Banding Artifact Reduction for a Class of Color Electrophotographic Printers With Underactuated Motor/Gear Configuration

A servo control architecture is proposed for a class of color electrophotographic printers with underactuated motor/gear configuration. The insufficiency and performance limitation of using single actuator (either motor or laser intensity control) to reduce periodic imaging artifact, i.e., banding, for this type of systems is presented. The proposed dual-actuator control scheme consists of a conventional Hinfin feedback controller and a nonlinear feedforward controller. The feedback controller regulates the motor velocity to reduce the effect of disturbances and system sensitivity on the intermediate transfer belt, and the feedforward controller modulates the laser intensity to compensate for the reflectance variation associated with the disturbances on the photoconductive drum. Experiments based on the proposed scheme are performed and show significant banding reduction on both the measured reflectance and the printed images.