IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To provide an image forming apparatus in which a motor for driving a belt is commonly used as a motor 90K for a K-photoreceptor so as to reduce the cost, and misalignment of a K-toner image formed by the K-photoreceptor in overlapping toner images of other colors is decreased.SOLUTION: The arrangement pitch L of photoreceptors 1Y, C, M, K of the respective colors along a moving direction of an intermediate transfer belt 8 is set to be integral multiple of a perimeter length (more particularly, twice) of a driving roller 12. A motor control unit 150 and a main control unit are configured to carry out the same fine adjustment for the speed on a motor 90K for the K-photoreceptor and a color photoreceptor motor 90YCM sharing among the Y-, M-, and C-photoreceptors 1Y, C, M, based on detection results of the belt moving velocity by a follower encoder 171 fixed to a rotation shaft of a follower roller 14.