Integrated finger print sensor

• US 9,881,196 B2
• Filed: 11/18/2016
• Issued: 01/30/2018
• Est. Priority Date: 02/22/2013
• Status: Active Grant

• Current Assignee: IDEX Biometrics ASA
• Original Assignee: Idex ASA
• Inventors: Bernstein, Ralph W., Christie, Nicolai W., Bredholt, Geir Ivar, Slgedal, yvind
• Primary Examiner(s): DINH, DUC Q
• Application Number:
  US15/355,415
• Publication Number:
  US 20170068836A1
• Time in Patent Office: 438 Days
• Field of Search: 345173-175
• CPC Class Codes: G06F 2203/04106 Multi-sensing digitiser, i.e. digitiser using at least two different sensing technologies simultaneously or alternatively, e.g. for detecting pen and finger, for saving power or for improving position detection
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G06V 40/1329 Protecting the fingerprint sensor against damage caused by the finger

Abstract

A fingerprint sensor and fingerprint sensor system especially for integration in a device having an overlay made of an insulating material comprises a plurality of sensing elements positioned on a first side of the overlay; a plurality of probes positioned in a predetermined pattern defining a fingerprint sensing area on a second side of the overlay, the plurality of probes extending from the first side of the overlay at least partially through the overlay; a plurality of conductor leads on the first side of the overlay interconnecting the plurality of probes with the plurality of sensing elements; a plurality of amplifiers connected to the plurality of sensing elements, the number of amplifiers being less than the number of sensing elements; and an activation circuit connected to the plurality of sensing elements, the activation circuit being adapted to output at least one activation signal.

Claims

1. A fingerprint sensor configured for integration in a device having an overlay made of an insulating material, the fingerprint sensor comprising:

a plurality of sensing elements positioned on a first side of the overlay;

a plurality of probes defining a fingerprint sensing area on a second side of the overlay, the plurality of probes comprising a first group of probes and a second group of probes, wherein each probe of the first group of probes extends from the first side of the overlay partially through the overlay and each probe of the second group of probes extends from the first side of the overlay through the overlay; and

a plurality of conductor leads on the first side of the overlay interconnecting the plurality of probes with the plurality of sensing elements.

2. The fingerprint sensor of claim 1, further comprising a dielectric layer covering at least a portion of the second side of the overlay, wherein the dielectric layer covers at least one of probes of the second group of probes extending through the overlay.

3. The fingerprint sensor of claim 1, wherein the insulating material is selected from a group consisting of glass, poly methyl methacrylate and polycarbonate.

4. The fingerprint sensor of claim 1, wherein each sensing element is configured to be activated by an activation signal comprising an alternating current or voltage signal and to output a response signal modulated by the activation signal when activated.

5. The fingerprint sensor of claim 4, wherein the sensing elements are grouped in sets of sensing elements, and each sensing element in a set of sensing elements is adapted to be simultaneously activated by an activation signal common to all of the sensing elements in the set of sensing elements.

6. The fingerprint sensor of claim 1, wherein an end of each probe of the second group of probes is flush with the second side of the overlay.

7. The fingerprint sensor of claim 1, wherein an end of each probe of the second group of probes extends over the second side of the overlay.

8. The fingerprint sensor of claim 1, wherein an end of each probe of a first portion of the second group of probes is flush with the second side of the overlay and an end of each probe of a second portion of the second group of probes extends over the second side of the overlay.

9. The fingerprint sensor of claim 1, wherein the plurality of sensing elements is positioned on a substrate that is separate from the overlay, wherein the substrate is electrically connected to the conductor leads on the first side of the overlay.

10. The fingerprint sensor of claim 1, wherein the plurality of sensing elements comprises:

a sensing electrode,

an activation electrode configured to generate an activation signal to activate the sensing electrode, wherein the sensing electrode is configured to output a response signal modulated by the activation signal;

a pick-up electrode configured to receive the response signal; and

a dielectric layer separating the activation electrode and the pickup electrode from the sensing electrode.

11. The fingerprint sensor of claim 10, further comprising:

an activation line coupled to the activation electrode; and

a second dielectric layer separating the activation line from the activation electrode.

12. The fingerprint sensor of claim 11, wherein the activation line is electrically connected to the activation electrode through a conductive via.

13. The fingerprint sensor of claim 1, wherein the plurality of probes are positioned in a transparent section of the overlay, the conductor leads are routed to a processing unit outside the transparent area, and the probes and the conductor leads are made of an essentially transparent material.

14. The fingerprint sensor of claim 10, further comprising:

a plurality of amplifiers connected to the plurality of sensing elements, the number of amplifiers being less than the number of sensing elements, wherein each pick-up electrode is connected to one of the plurality of amplifiers; and

an activation circuit connected to the activation electrode, the activation circuit being adapted to output at least one activation signal.

15. The fingerprint sensor system of claim 14, wherein the activation circuit is further adapted to sequentially switch the activation signal to activate one of the sensing elements at one time.

16. The fingerprint sensor system of claim 14, wherein

the plurality of probes is arranged in a two-dimensional pattern, the two-dimensional pattern corresponding to m rows of sensing elements and n columns of sensing elements, where m≧

1 and n≧

1;

the pick-up electrode of each sensing element in a column is connected to one of n amplifiers through a common pick-up line;

the activation electrode of each sensing element in a row is connected to an activation signal through a common activation line; and

the activation circuit is configured to sequentially switch the activation signal to activate each of the sensing elements in a row such that a resulting signal is sensed on the respective pick-up electrode and amplified by the respective column amplifier.

17. The fingerprint sensor system of claim 14, wherein the activation circuit is further adapted to receive input from a touch-enabled display and to activate one of the sensing elements based on the received input.

18. The finger print sensor of claim 1, wherein the plurality of sensing elements comprises:

two or more drive lines disposed in a side-by-side arrangement, and

two or more pickup elements disposed in a side-by-side arrangement and oriented transversely to said drive lines.

19. A fingerprint sensor configured for integration in a device having an overlay made of an insulating material, the fingerprint sensor comprising:

a plurality of sensing elements positioned on a first side of the overlay;

a plurality of probes defining a fingerprint sensing area on a second side of the overlay, the plurality of probes comprising a first group of probes and a second group of probes, wherein each probe of the first group of probes extends from the first side of the overlay through the overlay and has an end that is flush with the second side of the overlay and each probe of the second group of probes extends from the first side of the overlay through the overlay and has an end that extends over the second side of the overlay; and

a plurality of conductor leads on the first side of the overlay interconnecting the plurality of probes with the plurality of sensing elements.