A developer cartridge includes a housing, a developing roller, an agitator, a memory, and a cover. The housing is configured to store toner therein and has one end portion and the other end portion in a first direction. The developing roller is rotatable about a first axis extending in the first direction. The agitator is rotatable about a second axis extending in the first direction. The agitator is positioned spaced apart from the developing roller. The memory includes an electrical contact surface. The electrical contact surface is positioned at an outer surface of the housing and at the one end portion of the housing in the first direction, and is disposed between the developing roller and the agitator in a second direction from the first axis toward the second axis. The cover has an opening open in the second direction and covers the electrical contact surface.

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 developing cartridge includes: a casing; a developing roller rotatable about an axis extending in a first direction; a first agitator; an agitator gear; a first protrusion; a developing memory; a first electrical contact surface; and a first holder holding the first electrical contact surface. The agitator gear includes a large diameter gear and a small diameter gear positioned between the large diameter gear and the casing in the first direction. The first protrusion protrudes outward from one end of the casing in the first direction, and is positioned between the casing and the large diameter gear in the first direction. The first protrusion is positioned away from the small diameter gear. The first holder is positioned farther from the first protrusion than the large diameter gear is in the first direction. The first holder and the first electrical contact surface are movable relative to the casing.

A developer cartridge according to one aspect is attachable to a photoconductor unit that comprises a photoconductive drum. The developer cartridge may comprise a main body having an opening, the main body comprising an electric circuit, a front cover configured to move to an opening position in which the opening of the main body is exposed and to a closing position in which the opening of the main body is closed, a first terminal electrically connected to the electric circuit, a photosensitive drum, and a developer cartridge comprising a developing roller, developing frame having a pressed portion, memory unit and second terminal. The front cover may include a pressing portion configured to press the pressed portion of the developing frame in a direction from the developing roller toward the photosensitive drum, and wherein the second terminal faces to the front cover when the front cover is in the closed position.

A consumable chip applied to a consumable includes a memory and a controller. The memory is used to store information of a consumable product of an image formation device. The controller is configured to control the consumable chip to generate a predetermined signal to cause the image formation device to perform a target operation according to the predetermined signal. The consumable chip is mounted at the consumable. The consumable is detachably mounted at the image formation device.

A developing cartridge includes: a casing; a developing roller rotatable about an axis extending in a first direction; a first agitator; an agitator gear; a first protrusion; a developing memory; a first electrical contact surface; and a first holder holding the first electrical contact surface. The agitator gear includes a large diameter gear and a small diameter gear positioned between the large diameter gear and the casing in the first direction. The first protrusion protrudes outward from one end of the casing in the first direction, and is positioned between the casing and the large diameter gear in the first direction. The first protrusion is positioned away from the small diameter gear. The first holder is positioned farther from the first protrusion than the large diameter gear is in the first direction. The first holder and the first electrical contact surface are movable relative to the casing.

An image forming apparatus includes a main casing, a cartridge, and a controller. The cartridge is attachable to the main casing. The cartridge includes a cartridge memory configured to store identification information. The controller is configured to perform a rewriting process to rewrite the identification information to information indicating that the cartridge is the normal cartridge, in a case where the controller receives a cancellation instruction to instruct to cancel the service contract and the identification information, which is stored in a cartridge memory of the cartridge attached to the main casing, indicates that the cartridge is the contract cartridge.

An example image forming apparatus includes a main body, a toner refilling portion, and a controller. On the main body, a development cartridge is mounted. The toner refilling portion is connected to the development cartridge and a toner refill cartridge inserted through a communicating portion of the main body and thus receives, from the toner refill cartridge, authentication information obtained from the toner refill cartridge, thereby adjusting a toner inflow from the toner refill cartridge to the development cartridge. A controller determines whether to allow a toner refill using the toner refill cartridge based on the authentication information obtained from the toner refill cartridge and authentication information obtained from the image forming apparatus and controls the toner refilling portion according to a determination result.

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.

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.