Patent ID: 8823994

Claim:
An image reading device comprising: a light source configured to irradiate a target to be read with light; an image sensor that includes a plurality of photoelectric conversion elements and is configured to read, based on reflected light from the target to be read, the target to be read for each line having a predetermined width in a sub scanning direction; a transport unit configured to move the light source or the target to be read in the sub scanning direction; and a control unit that, during the reading of the target to be read by the image sensor, causes the light source to light up at a predetermined amount of light for a predetermined fixed lighting time and causes the transport unit to move to change a read time per line and a read rate of the image sensor, wherein while, during the reading of the target to be read by the image sensor, the control unit causes the transport unit to accelerate the read rate to a reference read rate which is the read rate at which the read time per line is a predetermined reference read time or to decelerate the read rate from the reference read rate, the control unit causes the light source to light up, within the read time, with timing brought close to a read section from a lighting start point to a lighting end point in the case of reading the one line in the reference read time.