Image forming apparatus having a rotating polygonal mirror

Abstract

A method for controlling an image forming apparatus for forming a color image by superposing images formed at image forming units, each provided for a corresponding one of a plurality of color components, includes a first skipping step of skipping part of a main-scanning synchronizing signal in a first image forming unit for forming an image of a first color component, a first generation step of generating a sub-scanning reference signal based on the main-scanning synchronizing signal skipped in the first skipping step, a first exposure-scanning control step of controlling exposure scanning in a second image forming unit based on the main-scanning synchronizing signal skipped in the first skipping step and the sub-scanning reference signal generated in the first generation step, a second generation step of generating a sub-scanning reference signal in the second image forming unit for forming an image of a second color component, based on the sub-scanning reference signal generated in the first generation step, a second skipping step of performing skipping by determining a timing of skipping of the main-scanning synchronizing signal in the second image forming unit based on the sub-scanning reference signal generated in the second generation step, and an exposure-scanning control step of controlling exposure scanning in the second image forming unit based on the main-scanning synchronizing signal skipped in the second skipping step and the sub-scanning reference signal generated in the second generation step.

Dependencies are inferred from the claim text.