Image forming apparatus with speed control based on belt thickness information

摘要

An image forming apparatus includes a plurality of image bearing members (13C,13M,13Y,13K), an image forming device for forming images of plural colors on the plurality of image bearing members, a recording material conveying belt (8) for bearing and conveying a recording material thereon, a drive roller (12) for transmitting a driving force to the recording material conveying belt, the images of plural colors on the plurality of image bearing members formed by the image forming device being successively transferred to the recording material formed on the recording material conveying belt in superposed relationship with one another, and a control device for controlling the rotating speed of the drive roller on the basis of the thickness information of the recording material conveying belt in the direction of movement of the recording material conveying belt.