Patent ID: 6947065

Claim:
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, said method comprising: 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 said first skipping step; a first exposure-scanning control step of controlling exposure scanning in the first image forming unit based on the main-scanning synchronizing signal skipped in said first skipping step and the sub-scanning reference signal generated in said first generation step; a second generation step of generating a sub-scanning reference signal in a second image forming unit for forming an image of a second color component, based on the sub-scanning reference signal generated in said 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 said second generation step; and a second exposure-scanning control step of controlling exposure scanning in the second image forming unit based on the main-scanning synchronizing signal skipped in said second skipping step and the sub-scanning reference signal generated in said second generation step.