Fingerprint recognition module having a thin-film structure and comprising resistive, temperature-sensitive elements

• US 7,720,265 B2
• Filed: 05/15/2003
• Issued: 05/18/2010
• Est. Priority Date: 05/17/2002
• Status: Active Grant

• Current Assignee: NEXT Biometrics Group ASA
• Original Assignee: Inabillion As
• Inventors: Aurich, Joachim, Igel, Günter, Büstgens, Burkhard, Urban, Gerald
• Primary Examiner(s): Perungavoor; Sath V
• Application Number:
  US10/513,331
• Publication Number:
  US 20060050935A1
• Time in Patent Office: 2,560 Days
• Field of Search: 382/124
• US Class Current: 382/124
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing

Abstract

The invention relates to a fingerprint recognition module comprising a substrate consisting of a material that is electrically insulating at least on its upper side and at least partially thermally insulating. Said substrate receives a composite of structured thin films on its surface, which directly forms a measuring field on the surface of the substrate for measuring a fingerprint. Said composite consists of an array of resistive, temperature-dependent elements, and contains strip conductors which connect the resistive, temperature-dependent elements to at least one connection field located on the substrate, outside the measuring field, and form part of the composite of structured thin films. The substrate also contains at least one microelectronic switching circuit which is electrically connected to the at least one connection field and contains the switching circuits by which means the thin film structures are controlled in order to heat the resistive, temperature-sensitive elements, the resistive, temperature-sensitive elements are read out, and the data is retransmitted.

Claims

1. A fingerprint recognition module comprising:

a substrate,

a composite of structured thin films on the surface of the substrate, that forms a measuring field on a portion of the substrate for measuring a fingerprint, including linear, resistive, temperature-sensitive elements arranged in rows and columns, and that contains thin-film structures for heating the linear, resistive, temperature-sensitive elements, and that contains strip conductors, connecting the linear, resistive, temperature-sensitive elements with a connection field located on the substrate outside of the measuring field, and

a microelectronic analyzing switching circuit, electrically connected with the connection field and containing a switching circuit with which the thin-film structures for heating the linear, resistive, temperature-sensitive elements are controlled, the linear, resistive, temperature-sensitive elements are read out, and data are relayed,

wherein the thin-film structures for heating comprise a plurality of sets of series connected longitudinal heating conductors, each set of series connected longitudinal heating conductors being situated under or above the resistive, temperature-sensitive elements of at least one respective column of resistive, temperature-sensitive elements in such a way that, when current flows through the series connected longitudinal heating conductors of the set, the longitudinal heating conductors of that set heat, at the same time, the resistive, temperature-sensitive elements of the at least one respective column.

2. The fingerprint recognition module according to claim 1, wherein the microelectronic analyzing switching circuit contains a process computer, including computing and memory storage units, that, by means of software, verify the measured fingerprint in relation to one or several stored fingerprints.

3. The fingerprint recognition module according to claim 1, wherein the substrate includes glass.

4. The fingerprint recognition module according to claim 1, wherein the portion of the substrate adjoining the composite of structured thin films is elastic in comparison to the composite of structured thin films.

5. The fingerprint recognition module according to claim 1, wherein the portion of the substrate adjoining the composite of structured thin films has a thermally insulating effect.

6. The fingerprint recognition module according to claim 1, wherein the substrate includes rigid or flexible plastic.

7. The fingerprint recognition module according to claim 1, wherein the portion of the substrate adjoining the composite of structured thin films includes plastic.

8. The fingerprint recognition module according to claim 1, wherein the strip conductors comprise row conductor strips and column conductor strips and wherein each set of longitudinal heating conductors is connected at its one end with a column lead of exactly one column conductor strip and at its other end with the other end of further sets of longitudinal heating conductors in the form of a switching junction.

9. The fingerprint recognition module according to claim 8 wherein the switching junction is connected with an electric switching element, contained in the microelectronic analyzing switching circuit, by means of which the heating function can be switched.

10. The fingerprint recognition module according to claim 1, further comprising a surface layer made of electrically conductive material that is grounded.

11. The fingerprint recognition module according to claim 1, wherein the thin-film composite is coated in whole or in part with a poorly wetting surface layer or with a layer with Lotus effect.

12. The fingerprint recognition module according to claim 1, wherein the thin-film composite is coated in whole or in part with a surface abrasion-reducing layer.

