 2 including the steps of:

obtaining an average value of said electrical parameters sensed between said selected ones of said plurality of different points, and thereafter comparing the value of said electrical parameter sensed at each of said Selected ones of said plurality of different points with said average value prior to deriving said signal image.

4. A method in accordance with claim 2 including:

sensing for an electrical property between only adjacent points at each of a plurality of pairs of adjacent points on the surface of the skin of said body member.

5. A device for obtaining an electrical signal image of a skin point of a human being such as a fingerprint by measuring electrical parameters of the surface of said skin comprising:

a plurality of electrical sensing means closely spaced in a matrix to contact and distinguish between ridges and valleys of said skin pattern for obtaining a measure of an electrical parameter of said skin representative of said ridges and valleys between selected ones of a plurality of different points on the surface of said skin, and means for supporting said sensing means in a position to engage said skin for measuring purposes.

6. The device of claim 5 including means for sequentially and separately selecting different ones of said sensing means for sequentially and separately obtaining a measure of said electrical parameter between said selected ones of said plurality of different points on said skin of said body member.

7. A device in accordance with claim 6 including:

means for obtaining a measure of the average value of said electrical parameter at a plurality of different points on said skin of said body member under investigation, and means for comparing said average values with said measurements obtained at each of said sensing means.

8. A device in accordance with claim 5 including:

means for obtaining an average value of all of said electrical parameters sensed between said selected ones of said plurality of points on said skin of said body member under investigation, and means for comparing said average value with the value of each of said electrical parameters as sensed at each of said selected ones of said plurality of different points.

9. A device for detecting a skin surface pattern of a human being such as a fingerprint by measuring electrical parameters of said skin comprising:

a matrix of a plurality of closely spaced electrical sensing means for contacting and distinguishing between ridges and valleys of said skin pattern by obtaining a measure of an electrical parameter of said skin surface between a plurality of different points, each sensing means comprising a pair of spaced first and second contacts for contacting the surface of said skin, a first set of electrical conducting means, each conducting means of the first set electrically connecting together a plurality of different ones of said first contacts, a second set of electrical conducting means, each conducting means of said second set electrically connecting together a plurality of different ones of said second contacts, and means for supporting and positioning said first and second contacts of each sensing means in a sensing surface for engaging said surface of said skin for measuring purposes.

10. The device of claim 9 comprising:

means for sequentially and separately selecting different ones of said pairs of first and second contacts for obtaining a measure of said electrical parameter between a plurality of different points on said skin of said body member.

11. A device for measur-ing an electrical parameter of the skin of a body member comprising:

a plurality of spaced sensing means for obtaining a measure of an electrical parameter of said body member between a plurality of different points, each sensing means comprising a pair of spaced first and second contacts for contacting the surface of the skin of said body member, a first set of electrical conducting means, each conducting means of the first set electrically connecting together a plurality of different ones of said first contacts, a second set of electrical conducting means, each conducting means of Said second set electrically connecting together a plurality of different ones of said second contacts, means for supporting and positioning said first and second contacts of each sensing means in a sensing surface for engaging said surface of said skin of said body member for measuring purposes, means for sequentially and separately selecting different ones of said pairs of first and second contacts for obtaining a measure of said electrical parameter between a plurality of different points on said skin of said body member, means for obtaining a measure of the average value of said electrical parameter at a plurality of different points on the skin of said body member under investigation, and means for comparing said average value to said measurements obtained as each of said pairs of first and second contacts are sequentially and separately selected.

12. A device for measuring an electrical parameter of the skin of a body member comprising:

a plurality of spaced sensing means for obtaining a measure of an electrical parameter of said body member between a plurality of different points, each sensing means comprising a pair of spaced first and second contacts for contacting the surface of the skin of said body member, a first set of electrical conducting means, each conducting means of the first set electrically connecting together a plurality of different ones of said first contacts, a second set of electrical conducting means, each conducting means of said second set electrically connecting together a plurality of different ones of said second contacts, means for supporting and positioning said first and second contacts of each sensing means in a sensing surface for engaging said surface of said skin of said body member for measuring purposes, a source of electrical current, means for sequentially and separately coupling said source to each of said first conducting means, gate means for normally blocking the flow of current from each of said second conducting means, and means for controlling said gate means to allow current sequentially and separately to flow from each of said second conducting means during the time that said source is coupled to each of said first conducting means for obtaining a measure of said electrical parameter at a plurality of different points on said skin of said body member.

13. The device of claim 12 comprising:

means for obtaining a measure of the average value of said electrical parameter at a plurality of different points on the skin of a body member under investigation, and means for comparing said average value with said measurements of said electrical parameter as obtained at each of said plurality of different points on said skin of said body member under investigation.

