MULTIFUNCTION FINGERPRINT SENSOR

• US 20160314334A1
• Filed: 04/25/2016
• Published: 10/27/2016
• Est. Priority Date: 04/23/2015
• Status: Active Grant

• Current Assignee: Shenzhen Goodix Technology Co., Ltd.
• Original Assignee: Shenzhen Huiding Technology Co., Ltd. (Shenzhen Goodix Technology Co., Ltd.)
• Inventors: He, Yi, Pi, Bo
• Granted Patent: US 10,325,142 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G06V 40/1318 using electro-optical elements or layers, e.g. electroluminescent sensing
• CPC Class Codes: G06V 40/1394 using acquisition arrangements

Abstract

In one aspect, a fingerprint sensor device includes sensing circuitry to generate a sensor signal responsive to detecting a contact input associated with a fingerprint. The sensing circuitry includes a fingerprint sensor to detect the contact input and generate a signal indicative of an image of the fingerprint. The sensing circuitry includes a live finger sensor to generate a signal indicative of an identification of the fingerprint as belonging to a live finger. The generated sensor signal includes the signal indicative of the image of the fingerprint and the signal indicative of the identification of the fingerprint as belonging to a live finger. The fingerprint sensor device includes processing circuitry communicatively coupled to the sensing circuitry to process the generated sensor signal to determine whether the contact input associated with the fingerprint belongs to a live finger.

Claims

1. A fingerprint sensor device, comprising:

sensing circuitry to generate a sensor signal responsive to detecting a contact input associated with a fingerprint, the sensing circuitry including;

a fingerprint sensor to detect the contact input and generate a signal indicative of an image of the fingerprint, and

a live finger sensor to generate a signal indicative of an identification of the fingerprint as belonging to a live finger,

wherein the generated sensor signal includes the signal indicative of the image of the fingerprint and the signal indicative of the identification of the fingerprint as belonging to a live finger; and

processing circuitry communicatively coupled to the sensing circuitry to process the generated sensor signal to determine whether the contact input associated with the fingerprint belongs to a live finger.

2. The fingerprint sensor device of claim 1, wherein the fingerprint sensor includes a capacitive sensor, an optical sensor, or both capacitive and optical sensors.

3. The fingerprint sensor device of claim 1, wherein the fingerprint sensor is configured to obtain information regarding ridges and valleys of the fingerprint.

4. The fingerprint sensor device of claim 1, wherein the live finger sensor is configured to analyze the signal indicative of the image of the fingerprint to identify dynamic changes in image details over a period of time.

5. The fingerprint sensor device of claim 1, wherein the live finger sensor includes a light source and a light detector.

6. The fingerprint sensor device of claim 1, wherein:

the light source includes a light emitting diode or a laser diode; and

the light detector includes a photodiode.

7. The fingerprint sensor device of claim 4, wherein:

the light source is configured to emit light toward a source of the fingerprint; and

the light detector is configured to detect scattered light that is scattered from the source of the fingerprint responsive to the emitted light.

8. An electronic device, comprising:

a central processor; and

a fingerprint sensor device in communication with the central processor, wherein the fingerprint sensor device includes;

a sensing circuitry to generate a sensor signal responsive to detecting a contact input associated with a fingerprint, the sensing circuitry including;

a fingerprint sensor to detect the contact input and generate a signal indicative of an image of the fingerprint, and

a live finger sensor to generate a signal indicative of an identification of the fingerprint as belonging to a live finger,

wherein the generated sensor signal includes the signal indicative of the image of the fingerprint and the signal indicative of the identification of the fingerprint as belonging to a live finger;

processing circuitry communicatively coupled to the sensing circuitry to process the generated sensor signal to determine whether the contact input associated with the fingerprint belongs to a live finger; and

an interface to bridge signal flow between the fingerprint sensor device and the central processor of the electronic device.

9. The electronic device of claim 8, wherein the electronic device includes a smartphone, a tablet computer, a laptop computer, or a wearable device.

10. A method of detecting a live finger during a fingerprint scan, the method comprising:

detecting, by a fingerprint sensor, a contact input associated with a source of a fingerprint;

generating an image signal from the fingerprint sensor responsive to the detected contact input, wherein the generated image signal from the fingerprint sensor is indicative of one or more images of the fingerprint;

generating, by a live finger sensor, a live finger detection signal indicative of whether a source of the fingerprint making the contact is a live finger; and

processing, by processing circuitry, the generated image signal and the live finger detection signal to determine whether the detected contact and the associated one or more fingerprint images are from a live finger.

