Patent ID: 7485837

Claim:
An image sensor comprising a standard portion and a reference portion, each of the standard portion and the reference portion comprising a pixel array, a pixel array charge detector producing a signal corresponding to a light amount received in the pixel array, a control electrode controlling supply of charges from the pixel array to the pixel array charge detector, monitoring pixels monitoring an average light amount of the pixel array, and a monitoring charge detector producing a signal corresponding to a light amount received in the monitoring pixels, wherein: the image sensor further comprises a signal control portion carrying out control so that each of the output signals from the pixel array charge detectors of the standard portion and the reference portion is kept constant; the signal control portion comprising a minimum detector, a comparator, a reference voltage generator, and a control signal generating portion, the minimum detector producing an output signal corresponding to one of the two output signals from the monitoring charge detectors of the standard portion and the reference portion which has a lower level, the comparator comparing an output from the minimum detector with a reference voltage generated by the reference voltage generator, the control signal generating portion controlling the control electrodes of the standard portion and the reference portion on the basis of a result of comparison by the comparator.