There are demands for stable connections of contact points between a process cartridge, including a development device, and an image forming device. A development contact point, a first contact point, and a second contact point are disposed in this order on the inside in a perpendicular direction with respect to an insertion direction in which a development device is inserted into an image forming apparatus.

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.

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 casing; a developing roller extending in a first direction; a boss movable with the casing; and a first lever movable relative to the casing. The first lever includes: one end portion functioning as a point of effort; another end portion functioning as a point of load; a shaft functions as a fulcrum and positioned between the one end portion and the another end portion; and a first hole into which the boss is fitted. By the one end portion receiving a driving force, the first lever is pivotally movable about the shaft. A dimension of the first hole in a second direction crossing the first direction is greater than a dimension in the second direction of the boss. In a case where the casing moves in the second direction relative to the first lever, the boss moves in the second direction within the first hole.

Movement and/or urging of a developer carrying member is carried out with high precision. A cartridge that is mountable to an apparatus main assembly of an image forming apparatus, the cartridge includes a developing roller; a frame supporting the developing roller; a movable part movably supported by the frame and movable to a first position and to a second position relative to the frame; and an elastic part provided between the frame and the movable part to urge the movable part. The movable part includes a first force receiving part that receives force from the apparatus main assembly, in a direction of moving from the first position to the second position, and a second force receiving part that receives force from the apparatus main assembly, in a direction of moving from the second position to the first position. When the movable part receives force from the apparatus main assembly at the first force receiving part and is at the second position, the movable part receives urging force from the elastic part in a direction of moving the movable part from the second position to the first position.

A developing roller is located nearer a first end than a second end in a first direction. A first boss extends in a second direction and is movable together with a housing. The first boss bears the weight of a developer cartridge when the first boss is supported by a support surface of a first side plate of a drum unit, and is located away from the developing roller in the first direction and the third direction. A first pressure receiving surface is located farther away from the developing roller than the first boss in the third direction. The pressure receiving member receives a pressing force in the third direction from a pressing member of the first side plate of the drum unit. The first boss is located away from the developing roller in the first direction by a first distance. The first pressure receiving surface is located away from the developing roller in the first direction by the first distance or by a second distance smaller than the first distance.

A process cartridge comprises a photosensitive drum and a developing roller. A coupling member is provided adjacent to one axial end of the developing roller. The coupling member includes a driven portion, and an intermediary portion configured and positioned to engage with the driven portion. The intermediary portion is also configured to be movable relative to the driven portion in a direction crossing the axis of the developing roller while maintaining engagement with the driven portion. The coupling member further includes a driving portion configured and positioned to receive a driving force for rotating the developing roller. The driving portion is also configured to engage with the intermediary portion, and to be movable relative to the intermediary portion in a direction crossing the axis of the developing roller while maintaining engagement with the intermediary portion.

In an image forming apparatus having a drum unit and a developing unit attachable to or detachable from an apparatus body, when the drum unit is inserted into or removed from the apparatus body, operation in the following first to third sections occurs in order or reverse. The first section is a predetermined section on a removal side from the innermost position of the drum unit. In the first section, the developing unit is inserted/removed integrally with the drum unit. In the second section, only the drum unit is inserted or removed. Meanwhile, the developing unit gradually rotates to switch the contact or separated states in conjunction with the insertion or removal of the drum unit. In the third section, only the drum unit is inserted into or removed from the apparatus body while the developing unit is separated.

A developing cartridge includes: a developing roller rotatable about an axis extending in a first direction; a casing; a first cam and a first gear rotatable together relative to the casing about a first axis extending in the first direction; and a second cam and a second gear rotatable together relative to the casing about a second axis extending in the first direction. The second gear contacts the first gear. When the developing cartridge is attached to a drum cartridge including a photosensitive drum: at a first position of the first cam, the second cam is at a third position and the developing roller and the photosensitive drum contact each other; and at a second position of the first cam, the second cam is at a fourth position and contacts a part of the drum cartridge to move the developing cartridge to separate the developing roller from the photosensitive drum.

An image forming apparatus includes a drum unit, a developing device, a development holder, and a sliding member. The drum unit includes a photosensitive drum. The developing device includes a developing roller. The development holder is swung so as to bring and separate the developing roller close to and apart from the photosensitive drum. The sliding member is slidable in an axial direction of the developing roller. The development holder is swung so as to bring the developing roller close to the photosensitive drum in association with a sliding of the sliding member from a first position to a second position, and the development holder is swung so as to separate the developing roller apart from the photosensitive drum in association with a sliding of the sliding member from the second position to the first position.