Patent ID: 7719726

Claim:
An image reading apparatus for acquiring a read signal of an image by receiving and photoelectrically converting a light reflected from a document, comprising: an illumination unit having a plurality of light emitting elements adapted to illuminate a document; a light receiving unit adapted to receive a light reflected from the document; an alien substance detection unit adapted to detect a location of an alien substance on an original plate, based on the reflected light received by said light receiving unit; and an illumination control unit adapted to control the light emitting elements of said illumination unit to selectively illuminate the location in which the alien substance has been detected by said alien substance detection unit, wherein said illumination control unit controls light emitting elements corresponding to respective locations of detected alien substances to be lighted when a distance between detected two alien substances is equal to or longer than a predetermined distance, and light emitting elements located between detected two alien substances to be lighted when a distance between the detected two alien substances is shorter than the predetermined distance.