An image forming apparatus includes an apparatus main body, a process cartridge, a scanner unit, and a toner cartridge. The process cartridge is detachably mounted on the apparatus main body. The process cartridge includes: a photosensitive drum configured to rotate about a rotational axis extending in a first direction; and a development unit configured to supply toner to the photosensitive drum. The toner cartridge is configured to store toner. At least part of the photosensitive drum, at least part of the scanner unit, and at least part of the toner cartridge are aligned in a second direction in this order. The second direction is perpendicular to both the first direction and to a vertical direction. The at least part of the photosensitive drum, the at least part of the scanner unit, and the at least part of the toner cartridge overlap one another as viewed from the second direction.

A developing cartridge includes: a developing roller; a casing having an outer surface; a first shaft rotatable about a rotational axis; a first arm; and a cam. The first arm and the cam extend radially outward from an outer periphery of the first shaft and pivotally movable along with rotation of the first shaft. The cam has: one end connected to the first shaft; another end positioned farther from the rotational axis than the one end is farther from the rotational axis; and a pressure contact surface inclined so as to approach the outer surface of the casing as extending from the one end toward the another end. When a pressing force is applied to the pressure contact surface, the first arm pivotally moves from a first position to a second position along with: pivotal movement of the cam; and the rotation of the first shaft.

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.

A developing cartridge includes a storage medium. A first contact portion is provided in a photoconductor unit and configured to be electrically connected to the storage medium. A second contact portion is provided in an apparatus body. The photoconductor unit is configured to, in a case of attaching the photoconductor unit to the apparatus body, move from a first position to a second position while being guided by a guide member and then move from the second position to a third position below the second position. At least one of the first contact portion and the second contact portion is capable of being displaced such that engagement between the first contact portion and the second contact portion is performed while the photoconductor unit moves by being guided by the guide member, and the engagement is maintained while the photoconductor unit moves from the second position to the third position.

An image forming apparatus includes an attaching and detaching unit, an attached and detached section, and a pressing member. The attaching and detaching unit includes a developing device including a developer bearer to develop a latent image on a latent image bearer and is detachably attached to the attached and detached section. The attached and detached section includes the latent image bearer, a main reference portion, and a sub-reference portion. The main reference portion contacts a main reference part of the attaching and detaching unit. The sub-reference portion contacts a sub-reference part of the attaching and detaching unit. The pressing member presses the attaching and detaching unit to generate a biasing force biasing the developer bearer toward the latent image bearer and a rotational moment toward the sub-reference portion of the attached and detached section around the main reference part with respect to the attaching and detaching unit.

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 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.

A photosensitive member cartridge detachably mountable to a main assembly of an image forming apparatus for forming an image, includes a frame; a photosensitive drum on which and which is provided in the frame; a transfer member for transferring an image formed on the drum onto the sheet; a mounting portion for detachably mounting a developing cartridge including a developer carrying member onto the drum and a memory for storing information; a first electrical contact provided on the frame and electrically connectable with a main assembly electrical contact provided in the main assembly when the cartridge is mounted to the main assembly; and a second electrical contact provided on the frame for electrically connecting the memory and the first electrical contact portion with each other when the developing cartridge is mounted to the mounting portion.

A replaceable unit for an electrophotographic image forming device includes a housing having a reservoir for holding toner. An electrical connector is positioned on a first side of the housing. The electrical connector includes an electrical contact for contacting a corresponding electrical contact in the image forming device. The electrical contact of the replaceable unit is electrically connected to processing circuitry mounted on the housing. The electrical connector is movable between a first position and a second position. The electrical contact of the replaceable unit moves outward from the first side of the housing along a side-to-side dimension of the housing when the electrical connector moves from the first position to the second position. The electrical contact of the replaceable unit faces downward when the electrical connector is in the second position permitting the corresponding electrical contact to contact the electrical contact of the replaceable unit from below.

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.