Image forming apparatus

Abstract

An image forming apparatus includes a photoreceptor; an image signal generating unit configured to generate an image signal based on input image data; a light emitting portion configured to emit light based on the image signal and expose the photoreceptor; a driving unit configured to drive the light emitting portion; a first substrate in which the driving unit is provided and a plurality of the light emitting portions is provided in a direction parallel to a rotational axis direction of the photoreceptor; an exposure head including the first substrate; a reference clock signal generating unit configured to generate a reference clock signal that is a clock signal of a constant frequency; a modulated clock signal generating unit configured to generate a modulated clock signal by performing spread spectrum on the reference clock signal, the modulated clock signal being a composite wave in which odd-order harmonics are combined with a fundamental wave when a triangular wave is subjected to Fourier series expansion; a transmission unit configured to superimpose the modulated clock signal on the image signal and transmit the superimposed signal to the first substrate; a second substrate on which the image signal generating unit, the modulated clock signal generating unit, and the transmission unit are provided; and an extraction circuit that is mounted on the first substrate and extracts the modulated clock signal from the superimposed signal transmitted from the transmission unit.