IMAGE SENSOR, CAMERA, SUPERVISORY SYSTEM, AND DRIVING METHOD FOR IMAGE SENSOR

摘要

PROBLEM TO BE SOLVED: To provide an image sensor having a motion detection function.SOLUTION: A pixel comprises: a photoelectric conversion element; a node for storing electric potential depending on a charge amount generated in the photoelectric conversion element; a capacitance element connected in series between the photoelectric conversion element and the node; a reset circuit for resetting electric potential of the node; an amplifier circuit for outputting a signal depending on the electric potential of the node; and a switch for controlling electric conduction between the amplifier circuit and a vertical signal line. An optical signal is detected by the photoelectric conversion element with the node fixed at fixed potential. After that, making the node be in an electrically floating state makes the node store the electric potential of the optical signal in the reversed state. Detecting the optical signal while keeping the node in the state of storing the electric potential makes the electric potential of the node increase depending on output electric potential of the photoelectric conversion element. Thereby, the electric potential of the node corresponds to difference potential between optical signals having different light-receiving periods.