A developing cartridge includes: a developing roller; a coupling for rotating the developing roller; a shaft; and a clutch. The developing roller is rotatable about a first axis extending in an axial direction. The coupling is rotatable about a second axis extending in the axial direction. The shaft rotatably supports the coupling. The clutch is rotatable together with the coupling about the shaft in a case where the coupling rotates in a first rotational direction. In a case where the coupling rotates in a second rotational direction opposite to the first rotational direction, the clutch engages with a portion of the shaft and the clutch and the coupling do not rotate.

A cartridge includes a developing roller and a coupling member for receiving a rotational force for rotating the developing roller. The cartridge also includes a frame having a bearing configured to rotatably support the cylinder and a regulating wall capable of regulating movement of the coupling member by contacting the coupling member. A spring presses the coupling member to contact the regulating wall, and the bearing encompasses the regulating wall as seen along a rotational axis of the cylinder.

A developer container includes a frame having a developer storage chamber which stores a conveying member, a developing chamber in which a developer bearing member and a supplying member are arranged, a partition partitioning the developer storage chamber and the developing chamber and provided with a first opening, and a second opening which connects an interior of the developing chamber and an exterior of the frame. A filter allows passage of air and restricts passage of the developer, with the filter being fixed to the frame so as to cover the second opening. The conveying member is deformable such that the developer is conveyed from the developer storage chamber to the developing chamber via the first opening by deformation of the conveying member being released, and the conveying member conveys the developer such that the developer passes above the supplying member.

Provided are a developing roll for an electrophotographic device and a method for manufacturing a developing roll for an electrophotographic device, with which toner fusion and toner filming are suppressed. A developing roll for an electrophotographic device includes a shaft body and an elastic body layer formed on an outer circumference of the shaft body. The surface of the elastic body layer has a plurality of large protruding parts having a width of 3.0 to 12 μm and a height of 3.0 to 12 μm, and the side surface of the large protruding part 16 has a plurality of small protruding parts which form convex-concavity having a ten-point average roughness Rz of 2.0 to 4.0 μm.

A developing cartridge includes a casing, a developer-carrying member, a supply member, a developing electrode, a supply electrode, and an insulating member. The casing is configured to accommodate therein developer. The developer-carrying member is configured to rotate about a rotational axis and carry the developer thereon. The supply member is configured to supply the developer to the developer-carrying member. The developing electrode is configured to be electrically connected to the developer-carrying member. The supply electrode is configured to be electrically connected to the supply member. The insulating member insulates the developing electrode and the supply electrode with each other. The developing electrode, the insulating member, and the supply electrode are overlapped in this order in an axial direction of the rotational axis.

A developing device includes a developer roller to rotate in a rotation direction, a photosensitive body adjacent the developer roller, and an air flow passage extending through a non-image forming region at a longitudinal end of the developer roller. A closest position is defined where the developer roller and a photosensitive body are closest to one another. The air flow passage extends from inside the developing device and forms an air flow directed toward an upstream side of the closest position, relative to the rotation direction of the developer roller.

An image forming apparatus includes a developing roller, a motor, a motor control portion configured to control the motor, a drive switching unit configured to switch between transmission and non-transmission of the rotational driving force of the motor relative to the developing roller, a current detection portion configured to detect a current value of a current to the motor, and an acquisition unit configured to acquire information relating to a rotation amount of the developing roller. The acquisition unit is configured to acquire the information relating to the rotation amount of the developing roller on the basis of a transmission timing at which the rotational driving force is allowed to be transmitted to the developing roller by the drive switching unit and a non-transmission timing at which the rotational driving force is prevented from being transmitting to the developing roller by the drive switching unit.

A developing cartridge includes a developing frame body rotatably supporting a developing roller. A first end member is attached to the first end of the developing frame and a second end member is attached to the second end of the developing frame body. The first end member and the second end member are rotatable independently of each other and relative to the developing frame body about a rotational axis common to the first end member and the second end member, and with rotation of the developing frame body relative to the first end member and the second end member, the developing roller moves from a first position to a second position in a direction that crosses a position of an axis of the developing roller when the developing roller is in the first position.

An image forming apparatus has a normal image formation mode and a wide color gamut image formation mode in which an amount of a developer per unit area of a developer image of at least a color that differs from a prescribed color among a plurality of colors is increased as compared to the normal image formation mode. Image data is generated such that an image portion formed in the prescribed color in an image formed on a recording material is formed solely by a developer image of the prescribed color in the normal image formation mode, but formed by superimposing a developer image of a color that differs from the prescribed color on a developer image of the prescribed color or formed solely by a developer image of a different color in place of a developer image of the prescribed color in the wide color gamut image formation mode.

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.