Solid-state image pickup device and driving method therefor

In a MOS solid-state image pickup device including two capacitors storing electric charges of pixels in two rows for each column and two charge-voltage conversion amplifiers for outputting pixel signals corresponding to the electric charges stored in the capacitors, a switch for selectively short-circuiting input terminals of the charge-voltage conversion amplifiers and a switch for short-circuiting output terminals of the charge-voltage amplifiers are provided. In a first driving mode, the switches are not short-circuited so that analog signals are read in the form of dual-rail outputs. In a second driving mode, the switches are short-circuited so that an average of the analog signals is read.