A power transmission member includes: a male member formed from a resin material and including a plurality of engagement teeth arranged at regular intervals in a circumferential direction when viewed in an axial direction, the engagement teeth having a uniform thickness in a radial direction; a female member including a to-be-engaged portion to which the engagement teeth are fitted as a result of the female member moving in the axial direction relative to the male member; and a fitting member disposed at the male member and the female member, the fitting member fitting the engagement teeth to the to-be-engaged portion while the male member and the female member are located in predetermined opposing positions in the circumferential direction to engage the male member and the female member with each other.

An image forming apparatus includes: a process cartridge; and an apparatus main body to which the process cartridge is attachable and from which the process cartridge is detachable. The process cartridge includes: a photoconductive drum, and an electrode connected to the photoconductive drum and having a contact surface facing downward. The apparatus main body includes: a support frame supporting one end portion of the process cartridge in an axis direction of the photoconductive drum, a ground metal plate supported by the support frame and connected to ground, and a spring supported by the support frame and configured to contact with the contact surface of the electrode from below to connect the electrode and the ground metal plate.

An image formation apparatus includes a development unit, a circuit board, a conduction member, a coil spring, and a holding member. The development unit develops an electrostatic image formed on a photoconductive drum. The circuit board supplies a voltage to the development unit. The conduction member electrically connects the development unit and the circuit board. The coil spring includes a coil part in contact with the conduction member and an arm part of the coil spring provided integrally with the coil part and extending from an end of the coil part outward in a radial direction with respect to the coil part. The holding member includes a spring regulation part to regulate movement of the coil spring in the radial direction. The holding member holds the coil spring in contact with the conduction member. The arm part includes a hook portion to engage with a portion of the holding member.

A cartridge for an image forming apparatus includes: a process unit to be used to form an image; a first member including a first resin material; a second member including a second resin material having higher flame retardant capability than the first resin material; and an electrode member including a contact section configured to be supplied with power from an apparatus main body of the image forming apparatus. The electrode member is configured to electrically connect the apparatus main body to the process unit. The second resin material of the second member has a greater density than the first resin material of the first member. The contact section is located in the vicinity of the first and second members and is closer to the second member than to the first member.

An image forming apparatus includes an apparatus body including a control board, a draw-out unit including a photosensitive drum configured to bear a toner image and rotate about a rotation axis, a developing unit, and a unit contact, the developing unit including a developing roller and a memory, and a door configured to face the draw-out unit at a closed position. The door includes a door contact electrically connected to the control board. The draw-out unit includes a facing surface configured to face the door positioned at the closed position, and a grip portion provided at a center portion of the facing surface in an axial direction of the rotation axis. The unit contact is provided in a region outside an end surface of the grip portion in the axial direction and below the grip portion in a vertical direction.

In an image forming apparatus, a process frame is movable into and out of a main casing in a first direction. The process frame includes a first wall and a second wall spaced apart from the first wall in a second direction. A first cartridge is detachably mountable to the process frame in a third direction crossing the second direction. A first electrode protrudes from an outer surface of the first cartridge outwardly in the second direction. In a state where the first cartridge is mounted to the process frame, the first cartridge is positioned between the first wall and second wall of the process frame in the second direction and a portion of the first wall aligns with the first electrode in the third direction such that the portion of the first wall is overlapped with the first electrode as viewed in the third direction.

A toner cartridge according to one example embodiment includes a reservoir for holding toner. An outlet is positioned on a front of the toner cartridge for exiting toner from the toner cartridge. First, second and third electrical contacts are positioned on a first side of the toner cartridge for contacting corresponding first, second and third electrical contacts in an image forming device. Each of the first, second and third electrical contacts of the toner cartridge is electrically connected to a respective imaging component positioned on the toner cartridge. The first, second and third electrical contacts of the toner cartridge are positioned such that an imaginary line that angles downward in a direction from a rear of the toner cartridge toward the front of the toner cartridge passes through the first, second and third electrical contacts of the toner cartridge.

The developing cartridge herein has a housing, a developing roller rotatably supported by it, the developing roller rotating about an axis in a direction, a supply roller rotatably supported by the housing and configured to convey a developer to the developing roller, the supply roller having a supply roller shaft, a driving gear on a driving side of the housing in the direction, and an electrode electrically connected to the developing roller shaft. The electrode has first and second parts, and an intermediate part connecting them. The first part is on an opposite side of the driving side of the housing, the second part is on the driving side, and the opposite side of the driving side and the driving side are opposite ends of the housing in the direction, and the second part is simultaneously in contact with the supply roller shaft and the developing roller shaft.

In a cartridge, a developing roller is configured to rotate around a first rotational axis extending in a predetermined direction and to carry developer thereon, the developing roller having a first end and a second end apart from each other in the predetermined direction, a from-first-to-second direction being defined along the predetermined direction as being directed from the first end to the second end. A developing electrode is formed of a conductive material and is configured to be electrically connected to the developing roller, the developing electrode including a main part and a protruding portion protruding from the main part in the from-first-to-second direction. A detection body is formed of an insulating material and is rotatably supported by the protruding portion, the detection body including a first opening that exposes part of the protruding portion and a covering portion covering part of the protruding portion.

A drum cartridge includes: a drum frame to which a developing cartridge is attachable; a photosensitive drum; and a first storage medium. The drum frame has one end portion and another end portion spaced apart from the one end portion in a first direction. The photosensitive drum is rotatable about a first axis extending in a second direction and is positioned at the one end portion of the drum cartridge. The first storage medium includes a first electrical contact surface. The first storage medium is positioned at an outer surface of the drum frame, the outer surface being exposed in a state where the developing cartridge is attached to the drum frame.