Patent ID: 7391533

Claim:
An image reading apparatus comprising: an imaging unit including a plurality of channels, arranged to output on an each channel basis an effective signal output from a light receiving portion that is capable of receiving light from an object, and to output on an each channel basis an OB signal output from a light shielding portion that shields light from the object; a storage unit arranged to store the signals output from said imaging unit; a signal correction unit arranged to correct the effective signal in accordance with the OB signal on the each channel basis; a sorting unit arranged to sort the signals output from said imaging unit on each channel basis; and a controller arranged to effect control so that the effective signal of each channel is corrected by said signal correction unit in accordance with a first signal stored in the storage unit and the OB signal of each channel which is output from the light shielding portion, wherein the first signal and the OB signal are output on the each channel basis from the light receiving portion and are sorted by said sorting unit.