A photoelectric conversion element includes: a plurality of light receiving elements that are arranged in a main-scanning direction, are arranged in a sub-scanning direction according to colors of light to be received, and accumulates electric charge due to light exposure; and a plurality of AD conversion units that convert analog signals that indicate quantities of electric charge accumulated in the light receiving elements into digital signals are provide for each of groups each consisting of a predetermined number of pixels corresponding to the light receiving elements arranged in the sub-scanning direction. The AD conversion units convert the analog signals into the digital signals in an order in which the light receiving elements in the group are exposed to light. The light receiving elements constitute a correction unit that performs correction so as to reduce a difference relating to the timings in the sub-scanning direction.