An image forming apparatus includes a toner cartridge which is detachably mounted from a first direction to store a toner; and a processing unit which is detachably mounted from a second direction perpendicular to the first direction and is provided with a photoconductor, a developing section for supplying a toner fed from the toner cartridge to the surface of the photoconductor to convert an electrostatic latent image to a toner image and a cleaning section for collecting the toner adhered on the surface of the photoconductor.

A drum frame includes first and second frames supporting a photosensitive drum, and a support frame configured to support a toner cartridge. The support frame is not movable relative to the photosensitive drum. The support frame has a passage opening through which toner from the toner cartridge passes in a state where the toner cartridge is supported by the support frame. A development housing has a reception opening configured to receive toner that has passed through the passage opening. The reception opening is larger than the passage opening. The development housing supports a development roller. The development housing is movable relative to the photosensitive drum. A seal is located around the passage opening and away from the passage opening. The seal is in contact with the support frame and an edge of the reception opening. The seal seals between the support frame and the edge of the reception opening.

A drum frame includes a first frame, a second frame, and a partition portion. The first frame supports one end of a photosensitive drum in a first direction. The second frame supports another end of the photosensitive drum in the first direction. The partition portion is not movable relative to the photosensitive drum. The partition portion has a passage opening through which toner from a toner cartridge passes. A development housing has a reception opening configured to receive toner that has passed through the passage opening. The reception opening is larger than the passage opening. The development housing is movable relative to the photosensitive drum. A seal is located around the passage opening and the reception opening. The seal seals between the partition portion and the development housing. A conveyor is located in the development housing. The conveyor faces the partition portion via the reception opening.

An image forming apparatus includes an apparatus main body, a first unit configured to be attached to the apparatus main body, a second unit configured to be attached to the apparatus main body and configured (1) to be drawn out from the apparatus main body together with the first unit and (2) to be drawn out from the apparatus main body while the first unit is accommodated in the apparatus main body, and a restriction structure configured to restrict the first unit from being drawn out from the apparatus main body in a case where the second unit is drawn out from the apparatus main body while the first unit is accommodated in the apparatus main body.

An electrophotographic photoreceptor includes a conductive substrate, a charge-generating layer provided on or above the conductive substrate, a charge transport layer provided on the charge-generating layer and containing inorganic oxide particles, the charge-generating layer and the charge transport layer forming a photosensitive layer, and an inorganic protective layer provided on the photosensitive layer, in which in a cross-sectional observation of the charge transport layer, the relationship between the percentage area A of inorganic oxide particles contained in a surface level and the percentage area B of inorganic oxide particles contained in an inner level satisfies the percentage area A>the percentage area B of the charge transport layer, with the boundary therebetween at the thickness of the charge transport layer.

The developing cartridge includes a housing, a developing roller, a memory, a holder, and a cover, the developing roller rotates about a developing axis extending in a first direction, and the holder holds the electrical contact surface. The housing has a first boss extending in the first direction toward the cover, and a screw for attaching the cover to the housing is fastened to the first boss. The holder has a hole extending in the first direction, and the first boss is inserted into the hole. Thus, the first boss has a function of receiving a screw for attaching the cover to the housing and a function of holding the holder. This can reduce the number of parts of the developing cartridge.

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.

A cartridge detachably mountable to a main assembly of an image forming apparatus includes a photosensitive member unit including a photosensitive drum; a sheet configured to remove a deposited matter from a surface of the drum, the sheet being in contact with the surface of the drum at an end portion of the drum with respect to a rotational axis direction of the member; and a developing unit detachably mounted to the member unit, the developing unit including a developing roller configured to supply toner to the drum, and a storage portion configured to store the deposited matter removed from the surface of the drum by the sheet.

An image forming device, including: a housing; a drawer movable between an inside position at which the drawer is located inside the housing and an outside position at which the drawer is located outside the housing; a drum cartridge including a photoconductive drum and a developer roller and mountable on the drawer; a toner cartridge storing toner to be supplied to the developer roller and mountable on the drawer, wherein the drawer includes a first guide that guides the toner cartridge in mounting the toner cartridge on the drawer, and wherein the drum cartridge includes a second guide connected to the first guide in a state in which the drum cartridge is mounted on the drawer, the second guide being configured to guide the toner cartridge in mounting the toner cartridge on the drawer in the state in which the drum cartridge is mounted on the drawer.