An image forming apparatus cartridge includes a coupling member having an axis about which the coupling member is rotatable. The coupling member includes a first end portion operatively connected to a developer roller and a developer supplying roller and a second end portion for receiving a rotational force. The coupling member is movable between a first position in which the axis of the coupling member is substantially parallel to and offset from the axis of the developer roller, a second position in which the axis of the coupling member is inclined with respect to the position of the axis when the coupling member is in the first position, and a third position in which the axis of the coupling member is inclined with respect to the position of the axis when the coupling member is in the first position in a direction opposite to the direction the coupling member is inclined when in the second position.

According to one embodiment, an image forming apparatus includes an image carrier, a cleaning member, a determination unit, and a control unit. The image carrier carries a developer image. The cleaning member removes a developer adhering to a surface of the image carrier by a frictional force when the image carrier is rotated in a first direction. The determination unit determines an image forming amount in a plurality of continuous image forming jobs. The control unit rotates the image carrier in the first direction during the image forming period and in a second direction opposite to the first direction at reverse rotation timing, and changes a condition for rotation in the second direction according to the determination result.

An image forming apparatus at least includes: an image bearing member; a developer container; a developer carrying member; and a controller that controls a power source that applies a voltage to the developer carrying member, wherein the developer carrying member has at least a base and a surface layer, the surface layer has an electron donating portion that mainly donates charge to the developer when the developer and the surface layer makes frictional contact to exchange charge and an electron accepting portion that mainly accepts charge from the developer, and the controller applies an AC voltage to the developer carrying member during a period in which an image forming operation is not performed and the developer carrying member is driven, the AC voltage being different from that applied during an image forming period.

When, in a state where a developer borne by a developer bearing member is sandwiched by an opposing portion of an image bearing member and the developer bearing member, C denotes capacitance between the image bearing member and the developer bearing member, ΔV denotes a development contrast, Q/S denotes a charge amount per unit area of the developer borne by the developer bearing member, and Δv denotes a peripheral velocity ratio which is a ratio of a peripheral velocity of the developer bearing member to a peripheral velocity of the image bearing member, a first peripheral velocity ratio is set so that |Q/S×Δv|≤|C×ΔV| is satisfied, and a second peripheral velocity ratio which is larger than the first peripheral velocity ratio is set so that |Q/S×Δv|>|C×ΔV| is satisfied.

An electrophotographic image forming apparatus comprises a main assembly that includes moving force applying portion, a main assembly engaging portion having a driving shaft and a rotational force applying portion provided on the driving shaft, and an electrophotographic photosensitive drum. A cartridge is dismountable from the main assembly without dismounting the electrophotographic photosensitive drum from the main assembly. The cartridge includes a developing roller for developing a latent image formed on the electrophotographic photosensitive drum, a rotatable member for transmitting a rotational force to the developing roller, and a coupling member including a rotational force receiving portion engageable with the rotational force applying portion to receive a rotational force from the main assembly engaging portion, and a rotational force transmitting portion for transmitting the rotational force to the rotatable member. The cartridge also includes a frame including a moving force receiving portion that receives a moving force from the moving force applying portion, the frame supporting the developing roller and the rotatable member.

An image forming apparatus includes an image bearer, a charger, a developing device, and a transferor. The charger is disposed in contact with the image bearer to charge the image bearer. The developing device supplies toner to the image bearer to form a toner image on the image bearer. The transferor transfers the toner image on the image bearer to a recording medium or an intermediate transferor. The developing device collects transfer residual toner remaining on the image bearer after transfer of the toner image. The toner contains base particles and an external additive. The external additive has a volume average particle diameter of 5 nm or more and 50 nm or less. A content of the external additive is 1.8% by mass or less in the toner.

An imaging system includes a rotatable image carrier; a rotatable developer carrier, a storage container, and an air flow generator. The developer carrier transfers toner to the image carrier at a developing region located between the image carrier and the developer carrier. The storage container stores the developer carrier. The air flow generator is separated from the storage container by a gap, and rotates in a rotational direction that is opposite to a rotational direction of the developer carrier, to channel an air flow through the gap when the air flow generator rotates.

An image forming apparatus according to aspects of the present disclosure includes a cover, an interlocking mechanism, a sensor, a separation mechanism, a controller. In a state where the cover moves from a closed position to an open position while no power is supplied to the controller, a state of the interlocking mechanism changes from a first state to a second state. In a state where the sensor does not detect that the interlocking mechanism is in the second state when power supply to the controller is started, the separation mechanism keeps the developing roller located at a separation position at the separation position. On the other hand, in a state where the sensor detects that the interlocking mechanism is in the second state when power supply to the controller is started, the separation mechanism moves the developing roller located at a contact position to the separation position.

When, in a state where a developer borne by a developer bearing member is sandwiched by an opposing portion of an image bearing member and the developer bearing member, C denotes capacitance between the image bearing member and the developer bearing member, ΔV denotes a development contrast, Q/S denotes a charge amount per unit area of the developer borne by the developer bearing member, and Δv denotes a peripheral velocity ratio which is a ratio of a peripheral velocity of the developer bearing member to a peripheral velocity of the image bearing member, a first peripheral velocity ratio is set so that |Q/S×Δv|≤|C×ΔV| is satisfied, and a second peripheral velocity ratio which is larger than the first peripheral velocity ratio is set so that |Q/S×Δv|>|C×ΔV| is satisfied.

In an example of the disclosure, a print apparatus component to be cleaned is rotated about a rotational axis. A cleaning element having a cleaning surface in contact with the print apparatus component is rotated. The cleaning element is oscillated in a direction parallel to the rotational axis. Rotation and oscillation of the cleaning element are varied according to a predetermined function to remove a residue from the print apparatus component.