A process cartridge which is detachably attachable to an image forming apparatus main body and which has a photosensitive drum is provided with a light guide. This light guide guides light from an LED lamp provided in the image forming apparatus main body to the surface of the photosensitive drum, thus...http://www.google.de/patents/US6738588?utm_source=gb-gplus-sharePatent US6738588 - Image forming apparatus and process cartridge detachably attachable to the same
