Detector for recognizing the living character of a finger in a fingerprint recognizing apparatus

• US 6,175,641 B1
• Filed: 04/02/1998
• Issued: 01/16/2001
• Est. Priority Date: 10/06/1995
• Status: Expired due to Fees

• Current Assignee: Dermo Corporation Limited
• Original Assignee: Dermo Corporation Limited
• Inventors: Kiss, Imre, Podmaniczky, András, Tálosi, János, Kalló, Péter
• Primary Examiner(s): Boudreau, Leo H.
• Assistant Examiner(s): Werner, Brian P.
• Application Number:
  US09/051,154
• Time in Patent Office: 1,020 Days
• Field of Search: 382/124, 382/312, 382/125, 382/318, 382/126, 382/315, 382/127, 382/116, 356/71, 340/825.34
• US Class Current: 382/124
• CPC Class Codes: A61B 5/1172 using fingerprinting
• CPC Class Codes: G06V 40/13 Sensors therefor
• CPC Class Codes: G06V 40/1394 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).

Claims

1. A detector for recognizing the living character of a finger in an opto-electronic fingerprint recognizing apparatus, in which a full two-dimensional image of the fingerprint is captured, and in operation the detector is in contact with a print area of a living finger constituting a print forming element, the fingerprint recognizing apparatus comprises a print detector for examining said print area, the print detector having a print imaging surface partially covered by said print area, the detector comprising:

an electrode system made of an electrically conductive material, and arranged on a portion of said print detector covered by said print area, and being coupled to said print imaging surface;

an electrical evaluation unit coupled through electrical contacts to the electrode system, said electrical evaluation unit sensing a change in state of the electrode system caused by the proximity of the print forming element;

wherein said electrode system comprises interdigital electrodes covered completely by a non-conductive layer; and

wherein said print imaging surface is constituted by said electrically non-conductive and light transparent material comprised of a thin separate layer deposited on the print detector so as to cover at least a dominant portion of said print area, said electrode system and said electrical contacts, and said electrode system and said electrical contacts are made of light transparent and electrically conductive material configured to allow print images to be captured of the print forming element on at least one portion of the print area covered by said electrode system and said electrical contacts, and said electrode system is designed for determining dielectric constant.

2. The detector as claimed in claim 1, wherein said electrode system simultaneously determines the dielectric constant of the print forming element while the print image of the print forming element is captured.

3. A detector for recognizing the living character of a finger in an opto-electronic fingerprint recognizing apparatus, in which a full two-dimensional image of the fingerprint is captured, and in operation the detector is in contact with a print area of a living finger constituting a print forming element, the fingerprint recognizing apparatus comprises a print detector for examining said print area, the print detector having a print imaging surface partially covered by said print area, the detector comprising:

an electrode system made of an electrically conductive material, and arranged on a portion of said print detector covered by said print area, and being coupled to said print imaging surface;

an electrical evaluation unit coupled through electrical contacts to the electrode system, said electrical evaluation unit sensing a change in state of the electrode system caused by the proximity of the print forming element;

wherein said electrode system comprises at least one double dot electrode;

wherein said print imaging surface is constituted by an electrically non-conductive and light transparent material comprised of a thin separate layer deposited on the print detector so as to cover at least a dominant portion of said print area, said electrode system and said electrical contacts, and said electrode system and said electrical contacts are made of light transparent and electrical conductive material configured to allow print images to be captured of the print forming element on at least one portion of the print area covered by said electrode system and said electrical contacts, and

wherein said electrode system is designed for determining electrical impedance, and said electrically non-conductive layer leaves said double dot electrode and a close vicinity thereof uncovered while covering lead out contacts of the electrode system.

4. The detector as claimed in claim 3, wherein said electrode system simultaneously determines electrical impedance of the print forming element while the print image of the print forming element is captured.

5. A detector for recognizing the living character of a finger in an opto-electronic fingerprint recognizing apparatus, in which a full two-dimensional image of the fingerprint is captured, and in operation the detector is in contact with a print area of a living finger constituting a print forming element, the fingerprint recognizing apparatus comprises a print detector for examining said print area, the print detector having a print imaging surface partially covered by said print area, the detector comprising:

an electrode system made of an electrically conductive material, and arranged on a portion of said print detector covered by said print area, and being coupled to said print imaging surface;

an electrical evaluation unit coupled through electrical contacts to the electrode system, said electrical evaluation unit sensing a change in state of the electrode system caused by the proximity of the print forming element;

wherein said electrode system comprises at least one double dot electrode;

wherein said print imaging surface is constituted by an electrically non-conductive and light transparent material comprised of a thin separate layer deposited on the print detector so as to cover at least a dominant portion of said print area, said electrode system and said electrical contacts, and said electrode system and said electrical contacts are made of light transparent and electrically conductive material configured to allow print images to be captured of the print forming element on at least one portion of the print area covered by said electrode system and said electrical contacts, and the electrode system comprises fiber ends of electrically conductive wires embedded in the non-conductive material of said print detector and said fiber ends forming part of said print imaging surface, wherein the remaining portion of said print imaging surface constitutes said non-conductive portion.

