Patent ID: 8849156

Claim:
A cartridge detachably mountable to a main assembly of an image forming apparatus including a main assembly coupling, a positioning portion, and a rotational limiting portion, said cartridge comprising: a photosensitive drum; a portion-to-be-positioned configured and positioned to contact the positioning portion to position said cartridge in a direction crossing an axis of said photosensitive drum when said cartridge is mounted to the main assembly of the apparatus along the axis of said photosensitive drum; a drum coupling provided at one end portion side with respect to a longitudinal direction of said cartridge, said drum coupling configured to engage with the main assembly coupling to transmit a driving force to said photosensitive drum when said cartridge is mounted to the main assembly of the apparatus; and a portion-to-be-limited provided at a position below said photosensitive drum at the other end portion side of said cartridge with respect to a longitudinal direction of the cartridge, said portion-to-be-limited configured to limit rotation caused by transmission of the driving force from the main assembly coupling to said drum coupling of said cartridge relative to the positioning portion by contacting the rotation limiting portion when said cartridge is mounted to the main assembly of the apparatus, wherein said portion-to-be-limited is a recess portion provided at the bottom wall of said cartridge.