Signal strength enhancement in a biometric sensor array

• US 9,158,958 B2
• Filed: 07/24/2014
• Issued: 10/13/2015
• Est. Priority Date: 10/28/2010
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Wickboldt, Paul, Dean, Gregory Lewis, Thompson, Erik Jonathon, Molesa, Steven, Jandu, Jaswinder, Smith, Patrick
• Primary Examiner(s): Seth, Manav
• Application Number:
  US14/339,656
• Publication Number:
  US 20150030217A1
• Time in Patent Office: 446 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 21/32 using biometric data, e.g. fingerprints, iris scans or voiceprints
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G06K 19/07756 the connection being non-galvanic, e.g. capacitive
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G06V 40/1335 Combining adjacent partial images (e.g. slices) to create a composite input or reference pattern; Tracking a sweeping finger movement
• CPC Class Codes: G06V 40/1365 Matching; Classification
• CPC Class Codes: G07C 9/25 using biometric data, e.g. fingerprints, iris scans or voice recognition
• CPC Class Codes: G07C 9/26 using a biometric sensor integrated in the pass
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 27/14678 Contact-type imagers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/15788 Glasses, e.g. amorphous oxides, nitrides or fluorides
• CPC Class Codes: H01L 2924/19105 in a side-by-side arrangement on a common die mounting substrate
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H04L 9/3231 Biological data, e.g. fingerprint, voice or retina network architectures or network communication protocols for supporting authentication of entities using biometrical features in a packet data network H04L63/0861
• CPC Class Codes: H04N 21/4415 using biometric characteristics of the user, e.g. by voice recognition or fingerprint scanning cryptography using biological data H04L9/3231; authentication in networks using biometric H04L63/0861

Abstract

A biometric imager may comprise a plurality of sensor element traces formed in or on a sensor substrate which may comprise at least a portion of a display screen defining a biometric sensing area and forming in-active pixel locations; an auxiliary active circuit formed in or on the sensor substrate on the periphery of the biometric sensing area and in direct or indirect electrical contact with the sensor element traces; and providing a signal processing interface to a remotely located controller integrated circuit. The sensor element traces may form a portion of one dimensional linear sensor array or pixel locations in a two dimensional grid array capacitive gap biometric imaging sensor. The auxiliary circuit may provide pixel location selection or pixel signal amplification. The auxiliary circuit may be mounted on a surface of the display screen. The auxiliary circuit further comprising a separate pixel location selection controller circuit.

Claims

1. A method of imaging a biometric object comprising:

utilizing a biometric image sensor, the biometric image sensor comprising;

a plurality of capacitive gap sensor electrode traces forming an array of biometric sensor imaging pixel locations within a biometric sensing area of the biometric image sensor,

at least one of the sensor electrode traces forming a drive signal transmitter electrode and at least one of the sensor electrode traces forming a resulting signal receiver electrode trace, the respective drive signal transmitter electrode and respective resulting signal receiver electrode trace being formed on one of a single side of a first substrate and an opposite side of the first substrate;

wherein a change in a resulting signal received by the resulting signal receiver electrode trace is indicative of a biometric image characteristic at a respective pixel location in the array;

utilizing a controller contained in an integrated circuit mounted to a second substrate remote from the biometric sensing area and in electrical contact with the sensor electrode traces;

utilizing an intermediate logic circuit formed between the controller and the sensor electrode traces in the biometric sensing area, wherein the intermediate logic circuit is formed on at least one of the first substrate and a third substrate mounted to the first substrate,

the intermediate logic circuit configured to control an activation sequence for a subset of the plurality of the capacitive gap sensor array pixel locations in response to a single signal from the controller to the intermediate logic circuit.

2. The method of claim 1 wherein the first substrate and the second substrate comprise a single substrate.

3. The method of claim 2 wherein the single substrate comprises one of a flexible dielectric and a glass substrate.

4. The method of claim 1 wherein the single signal from the controller comprises a first coded control signal, and the intermediate logic circuit is configured to, in response to receiving the single signal, individually address a subset of resulting signal receiver electrode traces and communicatively couple the respective resulting signal receiver electrode trace to a first input of the controller.

