It is an object of the present invention to provide an electrophotographic photosensitive member capable of suppressing the environmental fluctuation in the electrical characteristics. The present invention provides the electrophotographic photosensitive member in which the surface layer contains the compound having the specific structure.

A printing drum mounting system and method of assembling the mounting system. The mounting system comprising a rotatable shaft; a first mount and a second mount arrangeable on the shaft to clamp a printing drum therebetween, wherein the first mount comprises a first engaging surface to form a mating contact with a corresponding first end surface of the printing drum and the second mount comprises a second engaging surface to form a mating contact with a corresponding end surface of the printing drum; a double-walled flexure to flexibly mount the first engaging surface and the shaft, the flexure to provide the first engaging surface with a single degree of freedom of axial movement relative to the shaft and to maintain mating contact between the first engaging surface and the first end surface of the printing drum as the printing drum thermally expands and contracts; and a releasable fixing to align and rigidly engage the second engaging surface relative to the shaft.

An image forming apparatus includes a drum cartridge and developing cartridge. The drum cartridge may include a photosensitive drum rotatable about a first axis extending in an axial direction. The developing cartridge may include a developing roller rotatable about a second axis extending in the axial direction. The image forming apparatus may include a main casing including a slot extending in the axial direction. The image forming apparatus may include a first inner surface positioned inside of the slot, and a second inner surface positioned inside of the slot farther from the cover in the axial direction than the first inner surface from the cover in the axial direction. The first and second inner surfaces may be configured to press the developing roller toward the photosensitive drum.

A drum unit detachably mountable to a main assembly of an electrophotographic image forming apparatus includes a photosensitive drum and a coupling member provided on the photosensitive drum. The coupling member includes a driving force receiving portion and a supporting portion movably supporting the driving force receiving portion. The supporting portion includes a first extended portion and a second extended portion which extend at least in an axial direction of the photosensitive drum.

Provided is an electrophotographic electroconductive member, including: an electroconductive support; an electroconductive layer; and a surface layer in order, wherein an impedance is 1.0×10.sup.3Ω to 1.0×10.sup.8Ω at an outer surface of the electroconductive member, in the surface layer, an electronic electroconductive agent is dispersed, the electroconductive layer has a matrix containing a cross-linked product of a first rubber and domains each containing a cross-linked product of a second rubber and electroconductive particles, and wherein, and wherein among the domains observed in specified observation regions, 80% by number or more of the domains satisfy (1) and (2): (1) a proportion of sectional areas of the electroconductive particles with respect to the domain is 20% or more; (2) A/B is 1.00 to 1.10 when A is a perimeter of the domain and B is an envelope perimeter.

An electrophotographic photoreceptor includes an electrically conductive substrate, and a laminate-type photosensitive layer formed on the electrically conductive substrate. An allowable range of a charging voltage Vx to be applied to the electrophotographic photoreceptor by a charging device is V.sub.0−150≤V.sub.x≤V.sub.0+150, and an electrostatic capacitance per unit area of the electrophotographic photoreceptor is 90 pF/cm.sup.2 or more. VO is an initial charging voltage applied to the electrophotographic photoreceptor. Also, an image forming apparatus and an image forming cartridge can be provided with the electrophotographic photoreceptor.

A process cartridge which allows any spot and stripe as image defects to be suppressed is provided. A process cartridge, in which an electroconductive layer of a charging member has a matrix including a first rubber, and domains dispersed in the matrix, the domains include a second rubber and an electron electroconductive agent, at least some of the domains are exposed on a surface of the charging member, when a volume resistivity of the matrix is 10.sup.5 times or more a volume resistivity of the domains, a protective layer of an electrophotographic photosensitive member includes a metal oxide particle, and when a number average primary particle size of the metal oxide particle is defined as Sm and an average value of equivalent circle diameters of the domains is defined as Sd, the Sd/Sm satisfies the following expression (1): 0.5<Sd/Sm<100 . . . expression (1).

Examples include an end cap system for a developer unit in a liquid photographic printer. The end cap system includes an end cap and a film that includes a first outermost superficial layer and a second outermost superficial layer opposed to the first outermost superficial layer. The first outermost superficial layer is a pressure sensitive adhesive layer applied to a portion of an inner surface of the end cap. The second outermost superficial layer is a low surface energy layer to be exposed to liquid photographic printing fluid during printing.

An image forming apparatus includes first and second image forming portions and a belt. The first and second image forming portions include first and second image bearing members, and first and second transferring members, respectively. The belt nips and feeds a recording material between itself and the first image bearing member and between itself and the second image bearing member in a first transferring portion and a second transferring portion, respectively. The first image forming portion is disposed upstream of the second image forming portion in a moving direction of the recording material, and a plurality of members including the first and second image bearing members are integrally assembled and are mountable on or dismountable from a main assembly of the image forming apparatus. A film thickness of a surface of the first image bearing member is larger than a film thickness of a surface of the second image bearing member.

A process cartridge including: an electrophotographic photosensitive member having a drum shape; a developing unit for developing an electrostatic latent image on the surface of the electrophotographic photosensitive member with toner; and a cleaning blade for removing the toner on the surface of the electrophotographic photosensitive member, the cleaning blade being in contact with the electrophotographic photosensitive member, wherein the electrophotographic photosensitive member comprises wrinkles on the surface of the electrophotographic photosensitive member, and wherein the toner has a fluidity torque E of 320 mJ or more.