An image forming apparatus includes a motor, a container detection sensor, and a controller. When a toner container is attached, the motor generates a driving force for rotating a toner conveying member in the toner container. The container detection sensor is arranged at a position where the container detection sensor comes into contact with an outer periphery of a cam connected to the toner conveying member when the toner container is attached. The controller distinguishes between at least three attachment states of the toner container based on a sensor signal of the container detection sensor.

An image forming device may comprise: an attaching unit to which a removable toner bottle is attached; a toner storage that stores toner supplied from the toner bottle attached to the attaching unit; a detector that detects an empty state of toner in the toner storage; and a hardware processor that: supplies toner to the toner storage from the toner bottle when the toner bottle attached to the attaching unit is new; and switches a state of the toner bottle to an old state from a new state if the empty state detected by the detector is released.

In an image forming apparatus, a consumable is mounted in the main casing. The consumable includes a consumable memory. A controller performs a consumable determination process to determine based on type information stored in a consumable memory whether the consumable mounted in the main casing is a special consumable. The controller performs a transmission process in a case where the consumable determination process determines that the consumable mounted in the main casing is the special consumable. The transmission process transmits via the communication interface a request to an external device which communicates with the image forming apparatus. The request is to cancel an agreement which is concluded for another image forming apparatus as a contract subject. The another image forming apparatus is different from the image forming apparatus.

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.

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.

A process cartridge mountable in and dismountable from an image forming apparatus includes a frame, a storing portion provided on a mounting surface of the frame and configured to store information on the process cartridge, a projection projecting outwardly of the mounting surface in a direction normal to the mounting surface, and an electrical contact portion mounted on the projection and electrically connected to the storing portion.

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.

An image forming device may comprise: an attaching unit to which a removable toner bottle is attached; a toner storage that stores toner supplied from the toner bottle attached to the attaching unit; a detector that detects an empty state of toner in the toner storage; and a hardware processor that: supplies toner to the toner storage from the toner bottle when the toner bottle attached to the attaching unit is new; and switches a state of the toner bottle to an old state from a new state if the empty state detected by the detector is released.

The image forming apparatus includes a user interface, a controller, and a main memory. The controller provides an error notification to the user interface in a case where drum cartridge information read from the main memory does not match drum-cartridge identification information stored in a drum-cartridge memory of a drum cartridge and replacement of the drum cartridge replacement is not necessary. The controller may also provide an error notification to the user interface in a case where a toner cartridge information read from the main memory does not match toner-cartridge identification information stored in a toner-cartridge memory of a toner cartridge and replacement of the toner cartridge is not necessary.

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.