Image forming apparatus including switching structure for separating a photosensitive drum and a developing roller after completion of printing

摘要

A photosensitive drum 25 is rotated counterclockwise by a predetermined angle upon completion of printing. A release belt 44 is caused to rotate in the same direction by surface friction between a nip release belt 49 and a surface of the photosensitive drum 25. At this time, a pitch roller 47 provided at both ends of a developing roller 27 is rotated clockwise while guided along a roller guide hole 61 of the release belt 44, runs onto an upper plane of the nip release belt 49, and releases the developing roller 27 from the photosensitive drum 25 with a clearance which is substantially equal to the thickness of the nip release belt 49.