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.

A drum cartridge includes a frame on which a toner cartridge is attachable, a photosensitive drum, and a drum memory. The drum cartridge relays information stored in the toner memory to the image forming apparatus when the toner cartridge is attached to the frame.

A cartridge removably attachable to an image forming apparatus, including a resin-made casing, a planar memory chip configured to store information to be outputted to the image forming apparatus, a recess portion provided on an outer surface of the casing to fit the memory chip, and a regulating portion formed integrally with the casing and provided to project out of the outer surface of the casing in a direction intersecting with a surface of the memory chip to regulate a move of the memory chip in the direction intersecting with the surface of the memory chip, wherein the memory chip is attached to the recess portion in a condition of displaceable within the recess portion in a posture substantially surrounded by side wall of the recess portion.

An image forming apparatus includes a controller, a drum cartridge and a toner cartridge. The controller is configured to perform determining a value of a first initial developing bias for a first toner cartridge based on a cumulative number of drum rotations that is stored in a drum memory of the drum cartridge at the time when the cumulative dot count stored in the toner memory of the first toner cartridge is equal to zero. After determining the first initial developing bias, the controller is configured to perform determining a value of a second initial developing bias for a second toner cartridge based on the cumulative number of drum rotations that is stored in the drum memory at the time when the cumulative dot count stored in the toner memory of the second toner cartridge is equal to zero.

A drum cartridge includes: a drum frame to which a developing cartridge is attachable; a photosensitive drum rotatable about an axis extending in a first direction; a memory having an electrical contact surface; and a resilient member positioned between the electrical contact surface and the drum frame. The resilient member is configured to expand and compress in a second direction crossing the electrical contact surface between a first state and a second state, the resilient member having a shorter length in the second state than in the first state. A distance between the drum frame and the electrical contact surface in the second direction when the resilient member is in the second state is smaller than a distance between the drum frame and the electrical contact surface in the second direction when the resilient member is in the first state.

A cartridge includes a photosensitive drum rotatable about an axis extending in an axial direction; a memory including a storing element configured to store information, a memory contact electrically connected to the storing element, and a substrate having a surface on which the memory contact is provided; and a frame which supports the photosensitive drum, on which the substrate is mounted, and which includes a first end with respect to the axial direction and a second end opposite from the first end. The frame includes a container provided with an accommodating chamber for accommodating a developer collected from the photosensitive drum and with an opening communicating with the accommodating chamber and includes a mounting member mounted on the container so as to cover the opening. The mounting member includes a supporting portion for supporting the substrate.

A toner container includes a container body, an opening, a cover, a toner discharge port, a shutter, a cylindrical structure, protrusions, and an identifier. The shutter is attached to the cover and includes a main shutter covering the toner discharge port. The main shutter moves between a closed position to close the toner discharge port and an open position to open the toner discharge port. The protrusions are on both sides of the cover and protrude in a direction orthogonal to a toner container mounting direction. The identifier is on the cover to indicate a toner color. The cylindrical structure's leading end is downstream of leading ends of the protrusions in the mounting direction. The main shutter's leading end is downstream of the protrusions' leading ends in the mounting direction when the main shutter is in the closed position. The protrusions are downstream of the identifier in the mounting direction.

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.

A drum cartridge includes a frame on which a toner cartridge is attachable, a photosensitive drum, and a drum memory. The drum cartridge relays information stored in the toner memory to the image forming apparatus when the toner cartridge is attached to the frame.

A toner container includes a container body, an opening, a cover, a toner discharge port, a shutter, a cylindrical structure, protrusions, and an identifier. The shutter is attached to the cover and includes a main shutter covering the toner discharge port. The main shutter moves between a closed position to close the toner discharge port and an open position to open the toner discharge port. The protrusions are on both sides of the cover and protrude in a direction orthogonal to a toner container mounting direction. The identifier is on the cover to indicate a toner color. The cylindrical structure's leading end is downstream of leading ends of the protrusions in the mounting direction. The main shutter's leading end is downstream of the protrusions' leading ends in the mounting direction when the main shutter is in the closed position. The protrusions are downstream of the identifier in the mounting direction.