Patent ID: 8576314

Claim:
A photosensor device comprising: a photodiode array in which a plurality of photodiodes are arranged in an array shape; a plurality of scanning lines which are coupled to first electrodes of the photodiodes in respective lines of the photodiode array; a plurality of read lines which are coupled to second electrodes of the photodiodes in respective columns of the photodiode array; a scanning circuit which is coupled to the plurality of scanning lines and sequentially supplies a selected scanning signal to the respective scanning lines in each horizontal scanning period; and a signal processing circuit which is coupled to the plurality of read lines and loads each voltage fluctuation of the read lines in one horizontal scanning period as signal voltage when reading a signal; wherein each of the photodiodes is made of amorphous silicon or microcrystal silicon; wherein a forward bias voltage is applied to each of the photodiodes when reading a signal; and wherein a first voltage level period of the selected scanning signal that is sequentially supplied to the respective scanning lines from the scanning circuit is changed to change sensor sensitivity of the photosensor device.