Patent ID: 8633957

Claim:
An image forming apparatus that emits light from a light emitting element for a toner image forming region on a photosensitive member according to input image data and exposes the photosensitive member, the image forming apparatus comprising: a first clock output unit that outputs a clock to slightly emit light from the light emitting element for a non-toner image forming region on the photosensitive member; a second clock output unit that outputs a clock for emitting light from the light emitting element and exposes the photosensitive member for the toner image forming region on the photosensitive member according to the image data; and a control unit that, based on the clock output from said first clock output unit, controls the light emitting element to slightly emit light to slightly expose the photosensitive member, wherein said first clock output unit outputs the clock for performing the slight exposure with a frequency diffused within a predetermined frequency range, wherein said first clock output unit diffuses a frequency of the clock for performing the slight exposure around a frequency of the clock output from said second clock output unit, wherein said second clock output unit is configured to output a clock for a first print mode in which the light emitting element emits light to perform the exposure in the first print mode, and a clock for a second print mode in which the light emitting element emits light to perform the exposure in the second print mode different from that in the first print mode, the clock for the first print mode being different from the clock for the second print mode, and wherein said first clock output unit diffuses the frequency of the clock for performing the slight exposure in the second print mode with a frequency around the clock for the first print mode or the clock for the second print mode in each of the first print mode or the second print mode.