Patent ID: 7428010

Claim:
A photosensor system comprising: a photosensor array comprising a plurality of photosensors arrayed two-dimensionally; an image reading section which reads a subject image at a predetermined image reading sensitivity, corresponding to a charge accumulating period, by using the photosensor array; sensitivity adjustment image reading means for reading a sensitivity adjustment subject image using a plurality of image reading sensitivities; optimal image reading sensitivity deriving means for deriving an image reading sensitivity optimal for reading the subject image, based on a pixel data group relating to an image pattern of the subject image read by the sensitivity adjustment image reading means; wherein the optimal image reading sensitivity deriving means comprises specific data removal means for removing from the pixel data group specific pixel data including at least pixel data having a maximum or minimum value in the pixel data group, without judging whether or not the specific pixel data is defective, so as to correct the pixel data group, wherein the optimal image reading sensitivity is derived based on the corrected pixel data group; image reading sensitivity setting means for setting the optimal image reading sensitivity as the image reading sensitivity in the image reading section; and reading control means for controlling execution of reading of the subject image, by using the image reading sensitivity set by the image reading sensitivity setting means.