A sliding bearing is made of a resin and includes a tubular portion that includes an outer peripheral surface including a D-cut surface. A flange portion, which protrudes from the D-cut surface, is formed at one end portion of the tubular portion. An engagement portion is formed at the other end portion of the tubular portion. A protruding portion is formed on the outer peripheral surface of the tubular portion at a circumferential position that is outside a region in which the D-cut surface is formed and that is outside a region in which the engagement portion is formed.

An image forming apparatus, having a cartridge and a main body, is provided. The cartridge has a cartridge-side coupling to transmit a driving force to a drivable member in the cartridge. The cartridge is detachably attached to the main body. The main body includes a body-side coupling movable between a connecting position, at which the body-side coupling is connected with the cartridge-side coupling, and a separated position, at which the body-side coupling is separated from the cartridge-side coupling; a joint cam movable between a first position, at which the joint cam locates the body-side coupling at the connecting position, and a second position, at which the joint cam locates the body-side coupling at the separated position; and a rotator having a dent. The dent allows entry of an end portion of the joint cam there-into when the joint cam is located at the first position.

[TASK] An object of the present invention is to provide an image developing apparatus and a process cartridge with which an image quality can be improved while reducing a number of parts and reducing an amount of remaining developer. [SOLUTION] A process cartridge detachably mountable to an electrophotographic image forming operators includes a developing chamber including a developing roller and a developer supplying roller; a developer accommodating container accommodating the developer provided below the developing chamber with respect to gravity direction, wherein the developer is fed into the developing chamber while being stirred by a feeding member. The developer supplying roller rotates such that a surface thereof moves in the same direction as a surface of the developing roller at a position where the developer supplying roller contacts the developing roller. A surface speed of the developer supplying roller is higher than a surface speed of the developing roller. The developer supplying roller is rotationally driven by receiving a driving force at a position upstream of the developing roller.

A drive transmission device includes an intermediate gear, a housing portion, and a support portion. The intermediate gear meshes with a first gear and a second gear to transmit a rotational driving force from the first gear to the second gear. The housing portion is formed from resin and includes a pair of cover portions, covering both sides of a gear train including the intermediate gear, to house the gear train. The support portion is formed from metal and supports the rotation shaft of the intermediate gear at a position outside the housing portion.

A developer storage container includes a storage portion, a communication portion, and a gear portion. The storage portion conveys developer stored therein in a conveying direction parallel to a rotation axis by being rotated around the rotation axis in a specific direction. The communication portion has a tubular shape coaxial to the rotation axis and extending in the conveying direction from an end of the storage portion on a downstream side in the conveying direction, includes an inner peripheral part that gradually increases its diameter in the conveying direction, and connects the storage portion to an opening portion that has an opening facing the conveying direction. The gear portion is provided for an outer peripheral part of the communication portion and receives a rotational driving force supplied from the outside.

An image forming apparatus is provided. The image forming apparatus for selectively feeding printing media to an image former of a main body through a cassette and a multipurpose tray includes a tray feeder configured to feed printing media placed in the multipurpose tray, a cassette feeder configured to feed printing media placed in the cassette, a power train configured to transmit power generated from a driving motor, and a power switching unit configured to transmit power transmitted to the power train to the tray feeder or the cassette feeder as the multipurpose tray is moved to a use position or a non-use position.

To provide a structure for the process cartridge for receiving input of driving force from outside thereof.

The main assembly of the electrophotographic image forming apparatus includes a driving output member provided with an output gear portion and an output coupling portion. The process cartridge that can be mounted to and dismounted from the main assembly of the electrophotographic image forming apparatus includes a photosensitive member, an input coupling portion provided at the end of the photosensitive member and capable of coupling with the output coupling portion, and an input gear portion capable of meshing with the output gear portion.

An example image forming apparatus includes a frame, a first shaft supported by the frame, and a first coupler. The first coupler includes a body coupled to one end of the first shaft and a first protrusion protruding from the body in an axial direction of the first shaft, the first protrusion having a first surface and a second protrusion protruding from the first surface. The second protrusion is to lock with a groove to mount a cartridge on the frame, the first shaft is to provide a rotational force in a first rotational direction to rotate the second protrusion of the first coupler and to insert the second protrusion into the groove to lock with the cartridge, and the first surface of the first protrusion of the first coupler is to contact a second surface to transmit the rotational force to the second coupler in the first rotational direction.

In an image formation device, a driven gear is coupled to a far end portion in a unit inserting and withdrawing direction of a rotary fixing member or a rotary pressure member of a fixing unit. A driving gear is provided in a far end portion of a fixing unit housing part and engages with the driven gear when the fixing unit is housed in the fixing unit housing part. The driving gear and the driven gear are formed so that a transmission force transmitted from the driving gear to the driven gear in a mutual engagement position has a component so directed as to horizontally press the fixing unit against columns making a pair. The fixing unit as housed in the fixing unit housing part is pressed by the transmission force against the columns and positioned in a direction orthogonal to the unit inserting and withdrawing direction.

A driving-force transmission member includes a coupling portion that includes a driving-force transmission surface and that transmits a driving force to a cartridge coupling, a first helical gear portion that engages with a driven gear of a cartridge to transmit the driving force, and a second helical gear portion that engages with a drive gear to receive the driving force. The portions rotate integrally with each other when the driving-force transmission member rotates about the axis of rotation. The driving-force transmission surface is shaped with a twist in the same direction as the driving-force transmission member. Helical teeth of the first helical gear portion are shaped with a twist in the same direction as the driving-force transmission surface. Helical teeth of the second helical gear portion are shaped with a twist in a direction opposite to the twist direction of the helical teeth of the first helical gear portion.