Apparatus for forming multiple toner images in register with each other on a substrate

摘要

The apparatus includes an endless belt, an imaging station, a number of developing stations, and a number of transfer stations. A controllable belt drive drives the endless belt along a path through the imaging station, the developing stations and the transfer stations. A preformed timing mark is carried on the belt and a sensor is provided for sensing the passage of the timing mark past a sensing position. A control device controls the belt drive to run at a constant speed and controls the speed of the belt in response to the sensing of the timing mark. The maintenance of a constant belt speed can be more reliably assured.