A developing cartridge includes a casing having an outer surface, a developing roller, a first electrode, and a boss. The developing roller is movable together with the casing and includes a developing roller shaft extending along a first axis extending in a first direction. The developing roller is rotatable about the first axis. The first electrode is positioned at one end portion in the first direction of the developing roller shaft, and electrically connected to the developing roller shaft. The boss is positioned at one end portion in the first direction of the outer surface. The boss extends in the first direction and is engageable with the drum unit. A part of the first electrode is configured to contact with a second electrode of the drum unit as a result of pivotal movement of the developing cartridge about the boss relative to the drum unit.

A charging member may include a surface layer. The surface layer may include a urethane resin, an electron conducting agent, an azo-based metal complex compound, and a quaternary ammonium salt.

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.

An image forming apparatus includes a photosensitive member, a charging member, a charging power source, a developing member, a transfer member, a transfer power source, an acquiring portion, and a controller. The controller controls a charging voltage to be a first charging voltage when an electric resistance value of the transfer member is a first resistance value and to be a second charging voltage not less than the first charging voltage in absolute value when the electric resistance value is a second resistance value lower than the first resistance value, and so that a charge amount of the charging voltage when the electric resistance value is changed from the second resistance value to a third resistance value lower than the second resistance value is larger than a change amount of the charging voltage when the electric resistance value is changed from the first resistance value to the second resistance value.

An image forming operation forms an image on a transfer target in a state in which a developing member is located at a first position where a developer is supplied to an image bearing member and a first charging voltage is applied to a charging unit. The image forming operation is followed by: a first rotating operation of rotating the image bearing member in a state in which the developing member is located at the first position and a second charging voltage smaller in absolute value than the first charging voltage is applied; and a second rotating operation of rotating the image bearing member in a state in which the developing member is located at a second position where the developer is not supplied to the image bearing member and a third charging voltage smaller in absolute value than the second charging voltage is applied.

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.

An image forming apparatus includes a rotatable photosensitive member, a charging member, an exposure unit, a developing member, a transfer member, and a pre-exposure unit. The pre-exposure unit exposes a surface of the photosensitive member after the toner image is transferred to the recording material and before being charged by the charging member. The pre-exposure unit includes a substrate disposed adjacent to one end of the photosensitive member with respect to a longitudinal direction of the photosensitive member, and in which a first light emitting element and a second light emitting element having directional characteristics narrower than that of the first light emitting element are mounted.