| 摘要 |
PROBLEM TO BE SOLVED: To conform the respective color image drawing positions one another by the small correction amount. SOLUTION: Tone image patterns for sensing position shifts for respective color components are formed on an intermediate transfer body, and the positions of the toner image patterns are sensed by image position sensors 54S, 54C and 54E, and respective color component drawing positions are computed by an image position computation sections 56. Based on the drawing positions, the target values of respective color drawing positions are set as an intermediate value between the maximum value and the minimum value of color shifts by a CPU 60 and output to a correction control section 62. A laser beam source 14, a polygon motor 64 and a skew motor 66 are controlled by the correction control section 62 so that the target values conform to respective color drawing positions and correct the color shifts of respective colors. |
