Electrophotographic image forming apparatus to which a process cartridge is detachably mountable and process cartridge comprising cartridge drum positioning portion or recess

摘要

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus includes: a cartridge frame; an electrophotographic photosensitive drum supported on the cartridge frame; a process device actable on the photosensitive drum; a cartridge drum positioning portion for positioning the photosensitive drum to the main assembly of the apparatus by engagement with a main assembly drum positioning portion provided in the main assembly of the apparatus when the process cartridge is mounted to the main assembly of the apparatus; and a cartridge frame positioning portion for positioning the cartridge frame to the main assembly of the apparatus by engagement with a main assembly frame positioning portion provided in the main assembly of the apparatus when the process cartridge is mounted to the main assembly of the apparatus.