Electrophotographic apparatus having an intermediate transfer device and registration controlling methods therefor

摘要

Registration controlling methods are provided for a color electrophotographic apparatus capable of forming an image without color registration errors and uneven color. This is accomplished by preventing a photosensitive medium from being undesirably moved in the direction perpendicular to the transportation direction caused by an electrostatic attractive force between the photosensitive medium and an intermediate transfer device, even if there is a twist between the fixed axis of the member supporting the photosensitive medium and the axis of the member supporting the intermediate transfer device. With these methods, a fur brush cleaner made of a conductive brush is detached from the intermediate transfer device during the time period after the start of driving the photosensitive medium and until the front edge of the photosensitive medium reaches the intermediate transfer device. A small amount of toner therefore always exists between the intermediate transfer device and the photosensitive medium during the transportation of the photosensitive medium, thereby reducing the electrostatic attractive force between the intermediate transfer device and the photosensitive medium and preventing the photosensitive medium from being undesirably moved in the direction perpendicular to the transportation direction. Also during this time period, the photosensitive medium is irradiated by a fade lamp to reduce electric charges on the photosensitive medium.