14. A system for obtaining a measure of an electrical parameter of the skin of a body member at a plurality of different points comprising:

a device having a plurality of different sensing means for sensing for said electrical parameter at a plurality of different points on the skin, selecting means for sequentially selecting each sensing means for obtaining a measure of said electrical parameter at different points on the skin, means for controlling said selecting means to cycle said selecting means through its selection sequence at least twice, averaging means for obtaining an average value of said electrical parameter as sensed by said plurality of sensing means, comparing means for comparing the output of said averaging means with the output of each sensing means, and means for applying the output of each sensing means to said averaging means during one cycle and the output of each sensing means to said comparing means during a subsequent cycle.

15. The system of claim 14 wherein said comparison means forms the ratio between the output obtained by each sensing means and the output of said averaging means.

16. The system of claim 15 comprisIng:

means having a predetermined threshold for comparison with the output of said comparison means for obtaining a measurement of the presence or absence of skin contact with each sensing means of said device, said comparison means comprising automatic gain control means for adjusting the amplitude of its output as an inverse function of the electrical conductivity of the skin of the body member.

17. A device for measuring an electrical parameter of the skin of a body member comprising:

a first set of electrical conducting means electrically isolated from each other and having surfaces in a plane exposed for contacting the skin, each conducting means of said first set having a plurality of apertures extending therethrough, a second set of electrical conducting means electrically isolated from each other and from said first set of conducting means, said second set of conducting means being located below said first set of conducting means, and a plurality of contact members extending from each con-ducting means of said second set, each contact member extending through one of said aper-tures formed through said conducting means of said first set and having a surface in said plane exposed for contacting the skin, each contact member of said second set of said device being electrically isolated from said electrical conducting means of said first set.

18. A device for measuring an electrical property of the skin of a body member comprising:

a plurality of sensing means for obtaining a measure of an electrical property of said body member at a corresponding plurality of different locations on the surface of the skin of said body member, each of said sensing means comprising a different pair of adjacent contacts spaced from every other pair of contacts, there being no contact common to all pairs, and means for supporting each contact pair to engage the skin of said member at a corresponding one of said locations on the surface of the skin.

19. The device of claim 18 wherein said sensing means includes means for measuring the electrical conductance between the contacts of each pair of contacts.

20. The device of claim 18 further comprising means for sequentially and separately selecting different ones of said sensing means for sequentially and separately obtaining a measure of said electrical property at the corresponding locations on the surface of the skin of the body member.

21. The device of claim 18 further comprising means for producing an electrical signal having a magnitude proportional to the measure of the electrical property obtained at each of said different locations.

22. The device of claim 21 further comprising means for comparing each such electrical signal with a predetermined signal and for producing a resultant signal having a magnitude which is proportional to the ratio of the magnitude of the electrical signal to the magnitude of the predetermined signal.

23. A device for sensing a skin surface pattern of a human being by measuring electrical parameters of said skin surface comprising:

a plurality of closely spaced sensing means to detect the ridges and valleys of said skin surface, each said sensing means including a pair of adjacently spaced first and second contacts for contacting said surface of the skin, a first set of electrical conducting means, each conduct-ing means of the first set electrically connecting together a plurality of different ones of said first contacts, a second set of electrical conducting means, each con-ducting means of said second set electrically connecting together a plurality of different ones of said second contacts, and means for supporting and positioning said first and second contacts of each sensing means in a sensing surface for engaging said surface of said skin for measuring purposes.

24. A device for measuring an electrical parameter of the skin of a body member comprising:

a plurality of spaced sensing means, each including a pair of adjacently spaced first and second contacts for contacting the surface of the skin of said body member, a first set of electrical conducting means, each conduct-ing means of the first set electrically connecting together a plurality of different ones of said first contacts, a second set of electrical conducting means, each con-ducting means of said second set electrically connecting together a plurality of different ones of said second contacts, means for supporting and positioning said first and second contacts of each sensing means in a sensing surface for engaging the surface of the skin of said body member for measuring purposes, and means for sequentially and separately selecting different ones of said pairs of first and second contacts for obtaining a measure of said electrical parameter between points on the skin of said body member contacted by the first and second contacts of each of said different ones of said pairs.

25. The device of claim 24 wherein said sensing means comprises means for measuring the electrical conductance between the first and second contacts of selected pairs of contacts.

26. The device of claim 24 further comprising means for producing electrical signals each of whose magnitudes is propor-tional to the measure of said electrical parameter obtained between said points contacted by the first and second contacts of each of said different ones of said pairs.

27. The device of claim 26 further comprising means responsive to each of said electrical signals for producing a digital signal representative of the electrical signal, and means for comparing each of said digital signals with one or more preselected digital signals.