An image forming apparatus includes: a drum cartridge; a toner cartridge; a toner data electrical contact surface; a drum data electrical contact surface; and a controller. The drum cartridge includes: a drum memory storing data relating to the drum cartridge; and a first drum electrical contact for communication of data stored in the drum memory. The toner cartridge includes a board having: a first relay electrical contact for relaying the data stored in the drum memory; a toner memory storing data relating to the toner cartridge; and a first toner electrical contact for communication of data stored in the toner memory. The controller is configured to: read the data stored in the drum memory through the drum data electrical contact surface contacting the first relay electrical contact; and read the data stored in the toner memory through the toner data electrical contact surface contacting the first toner electrical contact.

A drum unit includes a photosensitive drum, a developing unit, a toner cartridge, a connector and a relay board. The photosensitive drum is rotatable about a first axis extending in an axial direction. The developing unit includes a magnetic roller, a developer container, a conveyer member and a toner sensor. The developer container accommodates therein carrier, and has an inlet. The conveyer member is positioned in the developer container, and configured to convey toner and the carrier from the inlet toward the magnetic roller. The toner cartridge accommodates therein toner and is attachable to the developer container to replenish toner in the developer container through the inlet. The connector is electrically connected to an image forming apparatus. The relay board electrically connects the toner sensor to the connector. The relay board is configured to transmit a detection signal from the toner sensor to the image forming apparatus.

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 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 and a magnetic sensor electrically connected to the electrical contact. The electrical connector is movable between a first position and a second position. When the electrical connector moves from the first position to the second position, the electrical contact of the replaceable unit moves from a retracted position to an operative position. When the electrical connector moves from the first position to the second position, the magnetic sensor moves from a misaligned position to an aligned position with a point in a path of movement of a magnet for sensing a magnetic field of the magnet.

A developing cartridge includes: a casing configured to accommodate therein toner; a developing roller; a supply roller configured to supply the toner to the developing roller; a layer thickness regulation blade in contact with a circumferential surface of the developing roller; a developing electrode electrically connected to the developing roller; and a supply electrode electrically connected to the supply roller and the layer thickness regulation blade. The supply electrode includes: an electrode member electrically connected to a rotation shaft of the supply roller and movable in a direction perpendicular to the rotation shaft; and a connection member in contact with and electrically connecting the electrode member and the layer thickness regulation blade. The electrode member is movable relative to the connection member in the direction perpendicular to the rotation shaft in a state where the electrode member is in contact with the connection member.

A replaceable unit for an electrophotographic image forming device according to one example embodiment includes an electrical contact positioned on a first side of a housing of the replaceable unit for contacting an electrical contact in the image forming device. A guide on the first side of the housing is positioned closer to a front of the housing than the electrical contact and leads rearward toward the electrical contact. The guide includes an inside surface that faces inward sideways toward a second side of the housing. At least a portion of the inside surface is angled inward sideways from front to rear permitting contact between the inside surface and an electrical connector in the image forming device to draw the electrical connector in the image forming device inward sideways relative to the replaceable unit during insertion of the replaceable unit into the image forming device.

An image forming apparatus has a body frame and a slide frame. The slide frame is configured to be pulled out from the body frame along a sliding direction. A plurality of image forming cartridges is detachably mounted on the slide frame. A plurality of electrode members is mounted on the slide frame and aligned along the sliding direction so as to correspond to the image forming cartridges. A body-side contact portion of each of the electrode members is electrically connected to the body frame. A cartridge-side contact portion of the electrode member is electrically connected to the image forming cartridge. The image forming cartridge is connected to the body via the corresponding electrode member when the slide frame mounting the image forming cartridges is inserted to the body frame.

A drum cartridge mountable to an image forming apparatus in a mounting direction, the drum cartridge including: a frame having an opening, the frame allowing a toner cartridge to be attached, and the frame including a housing configured to accommodate therein a toner and a first storage medium including a first electric contact; a photosensitive drum; and a second storage medium including a second electric contact and located at an outer surface of the frame, and in a state where the toner cartridge is mounted to the frame, the first storage medium is exposed via the opening and the second storage medium is aligned with the first storage medium in the mounting direction of the drum cartridge.

A cartridge includes: a housing; a storage medium having an electrical contact surface; and a holder movable relative to the housing. The holder includes a first holder member and a second holder member movable relative to the first holder member. The first holder member includes at least one pawl and holds the electrical contact surface at one end surface of the first holder member in a first direction crossing the electrical contact surface. The second holder member includes at least one corner part engageable with the at least one pawl to provide an engaging portion therebetween. The second holder member has a through-hole that is open at another end face of the second holder member in the first direction. The engaging portion is accessible from an outside of the holder through the through-hole.

Provided is a method for removing a first holder member from a second holder member in a cartridge. The cartridge includes: a housing; the first holder member holding an electrical contact surface; and the second holder member supported by the housing. The first holder member includes a pawl, and the second holder member includes a corner part engageable with the pawl of the first holder member. The electrical contact surface is held at one end surface of the first holder member in a first direction crossing the electrical contact surface. The method includes: disengaging the pawl from the corner part; and separating the housing and the second holder member from the first holder member in the first direction away from the one end surface of the first holder member.