PURPOSE: To prevent adverse effect on a picture due to the dispersion in the characteristic of an element in a selected path by amplifying a picture element signal outputted according to the ratio of the capacitance of a photo diode and a readout use capacitor so as to obtain a readout signal based on a precharge voltage.
CONSTITUTION: A voltage signal corresponding to a signal charge in a photo diode D1 is given to an output capacitor C1 via an amplifier MOSFETQ21 and a readout switch MOSFETQ31 and when the capacitor C1 is charged up by a voltage corresponding to the signal charge of the photo diode D1, the switch MOSFETQ2 is turned off. Thus, the other electrode of the capacitor C1 is brought into a floating state. Then precharge operation is started to the photo diode D1 by a shift register SR. Since the signal charge given to a holding capacitor is based on the precharge voltage, the dispersion in the process of a precharge MOSFETQ11 is cancelled into zero.
FUJII TATSUHISA
TAKEMOTO KAYAO
