SOLID STATE IMAGE PICKUP DEVICE AND DRIVING METHOD THEREOF TO IMPROVE SIGNAL-TO-NOISE RATIO

摘要

PURPOSE: A solid state image pickup device is provided to improve an S/N(signal to noise) ratio in both modes in which a pixel signal is added and not added without increasing the area of a chip. CONSTITUTION: An accumulation capacitor selecting unit selects the first accumulation capacitor in adding an amplification signal of the unit cell(500) of a plurality of rows and selects the second accumulation capacitor when the addition process is not performed. The capacitance value of the first accumulation capacitor is smaller than the capacitance value of the second accumulation capacitor. The capacitance value of the second accumulation capacitor is a necessary minimum capacitance value to read out a signal accumulated in the second accumulation capacitor.