A process cartridge includes a frame, a photosensitive drum supported by the frame, a developing roller supported by the frame, and a coupling operatively connected to the photosensitive drum. A helical gear is positioned at the side of the process cartridge, the helical gear being rotatable about an axis thereof. A stopper is positioned at the side of the process cartridge, with the stopper having a surface extending in an axial direction of the photosensitive drum and facing the axis of the photosensitive drum. As measured in an axial direction of the photosensitive drum, at least a part of exposed teeth of the helical gear is positioned farther an end of the photosensitive drum than a tip of the projection of the coupling is positioned from the end of the photosensitive drum.

An example cartridge may be detachably attached to a main body of an image forming apparatus. The cartridge includes a rotation member and a driven coupler to receive a rotation force to rotate the rotation member. The driven coupler includes a power transmission member connected to the rotation member, an extension member extending from the power transmission member and including an outer diameter portion, a hollow portion, and a through portion, a protrusion member located at the hollow portion and movable between a protrusion position for receiving the rotation force and a retreat position, a switching member inserted into the hollow portion and movable between first and second positions for locating the protrusion member at the protrusion position and the retreat position, respectively, and an elastic member to apply an elastic force to the switching member in a direction for location at the second position.

A developing cartridge and an electronic imaging apparatus, where the developing cartridge is detachable installed in the electronic imaging apparatus, and includes a cartridge, a power reception member, a rotary member and an activation member; the cartridge includes a first side wall and a second side wall provided opposite to each other along a first direction, where a power reception member is located at the first side wall, a rotary member is installed between the first side wall and the second side wall, one end of the rotary member is provided with a first gear, and the other end of the rotary member is provided with a second gear, an activation member is located at the second side wall; and the activation member includes a movable member and a trigger part provided at the movable member.

A developing cartridge includes: a developing roller rotatable about an axis extending in a first direction; a casing having a first outer surface and a second outer surface spaced apart from each other in the first direction; a first separation member positioned at the first outer surface; and a second separation member positioned at the second outer surface. The second separation member has a first end portion configured to contact a body-side cam of an image-forming apparatus. In a state where a drum cartridge is attached to an apparatus body of the image-forming apparatus in an attached state of the developing cartridge to the drum cartridge, the first separation member is pressed by a drum cam of the drum cartridge, and the first end portion of the second separation member is pressed by the body-side cam to move the developing roller from a contacting position to a separated position.

A developing cartridge includes: a developing roller; a coupling for rotating the developing roller; a shaft; and a clutch. The developing roller is rotatable about a first axis extending in an axial direction. The coupling is rotatable about a second axis extending in the axial direction. The shaft rotatably supports the coupling. The clutch is rotatable together with the coupling about the shaft in a case where the coupling rotates in a first rotational direction. In a case where the coupling rotates in a second rotational direction opposite to the first rotational direction, the clutch engages with a portion of the shaft and the clutch and the coupling do not rotate.

An image carrier unit includes an image carrier including a cylindrical main body portion and a pair of flange portions attached to both ends of the main body portion, a first cleaning member that rotates in contact under a prescribed pressure with an outer circumferential surface of the main body portion, a unit frame that rotatably supports the image carrier and the first cleaning member, and an image carrier protective cover that includes a cover main body extending in an axial direction of the image carrier and a side surface portion that is disposed on one end side of the cover main body. On the side surface portion, an image carrier holding portion is formed that performs positioning of the image carrier with respect to the unit frame and releases a pressure contact state between the image carrier and the first cleaning member.

A drum unit usable with a process cartridge includes a photosensitive drum having an axis L1; and a coupling member having an axis L2 and connected to an end portion of the photosensitive drum, the coupling member being provided with a projection extending toward an end portion of the coupling member, wherein the coupling member is movable along the axis L2 between a first position, and a second position in which the projection is closer to the photosensitive drum than in the first position, wherein the projection is provided with a force receiving portion for receiving a rotational force and an outer surface facing away from the axis L2, and wherein at least a part of the outer surface is more distant from the axis L2 as is further from the photosensitive drum in a direction of the axis L1.

A process cartridge including: a photosensitive member cartridge including a photosensitive member; and a developing cartridge including a developer carrier. The developing cartridge further includes: an inputting portion; a first cover; and a second cover. The first cover has a first engagement portion configured to move the developer carrier away from the photosensitive member. The first engagement portion is positioned between an axis of the developer carrier extending in an axial direction and an axis of the inputting portion extending in the axial direction, when projected in the axial direction. The second cover has a second engagement portion configured to move the developer carrier away from the photosensitive member. The second engagement portion is positioned between the axis of the developer carrier and the axis of the inputting portion, when projected in the axial direction.

A cartridge includes a drum unit and a development unit. The drum unit includes a photosensitive drum, a frame, a transfer roller, and a cleaning member. The development unit includes a development roller, and a memory. The cleaning member is configured to come into contact with the photosensitive drum at a region between a development nip portion and a transfer nip portion in a circumferential direction of the photosensitive drum and at an end portion of the photosensitive drum in a direction of the rotational axis. The frame has an exposing hole through which the memory is exposed from the frame, and a recessed portion that is adjacent to the exposing hole in the direction of the rotational axis, and stores foreign matters removed from the photosensitive drum by the cleaning member.

A developing cartridge includes: a casing; a developing roller; a shaft; and a cam. The casing is configured to accommodate developer therein. The developing roller is rotatable about a first axis extending in an axial direction. The shaft extends along a second axis extending in the axial direction. The shaft is movable along the second axis. The cam is movable along the second axis in response to axial movement of the shaft. The cam has a cam surface non-parallel with the second axis.