Patent ID: 8218988

Claim:
An image forming apparatus with a transfer belt cleaning function comprising: a transfer belt on which a toner image on a photoreceptor is transferred; a secondary transfer unit for transferring the toner image on the transfer belt to a recording medium; an optical sensor for detecting a reference toner image on the transfer belt; a shutter for protecting the detecting surface of the optical sensor; an opening/closing portion for opening and closing the shutter; a controller for detecting the opening and closing of the shutter from the output from the optical sensor and controlling the opening and closing of the shutter based on the detected result; a cleaning member, disposed on the upstream side of the detecting surface of the optical sensor in a direction of transfer belt being carried, for cleaning the surface of the transfer belt, wherein the cleaning member is arranged obliquely to the direction perpendicular to the direction of the transfer belt being carried when the cleaning member contacts the transfer belt; and a cleaning member separation/contact assembly which moves the cleaning member away from the surface of the transfer belt when the shutter is opened and brings the cleaning member into contact with the surface of the transfer belt when the shutter is closed.