Patent ID: 6421076
Filing Date: 2002-07-16
Classification: H04N

Abstract:
An image forming apparatus in which a photoreceptor is scanned with a plurality of light beams respectively to form a plurality of images thereon and the plurality of images are overlapped to generate a single image, the image forming apparatus comprising:a detection part that detects, for each image, a positional deviation magnitude of that image in a direction orthogonal to a scanning direction with the light beams; a correction part that calculates, for each light beam, a deviation of a modulation start timing of that light beam useable to correct the positional deviation magnitude for the respective image detected by the detection part, and determines for each light beam, the modulation start timing of that light beam based on a combination of the deviations of the modulation start timings of all of the light beams, using a time required for one scanning with the light beam as a unit for changing the modulation start timing of each light beam; and a modulation control part that controls, for each light beam, the modulation of that light beam according to the modulation start timing determined by the correction part for that light beam.