Image forming apparatus

An image forming apparatus includes a photosensitive member, light-emitting chips, and a controller integrated circuit (IC). Provided in each of the light-emitting chips are a plurality of light-emitting units that emit light for exposing the photosensitive member, a circuit unit that turns on and off the plurality of light-emitting units based on image data, and a storage unit that stores control data indicating a target amount of light of the plurality of light-emitting units. The light-emitting chips are arranged along a rotational axis direction of the photosensitive member. Each of the light-emitting chips is connected to the controller IC by a different one of a plurality of signal lines. In a case where the output control data is transmitted from the controller IC to each of the light-emitting chips via the different one of the plurality of signal lines, the transmitted control data is stored in the storage unit.