US Patent 7566856 Image reading apparatus and controlling method thereof

An image reading apparatus includes light sources, an image sensor, a data generating unit, and a carrier unit. The light sources are sequentially turned on for an identical period once in a single line period. The image sensor reads information from a print medium irradiated by the light sources. The data generating unit generates pixel data corresponding to the information. The carrier unit carries the print medium such that the image print medium is scanned by the image sensor in a sub-scanning direction. The single line period is equal to or more than twice a period from when first one of the light sources is turned on until last one of the light sources is turned off.