An image forming apparatus according to an embodiment includes an image forming section having a cartridge detachably mounted thereto. The cartridge holds a color erasable material which is erasable by heating to a color erasing temperature. The cartridge includes a housing configured to hold the color erasable material and a temperature sensing unit configured to detect a storage temperature of the housing. The apparatus includes a display unit and a control section. The control section receives a maximum storage temperature of the housing, and determines whether the received maximum storage temperature is greater than the color erasing temperature. The control section controls the display unit to display a message indicating whether the received maximum storage temperature is greater than the color erasing temperature.

A developer cartridge comprises a first gear. The first gear may include a first protrusion extending in a radial direction of the first gear. The first protrusion may be positioned at a circumference of a column of the first gear. The first protrusion may be spaced apart from a second end face opposite to a first end face facing an exterior surface of a casing configured to accommodate developer therein. The first protrusion may be further from the second end face than a large-diameter gear in an axial direction. A rotational circumference of the first protrusion defined by rotation of the first protrusion and a portion of the large-diameter gear are aligned in the axial direction.

A developer cartridge comprises a first gear. The first gear may be rotatable about a first axis extending in an axial direction. The first gear may include a first surface rotatable with the first gear, and a second surface rotatable with the first gear. The first surface may extend in a circumferential direction of the first gear. The second surface may extend in the circumferential direction. The second surface may be separated from the first surface in the circumferential direction. A length of the second surface in the circumferential direction may be greater than a length of the first surface in the circumferential direction.

A physical unclonable function (PUF) located on a supply item for an imaging device is disclosed. The PUF has a toothed rack configured to mate with a gear. During reading operations, the gear turns and translates the PUF linearly under a magnetic sensor. This configuration is inexpensive and robust. Other devices are disclosed.

A system with a container including a protrusion, and a receiver to receive the container. The receiver includes a slide block that is movable relative to a body of the receiver, the slide block including two surfaces, a first surface, initially contacted by the protrusion of the container during insertion of the container into the receiver, having a first slope to resist movement of the container towards the receiver, and a second surface, subsequently contacted by the protrusion of the container during the insertion of the container into the receiver, having a second slope to interact with the protrusion of the container to assist movement of the container towards the receiver. This construction provides the user with a changing insertion force to indicate proper mounting of the container.

A physical unclonable function (PUF) located on a supply item for an imaging device is disclosed. The PUF has a toothed rack configured to mate with a gear. During reading operations, the gear turns and translates the PUF linearly under a magnetic sensor. This configuration is inexpensive and robust. Other devices are disclosed.

An image indicating an option to purchase a contract cartridge according to a cancellation of a service contract may be displayed at a computer. The contract cartridge is useable in a contract state, and configured to be unusable in a normal (non-contract) state. In response to selection of the option, an instruction may be transmitted to modify a setting of the contract cartridge to allow use of the contract cartridge when the image forming apparatus is in the normal state.

A toner cartridge comprises a toner container which contains toner, a driving member which rotationally drives a conveying member, an agitating member which agitates a toner in the toner container while being rotated, a driven member which rotates in association with the driving member which is for rotationally driving the agitating member, and a rotational body which rotates according to rotation of the driven member, has a plurality of slits in rotational circumference for identifying a type of the toner cartridge, and has 1/K or more of the slits when a ratio of a rotational speed R1 (rad/s) of the driving member and a rotational speed R2 (rad/s) of the driven member is K=R2/R1.

A toner container is attachably and detachably formed at a container-attaching part of an image forming apparatus, and includes a first IC tag. The first IC tag is arranged on a circumferential surface of the toner container. The first IC tag makes communication with a reader arranged at the container-attaching part when the toner container is attached to the container-attaching part. The first IC tag cannot make communication with the reader when a distance between the first IC tag and the reader is less than a threshold distance (for example, less than 2 mm). With the first IC tag being arranged at a position opposite to the reader, the distance (for example, 1 mm) between the first IC tag and the reader is shorter than the threshold distance. The first IC tag is arranged at a position separate from the position opposite to the reader.

An image forming apparatus includes a main controller unit provided in a main body of the image forming apparatus. The main controller includes a replacement component management memory to store lifespan information of a replacement component is provided in An authentication operation is performed with respect to the replacement component management memory, and the lifespan information of the replacement component is encrypted and stored in the replacement component management memory. Accordingly, the security of the main controller unit may be enhanced and illegal use of the replacement component may be prevented.