Developing apparatus of electrophotographic printer

摘要

A developing apparatus of an electrophotographic printer for developing an image on a photoreceptive drum includes a disc rotating independently of the photoreceptive drum at both sides of the photoreceptive drum and having at least one cam groove formed on an outer circumferential surface thereof. A developing unit includes a housing containing developer and a developing roller supported by both sidewalls of the housing and having a shaft contacting the outer circumferential surface of the disc. An elastic member is provided at a rear surface of the housing and presses the developing apparatus toward the photoreceptive drum. Thus, since the disc having at least one cam groove is provided on the outer circumferential surface and rotates independently of the photoreceptive drum, the developing roller can be detached from the photoreceptive drum at a predetermined pressure.