Biometric image sensing

Patent metadata

Field	Value
Publication number	US-9659208-B2
Application number	US-201514946040-A
Country	US
Kind code	B2
Filing date	Nov 19, 2015
Priority date	Jan 15, 2010
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

An novel sensor is provided having a plurality of substantially parallel drive lines configured to transmit a signal into a surface of a proximally located object, and also a plurality of substantially parallel pickup lines oriented proximate the drive lines and electrically separated from the pickup lines to form intrinsic electrode pairs that are impedance sensitive at each of the drive and pickup proximal locations.

First claim

The invention claimed is:

1. A biometric sensor, comprising:
a plurality of drive lines;
a plurality of pickup lines oriented transversely to the drive lines and separated from the drive lines by a substrate;
an integrated circuit comprising drive electronics and detection electronics, wherein the substrate is disposed between the pickup lines and the integrated circuit, wherein the drive electronics comprise switches configured to multiplex the drive lines to a signal source, and wherein the detection electronics comprise one or more differential amplifiers and switches configured to multiplex the pickup lines to the one or more differential amplifiers; and
vias extending through the substrate for providing an electrical connection between the pickup lines and the integrated circuit.

2. The biometric sensor of claim 1 , further comprising a reference pickup line located outside a contact area defined by the drive lines and the pickup lines, and wherein the detection electronics are configured to subtract a signal on a pickup plate in contact with an object contacting the contact area from a signal on the reference pickup line.

3. The biometric sensor of claim 1 , wherein the switches of the detection electronics comprise a pickup switch associated with each pickup line for selectively connecting each pickup plate with the differential amplifier and for connecting each pickup line not connected to the differential amplifier to ground.

4. The biometric sensor of claim 2 , wherein the reference pickup line is separated from the other pickup plates by a first gap that is larger than a second gap separating the other pickup lines.

5. The biometric sensor of claim 1 , wherein the switches of the detection electronics comprise single pole double throw switches.

6. The biometric sensor of claim 1 , wherein the switches of the drive electronics comprise single pole single throw switches.

7. The biometric sensor of claim 1 , wherein the substrate has a top layer and a bottom layer, and wherein the pickup lines are located on the top layer and the integrated circuit is located on the bottom layer.

8. The biometric sensor of claim 7 , further comprising a plurality of pickup interconnects disposed on the bottom layer of the substrate and being connected to the integrated circuit, and wherein each via is connected to an associated one of the pickup interconnects.

9. The biometric sensor of claim 1 , wherein the substrate is composed of a dielectric material.

10. The biometric sensor of claim 1 , wherein the substrate is composed of a flexible material.

11. The biometric sensor of claim 1 , further comprising a dielectric layer disposed on top of the pickup lines.

12. The biometric sensor of claim 1 , wherein the substrate is composed of a rigid material.

13. The biometric sensor of claim 1 , wherein each via is electrically coupled to one associated pickup line and extends through the substrate and to an associated pickup interconnect that extends to the integrated circuit.

14. The biometric sensor of claim 1 , wherein the drive lines are parallel to one another and the pickup lines are parallel to one another.

15. The biometric sensor of claim 1 , wherein the pickup lines are disposed on a first side of the substrate and the drive lines are disposed on a second side of the substrate opposite the first side.

16. The biometric sensor of claim 15 , wherein the integrated circuit is disposed on the second side of the substrate.

17. The biometric sensing assembly of claim 16 , wherein the integrated circuit comprises drive electronics and detection electronics, wherein the drive electronics comprise switches configured to multiplex the drive lines to a signal source, and wherein the detection electronics comprise one or more differential amplifiers and switches configured to multiplex the pickup lines to the one or more differential amplifiers.

18. The biometric sensor of claim 1 , further comprising a plurality of conductive traces, each conductive trace including a first end connected to an end of an associated one of the pick-up lines and a second end, wherein each of the vias is connected to the second end of an associated one of the conductive traces to provide the electrical connection between the associated pickup line and the integrated circuit.

19. The biometric sensor of claim 18 , wherein the pickup lines are parallel to one another along their entire length, and the conductive traces are not parallel to one another along their entire length.

20. The biometric sensing assembly of claim 19 , wherein the switches of the detection electronics comprise a pickup switch associated with each pickup line for selectively connecting each pickup plate with the differential amplifier and for connecting each pickup line not connected to the differential amplifier to ground.

21. The biometric sensing assembly of claim 19 , wherein the switches of the detection electronics comprise single pole double throw switches.

22. The biometric sensing assembly of claim 19 , wherein the switches of the drive electronics comprise single pole single throw switches.

23. The biometric sensor of claim 1 , wherein each via is associated with a pickup plate and the spacing between adjacent vias is greater than the spacing between associated pickup plates.

24. A biometric sensor assembly, comprising:
a sensing grid comprising
a plurality of parallel drive lines; and
a plurality of parallel pickup lines oriented transversely to the drive lines and separated from the drive lines by a substrate, so as to form a capacitive sensing element at each location at which a pickup line overlaps a drive line;

an integrated circuit for controlling the sensing grid, wherein the substrate is disposed between the pickup lines and the integrated circuit;
a plurality of conductive traces, each conductive trace including a first end connected to an end of an associated one of the pick-up lines and a second end; and
a plurality of vias, each of the vias being connected to the second end of an associated one of the conductive traces and extending through the substrate for providing an electrical connection between the associated pickup line and the integrated circuit.

25. The biometric sensing assembly of claim 24 , further comprising a reference pickup line located outside the sensing grid, and wherein the detection electronics are configured to subtract a signal on a pickup plate in contact with an object contacting at least a portion of the sensing grid from a signal on the reference pickup line.

26. The biometric sensing assembly of claim 24 , wherein the reference pickup line is separated from the other pickup plates by a first gap that is larger than a second gap separating the other pickup lines.

27. The biometric sensing assembly of claim 26 , further comprising a plurality of pickup interconnects disposed on the bottom layer of the substrate and being connected to the integrated circuit, and wherein each via is connected to an associated one of the pickup interconnects.

28. The biometric sensing assembly of claim 24 , wherein the substrate has a top layer and a bottom layer, and wherein the pickup lines are located on the top layer and the integrated circuit is located on the bottom layer.

29. The biometric sensor assembly of claim 24 , wherein the substrate is composed of a dielectric m

Assignees

• Idex Asa

Inventors

• Benkley Iii Fred G

Classifications

• G01N27/04 Primary

  by investigating resistance · CPC title

• Y10T307/766

  Cross-Sectional Technologies · mapped topic

• G06K9/00053

  Physics · mapped topic

• G06K9/0002 Primary

  Physics · mapped topic

• G06V40/1329

  Protecting the fingerprint sensor against damage caused by the finger · CPC title