An image forming apparatus comprises a spacing member provided on a rotation shaft of a charging roller, the spacing member configured to include an engaging portion that engages with a rotation member, and to be rotatable between a spaced position at which a spaced state in which a photosensitive drum and the charging roller are spaced apart is maintained, and a released position at which the spaced state is released and the photosensitive drum and the charging roller are caused to be in contact; and a cover portion provided on the rotation shaft of the charging roller, and configured to cover an end face of the spacing member so that a fitting portion of the charging roller and the spacing member is covered.

An image forming apparatus includes an apparatus main body, a process cartridge, a scanner unit, and a toner cartridge. The process cartridge is detachably mounted on the apparatus main body. The process cartridge includes: a photosensitive drum configured to rotate about a rotational axis extending in a first direction; and a development unit configured to supply toner to the photosensitive drum. The toner cartridge is configured to store toner. At least part of the photosensitive drum, at least part of the scanner unit, and at least part of the toner cartridge are aligned in a second direction in this order. The second direction is perpendicular to both the first direction and to a vertical direction. The at least part of the photosensitive drum, the at least part of the scanner unit, and the at least part of the toner cartridge overlap one another as viewed from the second direction.

A developing blade has a protrusion that protrudes toward a developing roller in an opposing portion facing the developing roller. When a height of the protrusion from an opposing surface that faces the developing roller at a position further toward a tip side than the protrusion is denoted by H (mm) and a length of the opposing surface extending toward the tip side perpendicular to an axial line direction of the developing roller is denoted by L (mm), when viewing a cross section perpendicular to a rotation axis of the developing roller, the following conditions are satisfied:

0.05≦H≦0.3, and

0.15≦L≦1.0.

A process cartridge including a drum cartridge, a developing cartridge, and a waste toner container, is provided. The drum cartridge includes a photosensitive drum including a photosensitive layer and a rotation axis extending in an axial direction, a drum cleaner arranged to contact the photosensitive drum, a cleaner frame configured to accommodate the drum cleaner therein, and a waste toner conveyer tube connected with the cleaner frame. The developing cartridge is movable to be attached to and detached from the drum cartridge and includes a developer roller. The waste toner container is movable to be attached to and detached from the drum cartridge. When the developing cartridge and the waste toner container are attached to the drum cartridge, the waste toner container is connected with the waste toner conveyer tube and is located on an opposite side of the developing cartridge to the photosensitive drum.

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.

When a process cartridge is mounted, air introduced to inside an image forming apparatus via an intake unit flows in a space surrounded by a housing of the process cartridge, a contact unit, and an arm unit, and is exhausted via an exhaust unit. When another process cartridge having a housing larger in size than a housing of the process cartridge is mounted, the air introduced to inside the image forming apparatus via the intake unit flows in a space surrounded by the housing of the another process cartridge having the larger housing, a contact unit, and the arm unit, and is exhausted via the exhaust unit.

A first cartridge support is configured to support a drum cartridge. The first cartridge support is configured to move in a first direction between a first position at which the drum cartridge is mounted on a housing and a second position at which the drum cartridge is detachable. A second cartridge support is configured to support a development cartridge. The second cartridge support is configured to move in the first direction between a third position at which the development cartridge is mounted on the drum cartridge and a fourth position at which the development cartridge is detachable. In a state where the second cartridge support is located at the third position, the second cartridge support is located between the first cartridge support located at the first position and a cover located at a closed position with respect to the first direction.

An electrophotographic photosensitive member includes a support member, an undercoat layer, and a photosensitive layer adjacent to the undercoat layer in this order, wherein the undercoat layer contains a polymerized product of a composition including an electron transporting material having a polymerizable functional group, a cross-linking agent, and a thermoplastic resin having a polymerizable functional group, and at least one type of particles selected from the group consisting of resin particles having a hollow structure and rubber particles, wherein a content of the electron transporting material in the undercoat layer is 30% by mass or more with respect to a total mass of the composition, and wherein a content of the at least one type of particles in the undercoat layer is 10% by mass or more and 100% by mass or less with respect to the content of the electron transporting material.

The electro-conductive member has an electro-conductive support, and an electro-conductive layer, in which the electro-conductive layer has a matrix including a first rubber cross-linked product and domains dispersed in the matrix, each of the domains includes a second rubber cross-linked product and electro-conductive particles, an outer surface of the electro-conductive member has concave portions, a surface of at least a part of the domains is exposed to the outer surface of the electro-conductive member at bottom portions of the concave portions, a volume resistivity of the matrix is greater than 1×10.sup.12 Ωcm, a volume resistivity of the electro-conductive layer is 1×10.sup.5 Ωcm to 1×10.sup.8 Ωcm, and A2 is 20 times or more of A1.

There is provided a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including an electrophotographic photosensitive member and a charging member, wherein an outer surface of the charging member is composed of at least a matrix and at least a part of domains, a volume resistivity of the matrix is 1.0×10.sup.5 times or more of a volume resistivity of the domain, an average value Sd of circle equivalent diameters of the domains observed on the outer surface of the charging member is in a predetermined range, the electrophotographic photosensitive member contains a support, a photosensitive layer, and a protective layer in this order and when a surface roughness of the protective layer is measured, each of a protruding valley portion Rvk, a load length ratio Mr2, and Sd/Rvk is in a predetermined range.