Provided is an image forming apparatus, including: an image bearing member; an exposure unit; a developing member which is rotatable at a rotation speed different from the image bearing member; a developer supply member; a developing voltage-applying unit; a supply voltage-applying unit; and a control unit. The control unit controls execution of: an image forming operation in which a developer image is formed by supplying developer on the image bearing member; and a cleaning operation which removes a substance adhered to the image bearing member using the developing member. In the cleaning operation, the control unit controls the developing voltage-applying unit or the supply voltage-applying unit so that the cleaning force using the developing member becomes stronger than that in the image forming operation.

Provided is a developing device including: a toner; and a developer carrying member. The developer carrying member includes an electroconductive substrate and a surface layer on the substrate, the surface layer being a single layer and including a matrix containing a crosslinked urethane resin as a binder, wherein E1 ≥200 MPa and 10 MPa≤E2 ≤100 MPa, where E1 is an elastic modulus of the matrix in a first region from an outer surface of the surface layer to a depth of 0.1 and E2 is an elastic modulus of the matrix in a second region from a depth of 1.0 to 1.1 μm from the outer surface. The toner includes a toner particle containing a binder resin and a colorant and having a Martens hardness of 85 to 1,100 MPa when measured under a condition of a maximum load of 2.0×10.sup.−4 N.

A developing device includes a developing roller, a developing case, and a support. The developing roller includes a sleeve and a magnetic field generator. The sleeve is rotatable and includes a hollow shaft at an axial end of the sleeve. The magnetic field generator is irrotationally disposed inside the sleeve and includes a non-rotating shaft at an axial end of the magnetic field generator. The non-rotating shaft penetrates through the hollow shaft and projects outward. The developing case is configured to store developer and rotatably supports the hollow shaft. The support includes a fitting portion into which the non-rotating shaft of the magnetic field generator is irrotationally fitted. The support is supported on the developing case using the fitting portion as a main-positioning portion.

A developing cartridge includes: a casing; a developing roller; a shaft extending in a first direction; a first inclined surface; a second inclined surface; an elastic member; and a first protrusion. The shaft is movable in the first direction relative to the casing and the developing roller, and is movable in the second direction together with the same. The first inclined surface is positioned at one end portion of the shaft, while the second inclined surface is positioned at another end portion of the shaft. The first and second inclined surfaces are inclined relative to the first direction. The first protrusion is movable in the first direction together with the second inclined surface. The shaft is movable from a first position to a second position when the second inclined surface receives a pressing force directed in a direction from the another end portion to the one end portion.

There is provided an end member which is disposed in an end portion of a columnar rotating body mounted on an image forming apparatus main body, comprising: a tubular bearing member; and a shaft member held by the bearing member, in which the shaft member includes a rotating shaft which oscillates within a range of 18° or less with respect to a direction along an axis of the bearing member, a rotating force receiving member which is disposed in one end portion of the rotating shaft and is provided with an engaging member which is engaged with a driving shaft of the image forming apparatus main body, and a regulating member which is engaged with or disengaged from the rotating shaft or the rotating force receiving member by pressing, and switches a posture in which the engaging member is engaged with the driving shaft and a posture in which the engaging member is not engaged with the driving shaft.

[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.

An image forming apparatus includes a photosensitive drum, a developing member, an applying device forming a developing potential on the developing member, a driver rotationally driving the developing member, and a controller. The controller selectively executes an operation in first and second modes by controlling a circumferential speed ratio of a circumferential speed of the developing member to a circumferential speed of the drum and a potential difference between a surface potential of the image bearing member in a region where an electrostatic latent image is formed and the developing potential. In the first mode, the ratio is a first ratio of 50% to 100% and the potential difference is a first potential difference, and in the second mode the ratio is a second ratio larger than the first ratio and less than 150% and the potential difference is a second potential difference less than the first potential difference.

An image forming apparatus includes an image bearing member, a developing member that supplies a developer of a regular polarity, a developer supply member that supplies developer to the developing member, and a control unit that applies a first voltage to the developing member and a second voltage to the developer supply member. The control unit executes an image forming operation, and a rotational operation in which the developer supply member rotates in a state in which the first voltage of a regular polarity is applied thereto. The rotational operation includes a first rotational operation in which a potential difference is a first potential difference and a second rotational operation in which the developing member and the developer supply member rotate in a state in which the second voltage having the same polarity as the regular polarity and having a greater absolute value is applied.

A developer cartridge may include: a first gear having a small-diameter gear portion and a large-diameter gear portion; and a second gear including: a first columnar portion centered on a second axis; a second columnar portion having a smaller diameter than the first columnar portion; a first engagement portion extending along a portion of a peripheral surface of the first columnar portion and engageable with the small-diameter gear portion; a second engagement portion extending along a portion of a peripheral surface of the second columnar portion and positioned closer to a housing than the first engagement portion in an axial direction and engageable with the large-diameter gear portion; and a protruding portion protruding in the axial direction and rotatable together with the first engagement portion and the second engagement portion. The second engagement portion may engage the large-diameter gear portion after the first engagement portion engages the small-diameter gear portion.

A conveyance member includes: a shaft that is rotatably disposed in a passage through powder is conveyed; a first conveyance unit that is provided at the shaft to project in a direction away from the shaft, and includes a plurality of first slits obliquely extending toward the shaft and a first film having flexibility; and a second conveyance unit that is provided at the shaft to project in a direction opposite to the first conveyance unit from the shaft, and includes a plurality of second slits obliquely extending toward the shaft and a second film having flexibility.