Patent ID: 8908246

Claim:
An image reading device comprising: a light source; an image sensor configured to transfer an electric charge accumulated on an opto-electric conversion element to a shift register through a shift gate; and a reading controller configured to shift timing to start sensor reading on every line by inserting a dummy interval into a shift period for which the electric charge is transferred from the opto-electric conversion element, so as to arrange that a plurality of peak positions of noise included in a read image differ from one another on the respective lines by adjusting a timing of when the dummy interval is inserted into the shift period of the respective lines, wherein the dummy interval inserted in each line of the read image is at a different timing position than the dummy interval inserted in the next consecutive line of the read image, and wherein the reading controller: divides a period of one cycle of the noise into N (N is an integer, where N>=2) intervals; sums M (M is an integer, where 0<=M<=N−1) of the N intervals into which the period of one cycle of the noise is divided up to the dummy interval; and sets the number M for every consecutive line differently from one another.