In an authenticity determination system, an image forming apparatus acquires apparatus identification information for identifying the image forming apparatus from a memory of the image forming apparatus, and consumables container identification information for identifying a container of predetermined consumables from the container of the consumables mounted in the image forming apparatus. A server stores the apparatus identification information and the consumables container identification information in association with each other, receives the apparatus identification information and the consumables container identification information transmitted from the image forming apparatus, and determines whether the received apparatus identification information and the received consumables container identification information are stored in association with each other. When the information on the determination is affirmative, the image forming apparatus executes printing based on output source identification information including the apparatus identification information and the consumables container identification information on an output using the predetermined consumables.

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.

Provided is an image forming apparatus to and from which a replenishment container accommodating toner is attachable and detachable and which is configured to form a toner image on a recording material, the image forming apparatus including an image bearing member, a developer container, a developing bearing member, a replenishment port through which the developer container can be replenished with toner, a restriction member capable of transitioning to an allowance state in which a rotation of the replenishment container is allowed and to a restriction state in which the rotation of the replenishment container is restricted, a notification portion configured to notify a replenishment procedure for replenishing the developer container with toner from the replenishment container, and a controller configured to cause the notification portion to notify at least one step of the replenishment procedure.

An image forming apparatus includes a photoreceptor, a charger, an exposure unit, and a control unit. The charger charges a surface of the photoreceptor. The exposure unit exposes the photoreceptor charged by the charger using a light-emitting diode. The amount of light of a light-emitting diode gradually decreases over time. The control unit controls the exposure unit so that exposure energy by the exposure unit is constant.

An image forming apparatus includes a main unit, a main unit memory, a drum cartridge, a toner cartridge, and a controller. The main unit memory stores printer identification information. The drum cartridge includes a drum memory that stores drum identification information. The toner cartridge includes a toner memory that stores toner identification information. The controller is configured to store in the main unit memory the drum identification information stored in the drum memory and store in the drum memory the printer identification information stored in the main unit memory, if it determines that the drum cartridge installed in the main unit is new, and store in the main unit memory the toner identification information stored in the toner memory and store in the toner memory the drum identification information stored in the drum memory, if it determines that the toner cartridge installed in the main unit is new.

In an example, a method includes printing a set of images by transferring print agent between a roller of a print agent source and an electrophotographic surface in a plurality of transfer operations, wherein the roller is controlled to have a first voltage profile during each of the transfer operations. A variation in optical density which is consistent across the set of printed images may be detected, and a second voltage profile correction may be determined based on the variation in optical density. The method may further comprise printing a subsequent image by transferring print agent between the print agent source roller and the electrophotographic surface in a subsequent transfer operation, wherein the roller is controlled to have the second voltage profile during the subsequent transfer operation.

An example system may include a plurality of print devices, a supply attachment, and a device remote to the plurality of print devices. The plurality of print devices may receive the supply attachment. The device remote to the plurality of print devices may receive signals via the supply attachment that are indicative of print device information data from the plurality of print devices.

An example image forming apparatus includes a charger, a developing device, a sensor, and a controller. The charger may apply a plurality of charging voltages to a photoconductor, the plurality of charging voltages having different magnitudes and respectively corresponding to a plurality of area sections constituting a test pattern and the developing device may supply a developer to the photoconductor. The sensor may sense an image formed by the supplied developer and corresponding to the test pattern. The controller may determine a remaining lifetime of the photoconductor based on the image corresponding to the test pattern.

An image forming apparatus includes a developing roller, a motor, a motor control portion configured to control the motor, a drive switching unit configured to switch between transmission and non-transmission of the rotational driving force of the motor relative to the developing roller, a current detection portion configured to detect a current value of a current to the motor, and an acquisition unit configured to acquire information relating to a rotation amount of the developing roller. The acquisition unit is configured to acquire the information relating to the rotation amount of the developing roller on the basis of a transmission timing at which the rotational driving force is allowed to be transmitted to the developing roller by the drive switching unit and a non-transmission timing at which the rotational driving force is prevented from being transmitting to the developing roller by the drive switching unit.

An image forming system includes a recording processing portion, an acquirement processing portion, and an output processing portion. The recording processing portion records a consumed amount of a consumable consumed by an image forming apparatus per predetermined unit time. The acquirement processing portion acquires prediction data that indicates a predicted consumed amount of the consumable per the unit time for a time period from a predetermined standard time, based on a comparison result between: a first record result corresponding to a first time period extending to a reference time; and a second record result corresponding to a predetermined second time period extending to the standard time, among a record result recorded by the recording processing portion, the reference time being a predetermined specific time period earlier than the standard time. The output processing portion outputs the prediction data acquired by the acquirement processing portion.