Patent ID: 6718148
Filing Date: 2004-04-06
Classification: G03G

Abstract:
A process cartridge which is detachably mountable on a main body of an electrophotographic apparatus, said process cartridge comprising the following integrally supported therein:an electrophotographic photosensitive member configured to hold thereon a toner image; an intermediate transfer belt having a contact zone coming into contact with said electrophotographic photosensitive member; a primary-transfer means for primarily transferring the toner image from said electrophotographic photosensitive member to said intermediate transfer belt at the contact zone; a charge-providing means for providing the toner on said intermediate transfer belt with electric charges having a polarity reverse to a polarity the toner has at the time of the primary transfer and returning the toner on said intermediate transfer belt to said electrophotographic photosensitive member at the contact zone to clean said intermediate transfer belt; and an electrophotographic-photosensitive-member cleaning means for cleaning said electrophotographic photosensitive member; said process cartridge being dividable into an electrophotographic photosensitive member unit having said electrophotographic photosensitive member and an intermediate transfer belt unit having said intermediate transfer belt, and further comprising joining means for joining said electrophotographic photosensitive member unit and said intermediate transfer belt unit together; and the peripheral length L (mm) of said intermediate transfer belt, the average thickness t (mm) of said intermediate transfer belt and the diameter R (mm) of at least one of rollers over and around which said intermediate transfer belt is placed satisfying all the following expressions (1) to (4): â€ƒ(1) 2Ã—102&pgr;&lE;L/t&lE;4Ã—104&pgr;;(2) 2Ã—10âˆ’4&lE;t/R&lE;1.5Ã—10âˆ’2; (3) 0.005<t<0.6; and (4) 5<R<90.