Provided is an electrophotographic photosensitive member that suppresses image smearing at the time of its repeated use, and expresses satisfactory wear resistance and electric characteristics. The electrophotographic photosensitive member includes a support and a photosensitive layer in the stated order, wherein a surface layer of the electrophotographic photosensitive member contains a copolymer of a hole-transportable compound having a chain-polymerizable functional group and a specific compound having maleimide groups.

An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

A first side frame is apart from a second side frame in a first direction. A photosensitive drum is rotatable about a drum axis extending in the first direction. The photosensitive drum is rotatably supported between the first side frame and the second side frame. A grip portion extends in the first direction. A first connector extends in a second direction perpendicular to the first direction. The first connector connects the first side frame and a first end portion of the grip portion. The second connector extends in the second direction. The second connector connects the second side frame and a second end portion of the grip portion. A scanner unit is configured to expose the photosensitive drum to light. The scanner unit is located between the photosensitive drum and the grip portion as viewed in a third direction which is perpendicular to the first and second directions.

The electrophotographic photosensitive member includes a support and a photosensitive layer on the support, in which a surface layer of the electrophotographic photosensitive member contains a particle, the surface layer has a particle partially exposed from the surface layer among the particle contained in the surface layer, the particle has a volume average particle diameter of 50.0 nm or more and 350.0 nm or less; in a cross-section of the surface layer, the number of the particle partially exposed from the surface layer is 80% by number or more based on a total number of the particle contained in the surface layer; and a total volume of an exposed portion of the particle partially exposed from the surface layer is 30% by volume or more and 80% by volume or less based on an entire volume of the particle contained in the surface layer.

Provided is an electrophotographic photosensitive member that achieves satisfactory transferability. An electrophotographic photosensitive member including a charge generating layer, a charge transporting layer, and a protection layer laminated on a support in the stated order, wherein the protection layer contains a binder resin and particles, and wherein when an average thickness of the protection layer in a site free of the particles is represented by T and a volume-average particle diameter of the particles is represented by Dm in a cross-section of the protection layer, the following formula (a) is satisfied.

An image forming method includes forming an image with a toner using a photoconductor in which an intermediate layer and a photosensitive layer including a charge generating layer and a charge transport layer are formed overlying an electroconductive substrate, wherein the ionization potential of the surface of the photoconductor and the ionization potential of the surface of the toner satisfy the following relations 1 and 2,
|Ip (the surface of the photoconductor)Ip (the surface of the toner)|0.18 (eV) Relation 1
5.45 (eV)Ip (the surface of the photoconductor)5.53 (eV) Relation 2 where Ip (the surface of the photoconductor) represents the ionization potential of the surface of the photoconductor and Ip (the surface of the toner) represents the ionization potential of the surface of the toner.

A developing cartridge includes: a housing extending in a first direction; a developing roller; a memory held at the housing; a holder holding an electrical contact surface; and a relay component electrically connecting the memory to the electrical contact surface. The developing roller is rotatable about an axis extending in the first direction. The developing roller is positioned at one end portion of the housing in a second direction. The holder is movable relative to the housing in at least one of the second direction and a third direction crossing the first direction and the second direction. The third direction also crosses the electrical contact surface.

An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

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.

An image forming apparatus includes an image bearing member unit; a developing unit; an accommodating portion configured to accommodate the image bearing member unit and the developing unit and provided with an inserting opening; a door for the opening; a pressing mechanism for pressing and releasing the image bearing member unit and the developing unit relative to each other in interrelation with the openable member; and a contact surface provided on the openable member, the contact surface is contactable with an upstream end portion of one of the units, when the openable member is closed in a state that the upstream end portion is projected out of the opening, wherein an angle formed between a normal line of the contact surface and the inserting direction in a downstream side is not less than 90 degrees.