PIEZO BASED FINGERPRINT SENSOR STRUCTURE

• US 20140176332A1
• Filed: 12/20/2012
• Published: 06/26/2014
• Est. Priority Date: 12/20/2012
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Inventors: Alameh, Rachid M., Slaby, Jiri, Steuer, Paul R.
• Granted Patent: US 9,218,472 B2
• Time in Patent Office: Days
• US Class Current: 340/665
• CPC Class Codes: G06F 21/32 using biometric data, e.g. fingerprints, iris scans or voiceprints
• CPC Class Codes: G06V 40/1306 non-optical, e.g. ultrasonic or capacitive sensing
• CPC Class Codes: G06V 40/67 by interactive indications to the user
• CPC Class Codes: G08B 1/08 using electric transmission ; transformation of alarm signals to electrical signals from a different medium, e.g. transmission of an electric alarm signal upon detection of an audible alarm signal

Abstract

A device includes both a fingerprint sensor (112) and a piezo structure (114). The fingerprint sensor senses fingerprint data identifying a pattern of a fingerprint of a user. The fingerprint data for the user can be collected and analyzed in various manners in order to authenticate the sensed fingerprint. The piezo structure can be used in various manners, such as to collect data used to facilitate authenticating the sensed fingerprint data, to provide feedback to the user regarding when the fingerprint authentication process is complete, and/or to cause different types of vibration in order to facilitate sensing fingerprint data. Various additional feedback can also be provided to the user, using the piezo structure or other feedback mechanisms, such as feedback to notify the user to increase or decrease an amount of pressure he or she is applying to the fingerprint sensor.

Claims

1. A method comprising:

starting vibrating a sensor structure, in response to at least a first threshold pressure being applied to the sensor structure of a device by a finger;

analyzing fingerprint data sensed by the sensor structure, to authenticate a fingerprint of the finger; and

ceasing vibrating the sensor structure, in response to completing analyzing of the fingerprint data.

2. The method as recited in claim 1, the sensor structure comprising a fingerprint sensor situated on a piezo structure.

3. The method as recited in claim 1, further comprising varying vibration of the sensor structure while analyzing the fingerprint data.

4. The method as recited in claim 1, further comprising collecting the fingerprint data while varying vibration of the sensor structure, and the analyzing comprising analyzing the fingerprint data after collection of the fingerprint data is completed.

5. The method as recited in claim 1, further comprising in response to at least a second threshold pressure being applied to the sensor structure, providing feedback indicating to a user that too much pressure is being applied to the sensor structure, the second threshold pressure being greater than the first threshold pressure.

6. The method as recited in claim 1, further comprising:

identifying a target pressure; and

providing feedback indicating to the user whether a current pressure being applied to the sensor structure is greater than the target pressure or less than the target pressure.

7. The method as recited in claim 6, the providing feedback comprising varying vibration of the sensor structure in a first manner in response to the current pressure being greater than the target pressure, and varying vibration of the sensor structure in a second manner in response to the current pressure being less than the target pressure.

8. The method as recited in claim 6, the providing feedback comprising presenting by the device a first color in response to the current pressure being greater than the target pressure, and presenting by the device a second color in response to the current pressure being less than the target pressure.

9. The method as recited in claim 6, the providing feedback comprising providing a first audible tone in response to the current pressure being greater than the target pressure, and providing a second audible tone in response to the current pressure being less than the target pressure.

10. The method as recited in claim 6, the target pressure having been identified during an enrollment process in which the fingerprint data was sensed and stored for use in subsequently authenticating fingerprints.

11. The method as recited in claim 1, the analyzing comprising:

collecting multiple fingerprint data samples at different times and while the sensor structure is vibrated using various different vibration patterns;

generating candidate fingerprint data by combining the collected fingerprint data samples;

comparing the candidate fingerprint data to stored fingerprint data;

authenticating the fingerprint in response to the candidate fingerprint data matching the stored fingerprint data; and

failing authentication of the fingerprint in response to the candidate fingerprint data not matching the stored fingerprint data.

12. The method as recited in claim 11, the combining the collected fingerprint data samples comprising averaging locations of minutiae in the multiple fingerprint data samples.

