An image forming apparatus, having a first photosensitive drum, a first developing roller, a first shifting member movable between a contacting position and a separating position, a motor, a first joint, a first clutch operable in one of a transmittable condition and a discontinuing condition, a first shifting cam rotatable between a first position, in which the first shifting cam locates the first shifting member at the contacting position, and a second position, in which the first shifting cam locates the first shifting member at the separating position, and a first switching cam rotatable between a third position, in which the first switching cam places the first clutch in the transmittable condition, and a fourth position, in which the first switching cam places the first clutch in the discontinuing condition, alongside the first shifting cam rotating between the first position and the second position, is provided.

A rotating force transmitting part for an electrophotographic photosensitive drum for a main assembly of the electrophotographic image forming apparatus, wherein the main assembly of the electrophotographic image forming apparatus includes a driving shaft, to be driven by a motor, having the rotating force applying portion, and wherein the electrophotographic photosensitive drum is dismountable from the main assembly of the electrophotographic image forming apparatus in a direction substantial perpendicular with an axial direction of the driving shaft, the rotating force transmitting part includes a coupling member engageable with the rotational force applying portion to receive a rotational force for rotating the electrophotographic photosensitive drum in the state in which electrophotographic photosensitive drum is mounted to the main assembly of the electrophotographic image forming apparatus, wherein the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the electrophotographic photosensitive drum to the electrophotographic photosensitive drum and a disengaging angular position in which the coupling member is inclined away from the axis of the electrophotographic photosensitive drum from the rotational force transmitting angular position, wherein when the process cartridge is dismounted from the main assembly of the electrophotographic image forming apparatus in a direction substantially perpendicular to the axis of the electrophotographic photosensitive drum, the coupling member moves from the rotational force transmitting angular position to the disengaging angular position.

A developing device may include an auger or an agitator that is capable of supplying toner in a toner accommodation chamber to a developing chamber and is rotatable about an auger axis extending in an axial direction, a transporting gear that is rotatable together with the auger or the agitator, and a moving gear that is in mesh with a coupling gear and is rotatable both counterclockwise and clockwise. The moving gear is movable while being in mesh with the coupling gear between a first position where the moving gear is in mesh with the transporting gear and a second position where the moving gear is out of mesh with the transporting gear. The moving gear moves to the first position when the coupling gear rotates counterclockwise and to the second position when the coupling gear rotates clockwise.

A cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the cartridge includes (i) a rotatable developing roller for developing a latent image formed on a photosensitive member; (ii) a first drive transmission member capable of receiving a rotational force originated by the main assembly; (iii) a second drive transmission member capable of coupling with the first drive transmission member and capable of transmitting the rotational force received by the first drive transmission member to the developing roller; and (iv) a coupling disconnection member including a force receiving portion capable of receiving the force originated by the main assembly, and an urging portion capable of urging at least one of the first drive transmission member and the second drive transmission member by the force received by the force receiving portion to separate one of the first drive transmission member and the second drive transmission member from the other, thereby disconnecting the coupling.

A direction in which a first drive transmission gear urges a first drive gear using a first urging portion when a drive force is not input to a first drive input portion is defined as a first direction. A direction in which a second drive transmission gear urges a second drive gear using a second urging portion when a drive force is not input to a second drive input portion is defined as a second direction. The second direction has a force component in a direction opposite to the first direction with respect to a straight line connecting a rotation center of the first drive gear and a rotation center of the second drive gear.

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.

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 cartridge includes a photosensitive drum, a development roller, a cartridge side gear, a movable member and a restricting portion. The cartridge is constituted such that when the cartridge side gear and a drive transmission member of a main assembly of an image forming apparatus are engaged with each other, the drive transmission member and a cover covering the drive transmission member is accommodated in a space surrounded by the restricting portion, the movable member and the cartridge side gear. the space includes, in a range downstream of the restricting portion and upstream of the cartridge side gear, a region in which a distance from the axis of the photosensitive drum exceeds Ra which is a distance from the axis of the photosensitive drum to the restricting portion. The cartridge is structured to accommodate the cover in the region.

A developing cartridge includes: a developing roller; a casing having an outer surface; a first shaft rotatable about a rotational axis; a first arm; and a cam. The first arm and the cam extend radially outward from an outer periphery of the first shaft and pivotally movable along with rotation of the first shaft. The cam has: one end connected to the first shaft; another end positioned farther from the rotational axis than the one end is farther from the rotational axis; and a pressure contact surface inclined so as to approach the outer surface of the casing as extending from the one end toward the another end. When a pressing force is applied to the pressure contact surface, the first arm pivotally moves from a first position to a second position along with: pivotal movement of the cam; and the rotation of the first shaft.

Power receiving unit and process cartridge are provided. The power receiving unit of a process cartridge is detachably mounted in an image formation apparatus configured with a power output unit that is swingable. An outer circumference of the power output unit contains a recessed portion, and the power receiving unit is engaged with the power output unit to receive a driving force. The power receiving unit includes a protrusion. The protrusion is disposed inside the power receiving unit. The protrusion is engaged with the recessed portion of the power output unit to receive the driving force. When the power receiving unit moves along an axial direction thereof and is in a contact engagement with the power output unit, the protrusion abuts against a front end of the power output unit to cause the power output unit to be tilted and swung.