An image forming apparatus controls the number of rotations of a photosensitive drum based on information related to the use of the photosensitive drum and a suspension time in a rotation operation of rotating the photosensitive drum after a lapse of the suspension time between a first image forming operation of forming an image on a transfer material and a second image forming operation performed after the first image forming operation.

Provided is a toner transfer device including: a carrier device that includes a surface on which a charged toner is carried; an electrode that attracts the toner from the surface of the carrier device; a conveyance path of a print medium which is formed between the carrier device and the electrode; and a power supply device that causes a potential difference to occur between the carrier device and the electrode to transfer the toner from the carrier device onto the print medium when the print medium is located in the conveyance path.

An electrostatic image developing toner includes toner particles containing a binder resin. In a differential scanning calorimetry curve of the toner particles, Tg1 is 58° C. or more and 68° C. or less, and Tg1−Tg2 is 20° C. or more and 40° C. or less, where Tg1 is a lowest onset temperature in an endothermic change during a first temperature increase, and Tg2 is a lowest onset temperature in an endothermic change during a second temperature increase.

An electrostatic image developing toner includes toner particles containing a binder resin. In a differential scanning calorimetry curve of the toner particles, Tg1 is 58° C. or more and 68° C. or less, and Tg1−Tg2 is 20° C. or more and 40° C. or less, where Tg1 is a lowest onset temperature in an endothermic change during a first temperature increase, and Tg2 is a lowest onset temperature in an endothermic change during a second temperature increase.

An image forming apparatus includes a developing device that forms a toner image, by developing an electrostatic latent image formed on a photoconductor drum, a charging device that electrically charges the photoconductor drum, a developing power source that applies a predetermined developing bias voltage to the developing device, and a calculation device that calculates a surface potential of the photoconductor drum, on a basis of the developing current flowing in the developing device. The developing power source applies the developing bias voltage in a plurality of levels, to the developing device. A current measurement device measures a developing current, with respect to the developing bias voltage of each level. The calculation device calculates the surface potential, on the basis of each developing current.

An image forming apparatus includes a rotatable photosensitive member, a charging member, an exposure unit, a developing member, a developing voltage applying portion, a transfer member, a first transfer voltage applying portion, a second transfer voltage applying portion, a common power source, and a controller. The controller carries out control so as to execute an image forming operation, and a non-image forming operation and so as to execute, as the non-image forming operation, a cleaning operation. The controller controls a change in output of the common power source so that a value of a voltage applied from the developing voltage applying portion to the developing member during the cleaning operation is made different from a value of a voltage applied from the developing voltage applying portion to the developing member during formation of the toner image.

An image forming apparatus includes an image carrier, a charging device, a developing device, a transfer device, a development power supply, a current measurement device, and a processor. The development power supply applies a predetermined bias voltage to the developing device. The processor functions as a calculator and a controller. The calculator calculates a surface potential of the image carrier based on the development current measured by the current measurement device. The controller controls the charging device, the developing device, the transfer device, and the development power supply. The controller sets a tentative transfer current to be flowed through the transfer device while the calculator calculates the surface potential.

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.

An image forming apparatus includes a developer bearing member, a supply member, first and second voltage application units, and a control unit. Assuming that a difference between a voltage to be applied to the developer bearing member by the first voltage application unit and a voltage to be applied to the supply member by the second voltage application unit in the image forming operation is defined as a first supply contrast, and a difference between the voltage to be applied to the developer bearing member by the first voltage application unit and the voltage to be applied to the supply member by the second voltage application unit in the preliminary rotation operation is defined as a second supply contrast, the control unit controls the second supply contrast to be less than the first supply contrast or to have polarity reversed from polarity of the first supply contrast.

A developing cartridge includes a casing, a rotating member, and an electrode member. The casing may be configured to accommodate therein developer. The rotating member has a rotational shaft extending in an axial direction. The rotating member is configured to rotate about the rotational shaft and carries the developer thereon. The electrode member is configured to be electrically connected to the rotating member. The electrode member covers at least part of the rotational shaft from an orthogonal direction orthogonal to the axial direction and is arranged to confront the casing in the axial direction. The electrode member is configured to move in the orthogonal direction in accordance with a movement in the axial direction.