13. A fingerprint recognition module comprising:

a substrate

a composite of structured thin films on the surface of the substrate, that forms a measuring field on a portion of the substrate for measuring a fingerprint, including linear, resistive, temperature-sensitive elements arranged in rows and columns, and that contains thin-film structures for heating the linear, resistive, temperature-sensitive elements, and that contains strip conductors, connecting the linear, resistive, temperature-sensitive elements with a connection field located on the substrate outside of the measuring field, and

a microelectronic analyzing switching circuit, electrically connected with the connection field and containing a switching circuit with which the thin-film structures for heating the linear, resistive, temperature-sensitive elements are controlled, the linear, resistive, temperature-sensitive elements are read out, and data are relayed,

wherein the strip conductors comprise row conductor strips and column conductor strips and wherein the microelectronic analyzing switching circuit holds the electrical potential of all row conductor strips at the same value.

14. A fingerprint recognition module comprising:

a substrate

a composite of structured thin films on the surface of the substrate, that forms a measuring field on a portion of the substrate for measuring a fingerprint, including linear, resistive, temperature-sensitive elements arranged in rows and columns, and that contains thin-film structures for heating the linear, resistive, temperature-sensitive elements, and that, contains strip conductors, connecting the linear, resistive, temperature-sensitive elements with a connection field located on the substrate outside of the measuring field, and

a microelectronic analyzing switching circuit, electrically connected with the connection field and containing a switching circuit with which the thin-film structures for heating the linear, resistive, temperature-sensitive elements are controlled, the linear, resistive, temperature-sensitive elements are read out, and data are relayed,

wherein the substrate includes a metal-plastic laminate and the plastic side of the laminate is coextensive with and disposed over the metal side of the laminate and serves as a substrate surface on which the composite of structured thin films is provided.

15. A fingerprint recognition module comprising:

a substrate,

a composite of structured thin films on the surface of the substrate, that forms a measuring field on a portion of the substrate for measuring a fingerprint, including linear, resistive, temperature-sensitive elements arranged in rows and columns, and that contains thin-film structures for heating the linear, resistive, temperature-sensitive elements, and that contains strip conductors, connecting the linear, resistive, temperature-sensitive elements with a connection field located on the substrate outside of the measuring field,

a microelectronic analyzing switching circuit, electrically connected with the connection field and containing a switching circuit with which the thin-film structures for heating the linear, resistive, temperature-sensitive elements are controlled, the linear, resistive, temperature-sensitive elements are read out, and data are relayed, and

a surface layer made of electrically conductive material, wherein an electric circuit comprising the thin-film structures for heating the resistive, temperature-sensitive elements is electrically closed via the surface layer made of electrically conductive material.

16. A fingerprint recognition module comprising:

a substrate,

a composite of structured thin films on the surface of the substrate, that forms a measuring field on a portion of the substrate for measuring a fingerprint, including linear, resistive, temperature-sensitive elements arranged in rows and columns, and that contains thin-film structures for heating the linear, resistive, temperature-sensitive elements, and that contains strip conductors, connecting the linear, resistive, temperature-sensitive elements with a connection field located on the substrate outside of the measuring field, and

a microelectronic analyzing switching circuit, electrically connected with the connection field and containing a switching circuit with which the thin-film structures for heating the linear, resistive, temperature-sensitive elements are controlled, the linear, resistive, temperature-sensitive elements are read out, and data are relayed,

wherein the thin-film structures for heating the resistive, temperature-sensitive elements are constructed as a surface layer made of electrically conductive material.

17. The fingerprint recognition module according to claim 16, wherein the surface layer includes transparent, electrically conductive material.

18. A fingerprint recognition module comprising:

a substrate,

a composite of structured thin films on the surface of the substrate, that forms a measuring field on a portion of the substrate for measuring a fingerprint, including linear, resistive, temperature-sensitive elements arranged in rows and columns, and that contains thin-film structures for heating the linear, resistive, temperature-sensitive elements, and that contains strip conductors, connecting the linear, resistive, temperature-sensitive elements with a connection field located on the substrate outside of the measuring field, and

a microelectronic analyzing switching circuit, electrically connected with the connection field and containing a switching circuit with which the thin-film structures for heating the linear, resistive, temperature-sensitive elements are controlled, the linear, resistive, temperature-sensitive elements are read out, and data are relayed,

wherein the microelectronic analyzing switching circuit is flip chip mounted over the substrate to make electrical connection with the connection field.

19. The fingerprint recognition module of claim 18, wherein the microelectronic analyzing switching circuit is mounted over a portion of the connection field.