Patent ID: 6968142

Claim:
An image forming apparatus for forming an image on a recording medium with a plurality of process cartridges detachably mounted thereto, comprising: a plurality of cartridge mounting portions configured and positioned to detachably mount the process cartridges each having an electrophotographic photosensitive drum, at least one process means for acting on the electrophotographic photosensitive drum, a cartridge frame holding the electrophotographic photosensitive drum and the process means, and exposing a portion of the electrophotographic photosensitive drum, a shutter member provided for movement between a protection position in which the shutter member protects an exposed portion, which is the portion of the electrophotographic photosensitive drum exposed out of the cartridge frame, and a retraction position in which the shutter member is downardly retracted from the protection position to expose the exposed portion of the electrophotographic photosensitive drum out of the cartridge frame, and a shutter opening and closing mechansim configured and positioned to move the shutter member: an openable and closable door; and a main body side shutter opening and closing mechansim configured and positioned to operate the shutter opening and closing mechansim of each of the process cartridges mounted to the cartridge mounting portions, in operative association with opening and closing operations of said openable and closable door to thereby move the shutter member of each of the process cartridges between the protection position and the retraction position, wherein said main body side shutter opening and closing mechanism comprises: a rotary member comprising: a pressed portion against which a pressing member provided on said openable and closable door abuts; and a gear portion; a cam gear meshing with said gear portion of said rotary member; a cam member provided integrally with said cam gear; and a shutter interlocking plate abutting against said cam member while substantially vertically extending along said plurality of cartridge mounting portions and disposed for vertical movement, said shutter interlocking plate moving up and down in conformity with the opening and closing operations of said openable and closable door.