13. A method comprising:

detecting fingerprint data of a finger sensed by a fingerprint sensor of a sensor structure;

identifying a target pressure previously applied to the fingerprint sensor when previously sensing the fingerprint data of the user;

analyzing the fingerprint data to authenticate a fingerprint of the finger; and

while analyzing the fingerprint data, providing feedback indicating to a user whether a current pressure being applied to the sensor structure is greater than a target pressure or less than the target pressure.

14. The method as recited in claim 13, the sensor structure comprising a fingerprint sensor situated on a piezo structure.

15. The method as recited in claim 13, the providing feedback comprising varying vibration of the sensor structure in one manner in response to the current pressure being greater than the target pressure, and varying vibration of the sensor structure in a different manner in response to the current pressure being less than the target pressure.

16. The method as recited in claim 13, the providing feedback comprising presenting one color in response to the current pressure being greater than the target pressure, and presenting a different color in response to the current pressure being less than the target pressure

17. The method as recited in claim 13, the providing feedback comprising providing one audible tone in response to the current pressure being greater than the target pressure, and providing a different audible tone in response to the current pressure being less than the target pressure.

18. The method as recited in claim 13, the identifying comprising identifying the target pressure during an enrollment process in which the fingerprint data was sensed and stored for use in subsequently authenticating fingerprints.

19. A device comprising:

a vibration control module configured to alter a vibration pattern of a piezo structure of the device over a duration of time;

a fingerprint sensor configured to detect multiple fingerprint data samples of a finger of a user over the duration of time, the multiple fingerprint data samples being detected during multiple different vibration patterns of the piezo structure; and

an authentication module configured to combine the multiple fingerprint data samples, and to authenticate a fingerprint of the user based on the combination of the multiple fingerprint data samples.

20. The device as recited in claim 19, wherein to combine the multiple fingerprint data samples is to average locations of minutiae in the multiple fingerprint data samples.

21. The device as recited in claim 19, the fingerprint sensor being situated on the piezo structure.

22. The device as recited in claim 21, further comprising a feedback module configured to in response to at least a threshold pressure being applied to the piezo structure, provide feedback indicating to the user that too much pressure is being applied to the fingerprint sensor.

23. A device comprising:

a sensor structure including,

a fingerprint sensor configured to sense a fingerprint data sample of a finger of a user, and

a piezo structure configured to detect a pressure applied to the sensor structure at a time when the fingerprint data sample is sensed; and

an authentication module configured to authenticate a fingerprint of the user based at least in part on the sensed fingerprint data sample and the pressure applied to the sensor structure at the time when the fingerprint data sample is sensed.

24. The device as recited in claim 23, further comprising a memory device that stores authentication data, the authentication data comprising one or more stored fingerprint data samples and an associated pressure for each stored fingerprint data sample.

25. The device as recited in claim 24, the one or more stored fingerprint data samples comprising multiple stored fingerprint data samples, the authentication module being further configured to:

identify one of the multiple stored fingerprint samples having an associated pressure that matches the pressure applied to the sensor structure at the time when the fingerprint data sample is sensed;

compare the sensed fingerprint data sample to the identified one of the multiple stored fingerprint samples; and

authenticate the fingerprint of the user in response to the sensed fingerprint data sample matching the identified one of the multiple stored fingerprint samples.

26. A device comprising:

a sensor structure including,

a piezo structure configured to detect a pressure applied to the sensor structure, and

a fingerprint sensor situated on the piezo structure and configured to sense fingerprint data of a finger of a user; and

a notification module configured to notify, in response to at least a threshold pressure being applied to the piezo structure, a power manager to change a power mode of the device.

27. The device as recited in claim 26, the power manager being configured to change the power mode of the device by initiating a power-on sequence for the device in response to being notified that at least the threshold pressure has been applied to the piezo structure.

28. The device as recited in claim 26, the power manager being configured to change the power mode of the device by initiating a wake sequence to wake the device from a sleep mode in response to being notified that at least the threshold pressure has been applied to the piezo structure.

29. The device as recited in claim 26, further comprising an authentication module configured to authenticate a fingerprint of the user based at least in part on the sensed fingerprint data sample, and the power manager being configured to change the power mode of the device only if authentication of the fingerprint is successful.