11. The method of claim 10, wherein processing the generated live finger detection signal includes analyzing fingerprint image dynamics.

12. The method of claim 10, wherein the fingerprint image dynamics includes a change in signal amplitude or bright points coordinates.

13. The method of claim 10, wherein:

generating the image signal includes capturing a sequence of fingerprint images; and

generating the live finger detection signal includes identifying changes in one or more image details over the sequence of captured fingerprint images.

14. A method for performing live finger detection, comprising:

detecting a contact input associated with a fingerprint by a fingerprint sensor;

applying, by a live finger sensor, one or more wavelengths of light to a source of the detected contact input associated with the fingerprint;

detecting, by the live finger sensor, scattered light that is scattered from the source of the contact input associated with a fingerprint responsive to the applied one or more wavelengths of light, wherein the detected scattered light includes information on a material of the source of the detected contact input associated with the fingerprint; and

determining whether the source of the detected contact input associated with the fingerprint is a live finger based on the information included in the detected scattered light.

15. The method of claim 14, wherein the information on the material of the source of the detected contact input associated with the fingerprint includes information on blood cells, heartbeat, blood flow induced speckle patterns, or a Doppler frequency change.

16. An electronic device, comprising:

a protective cover; and

a fingerprint sensor dispose near the protective cover, the fingerprint sensor includes;

a fingerprint sensor chip to scan a fingerprint; and

a live finger sensor to obtain information from a source of the fingerprint, the information indicative of whether the source of the fingerprint is a live finger, wherein the live finger sensor includes;

a light source to emit light of one or more wavelengths toward the source of the fingerprint, and

a light detector to detect scattered light that is scattered from the source of the fingerprint responsive to the emitted light, wherein the detected scattered light includes the information indicative of whether the source of the fingerprint is a live finger.

17. The electronic device of claim 16, wherein the fingerprint sensor includes:

a pressure sensor.

18. The electronic device of claim 17, wherein the fingerprint sensor includes:

flexible printed circuit (FPC) disposed over the pressure sensor.

19. The electronic device of claim 18, wherein the fingerprint sensor includes:

an integrated circuit board disposed over the FPC.

20. The electronic device of claim 19, wherein the light source and the light detector are integrated with the integrated circuit board.

21. The electronic device of claim 16, wherein the fingerprint sensor device is disposed under the protective cover.

22. The electronic device of claim 16, wherein the light source includes a light emitting diode or a laser diode.

23. The electronic device of claim 16, wherein the light detector includes a photodiode.

24. The electronic device of claim 16, wherein the light source is integrated with the fingerprint sensor chip.

25. The electronic device of claim 16, wherein the protective cover includes glass material that is at least partially transparent to the emitted light and the scattered light.

26. The electronic device of claim 25, wherein the glass cover includes a emitted light path window for the emitted light from the light source to travel to the source of the fingerprint.

27. The electronic device of claim 25, wherein the glass cover includes a scattered light path window for the scattered light from the source of the fingerprint to be received by the light detector.

28. The electronic device of claim 16, wherein the fingerprint sensor device includes a colored epoxy material layer disposed over the fingerprint sensor chip.

29. The electronic device of claim 24, wherein the fingerprint sensor device includes a metal ring structure disposed to surround the fingerprint sensor chip and under the colored epoxy material layer.

30. The electronic device of claim 16, wherein the protective cover is disposed to form a hole to receive the fingerprint sensor device within the hole of the protective cover.

31. The electronic device of claim 30, wherein the fingerprint sensor device includes a metal ring, and the fingerprint sensor device is disposed within the hole of the protective cover to form a gap between the metal ring and a side surface of the protective cover, wherein the gap form a light path for the emitted light emitted by the light source to reach the source of the fingerprint.

32. The electronic device of claim 30, wherein the fingerprint sensor device includes a sensor cover.

33. The electronic device of claim 32, wherein the sensor cover is at least partially transparent to the emitted light and the scattered light.

34. The electronic device of claim 32, wherein the sensor cover includes two layers of a material that is at least partially transparent to the emitted light and the scattered light.

35. The electronic device of claim 32, wherein the sensor cover includes a color layer between the two layers of the material that is at least partially transparent to the emitted light and the scattered light.

36. The electronic device of claim 32, wherein the sensor cover includes a mesh material.