A charge-modulation element includes a first charge-accumulation region, a second charge-accumulation region, a third charge-accumulation region, and a fourth charge-accumulation region, provided symmetric with respect to a center position of a light-receiving area, and a first field-control electrode pair, a second field-control electrode pair, a third field-control electrode pair, and a fourth field-control electrode pair, arranged on both sides of respective charge transport paths, for changing depletion potentials of the charge transport paths, which extend from the center position of the light-receiving area to the first charge-accumulation region, the second charge-accumulation region, the third charge-accumulation region, and the fourth charge-accumulation region.