A photosensor system including a photosensor array having a plurality of photosensors
arranged two-dimensionally comprises a driver circuit and a readout circuit for
applying signal voltages to each photosensor, and also a control circuit having
a function of controlling the voltages applied to each photosensor and adjusting
the sensitivity of each photosensor. During an image reading operation and a reading
operation for setting the sensitivity of each photosensor, a correction signal
is generated, which has an effective voltage that can adjust an effective voltage,
applied to each gate electrode of each photosensor, to 0 V, or to a value that
minimizes degradation of the characteristics of each photosensor. This correction
signal is applied to each gate electrode.
