Patent ID: 7812876

Claim:
A photoelectric conversion device comprising: a plurality of pixel output lines; a plurality of pixels each sequentially outputting first and second signals to a corresponding pixel output line, the first signal being a signal in darkness and the second signal being a signal in light; a plurality of amplifier units each amplifying first and second signals sequentially outputted to a corresponding pixel output line and outputting amplified first and second signals; a plurality of constant current sources each flowing a constant current through a corresponding pixel output line; a plurality of circuits each provided to a corresponding amplifier unit and including a first holding capacitor that holds an amplified first signal outputted from the corresponding amplifier unit, and a second holding capacitor that holds an amplified second signal outputted from that corresponding amplifier unit; a first common output line to which each of the plurality of circuits outputs the amplified first signal held in the first holding capacitor; a second common output line to which each of the plurality of circuits outputs the amplified second signal held in the second holding capacitor; and a common differential amplifier, which differentially amplifies the first and second amplified signals outputted to the first and second common output lines, wherein each of the plurality of pixels includes an amplifier MOSFET, the amplifier MOSFET and a constant current source corresponding to the pixel constituting a source follower circuit for sequentially outputting the first and second signals of the pixel to a corresponding pixel output line, each of the plurality of amplifier units includes: a variable amplifier stage, which amplifies first and second signals sequentially outputted to a corresponding pixel output line at a gain selected from a plurality of gains, and a buffer stage, which amplifies signals outputted from the variable amplifier stage to generate the amplified first and second signals.