Patent ID: 7697042

Claim:
A solid-state image pickup device comprising: a plurality of photoreceiving elements which are two-dimensionally arranged in a plurality of rows and columns; a plurality of signal lines to which the plurality of photoreceiving elements arranged in the column direction are connected, respectively; a clamp circuit comprising: a plurality of clamp capacitors connected such that each clamp capacitor has one terminal connected to one of the plurality of signal lines, to which none of the other clamp capacitors is connected, to receive and add pixel signals from the photoreceiving elements in one row, and the other terminal of each clamp capacitor for outputting the added pixel signals from the photoreceiving elements in the one row is connected commonly to the other terminals of the other clamp capacitors; and a switching device which is connected to the other terminals of said plurality of clamp capacitors and applies a reference voltage to said other terminals by a clamping operation, and which adds signals from the plurality of photoreceiving elements provided in the row direction along with the clamping operation; and an adding device which is connected to the other terminals of said plurality of clamp capacitors, and adds the added pixel signals from the other terminals of the clamping capacitors in the plurality of columns.