A memory holder cover holds a memory holder so as to be movable with respect to the memory holder cover. An electrical contact contacts an electrical contact surface of a memory from above in a state where a cartridge is located at an attached position at which the cartridge is attached to a main housing. The main housing includes a guide groove having upper and lower guide surfaces. The upper guide surface guides movement of a memory holder from above when the cartridge is attached and detached. The lower guide surface guides movement of the memory holder from below when the cartridge is attached and detached. In a state where the cartridge is located at the attached position, the electrical contact surface is parallel to at least part of the upper guide surface or at least part of the lower guide surface.

An electronic component includes a processor and a memory. The electronic component has a secure platform capable of storing at least one dual key pair and a corresponding digital signature. There is also a system including a host machine and an electronic component capable of being operated by the host machine. The electronic component has a processor, a memory, and a secure platform capable of storing at least one dual key pair and a corresponding digital signature. Another aspect describes a method, which includes reading a public key from an electronic component by a host machine, verifying the public key against a stored key in the host machine, digitally signing data using a private key from the electronic component, verifying the signed data against the stored key, and using the electronic component by the host machine only if the signed data and the public key are verified.

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 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.

An image forming apparatus includes an apparatus body, a cover, a cartridge, and a controller. The cartridge includes a second memory storing lifetime information indicating lifetime of the cartridge and identification information unique to the cartridge. In a case where the lifetime information indicates the initial value for the lifetime, the controller is configured to perform setting the cartridge to be usable in the image forming apparatus. In a case where the controller determines that the lifetime information does not indicate the initial value for the lifetime of the cartridge, the controller is configured to perform judging whether the identification information stored in the second memory matches a registration identification information stored in a first memory of the apparatus body. In a case where the identification information matches the registration identification information, the controller is configured to perform determining that the cartridge is usable for the image forming apparatus.

An image forming apparatus includes a developing cartridge, a main memory and a controller. The controller is configured to perform determining whether the developing cartridge is reached a lifetime on a basis of: at least one of s developing maximum printable number of sheets which corresponds to developing identification information, a maximum developing roller rotation number which corresponds to the developing identification information, and a maximum dot count which corresponds to the developing identification information; and at least one of a developing cumulative number of printed sheets, a cumulative developing roller rotation number and a cumulative dot count.

A drum cartridge attachable to and detachable from a main frame of an image forming apparatus includes: a photosensitive drum; a drum frame; and a drum contact. The photosensitive drum is rotatable about a drum axis extending in a first direction. A toner cartridge including a storage medium having an electrical contact surface is attachable to and detachable from the drum frame. In a state where the toner cartridge is attached to the drum frame, the drum contact is movable in the first direction between: a separated position in which the drum contact is positioned away from the electrical contact surface; and a contacting position in which the drum contact is in contact with the electrical contact surface. The drum contact moves from the separated position to the contacting position in accordance with attachment of the drum cartridge to the main 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.

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.

An example image forming apparatus includes a mainbody, a toner refilling portion, and a controller. On the mainbody, 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.