| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a color image forming apparatus which detects a mark or an optical pattern accurately so as to prevent an error and reduces color shift of a color image. <P>SOLUTION: The color image forming apparatus detects the mark 27 on an intermediate transfer belt by means of a detector S1 including a light emitting element 31a and a light receiving element 32a and a detector S2 including a light emitting element 31b and a light receiving element 32b. When the intermediate transfer belt is in a design position, the detectors S1 and S2 detect the mark in the same position X and at the same time T. Even if the face of the intermediate transfer body is externally displaced in the course of image formation, a mark detecting position on the design can uniquely be found. Thus, shift when images of distinct colors are superimposed, caused by a mark detection error, is reduced. Accordingly, color shift of the color image can be diminished. <P>COPYRIGHT: (C)2004,JPO |
