The control unit executes a mode of detecting the image density of the toner image for control. The control unit sets the target toner density so that the target toner density becomes smaller than before execution of the mode and also set the target transfer current so that the target transfer current becomes smaller, in a case where the image density detected in the mode is higher by a predetermined threshold or more than a reference density.

An image forming apparatus includes an acquisition unit and a determination unit. The acquisition unit acquires a print setting about at least one of items including a size of a recording medium used for printing, a type of the recording medium, and a conveyance speed of the recording medium. The determination unit determines a printing method to be executed among a plurality of printing methods including a first printing method for drawing an image having a density and a second printing method for drawing an image having a density that is higher than the density of an image printed by the first printing method. Where the print setting is acquired by the acquisition unit, the determination unit determines whether to permit execution of printing by the second printing method based on the print setting acquired by the acquisition unit.

According to one embodiment, a developing device forms a toner image on a photoconductive image carrier with toner supplied from a toner cartridge. A toner concentration sensor detects a toner concentration in the developing device. A toner supply motor supplies the toner from the toner cartridge to the developing device based on the toner concentration. A processor detects an empty toner based on a toner supply rate, a print rate of the image data, and toner characteristics that are characteristics of the toner supplied from the toner cartridge to the developing device, the toner supply rate being calculated based on a pixel count value that is an integrated value of pixel values of the image data and a toner supply motor count value that is an integrated value of drive times of the toner supply motor.

In an example, a printing device may include a cartridge including a print substance, a belt, and a controller including a processing resource and a memory resource. The processing resource may execute instructions to deposit a plurality of patches of the print substance from the cartridge onto the belt to determine a cartridge density based on a density of a sub-set of patches of the plurality of patches; and adjust a print substance output of the cartridge based on the determined density of the print substance in the cartridge.

An imaging system includes a storage container, a separating device and a restoring device. The storage container stores a developer including carrier and toner having restoring properties. The separating device separates the developer in the storage container into the carrier and the toner. The restoring device restores properties of the carrier and the toner generated by the separating device.

A print apparatus is disclosed. The print apparatus comprises a container-receiving unit for receiving a reusable print agent container; a print agent reservoir for storing print agent to be consumed by the print apparatus during a printing operation; a pump for transferring print agent between a reusable print agent container positioned in the container-receiving unit and the print agent reservoir; and processing circuitry. The processing circuitry is to operate the pump to transfer print agent of a first concentration from the reusable print agent container to the print agent reservoir; and, responsive to determining that a volume of print agent of the first concentration in the reusable print agent container has fallen below a threshold volume, operate the pump to transfer a volume of print agent of a second, lower concentration from the print agent reservoir to the reusable print agent container. A method and a machine-readable medium are also disclosed.

An image forming apparatus includes a developing device to contain a developer, the developer including a toner; a developer cartridge to supply the developer to the developing device; a toner concentration sensor to sense a toner concentration of the toner included in the developer contained in the developing device; and a controller. The controller controls, during a non-printing operation a sensor control voltage to adjust an output level of the toner concentration sensor, to control an output of the toner concentration sensor to satisfy a controlling condition, and detects an shape of the output of the toner concentration sensor after the controller controls the sensor control voltage to adjust the output level. The controller adjusts, during a printing operation, the output of the toner concentration sensor, based on the detected shape of the output of the toner concentration sensor, and adjusts supplying the developer from the developer cartridge to the developing device, according to the adjusted output of the toner concentration sensor, to control the toner concentration.

Examples described herein relate to a system consistent with the disclosure. For instance, the system may comprise a printing device including hardware to adjust a velocity of a development unit within the printing device, a memory resource, and a controller in communication with the memory resource to determine an average usage condition of the printing device, wherein the average usage condition is based on at least one of a print coverage and a quantity of pages printed by the printing device, and adjust a velocity of the development unit based on the average usage condition.

According to one embodiment, an apparatus includes a photoconductor, an exposure device, a developing device, a toner concentration sensor, a supply motor, and a processor. The exposure device exposes the photoconductor based on image data. The developing device forms a toner image on the photoconductor with toner supplied from a toner cartridge. The toner concentration sensor detects a toner concentration in the developing device. The supply motor supplies the toner from the toner cartridge to the developing device based on the toner concentration. The processor detects a toner container supply abnormality based on a toner supply rate and a print rate of the image data, the toner supply rate being calculated based on a pixel count value that is an integrated value of pixel values of the image data and a supply motor count value that is an integrated value of drive times of the supply motor.

An image forming apparatus includes a developer container, an agitator, a toner supply, a toner sensor, and a controller. The developer container contains a two-component developer that includes toner and carrier. The agitator stirs the two-component developer. The toner supply replenishes the developer container with additional toner. The toner sensor detects a toner density of the two-component developer in the developer container. The controller calibrates the toner sensor using the two-component developer. The controller compares a first detection value indicating a toner density at a first time with a second detection value indicating a toner density at a second time after a predetermined time period has elapsed since the first time. The controller issues a notification regarding a suitability of calibration based on a comparison result of the first detection value and the second detection value.