Patent ID: 7379101

Claim:
A photosensor system comprising: an image read section which includes an image read region formed by arranging a plurality of photosensors in a matrix form including a predetermined number of rows and columns, wherein the image read region includes a sensitivity adjustment image read region, and the sensitivity adjustment image read region includes a plurality of rows of the photosensors less than the predetermined number of rows, and wherein the image read section performs a read operation of a subject image by the image read region in accordance with a predetermined image read sensitivity; and a read operation sensitivity adjustment means for performing a read operation for sensitivity adjustment which includes: setting different charge accumulation periods with respect to the photosensors of different areas of the sensitivity adjustment image read region; reading an image for adjustment only in the sensitivity adjustment image read region based on the respective charge accumulation periods; and deriving an optimum image read sensitivity suitable for the read operation of the subject image in the image read section.