A developing cartridge may include a developing roller, a casing capable of containing a developer therein, a developing electrode movable with the casing and the developing roller and pivotable about a developing roller shaft of the developing roller in a direction, a first lever movable relative to the casing, and a holder configured to hold the first lever relative to the casing, in case where the developing electrode pivots from one side of the direction to an other side of the direction, the first lever stops the pivotable movement of the developing electrode from one side of the direction to the other side of the direction and the holder prevents the first lever from coming off the holder from the one side of the direction to the other side of the direction.

An image forming apparatus configured to form an image on a sheet, the image forming apparatus includes an apparatus body, and a detachable unit. The detachable unit includes a first positioned portion and a second positioned portion. The apparatus body includes a frame member having a first positioning portion and a second positioning portion which respectively engage with the first positioned and second positioned portion, so that the detachable unit is positioned with respect to frame member in the attaching direction and the first direction. The second positioning portion is arranged closer to a center portion of the detachable unit in the second direction than the first positioning portion.

An image forming apparatus includes an apparatus body including an opening portion, and an opening-and-closing member, a process unit detachably attached to and supported by the apparatus body, the process unit including an image bearing member, a toner storage portion, and a supply portion, a sheet supporting portion, and a rotary feeding member. When viewed in a gravity direction, the supply portion is disposed on a same side as a side on which the sheet supporting portion is disposed with respect to the image bearing member, and the opening portion is disposed on a side opposite to the side on which the sheet supporting portion is disposed with respect to the image bearing member. In a case where the opening-and-closing member is positioned at an opening position, the process unit is configured to be attached to and detached from the apparatus body through the opening portion.

A movable-member supporter includes: a first support member that includes a first support plate, a first guide unit provided at the first support plate, and a first connection section, the first guide unit guiding movement of a movable member and having one end that extends to one side surface of the first support plate, the first connection section being provided at the one side surface of the first support plate; and a second support member that includes a second support plate, a second guide unit provided at the second support plate, and a second connection section, the second guide unit guiding movement of the movable member and having one end that extends to one side surface of the second support plate, the second connection section being provided at the one side surface of the second support plate and being connected with the first connection section of the first support member.

A pull-in apparatus configured to pull in a unit toward a predetermined position in an apparatus body includes an arm member, a restriction member, a first action portion and a second action portion. The restriction member is movable between a lock position at which the restriction member restricts movement of the arm member in a first direction and a lock-release position at which the restriction member allows the movement of the arm member in the first direction. Movement of the restriction member from the lock position toward the lock-release position is restricted in a state in which the arm member is at a stand-by position, and is allowed in a state in which the arm member has been moved from the stand-by position in a second direction.

In an image forming apparatus, a tray unit to which a cartridge is detachably mounted, and that is configured to be capable of moving between an internal position situated within the apparatus main body and an external position situated outside, includes first and second side plates configured to support the cartridge, and they are each made of metal, and include a supporting portion and an outer side portion, the supporting portions includes positioning portions configured to come into contact with the cartridge to position the cartridge as to an image forming position. The apparatus main body includes first and second pressing members each capable of moving between pressing positions at which the cartridge is pressed, and separated positions separated from the cartridge. The first and second pressing members are disposed each intersecting with imaginary planes that is orthogonal to the longitudinal direction and intersect the positioning portions.

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.

One of two walls apart from each other in a first direction has an opening. A drum cartridge includes a photosensitive drum rotatable about a drum axis extending in the first direction when the drum cartridge is attached to a housing. The drum cartridge is movable through the opening between a first position at which an entirety of the drum cartridge is located inside the housing and a second position at which at least part of the drum cartridge is located outside the housing. The development cartridge includes a development roller rotatable about an axis extending in the first direction. The development cartridge is unattachable to and undetachable from the drum cartridge in a state where the drum cartridge is located at the first position. The development cartridge is attachable to and detachable from the drum cartridge in a state where the drum cartridge is located at the second 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.