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 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.

In a cartridge structure employing an inclinable coupling member engaging with a rotational force transmitting portion of an electrophotographic image forming apparatus, the coupling member is unable to engage with the rotational force transmitting portion of the electrophotographic image forming apparatus when the mounting and dismounting direction and the developing/spacing direction relative to the electrophotographic image forming apparatus of different from each other. Under the circumstances, a coupling lever contacting and retracting relative to the coupling member in interrelation with the mounting and dismounting operation of a developing cartridge B1, and a coupling spring for the coupling lever to apply an urging force to the coupling member are provided.

Movement and/or urging of a developer carrying memer 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 process cartridge includes a photosensitive drum; a developing roller; a developer supplying roller, provided in contact with the developing roller; a driving force receiving portion provided at a shaft end of the supplying roller; a first driving force transmitting portion; a second driving force transmitting portion; flexible sheets provided adjacent to an engaging portion between the first portion and the second portion to intermittently contact the second portion with rotation of the second portion, wherein a rotational direction of the roller is opposite to that of the roller, and a peripheral speed of the roller is larger than that of the roller.

Provided is a drive head (40), a drive assembly (20), and a process cartridge (10), wherein the drive head (40) is mounted to a gear (12), the drive head (40) comprises a shaft part (16), a claw (15), and a first elastic element (14), and the shaft part (16) is sleeved by the claw (15) which can move stretchably along the shaft part. The drive head (40), drive assembly (20), and process cartridge (10) have the advantage that the drive head (40) is hard to falling off.

An image forming apparatus, including a casing, a toner cartridge, and a process cartridge, is provided. The toner cartridge detachably attached to the casing stores toner therein. The process cartridge detachably attached to the casing includes a developing unit and a drum unit. The developing unit includes a developer roller and a toner conveyer tube. The toner conveyer tube has a first opening, through which the toner from the toner cartridge is acceptable into the toner conveyer tube while the toner cartridge and the process cartridge are attached to the casing. The drum unit includes a photosensitive drum supporting the toner conveyer tube by contacting a circumferential surface of the toner conveyer tube. The developing unit is pivotable with respect to the drum unit with the toner conveyer tube and the drum unit being slidable on each other.

A universal coupler includes: a driving shaft, a coupler holder, driving coupler, a driving coupling pin, and an elastic member. The driving shaft has a driving shaft a first pin hole. The coupler holder includes a bore, a separation prevention member that partially blocks the bore, and a coupling groove formed in the bore. The driving coupler includes a spherical portion that is located in the bore and in contact with the separation prevention member, a shaft insertion portion formed through the spherical portion, and a second pin hole that penetrates the spherical portion. The driving coupling pin is insertable into the driving pin hole, and has an end insertable into the coupling groove. The elastic member applies elasticity to the coupler holder in a direction that urges the spherical portion of the driving coupler against the separation prevention member.

To accomplish engagement between a coupling member and a drive transmission member of main assembly.

A drum unit includes a photosensitive drum and a coupling member which is provided adjacent to an end portion of the photosensitive drum and which is connected with the photosensitive drum so as to be capable of drive transmission. the coupling member is inclinable relative to a rotational axis of the photosensitive drum, and an inclination angle relative to photosensitive drum is reduced with rotational driving operation.

An image forming apparatus includes an apparatus body including a mounting portion, a drive transmission member provided on the apparatus body, and a cover portion configured to cover the drive transmission member. The mounting portion is configured to accommodate a cartridge including an input coupling portion and an input gear portion. The drive transmission member includes an output coupling portion configured to engage with the input coupling portion, and an output gear portion configured to engage with the input gear portion. The cover portion is located between the mounting portion and the drive transmission member and includes a first opening configured to expose the output coupling portion, and a second opening configured to expose the output gear portion.