| 摘要 |
<P>PROBLEM TO BE SOLVED: To form a high-definition color image with less color shift by suppressing a color shift detection error caused by the irregular rotation of a photoreceptor drum etc., and the irregular drive of a driving roller. <P>SOLUTION: The color image forming apparatus includes: a displacement detection pattern forming means; a displacement detection pattern detecting means for detecting the displacement detection pattern formed on an endless belt 3; a calculating means for calculating the color shift value of the detection color related to a reference color on the basis of the detection result by the displacement detection pattern detecting means; and a correcting means for correcting an image forming condition on the basis of the color shift amount calculated by the calculating means. The displacement detection patterns in respective colors are arranged by the displacement detection pattern forming means at pattern intervals obtained by equally dividing the integral multiple of a first cycle of periodical unevenness causing the displacement, and the displacement detection patterns in different colors are arranged at pattern intervals of integral multiple of a second cycle of periodical unevenness causing the displacement. <P>COPYRIGHT: (C)2007,JPO&INPIT |
