A developing apparatus includes a developer carrying member configured to carry developer, and a developer supply member configured to supply the developer to the developer carrying member, the developer supply member including a shaft, first and second driving members disposed at a first end and a second end of the shaft, respectively, and a toner supply unit disposed between the first end and the second end of the shaft, wherein the first driving member receives a driving force for rotating the developer supply member, and the second driving member outputs the driving force, and wherein the second driving member is mounted to the shaft without play in a rotational direction of the developer supply member with respect to the shaft.

In an image forming device, a first fixing member has a roller. A second fixing member has a belt to form a nip together with the first fixing member. A first motor drives the roller. A pressure modifying mechanism modifies a nip pressure at the nip to selected one of a first nip pressure and a second nip pressure smaller than the first nip pressure. A controller starts driving the first motor to drive the roller in a case where a print command is received in a state that the nip pressure is the second nip pressure. The controller modifies the nip pressure from the second nip pressure to the first nip pressure after the driving is performed and fixes the developer image on the sheet in a state that the nip pressure is the first nip pressure.

A mountable unit set usable with an electrophotographic-image-forming apparatus includes a cartridge and an attachment. A cartridge includes a photosensitive drum and a coupling member for receiving a driving force for rotating the photosensitive drum, from a driving shaft. An attachment includes a cylindrical portion for being mounted to a periphery of the driving shaft to suppress tilting of the driving shaft. Tilting of a driving-force transmitting member is suppressed.

An image forming apparatus includes a container that can store developer; an apparatus body by which the container is detachably supported; a detection portion, for determining an installed state of the container, provided for the apparatus body; and a control portion determining whether the container is unused based on a detection result by the detection portion. The container includes a displaceable member displaced between an initial position where the displaceable member is not detected by the detection portion and a detection position where the displaceable member is detected by the detection portion. When the container is in an initial installation state immediately after being installed in the apparatus body, the control portion determines the container is unused in a case where the displaceable member is not detected by the detection portion, and determines the container is used in a case where the displaceable member is detected by the detection portion.

A cartridge includes a developing roller, a downstream side drive transmission member, an upstream side drive transmission member, an elastic member for urging the downstream side drive transmission member toward a blocked position from a transmission position, and a maintaining member for maintaining the downstream side drive transmission member in the transmission position against an elastic force of the elastic member. The downstream side drive transmission member is coupled to the upstream side transmission member when the downstream side drive transmission member is in the transmission position, and the downstream side drive transmission member is not coupled to the upstream side transmission member when the downstream side drive transmission member is in the blocked position.

To provide a process cartridge, a drum unit capable of receiving a driving force from the main assembly, and an image forming apparatus including the process cartridge. A cartridge is provided with a movable member having a driving force receiving portion. The movable member moves between an advanced position and a retracted position.

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes a rotatable photosensitive drum; a rotatable developing roller configured to develop image formed on the drum, the developing roller being capable of contacting to and spacing from the drum; an urging force receiving portion configured to receive, from a main assembly side urging member, an urging force for spacing the developing roller from the drum; a cartridge side drive transmission member capable of the coupling with a main assembly side drive transmission member and configured to receive, from the main assembly side drive transmission member, a rotational force for rotating the developing roller; and a decoupling member capable of urging the cartridge side drive transmission member by the urging force received by the urging force receiving portion to decouple the cartridge side drive transmission member from the main assembly side drive transmission member.

A photosensitive member unit detachably mountable to a main assembly of an image forming apparatus, the image forming apparatus including a first main assembly side helical gear portion and a second main assembly side helical gear portion which are coaxially rotatable, the photosensitive member unit includes a photosensitive member rotatable about a rotational axis thereof; a first unit side helical gear portion for meshing engagement with the first main assembly side helical gear portion; and a second unit side helical gear portion for meshing engagement with the second main assembly side helical gear portion, wherein a twisting direction of a tooth of the second unit side helical gear portion is the same as the twisting direction of a tooth of first unit side helical gear portion, wherein a helix angle of the tooth of the second unit side helical gear portion is larger than a helix angle of the tooth of the first unit side helical gear portion, and wherein the first unit side helical gear portion and the second unit side helical gear portion are rotatable in a state in which the first unit side helical gear portion is in meshing engagement with the first main assembly side helical gear portion, and the second unit side helical gear portion is in meshing engagement with the second main assembly side helical 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.

A cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the cartridge includes (i) a rotatable developing roller for developing a latent image formed on a photosensitive member; (ii) a first drive transmission member capable of receiving a rotational force originated by the main assembly; (iii) a second drive transmission member capable of coupling with the first drive transmission member and capable of transmitting the rotational force received by the first drive transmission member to the developing roller; and (iv) a coupling disconnection member including a force receiving portion capable of receiving the force originated by the main assembly, and an urging portion capable of urging at least one of the first drive transmission member and the second drive transmission member by the force received by the force receiving portion to separate one of the first drive transmission member and the second drive transmission member from the other, thereby disconnecting the coupling.