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.

Provided is an electrophotographic photosensitive member having a satisfactory chargeability and being excellent in fogging suppression. The electrophotographic photosensitive member is an electrophotographic photosensitive member including a surface protective layer, wherein the surface protective layer is a polymerized film of a composition containing a compound having one of an acryloyloxy group or a methacryloyloxy group, a conductive particle, and an organic salt formed of at least one organic cation selected from the group consisting of: imidazolium; pyridinium; pyrrolidinium; piperidinium; a tetraalkylammonium; and a tetraalkylphosphonium, and at least one anion selected from the group consisting of organic or inorganic anions, and wherein the content of the organic salt is 0.1 mass % to 10.0 mass % with respect to the total mass of the conductive particle.

Provided is an electrophotographic photosensitive member including a support, a photosensitive layer, and a surface layer, wherein the surface layer includes a cured product of a composition containing at least one selected from the group consisting of: a charge-transportable compound; and electroconductive particles, and an organic salt having a polymerizable functional group, and wherein the organic salt is formed of an organic cation and at least one anion selected from the group consisting of: an organic anion; and an inorganic anion.

A drum cartridge includes: a photosensitive drum rotatable about an axis extending in a first direction; a first drum frame to which a developing cartridge is attachable; and a second drum frame having an outer surface; and a memory having an electrical contact surface. The first drum frame is at one end portion of the drum cartridge in a second direction and the second drum frame is at another end portion of the drum cartridge in the second direction. The electrical contact surface is positioned at the outer surface of the second drum frame and is movable in a predetermined direction relative to the second drum frame.

An image-forming apparatus includes: a main casing; a drawer movable in a first direction relative to the main casing; a process cartridge detachably mountable on the drawer; and a toner cartridge. The drawer includes a first drawer side plate and a second drawer side plate spaced apart from each other in a second direction crossing the first direction. The process cartridge includes: a photosensitive drum rotatable about an axis extending in the second direction when the process cartridge is mounted on the drawer; and a developing device for supplying toner to the photosensitive drum. When the process cartridge is mounted on the drawer and the toner cartridge is attached to the process cartridge, the toner cartridge has a length in the second direction greater than a distance in the second direction between the first drawer side plate and the second drawer side plate.

An image forming apparatus, having process units, a transfer unit, a motor, first through fourth cams, a color-linkage gear train, a monochrome-transmission gear train, and a color-transmission gear train, is provided. Each of the process units has a developing unit including a developing roller and a drum unit including a photosensitive drum. The color-linkage gear train rotates the first cam, the second cam, and the third cam in shifted phases. The monochrome-transmission gear train transmits a driving force from the motor to a monochrome clutch, which engages and disengages transmission of the driving force from the monochrome-transmission gear train to the fourth cam. The color-transmission gear train transmits the driving force from the motor to a color clutch, which engages and disengages transmission of the driving force from the color-transmission gear train to the color-linkage gear train.

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.

A cartridge includes a photosensitive drum and a casing rotatably supporting the photosensitive drum. A coupling is operatively connected to the photosensitive drum so as to be capable of transmitting a driving force toward the photosensitive drum. The coupling includes a main body, a movable portion movable relative to the main body of the coupling between a first position and a second position, and a projection configured to move in a circumferential direction of the coupling relative to the main body of the coupling in response to movement of the movable portion from the first position to the second position.

An image forming apparatus includes a photosensitive drum and an apparatus main body, the apparatus main body includes a transfer roller exerting a transfer pressing force on the photosensitive drum, a positioning portion positioning the photosensitive drum in first and second directions by being contacted by a bearing portion holding a rotation axis of the photosensitive drum, the first direction being in a virtual plane perpendicular to the rotation axis, and the second direction being a direction intersecting the first direction, and a pressing member exerting a holding-and-pressing force pressing the bearing portion toward the positioning portion, and, in a state in which the bearing portion is in contact with the positioning portion, the holding-and-pressing force has a component force in the first direction, and the transfer pressing force has a component force in the second direction that is oriented to press the bearing portion toward the positioning portion.

A drive transmitting device includes a first gear; a second gear in engagement with the first gear; wherein a first tooth which is at least one of teeth of the first gear has a tooth surface contacting a tooth of the second gear, wherein the tooth surface has such a shape that a contact point of the first tooth of the first gear to the tooth of the second gear is in a region of a first gear side with respect to a line of action which is formed by movement of a contact point between a tooth of the second gear and a second tooth of the first gear immediately before the first tooth with respect to a rotational moving direction of the first gear.