Image forming apparatus

Abstract

In an image forming apparatus using an electro-photographic technique and having an endless belt-shaped photosensitive body for transferring images, a mechanism is provided to maintain the photosensitive body at a constant transfer speed over its entire length irrespective of the effects of various devices in contact with it. A driving roller drives the photosensitive body by contacting its rear surface. One or more guide rollers are also in contact with the rear surface of the photosensitive body for guiding it in conjunction with the driving roller. A transmission such as a belt and pulley or gear mechanism transmits driving force from the driving roller to one or more of the guide rollers. When at least two guide rollers are provided, one is disposed between and above the driving roller and the second guide roller. The driving roller and the second guide roller are so disposed that the portion of the photosensitive body between them lies in a horizontal plane.

Dependencies are inferred from the claim text.