Patent Document ID: 8447077
Application ID: 11519383
Patent Status: 1

Claim One:
1. A method of determining motion of a fingerprint surface with respect to a sensor surface, comprising: sensing at least two temporally separated sets, each of a plurality of pixels in a fingerprint image along a sensor axis of the sensor surface, the sensing performed by a linear array of fingerprint image feature detection sensors spaced along the sensor axis; storing digital data corresponding to each of the plurality of pixels in each of the at least two sets of a plurality of pixels; processing the digital data to generate fingerprint motion data, wherein generating fingerprint motion data comprises comparing the digital data corresponding to each of the plurality of pixels in a first of the at least two sets of a plurality of pixels in the fingerprint image to the digital data corresponding to each of the plurality of pixels in a second of the at least two sets of a plurality of pixels in the fingerprint image, through sequentially shifting the pixels in the first of the at least two sets with respect to the pixels in the second of the at least two sets, until a match is found for the pixels in the first of the at least two sets with respect to the pixels in the second of the at least two sets; estimating the distance D traveled by the fingerprint surface with respect to the sensor surface by multiplying a pixel shift required to achieve the match times a pitch of the image feature detection sensors; and computing the velocity measurement D/T of the fingerprint surface with respect to the sensor surface by dividing the estimated distance D by the temporal difference T between sensing the first set of the at least two sets and the second set of the at least two sets.