5. The method of claim 1 wherein the single signal from the controller comprises a second coded control signal causing the intermediate logic circuit to both (1) individually address a third subset of resulting signal receiver electrode traces and provide a received resulting signal to a first output of the intermediate logic circuit and (2) individually address a fourth subset of resulting signal receiver electrode traces and connect the respective resulting signal receiver electrode trace to a second output of the intermediate logic circuit.

6. The method of claim 5 wherein the first output comprises a first input to a differential amplifier and the second output comprises a second input to the differential amplifier.

7. The method of claim 5 wherein the second coded control signal comprises an output of a shift register set by the controller, communicatively coupling the control logic routing respective individual resulting signal receiver electrode traces to the first output or second output.

8. The method of claim 7 wherein the intermediate logic circuit comprises logic circuit transistor switches formed on at least one of the first substrate and the third substrate.

9. The method of claim 8 wherein the logic circuit transistor switches comprise thin film transistors.

10. The method of claim 1 wherein the intermediate logic circuit further comprises a thin film transistor amplifier formed on one of the first substrate and the third substrate between a resulting signal electrode trace and the intermediate logic circuit.

20. The biometric object imaging sensor of claim 10 wherein the intermediate logic circuit further comprises a thin film transistor amplifier formed on one of the first substrate and the third substrate between a respective receiver electrode trace and the intermediate logic circuit.

11. A biometric object imaging sensor comprising:

a plurality of capacitive gap sensor electrode traces formed on one of a single side of a first substrate and an opposite side of the first substrate;

the plurality of sensor electrode traces forming an array of biometric sensor imaging pixel locations within a biometric sensing area of the biometric image sensor,

wherein at least one of the sensor electrode traces comprises a transmitter electrode trace and at least one of the sensor electrode traces comprises a receiver electrode trace, wherein a change in a resulting signal received by the receiver electrode trace is indicative of a biometric image characteristic at a respective pixel location in the array;

a controller contained in an integrated circuit mounted to a second substrate remote from the biometric sensing area and in electrical contact with the sensor electrode traces;

an intermediate logic circuit between the controller and the sensor electrode traces in the biometric sensing area, formed on at least one of the first substrate and a third substrate coupled to the first substrate, the intermediate logic circuit configured to control an activation sequence for a subset of the plurality of the capacitive gap sensor array pixel locations in response to a single signal from the controller to the intermediate logic circuit.

12. The biometric object imaging sensor of claim 11 wherein the first substrate and the second substrate comprise a single substrate.

13. The biometric object imaging sensor of claim 12 wherein the single substrate comprises one of a flexible dielectric and a glass substrate.

14. The biometric object imaging sensor of claim 11 wherein the single signal from the controller comprises a first coded control signal, configured to cause the intermediate logic circuit to one of (1) individually address a first subset of transmitter electrode traces and provide a drive signal to the transmitter electrode trace and (2) individually address a second subset of receiver electrode traces and connect the receiver electrode trace to an output of the biometric imaging sensor.

15. The biometric object imaging sensor of claim 11 wherein the single signal from the controller comprises a second coded control signal, configured to cause the intermediate logic circuit to both (1) individually address a third subset of receiver electrode traces and provide a first received resulting signal to a first output of the intermediate logic circuit and (2) individually address a fourth subset of the receiver electrode traces and provide a second received resulting signal to a second output of the intermediate logic circuit.

16. The biometric object imaging sensor of claim 15 wherein the first output comprises a first input to a differential amplifier and the second output comprises a second input to the differential amplifier.

17. The biometric object imaging sensor of claim 15 wherein the second coded control signal comprises an output of a shift register set by the controller, connected to control logic routing respective receiver electrode traces to the respective first output or second output.

18. The biometric object imaging sensor of claim 17 wherein the intermediate logic circuit comprises logic circuit transistor switches formed on at least one of the first substrate and the third substrate.

19. The biometric object imaging sensor of claim 18 wherein the logic circuit transistor switches comprise thin film transistors formed on the one of the first substrate and the third substrate.