An image forming apparatus includes: a casing having an opening; a cover for opening and closing the opening; a cartridge attachable to the casing through the opening; and a controller. The casing includes a first memory. The cartridge includes a second memory storing consumption state information representing a consumption state of the cartridge. The controller performs: determining whether the cartridge attached to the casing is unused; storing, when the attached cartridge is unused, the consumption state information acquired from the second memory in the first memory; determining, when the image forming apparatus is powered on or the cover is closed, whether the consumption state information in the first memory and the consumption state information in the second memory match; permitting use of the cartridge when the two sets of consumption state information match; and prohibiting use of the cartridge when the two set of consumption state information does not match.

A remaining-toner-amount detecting device includes: first sensor disposed at a supply channel for a toner; a second sensor disposed at a location different from the supply channel; detection processing that compares a capacitance detected by the first sensor with a determination threshold value to detect a toner end; and a memory that stores a capacitance detected by the second sensor in an initial period as initial reference data, and a capacitance detected by the second sensor after part replacement as post-replacement reference data. The detection processing circuitry sets, based on the initial reference data, the determination threshold value as an initial determination threshold value in the initial period, and re-sets the determination threshold value, from the initial determination threshold value, to a value based on the post-replacement reference data, as a post-replacement reference data after the part replacement.

An image forming apparatus to and from which a replenishment container accommodating toner is attachable includes a replenishment port to allow replenishment of toner from the replenishment container, which is arranged outside of the image forming apparatus, to a developer container therethrough in a state where the replenishment container is attached to the replenishment port, an opening/closing portion to open and close the replenishment port, and a locking member to move between a restricting position in which the locking member restricts movement of the opening/closing portion from the closed position to the open position, and an allowing position in which the movement of the opening/closing portion from the closed position to the open position is allowed. A controller maintains, when the replenishment container is attached to the replenishment port, the locking member in the restricting position in a case where a lifetime of the cartridge is less than a threshold.

An image forming apparatus includes a main body including a display, a drum cartridge configured to be mounted to the main bod, a toner cartridge configured to be mounted to the drum cartridge, and a controller. The drum cartridge includes a photosensitive drum, a developing chamber configured to accommodate toner, and a drum memory. The toner cartridge includes a housing configured to accommodate the toner. The controller is configured to store, in the drum memory, a cumulative toner receiving amount which is a cumulative amount of the toner supplied from the toner cartridge and received in the developing chamber, a cumulative toner consumption amount which is a cumulative amount of the consumed toner, and a cumulative drum printing sheet number which is a number of sheets on which an image is formed.

An example method of operating an image forming apparatus includes measuring a toner concentration supplied to a developing apparatus and increasing a driving speed of the developing apparatus based on the toner concentration not reaching a target toner concentration. The toner concentration is measured in a state where the driving speed of the developing apparatus is increased, and, based on the toner concentration not reaching the target toner concentration based on the driving speed of the developing apparatus being increased, an operating state of the image forming apparatus is determined based on a remaining amount of toner.

An image forming apparatus includes a developer container to and from which a replenishment container is attachable and detachable, the developer container including an accommodating portion, and a supporting portion, wherein the developer container includes a projection portion that is provided at one end portion thereof in the rotation axis direction of the developer bearing member and projects toward the supporting portion more than a center portion of the developer container in a crossing direction crossing the rotation axis direction, the projection portion communicates with the accommodating portion and includes, at a distal end portion thereof, an attachment portion configured such that the replenishment container is attachable thereto in a state of being exposed to the outside of the apparatus, and a replenishment port for replenishing the accommodating portion with developer from the replenishment container is defined in the attachment portion.

An example operation method of an image forming apparatus includes determining a state of a toner refill operation of injecting toner from a toner reload kit (TRK) into a cartridge in the image forming apparatus, based on completion of injecting toner from the TRK into the cartridge, controlling the TRK to store information indicating a toner refill completion in a memory of the TRK, based on completion of injecting toner from the TRK into the cartridge, updating information of an amount of remaining toner of the cartridge based on an amount of the toner injected into the cartridge from the TRK, and based on the information indicating the toner refill completion being stored in the memory of the TRK, unlocking a locking apparatus in the image forming apparatus so the TRK may be removed from the cartridge.

An image forming apparatus includes an intermediate transfer member, a cleaning member, and an image forming unit having a developer carrier. During an image forming job, when a ratio of an amount of toner consumed to a distance that the developer carrier is rotationally driven is greater than a threshold value, the image forming unit forms a first toner supply image for supplying toner to the cleaning member in a predetermined period that is from a time at which a first toner image is transferred to the intermediate transfer member to a time at which a second toner image is transferred to the intermediate transfer member. When the ratio is less than the threshold value, the image forming unit forms a second toner supply image for supplying toner to the cleaning member in the predetermined period and having a density that is higher than a first toner supply image density.

Printing apparatuses include a photoreceptor adapted to print an image by applying marking material to print media, a fuser adapted to heat the marking material on the print media, and a controller. The controller determines the amount of marking material per unit area of the image before the fuser heats the marking material on the print media. The controller rasterizes the image to produce a bitmap of the image, but the amount of marking material per unit area for the image is determined before completion of rasterization and marking of the image. The controller also adjusts the operating temperature of the fuser to a fusing temperature based on the amount of marking material per unit area of the image, causes the photoreceptor to print the image on the print media using the bitmap of the image, and causes the fuser to fuse the marking material to the print media.

An image forming apparatus of an embodiment includes an image forming unit, a waste toner collection container, a paddle motor, and a controller. The controller acquires a replenishment amount for each toner cartridge, when the image forming component is replenished with the toner from the plurality of toner cartridges, sets a coefficient for each replenishment amount of the toner cartridges, at least one of each set coefficient is different from the others, each of the replenishment amount is corrected by each coefficient, and drives the paddle motor according to a cumulative amount of each corrected replenishment amount.