Arbeitseinheit und elektrophotographisches Bilderzeugungsgerät

摘要

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus includes an electrophotographic photosensitive member; process means actable on the electrophotographic photosensitive member; an exposure zone, provided in a cartridge frame, for exposing a part of the electrophotographic photosensitive member to permit, when the process cartridge is mounted to the main assembly of the apparatus, detecting means provided in the main assembly to detect a density of a toner image formed on the electrophotographic photosensitive member, to project light emitted from the detecting means to the electrophotographic photosensitive member on which the toner image is formed, and to direct the light reflected by the electrophotographic photosensitive member to the detecting means.