Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge includes an electrophotographic photosensitive drum; a developing roller for developing an electrostatic latent image formed on the photosensitive drum; a magnet disposed inn the developing roller; a drum frame supporting the photosensitive drum; a developing device frame supporting the developing roller and the magnet; an engaging member mounted to one longitudinal end of the developing device frame in engagement with one end of the developing roller and with one end of the magnet, the engaging member is provided with a projected portion at an opposite end from the end where it is in engagement with one end of the developing roller and one end of the magnet; an elastic member urging the projected portion by its elastic force so as to urge the developing roller to the photosensitive drum.

Abstract: A developing device includes a rotatable developer carrying member for carring a developer; a magnet roller provided in the developer carrying member; a first electrode portion connected electrically with the developer carrying member, the first electrode portion being rotatable with the developer carrying member; a second electrode portion provided with a contact portion in sliding contact with the first electrode portion, the contact portion being disposed outside a longitudinal end portion of the magnet roller substantially at a center of rotation of the developer carrying member.

Abstract: A developing apparatus includes a cylindrical rotatable developer carrying member for carrying a developer to a developing position. A non-rotary insulating magnet roller, provided in the cylindrical developer carrying member. A electroconductive member provided on the magnet roller, the electroconductive member partly constituting a voltage supplying path for supplying a voltage to the developer carrying member. A sliding contact, provided on inside of the developing sleeve, for establishing electric connection between the electroconductive member, and an inside surface of the developer carrying member in the voltage supplying path.