FINGERPRINT IMAGE READING APPARATUS

An image reading apparatus which reads a fingerprint image, includes 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, a rotation sensing image extracting unit which extracts a rotation sensing image based on the reference value, and a determination unit which determines capture timing of the fingerprint image based on variations in the rotation sensing image.