Patent ID: 6867811

Claim:
A photosensor system comprising: a photosensor array including a plurality of photosensors in a two-dimensional array; an image reader which reads a subject image at a predetermined reading sensitivity by the photosensor array; a sensitivity-adjusting reader which causes the subject image to be read by a specific region of the photosensor array to read the subject image at a plurality of different image reading sensitivities at a corresponding plurality of stages for the specific region of the photosensor array; optimal image reading sensitivity extraction means for extracting an optimal image reading sensitivity suitable for the image reading operation based on a comparison of predetermined measurement amounts which correspond to the plurality of different image reading sensitivities and which relate to an image pattern of the subject image corresponding to the specific region of the photosensor array and read by the sensitivity-adjusting reader; and reading sensitivity setting means for setting the optimal image reading sensitivity to a reading sensitivity of the image reader.