A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes an electrophotographic photosensitive drum, a developing roller, a drum unit containing the drum, a developing unit containing the roller and being movable so the roller contacts and is spaced from the drum, and a first force receiver receiving a force from a main-assembly first force applier by movement of a door from open to closed positions when mounting the cartridge and a second force receiver movable from a stand-by position by movement of the first force receiver by a force received from the first force applier. The second force receiver takes a projected position receiving a force from the second force applier to move the developing unit so the roller moves out of contact with the drum, the projected position being higher than the stand-by position.

An electroconductive elastic body includes: a cross-linked product of a first ionic electro-conductive rubber, a cross-linked product of a second ionic electro-conductive rubber, and at least one of a fatty acid and a fatty acid metal salt; wherein the electroconductive elastic body has a matrix that includes the cross-linked product of the first ionic electro-conductive rubber, and a domain that includes the cross-linked product of the second ionic electro-conductive rubber; the cross-linked product of the second ionic electro-conductive rubber includes a polyether skeleton; an electrical resistance of the domain is lower than an electrical resistance of the matrix; in a waveform separation profile of the elastic body as obtained by a small-angle X-ray scattering method, A2 and A1 satisfy a relationship expressed by the following expression (1):
0.005≤(A2×C2/A1×C1)≤0.030  (1).

An image forming apparatus includes a body casing, a pressing member, a process cartridge, and a drawer. The body casing includes a positioning member. The pressing member is disposed inside the body casing. The process cartridge includes a photosensitive drum. The drawer is configured to support the process cartridge and to move, in a sliding direction orthogonal to an axis direction of the photosensitive drum, between an inside position that is a position inside the body casing and an outside position that is a position outside the body casing. The process cartridge includes an engagement portion and a spring. The engagement portion is configured to be positioned by the positioning member. The spring is configured to be pressed by the pressing member such that the engagement portion is pressed toward the positioning member.

An image forming apparatus that is capable of executing image forming operation includes an image bearing member; a developer carrying member that faces the image bearing member in a state of keeping a predetermined gap therefrom, and develops a latent image on the image bearing member using developer; a frame that supports the developer carrying member; applying units that applies developing voltage, in which DC voltage and AC voltage are superimposed, to the developer carrying member; a conductive member that is disposed in the frame; a detecting unit that detects AC current induced in the conductive member by applying the developing voltage to the developer carrying member; and a control portion that controls the applying units. The control portion controls the developing voltage in the image forming operation, based on the AC current which the detecting unit detects in a case where the voltage is applied by the applying units.

A fluorine-containing resin particle contains 0 or more and 30 or less carboxyl groups per 10.sup.6 carbon atoms and 0 ppm or more and 3 ppm or less of a basic compound.

An image forming apparatus includes a housing, a top cover having an opening, a process cartridge attachable to the housing, a toner cartridge attachable to the process cartridge, and an interlocking mechanism. The top cover is pivotally movable between a first position closing the opening and a second position opening the opening. In a state where the toner cartridge is attached to the process cartridge, the toner cartridge is pivotally movable between an attachment/detachment position where the toner cartridge is attachable to and detachable from the process cartridge; and a fixed position where the toner cartridge is fixed to the process cartridge. The interlocking mechanism is configured to pivotally move the toner cartridge to the attachment/detachment position when the top cover is moved to the second position, and to pivotally move the toner cartridge to the fixed position when the top cover is moved to the first position.

The present disclosure provides an electrophotographic photoreceptor including, on a conductive base, at least a photoreceptive layer or alternatively at least the photoreceptive layer and a protective layer laminated on the photoreceptive layer, in which both or either one of the photoreceptive layer and the protective layer contains a perimidine compound represented by general formula (I):

##STR00001##

(wherein X represents hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, and m represents an integer of 1 to 6).

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.

An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer on the conductive substrate. The outermost surface layer of the electrophotographic photoreceptor contains fluorine-containing resin particles, a fluorine graft polymer, and an acidic compound having an acid dissociation constant (pKa) of 3 or less in water at 25° C. The amount of the acidic compound relative to the outermost surface layer is 100 ppm or more and 10000 ppm or less.

Provided is a process cartridge detachably attachable to a main body of an electrophotographic apparatus, the process cartridge including: a developing unit including a toner; and an electrophotographic photosensitive member, wherein the toner includes a toner particle, the toner particle has a surface containing a polyvalent acid metal salt particle, and a surface layer of the electrophotographic photosensitive member contains at least one metal oxide particle among an aluminum oxide particle, a silicon dioxide particle, and a tin oxide particle.