Patent ID: 7306313

Claim:
A method of correcting a predetermined adjustment value for an image forming apparatus producing an image of each of separated colors in accordance with said predetermined adjustment value, comprising the steps of: forming a first base image from a base color output in accordance with said predetermined adjustment value, and forming a first correction image from a correction color to be a subject for correction output in accordance with a value obtained by changing said predetermined adjustment value within a predetermined range; determining a first adjustment value from the changed predetermined adjustment values based on a density output from a sensor detecting the density of an image forming portion; forming a second base image from the base color output in accordance with said predetermined adjustment value, and forming a second correction image from a correction color output in accordance with a plurality of adjustment values determined based on said first adjustment value; determining a second adjustment value from said plurality of adjustment values based on the density output from said sensor; and correcting said predetermined adjustment value for the correction color to the determined second adjustment value.