Finger biometric sensor including circuitry for acquiring finger biometric data based upon finger stability and related methods

Patent metadata

Field	Value
Publication number	US-9390306-B2
Application number	US-201314020398-A
Country	US
Kind code	B2
Filing date	Sep 6, 2013
Priority date	Sep 6, 2013
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A finger biometric sensor may include an array of finger biometric sensing pixels and processing circuitry coupled to the array of finger biometric sensing pixels. The processing circuitry may be capable of acquiring finger stability biometric data from a subset of the array, and determining whether a finger is stable relative to the array of finger biometric sensing pixels based upon the finger stability biometric data. The processing circuitry may also be capable of acquiring finger biometric data from the array of finger biometric sensing pixels when the finger is stable.

First claim

That which is claimed is:

1. A finger biometric sensor comprising:
an array of finger biometric sensing pixels;
a digital-to-analog converter (DAC) having a previous setting value and a current setting value associated therewith; and
processing circuitry coupled to the array of finger biometric sensing pixels and the DAC, and configured to
acquire finger stability biometric data from a subset of the array of finger biometric sensing pixels based upon a static placement of a user's finger adjacent the array of finger biometric sensing pixels, the finger stability biometric data comprising the previous and current setting values of the DAC,
determine whether a finger is stable relative to the array of finger biometric sensing pixels based upon a difference between the previous and current setting values of the DAC, and
acquire finger biometric data from the array of finger biometric sensing pixels when the finger is stable.

2. The finger biometric sensor of claim 1 , wherein the processing circuitry is configured to determine whether the finger is adjacent the array of finger biometric sensing pixels prior to acquiring the finger stability biometric data.

3. The finger biometric sensor of claim 2 , wherein the processing circuitry is configured to determine whether the finger is adjacent the array of finger biometric sensing pixels based upon a change in an oscillation frequency associated with the array of finger biometric sensing pixels.

4. The finger biometric sensor of claim 1 , wherein the subset of the array of finger biometric sensing pixels comprises a plurality of spaced apart sub-arrays of finger biometric sensing pixels.

5. The finger biometric sensor of claim 4 , wherein the plurality of spaced apart sub-arrays are arranged in a checkerboard pattern.

6. The finger biometric sensor of claim 4 , wherein the processing circuitry is configured to determine whether the finger is stable based upon whether a threshold number of sub-arrays is sensing the finger.

7. The finger biometric sensor of claim 6 , wherein the processing circuitry is configured to determine whether the finger is stable further based upon whether the threshold number of sub-arrays indicates stability over successive data acquisitions.

8. The finger biometric sensor of claim 1 , wherein the array of finger biometric sensing pixels comprises an array of electric field finger sensing pixels.

9. The finger biometric sensor of claim 1 , further comprising a finger coupling electrode adjacent the array of finger biometric sensing pixels; and wherein the processing circuitry further comprises drive circuitry coupled to the finger coupling electrode.

10. An electronic device comprising:
a housing;
wireless communications circuitry carried by the housing;
a finger biometric sensor carried by the housing and comprising
an array of finger biometric sensing pixels;
a digital-to-analog converter (DAC) having a previous setting value and a current setting value associated therewith; and
processing circuitry coupled to the array of finger biometric sensing pixels and the DAC, and configured to
acquire finger stability biometric data from a subset of the array of finger biometric sensing pixels based upon a static placement of a user's finger adjacent the array of finger biometric sensing pixels, the finger stability biometric data comprising the previous and current setting values of the DAC,
determine whether a finger is stable relative to the array of finger biometric sensing pixels based upon a difference between the previous and current setting values of the DAC, and
acquire finger biometric data from the array of finger biometric sensing pixels when the finger is stable.

11. The electronic device of claim 10 , further comprising an input device carried by the housing; and wherein the finger biometric sensor is carried by the input device.

12. The electronic device of claim 11 , wherein the input device comprises a pushbutton switch.

13. The electronic device of claim 10 , wherein the processing circuitry is configured to determine whether the finger is adjacent the array of finger biometric sensing pixels prior to acquiring the finger stability biometric data.

14. The electronic device of claim 13 , wherein the processing circuitry is configured to determine whether the finger is adjacent the array of finger biometric sensing pixels based upon a change in an oscillation frequency associated with the array of finger biometric sensing pixels.

15. The electronic device of claim 10 , wherein the subset of the array of finger biometric sensing pixels comprises a plurality of spaced apart sub-arrays of finger biometric sensing pixels.

16. The electronic device of claim 15 , wherein the processing circuitry is configured to determine whether the finger is stable based upon whether a threshold number of sub-arrays is sensing the finger.

17. The electronic device of claim 16 , wherein the processing circuitry is configured to determine whether the finger is stable further based upon whether the threshold number of sub-arrays indicates stability over successive data acquisitions.

18. The electronic device of claim 10 , further comprising a finger coupling electrode adjacent the array of finger biometric sensing pixels; and wherein the processing circuitry further comprises drive circuitry coupled to the finger coupling electrode.

19. A method of acquiring finger biometric data comprising:
acquiring finger stability biometric data from a subset of an array of finger biometric pixels, the finger stability biometric data comprising previous and current setting values of a DAC;
determining whether a finger is stable relative to the array of finger biometric sensing pixels based upon a difference between the previous and current setting values of the DAC based upon a static placement of a user's finger adjacent the array of finger biometric sensing pixels; and
acquiring the finger biometric data from the array of finger biometric sensing pixels when the finger is stable.

20. The method of claim 19 , further comprising determining whether the finger is adjacent the array of finger biometric sensing pixels prior to acquiring the finger stability biometric data.

21. The method of claim 20 , wherein determining whether the finger is adjacent the array of finger biometric sensing pixels comprises determining whether the finger is adjacent the array of finger biometric sensing pixels based upon a change in an oscillation frequency associated with the array of finger biometric sensing pixels.

22. The method of claim 21 , wherein the subset of the array of finger biometric sensing pixels comprises a plurality of spaced apart sub-arrays of finger biometric sensing pixels.

23. The method of claim 22 , wherein determining whether the finger is stable comprises determining whether the finger is stable based upon whether a threshold number of sub-arrays is sensing the finger.

24. The method of claim 23 , wherein determining whether the finger is stable comprises determining whether the finger is stable further based upon whether the threshold number of sub-arrays indicates stability over successive data acquisitions.

25. A finger biometric sensor comprising:
an array of finger biometric sensing pixels, each finger biometric sensing pixel having a pixel value associated therewith; and
processing circuitry coupled to the array of finger biometric sensing pixels an

Assignees

• Apple Inc

Inventors

• Minteer Gregory T
• Kraemer Eric P
• Gu Zhiqiang

Classifications

• G06V40/13 Primary

  Sensors therefor · CPC title

• G06V10/147

  Details of sensors, e.g. sensor lenses (fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19) · CPC title

• G06K9/00919

  Physics · mapped topic

• G06K9/00013 Primary

  Physics · mapped topic

• G06K9/209

  Physics · mapped topic