Apparatus and Method for Finger Activity on a Fingerprint Sensor

• US 20130021044A1
• Filed: 09/13/2012
• Published: 01/24/2013
• Est. Priority Date: 01/15/2009
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Validity Sensors Incorporated (Synaptics Incorporated)
• Inventors: Thompson, Erik Jonathon, Dean, Gregory Lewis, Jandu, Jaswinder, Erhart, Richard Alexander
• Granted Patent: US 8,593,160 B2
• Time in Patent Office: Days
• US Class Current: 324/658
• CPC Class Codes: G06F 1/1684 Constructional details or arrangements related to integrated I/O peripherals not covered by groups G06F1/1635 - G06F1/1675
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• 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

Abstract

An apparatus and method for detecting the presence of a finger on a fingerprint sensor is disclosed in one embodiment of the invention as including transmitting a probing signal, comprising a series of probing pulses, to a fingerprint sensing area. A response signal, comprising a series of response pulses, is received from the fingerprint sensing area in response to the probing signal. An upper reference signal is generated and finger activity is detected on the fingerprint sensing area by monitoring whether the peaks of the response pulses exceed the reference signal.

Claims

1. A method for detecting the presence of a finger on a fingerprint sensor, the method comprising:

transmitting a probing signal to a fingerprint sensing area, the probing signal comprising a series of probing pulses;

receiving a response signal from the fingerprint sensing area in response to the probing signal, the response signal comprising a series of response pulses;

establishing an upper reference signal; and

monitoring whether the peaks of the response pulses exceed the upper reference signal.