A developing cartridge including a casing, a developing roller, a developing roller gear, a gear cover, a first boss, and a pressure receiving surface. The developing roller is positioned closer to a first end portion of the casing than to a second end portion of the casing in a first direction. The first boss extends in a second direction and is movable together with the casing. The first boss is positioned away from the developing roller in the first direction by a first distance and also positioned away from the developing roller in a third direction. The pressure receiving surface is positioned further from the developing roller than the first boss is from the developing roller in the third direction. The pressure receiving surface is positioned away from the developing roller by the first distance or by a second distance shorter than the first distance.

A transmitting assembly of a toner cartridge is provided. The transmitting assembly comprises a gear member, a tubular member disposed at the gear member and having an axial hole, an axial member provided with a shaft portion inserting into the axial hole and a head portion, an elastic member applying force on the axial member away from the gear member, two engaging claws provided with body portions disposed at the head portion and claw portions located at the body portions, and a torsional member connected with the engaging claws and applying force turning the engaging claws outward. The claw portions are located at two sides of the axial member, and abutting ends of the body potions are located at a center of the head portion. Accordingly, the transmitting assembly can be engaged with and separated from a driving member of an electronic image forming apparatus with ease and smoothness.

A toner conveying device that conveys toner. The toner conveying device includes a housing, a toner guide portion, and at least two vibration motors. The housing has, in its inside, a toner conveyance path. The toner guide portion is provided in the housing and includes an opening through which toner flows in or out, and a guide passage communicating between the opening and the toner conveyance path. The at least two vibration motors apply vibrations to the toner guide portion. The vibration motors are started at different timings, and driven and controlled by drive signals in which a first pulse and a second pulse of different pulse widths alternately continue.

A process cartridge comprises an electrophotographic photosensitive drum having a photosensitive layer at a peripheral surface thereof, and process means actable on the electrophotographic photosensitive drum. The process cartridge also includes a coupling member 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.

An example image forming apparatus includes a main body, a driving motor rotatable in a first direction to provide a driving force to a developing cartridge and rotatable in a second direction opposite to the first direction, and a support assembly to, based on the developing cartridge being mounted to the main body, provide the driving force of the driving motor in the first direction to the mounted developing cartridge, and detach the mounted developing cartridge from the main body using the driving force of the driving motor in the second direction.

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 nondrive-side side member forms a part of a cartridge and includes a frame portion, and a regulation frame portion provided in the frame portion, to regulate movement of the cartridge. The frame portion has a hole provided to expose an electric contact. Further, a drive-side side member forms a part of a cartridge and includes a frame portion having a first hole and a second hole with a diameter larger than a diameter of the first hole, and a slit portion into which a memory for storing information is to be inserted.

An image forming apparatus includes a main body including a first guide portion and a second guide portion, a process cartridge including a photosensitive drum, a support frame configured to support the process cartridge and move between an inside position and an outside position. The support frame includes a first side frame. The first side frame includes a first guided portion to be guided by the first guide portion. The second side frame includes a second guided portion guided by the second guide portion A dimension of the first side frame is greater than or equal to a dimension of the first side frame. A dimension of the second side frame is greater than or equal to a dimension of the second side frame.

The present invention provides a cartridge which is dismountable from the main assembly without deteriorating usability performance in a predetermined direction substantially perpendicular to the rotational axis of an image bearing member, the main assembly being not provided with the mechanism for moving the main assembly side engaging portion in the rotational axis direction in response to the opening and closing operation of the main assembly cover of the main assembly.

With the movement of the cartridge in such a direction perpendicular to the rotational axis of the image bearing member in the dismounting of the cartridge from the main assembly of the electrophotographic image forming apparatus, the coupling member movable in a direction parallel with the rotational axis of the image bearing member enters a inside of a recess of the main assembly side engaging portion provided in the main assembly of the apparatus to receive a rotational force from the main assembly side engaging portion.

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.