An image forming apparatus of a type having a photoconductive drum surrounded by an exposure station, a toner dispenser, an image transfer roller, a pre-discharging lamp and a contact charging roller incorporates a novel apparatus and method for cleaning the transfer and charging rollers of toner and other contamination. The transfer roller first is cleaned by applying to it an electric bias of alternating polarity to repel toner to the photoconductive element. Charge induced on the photoconductive drum by the toner is neutralized by the contact charging roller, and thereafter, a cleaning element, such as a sponge, is moved into contact with the charging roller for cleaning it of toner. The transfer roller may be separated from the photoconductive drum during image exposure or in response to an exposure synchronization signal, to reduced image distortion caused by mechanical vibration of the drum.