Belt controls for a print engine for color electrophotography

In a print engine for use in a color electrophotographic system of the type including imaging means for selectively creating an image on a photosensitive receptor, the improvement comprising:

• first transfer means carrying said receptor thereon and having a characteristic first length;
• first reference means for detecting passage of a first predetermined location on said first transfer means past a first predetermined reference point and for providing a first reference signal in response thereto;
• second transfer means having a characteristic second length, said second length nominally being an integer submultiple of said first length;
• second reference means for detecting passage of a second predetermined location on said second transfer means past a second predetermined reference point and for providing a second reference signal in response thereto;
• first drive means for driving said first transfer means about a plurality of rollers, each roller of said plurality of rollers having an axis of rotation;
• second drive means for driving said second transfer means along a second predetermined path comprising a contact area wherein said second transfer means contacts said first transfer means and said first transfer means wraps around a particular one of said plurality of rollers;
• and
• control means connected to said first and second reference means for synchronizing said second drive means to said first drive means in response to said first and second reference signals such that said first transfer means and said second transfer means have a common predetermined angular velocity at said contact area, said predetermined angular velocity being measured with respect to said axis of rotation of said particular one of said plurality of rollers.