An image forming apparatus includes: a detection unit configured to detect an amount of developer stored in a developing container and to output remaining amount information; and a control unit configured to perform control, during a replenishment of the developer to the developing container using a replenishment container, to cause a display unit to display a message related to the replenishment. When the replenishment is instructed, the control unit is further configured to perform a first control during the replenishment in a case where the remaining amount information indicates a first remaining amount, and configured to perform a second control different from the first control during the replenishment in a case where the remaining amount information indicates a second remaining amount greater than the first remaining amount.

A developing cartridge includes a casing, a developer-carrying member, a supply member, a developing electrode, a supply electrode, and an insulating member. The casing is configured to accommodate therein developer. The developer-carrying member is configured to rotate about a rotational axis and carry the developer thereon. The supply member is configured to supply the developer to the developer-carrying member. The developing electrode is configured to be electrically connected to the developer-carrying member. The supply electrode is configured to be electrically connected to the supply member. The insulating member insulates the developing electrode and the supply electrode with each other. The developing electrode, the insulating member, and the supply electrode are overlapped in this order in an axial direction of the rotational axis.

An image forming apparatus in an embodiment includes an image carrying body, a transfer body, a first mechanism, a sensor, and a second mechanism. The image carrying body carries an image of a developer. The image of the developer is transferred onto the transfer body from the image carrying body. The first mechanism separates the transfer body from the image carrying body. The sensor detects a state of the surface of the transfer body. The second mechanism separates the sensor from the transfer body in association with the first mechanism.

An image forming apparatus in an embodiment includes an image carrying body, a transfer body, a first mechanism, a sensor, and a second mechanism. The image carrying body carries an image of a developer. The image of the developer is transferred onto the transfer body from the image carrying body. The first mechanism separates the transfer body from the image carrying body. The sensor detects a state of the surface of the transfer body. The second mechanism separates the sensor from the transfer body in association with the first mechanism.

An image forming apparatus includes an image former; a detector; and a hardware processor that: calculates a minimum area for each of the plurality of tones based on image data of the image, calculates a density ratio between the densities before and after the transferring is made for each of the plurality of tones from the densities detected by the detector, extracts as a first area a minimum area of a tone corresponding to a density ratio which switches from less than a predetermined threshold to equal to or more than the threshold, and extracts as a second area a minimum area of a tone the density ratio of which is a maximum, and changes a setting of a dot size of the image so that a size of the second area becomes the same as a size of the first area until the next setting change is performed.

According to one embodiment, there is provided a toner cartridge used in an image forming apparatus including a processor which forms a toner pattern image on a photoconductive member, transfers the toner pattern image on a medium, and changes an image forming condition based on a detection result obtained by optically detecting the toner pattern image transferred onto the medium, the toner cartridge including: a toner accommodating container accommodating a toner, and a memory. The memory stores reference data which is determined according to toner characteristics in the toner accommodating container, and is used for applying a reference value for an optical detection result of a toner pattern formed by the toner on the medium.

An image forming apparatus includes a latent image bearer configured to bear a latent image and a developing device configured to develop the latent image on the latent image bearer with developer. The developing device includes a plurality of developer bearers configured to bear the developer. The image forming apparatus further includes a rotation position detector configured to detect a rotation position of at least one of the plurality of developer bearers, a common power source configured to apply a developing bias to each of the plurality of developer bearers, and circuitry configured to cause the common power source to periodically vary the developing bias. The circuitry is configured to cause the plurality of developer bearers to rotate in a same rotation period; and vary an output value of the developing bias in a same period as the rotation period based on a detection result by the rotation position detector.

An image forming apparatus, including: a photoconductor; a developing device; a developer storage; a supplier configured to supply developer; an optical sensor; and a controller configured to execute: a developing process of developing an electrostatic latent image on the photoconductor; a usage-amount obtaining process of obtaining a usage amount of the developer; a supplying process of supplying the developer to the developing device every time when the obtained usage amount becomes equal to or greater than a first threshold; and a detecting process of detecting, by the optical sensor, an amount of the developer in the developing device every time when the obtained usage amount becomes equal to or greater than a second threshold larger than the first threshold, and wherein the controller is configured to execute the detecting process in a period different from a period in which the developing process is being executed.

An image forming apparatus includes a latent image bearer, an electrostatic latent image forming device, a potential sensor, a toner image forming device, a toner adhesion amount detector, and circuitry. The circuitry controls the electrostatic latent image forming device to create an adjustment pattern on the latent image bearer when the image forming apparatus is not printing, controls the potential sensor to detect an electric potential of the adjustment pattern, controls the electrostatic latent image forming device and the toner image forming device to create a test toner image during a printing period, controls the toner adhesion amount detector to detect a toner adhesion amount of the test toner image, and adjusts at least one image forming condition of the electrostatic latent image forming device and the toner image forming device based on the electric potential of the adjustment pattern and the toner adhesion amount of the test toner image.

A developing cartridge includes a casing, a developer-carrying member, a supply member, a developing electrode, a supply electrode, and an insulating member. The casing is configured to accommodate therein developer. The developer-carrying member is configured to rotate about a rotational axis and carry the developer thereon. The supply member is configured to supply the developer to the developer-carrying member. The developing electrode is configured to be electrically connected to the developer-carrying member. The supply electrode is configured to be electrically connected to the supply member. The insulating member insulates the developing electrode and the supply electrode with each other. The developing electrode, the insulating member, and the supply electrode are overlapped in this order in an axial direction of the rotational axis.