Hybrid optical and capacitive sensor

Patent metadata

Field	Value
Publication number	US-10102411-B2
Application number	US-201715415507-A
Country	US
Kind code	B2
Filing date	Jan 25, 2017
Priority date	Jan 25, 2017
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A hybrid capacitive and optical fingerprint sensor system includes: capacitive sensor electrodes; an optical image sensor having a plurality of image sensor pixels; light conditioning elements, configured to condition light from a sensing region of the hybrid capacitive and optical fingerprint sensor for detection by the optical image sensor; and a processing system having one or more controllers, configured to operate the capacitive sensor electrodes in a low-power mode of operation for the hybrid capacitive and optical fingerprint sensor, and to operate the optical image sensor to acquire an image from the sensing region of the hybrid capacitive and optical fingerprint sensor.

First claim

The invention claimed is:

1. A hybrid capacitive and optical fingerprint sensor, comprising:
capacitive sensor electrodes;
an optical image sensor having a plurality of image sensor pixels;
light conditioning elements, configured to condition light from a sensing region of the hybrid capacitive and optical fingerprint sensor for detection by the optical image sensor; and
a processing system having one or more controllers, configured to operate the capacitive sensor electrodes in a low-power mode of operation for the hybrid capacitive and optical fingerprint sensor, and to operate the optical image sensor to acquire an image from the sensing region of the hybrid capacitive and optical fingerprint sensor;
wherein the low-power mode of operation for the hybrid capacitive and optical fingerprint sensor includes operation of the capacitive sensor electrodes to determine coverage of the sensing region by a fingerprint, and adjusting a resolution at which the optical image sensor is operated based on the coverage of the sensing region by the fingerprint.

2. The hybrid capacitive and optical fingerprint sensor according to claim 1 , wherein the capacitive sensor electrodes are disposed in a capacitive sensor layer of the hybrid capacitive and optical fingerprint sensor, the optical image sensor is disposed in an optical sensor layer of the hybrid capacitive and optical fingerprint sensor, and the light conditioning elements are disposed in a conditioning layer of the hybrid capacitive and optical fingerprint sensor;
wherein the conditioning layer is disposed below the capacitive sensor layer and the optical sensor layer is disposed below the conditioning layer.

3. The hybrid capacitive and optical fingerprint sensor according to claim 1 , wherein the capacitive sensor electrodes and the light conditioning elements are disposed in a combined conditioning and capacitive sensor layer of the hybrid capacitive and optical fingerprint sensor, and the optical image sensor is disposed in an optical sensor layer of the hybrid capacitive and optical fingerprint sensor;
wherein the optical sensor layer is disposed below the combined conditioning and capacitive sensor layer.

4. The hybrid capacitive and optical fingerprint sensor according to claim 1 , wherein the capacitive sensor electrodes and the optical image sensor are disposed in a combined optical and capacitive sensor layer of the hybrid capacitive and optical fingerprint sensor, and the light conditioning elements are disposed in a conditioning layer of the hybrid capacitive and optical fingerprint sensor;
wherein the combined optical and capacitive sensor layer is disposed below the conditioning layer.

5. The hybrid capacitive and optical fingerprint sensor according to claim 1 , wherein the low-power mode of operation for the hybrid capacitive and optical fingerprint sensor includes operation of the capacitive sensor electrodes in a wake-on-finger mode, wherein the wake-on-finger mode includes using the capacitive sensor electrodes to detect whether a fingerprint is present in or proximate to the sensing region and, in response to detecting the presence of the fingerprint, activating a fingerprint sensing mode in which the optical image sensor is used to acquire an image from the sensing region of the hybrid capacitive and optical fingerprint sensor.

6. The hybrid capacitive and optical fingerprint sensor according to claim 1 , wherein the low-power mode of operation for the hybrid capacitive and optical fingerprint sensor includes operation of the capacitive sensor electrodes in a navigation mode, wherein the navigation mode includes using the capacitive sensor electrodes to detect presence, position, and/or movement of the fingerprint.

7. The hybrid capacitive and optical fingerprint sensor according to claim 1 , wherein the low-power mode of operation for the hybrid capacitive and optical fingerprint sensor includes detecting a response from the plurality of image sensor pixels, and adjusting settings for the optical image sensor based on a portion of the response corresponding to the coverage of the sensing region by the fingerprint.

8. The hybrid capacitive and optical fingerprint sensor according to claim 7 , wherein adjusting the settings for the optical image sensor includes adjusting exposure or gain settings for the optical image sensor.

9. The hybrid capacitive and optical fingerprint sensor according to claim 1 , wherein the low-power mode of operation for the hybrid capacitive and optical fingerprint sensor includes operation of the capacitive sensor electrodes to determine capacitive properties of an input on the sensing region, and based on the capacitive properties of the input, determining whether the input is a real biometric input.

10. The hybrid capacitive and optical fingerprint sensor according to claim 1 , wherein the capacitive sensor electrodes are interleaved among the plurality of image sensor pixels but are disposed outside of respective optical paths corresponding to the plurality of image sensor pixels.

11. The hybrid capacitive and optical fingerprint sensor according to claim 1 , wherein the capacitive sensor electrodes comprise a first set of electrodes corresponding to a wake-on-finger mode of the hybrid capacitive and optical fingerprint sensor and a second set of electrodes, separate from the first set of electrodes, corresponding to a navigation mode of the hybrid capacitive and optical fingerprint sensor.

12. A hybrid capacitive and optical fingerprint sensor, comprising:
capacitive sensor electrodes;
an optical image sensor having a plurality of image sensor pixels; and
light conditioning elements, configured to condition light from a sensing region of the hybrid capacitive and optical fingerprint sensor for detection by the optical image sensor;
wherein the capacitive sensor electrodes and the optical image sensor are disposed in a combined optical and capacitive sensor layer of the hybrid capacitive and optical fingerprint sensor, and the light conditioning elements are disposed in a conditioning layer of the hybrid capacitive and optical fingerprint sensor.

13. The hybrid capacitive and optical fingerprint sensor according to claim 12 , wherein the capacitive sensor electrodes are interleaved among the plurality of image sensor pixels but are disposed outside of respective optical paths corresponding to the plurality of image sensor pixels.

14. A processing system for a hybrid capacitive and optical fingerprint sensor having capacitive sensor electrodes, light conditioning elements, and an optical image sensor, the processing system comprising one or more controllers configured to execute processor-executable instructions to control the capacitive sensor electrodes and the optical image sensor, wherein execution of the processor-executable instructions facilitates:
operating the capacitive sensor electrodes in a low-power mode of operation for the hybrid capacitive and optical fingerprint sensor; and
operating the optical image sensor to acquire an image from a sensing region of the hybrid capacitive and optical fingerprint sensor;
wherein the low-power mode of operation for the hybrid capacitive and optical fingerprint sensor includes: operating the capacitive sensor electrodes to determine coverage of the sensing region by a fingerprint, and adjusting a resolution at which the optical image sensor is operated base on the coverage of the sensing region by the fingerprint.

15. The processing system according to claim 14 , wherein the low-power mode of operation for the hybrid capacitive and optical fingerprint sensor includes:
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Assignees

• Synaptics Inc

Inventors

• Lillie Jeffrey S
• Pude Mark
• Bohannon Eric
• Moule Eric
• Thompson Erik Jonathon
• Smith Patrick
• Kern Lynn

Classifications

• G06F3/042

  by opto-electronic means · CPC title

• G06F2203/04107

  Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds · CPC title

• G06F3/044

  by capacitive means · CPC title

• G06F2203/04106

  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 title

• G06K9/0002 Primary

  Physics · mapped topic