An image forming apparatus includes: a housing; a process cartridge including a photoconductive drum and a developing roller; a toner cartridge containing toner; and a drawer movable between an inner position and an outer position. The process cartridge includes a lock member movable between a lock position at which the lock member locks the process cartridge to the drawer, and a release position at which a lock between the process cartridge and the drawer is released. The lock member is located at the lock position in a state in which the process cartridge is mounted to the drawer, and the toner cartridge is mounted to the process cartridge. The lock member is located at the release position in a state in which the process cartridge is mounted to the drawer, and the toner cartridge is removed from the process cartridge.

A drum cartridge that enables a developing cartridge to be mountable thereon, includes a photosensitive drum rotatable about a shaft extending in a first direction, and an electrically conductive movable member. When the developing cartridge is mounted on the drum cartridge, the movable member applies pressure to a developing electrode included in the developing cartridge toward the photosensitive drum.

An image forming apparatus includes: a developing cartridge including a casing, a first electrical contact surface, and a holder movable relative to the casing; a drum cartridge including a drum frame, a second electrical contact surface, and a holder movable relative to the drum frame; and a main frame having an opening and including first and second guide frames facing in a facing direction, a first main electrical contact capable of being electrically connected to one of the first and second electrical contact surfaces, and a second main electrical contact positioned closer to the opening in an attachment direction and capable of being electrically connected to the remaining one of the first and second electrical contact surfaces. A distance in the facing direction between the first and second guide frames is reduced as the first and second guide frames extend toward the first main electrical contact in the attachment direction.

A developing cartridge includes: a casing; a developing roller rotatable about an axis extending in a first direction; a first agitator; an agitator gear; a first protrusion; a developing memory; a first electrical contact surface; and a first holder holding the first electrical contact surface. The agitator gear includes a large diameter gear and a small diameter gear positioned between the large diameter gear and the casing in the first direction. The first protrusion protrudes outward from one end of the casing in the first direction, and is positioned between the casing and the large diameter gear in the first direction. The first protrusion is positioned away from the small diameter gear. The first holder is positioned farther from the first protrusion than the large diameter gear is in the first direction. The first holder and the first electrical contact surface are movable relative to the casing.

Movement and/or urging of a developer carrying member is carried out with high precision.

A cartridge that is mountable to an apparatus main assembly of an image forming apparatus, the cartridge includes a developing roller; a frame supporting the developing roller; a movable part movably supported by the frame and movable to a first position and to a second position relative to the frame; and an elastic part provided between the frame and the movable part to urge the movable part. The movable part includes a first force receiving part that receives force from the apparatus main assembly, in a direction of moving from the first position to the second position, and a second force receiving part that receives force from the apparatus main assembly, in a direction of moving from the second position to the first position. When the movable part receives force from the apparatus main assembly at the first force receiving part and is at the second position, the movable part receives urging force from the elastic part in a direction of moving the movable part from the second position to the first position.

Movement and/or urging of a developer carrying member is carried out with high precision. A cartridge that is mountable to an apparatus main assembly of an image forming apparatus, the cartridge includes a developing roller; a frame supporting the developing roller; a movable part movably supported by the frame and movable to a first position and to a second position relative to the frame; and an elastic part provided between the frame and the movable part to urge the movable part. The movable part includes a first force receiving part that receives force from the apparatus main assembly, in a direction of moving from the first position to the second position, and a second force receiving part that receives force from the apparatus main assembly, in a direction of moving from the second position to the first position. When the movable part receives force from the apparatus main assembly at the first force receiving part and is at the second position, the movable part receives urging force from the elastic part in a direction of moving the movable part from the second position to the first position.

An image-forming apparatus includes an apparatus body and a process cartridge attachable to and detachable from the apparatus body. The apparatus body includes a sheet-feed roller and a body wall. The process cartridge includes: a photosensitive drum; a drum frame; a developing roller; a cleaner; a conveying pipe and a waste-toner container for storing waste toner removed from the photosensitive drum by the cleaner and conveyed by the conveying pipe. The waste-toner container is detachably mountable on the drum frame. The waste-toner container mounted on the drum frame is positioned opposite to the photosensitive drum with respect to the developing roller. The body wall of the apparatus body and a container wall of the waste-toner container constitute a part of a sheet-conveying guide for guiding conveyance of a sheet from the sheet-feed roller toward the photosensitive drum when the process cartridge is attached to the apparatus body.

A photosensitive member unit includes a photosensitive member, a transfer roller, a mounting portion capable of mounting a development unit including a development roller, a first gear and a second gear each provided at one end of the photosensitive member in an axial direction of the photosensitive member, and a third gear provided at one end of the transfer roller in an axial direction of the photosensitive member and configured to engage with the second gear. The first gear, the second gear, and the third gear are helical gears. A direction in which helical teeth of the first gear are inclined is opposite to a direction in which helical teeth of the second gear are inclined, and the direction in which the helical teeth of the first gear are inclined matches a direction in which helical teeth of the third gear are inclined.

An image forming apparatus includes a first process unit, a second process unit, a first toner cartridge, and a second toner cartridge. The first toner cartridge includes a cartridge housing and a first shutter movable between a first closed position and a first open position. The cartridge housing includes one end portion and the other end portion. The cartridge housing is rotatable between a first position at which the first shutter is positioned at the first closed position and a second position at which the first shutter is positioned at the first open position. When the cartridge housing moves from the second position to the first position, the one end portion of the cartridge housing comes close to the second toner cartridge and the other end portion of the cartridge housing goes away from the second toner cartridge.

A toner cartridge includes a housing capable of accommodating toner and having six peripheral walls, a first shutter, and a second shutter. The housing includes (i) a first surface formed on a first peripheral wall and having a first circumferential surface and (ii) a second surface and having a second circumferential surface, the first peripheral wall having a first hole, the second peripheral wall having a second hole. The first shutter is movable relative to the housing along the first circumferential surface between a first closed position at which the first opening is closed and a first open position at which the first opening is opened. The second shutter is movable relative to the housing along the second circumferential surface between a second closed position at which the second opening is closed and a second open position at which the second opening is opened.