US Patent 7920814 Intermediate transfer belt steering system

Disclosed are embodiments that use multiple, belt-steering systems to control and maintain alignment of an endless belt. The position of the edge of the belt is measured by multiple belt edge sensors and then corrected by at least two steering rollers connected to corresponding steering mechanisms. The steering mechanisms tilt the rollers in order to selectively adjust the lateral position of the belt. Steering can be controlled independently with the tilt of each steering roller being adjusted based solely on information obtain from a corresponding belt edge sensor. Alternatively, steering can be controlled dependently with the tilt of each steering roller being adjusted based on information obtain from multiple sensors at multiple locations and further based on the predictable impact of the simultaneous movement of both rollers on belt positioning. In addition, at least one of the steering rollers can also be configured as a drive roller.