6. The detector as claimed in claim 5, wherein said electrically conductive wires are comprised of thin wires or glass fibers doped by metal ions configured so that said electrically conductive wires do not interfere with capturing the full two-dimensional image of the fingerprint.

7. An optical-electronic print recognizing device for capturing print images of a print forming element comprising:

a print detector structure made of an electrically insulating and light transparent material and defining a print area for receiving a print forming element;

an electrode system coupled to said print detector structure for generating a change in state when the print forming element is proximate to at least one portion of the print area covered by the electrode system;

an electrical evaluation system coupled through electrical contacts to the electrode system for evaluating when the electrode system changes state;

an electrically insulating and light transparent layer deposited on the print detector structure so as to cover at least a dominant portion of the print area, the electrode system, and the electrical contacts for selectively insulating the print forming element from the electrode system and the electrical contacts; and

wherein the electrode system is made of a light transparent and electrically conductive material for allowing a print image to be captured of the print forming element on the at least one portion of the print area covered by the electrode system, and is configured for determining a dielectric constant of the print forming element.

8. The optical-electronic print recognizing device of claim 7, wherein the electrode comprises a plurality of interdigital electrodes covered by said insulating layer.

9. The detector as claimed in claim 7, wherein said electrode system simultaneously determines the dielectric constant of the print forming element while the print image of the print forming element is captured.

10. An optical-electronic print recognizing device for capturing print images of a print forming element comprising:

a print detector structure made of an electrically insulating and light transparent material and defining a print area for receiving a print forming element;

an electrode system coupled to said print detector structure for generating a change in state when the print forming element is proximate to at least one portion of the print area covered by the electrode system;

an electrical evaluation system coupled through electrical contacts to the electrode system for evaluating when the electrode system changes state;

an electrically insulating and light transparent layer deposited on the print detector structure so as to cover at least a dominant portion of the print area, the electrode system, and the electrical contacts for selectively insulating the print forming element from the electrode system and the electrical contacts;

wherein the electrode system is made of a light transparent and electrically conductive material for allowing a print image to be captured of the print forming element on the at least one portion of the print area covered by the electrode system, is configured for determining an electrical impedance of the print forming element, and further comprises at least one double dot electrode and at least one lead out contact, and said electrically insulating layer covers the at least one lead out contact while leaving the double dot electrode uncovered.

11. The optical-electronic print recognizing device of claim 10, wherein the electrically insulating and light transparent layer defines a window for exposing the double dot electrode to the print forming element and allowing the print forming element to be in electrical contact with the double dot electrode when the print forming element is proximate to the print area.

12. An optical-electronic print recognizing device for capturing print images of a print forming element comprising:

a print detector structure made of an electrically insulating and light transparent material and defining a print area for receiving a print forming element;

an electrode system coupled to said print detector structure for generating a change in state when the print forming element is proximate to at least one portion of the print area covered by the electrode system;

an electrical evaluation system coupled through electrical contacts to the electrode system for evaluating when the electrode system changes state;

an electrically insulating and light transparent layer deposited on the print detector structure so as to cover at least a dominant portion of the print area, the electrode system, and the electrical contacts for selectively insulating the print forming element from the electrode system and the electrical contacts; and

wherein the electrode system is made of a light transparent and electrically conductive wire for allowing a print image to be captured of the print forming element on the at least one portion of the print area covered by the electrode system, and the electrically conductive wire comprises a glass fiber doped by metal ions.

13. An optical-electronic print recognizing device for capturing print images of a print forming element comprising:

a print detector structure made of an electrically insulating and light transparent material and defining a print area for receiving a print forming element;

an electrode system coupled to said print detector structure for generating a change in state when the print forming element is proximate to at least one portion of the print area covered by the electrode system;

an electrical evaluation system coupled through electrical contacts to the electrode system for evaluating when the electrode system changes state;

an electrically insulating and light transparent layer deposited on the print detector structure so as to cover at least a dominant portion of the print area, the electrode system, and the electrical contacts for selectively insulating the print forming element from the electrode system and the electrical contacts; and

wherein the electrode system is made of a light transparent and electrically conductive material for allowing a print image to be captured of the print forming element on the at least one portion of the print area covered by the electrode system, and the electrically insulating and light transparent layer completely covers the electrode system and allows the print forming element to be placed within an electric field generated by the electrode system when the print forming element is proximate to the print area.