Patent Document ID: 20040208349
Application ID: 10825556
Patent Status: 0

Claim One:
1. An image reading apparatus which reads a fingerprint image, comprising: a roller rotatably mounted to the image reading apparatus, a given pattern being printed on part of an outer surface of the roller in a circumferential direction; a line sensor including a plurality of image pickup elements which read a fingerprint image from a finger that touches with the roller as well as the pattern printed on the roller; a generating unit which generates a reference value to each of the image pickup elements corresponding to part of the line sensor, which reads the pattern, based on image data of the pattern read by the line sensor; a rotation sensing image extracting unit which extracts a rotation sensing image based on the reference value generated by the generating unit; and a determination unit which determines capture timing of the fingerprint image read by the line sensor based on variations in the rotation sensing image extracted by the rotation sensing image extracting unit.