| 摘要 |
<P>PROBLEM TO BE SOLVED: To automatically detect and adjust the phase of a photoreceptor drum for each color when color shift is minimum, by printing a simple color shift detection pattern for a periodic color shift caused by eccentricity of a photoreceptor drum and photoreceptor drum drive gear. <P>SOLUTION: The phase adjustment mechanism includes: a color shift detecting section that detects a change in the optical density of the color shift detection pattern on an intermediate transfer body, thereby detecting the maximum amount of color shift of the photoreceptor drum rotated one time; a photoreceptor drum rotation phase detecting section that detects the rotated position of the photoreceptor drum for each color; and a photoreceptor drum rotating speed control section that controls the rotating speed of the photoreceptor drum for each color. In relation to the rotation phase of the photoreceptor drum for a reference color, the color shift detection pattern is formed by sequentially changing the rotation phase of the photoreceptor drum for a color to be corrected. The rotation phase of each photoreceptor drum is automatically adjusted so that the maximum amount of color shift of the photoreceptor drum rotated one time is reduced to lowest. <P>COPYRIGHT: (C)2007,JPO&INPIT |
