An image forming device including an image carrier, a charge device, a developer device, power supply circuitry that applies a charge bias and a developer bias to the charge device and the developer device, respectively, a detector, and a hardware processor that operates as: a control unit that changes a fogging margin, which is a difference between charge bias and developer bias, and controls the power supply circuitry to set the charge bias and developer bias accordingly; a calculation unit that calculates amounts of change between detected values; and a determination unit that obtains differences between amounts of change, determines whether each difference is less than a defined value, and determines a position of a boundary between a first range greater than or equal to the defined value and a second range less than the defined value as a fogging margin to be used in forming a print image.

Provided is an image forming apparatus, including: an image bearing member; an exposure unit; a developing member which is rotatable at a rotation speed different from the image bearing member; a developer supply member; a developing voltage-applying unit; a supply voltage-applying unit; and a control unit. The control unit controls execution of: an image forming operation in which a developer image is formed by supplying developer on the image bearing member; and a cleaning operation which removes a substance adhered to the image bearing member using the developing member. In the cleaning operation, the control unit controls the developing voltage-applying unit or the supply voltage-applying unit so that the cleaning force using the developing member becomes stronger than that in the image forming operation.

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 an image carrier, a charger, a developing member, a motor, a drive controller, and an application controller. The image carrier is rotatably provided. The charger charges the image carrier to a predetermined first polarity by receiving application of a voltage of the first polarity. The developing member develops an electrostatic latent image formed on the image carrier using the toner charged to the first polarity. The motor rotates the image carrier. The drive controller executes stop control for stopping driving of the motor. The application controller stops voltage application to the charger based on a current flowing through the motor after execution of the stop control.

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.

Provided is an image forming apparatus, including: an image bearing member; an exposure unit; a developing member which is rotatable at a rotation speed different from the image bearing member; a developer supply member; a developing voltage-applying unit; a supply voltage-applying unit; and a control unit. The control unit controls execution of: an image forming operation in which a developer image is formed by supplying developer on the image bearing member; and a cleaning operation which removes a substance adhered to the image bearing member using the developing member. In the cleaning operation, the control unit controls the developing voltage-applying unit or the supply voltage-applying unit so that the cleaning force using the developing member becomes stronger than that in the image forming operation.

A region of an image bearing member that comes into contact with a recording material at a nip in a state in which the recording material is held by the nip is a first region, and a region of the image bearing member that does not come into contact with the recording material at the nip in a state in which the recording material is not held by the nip is a second region. A controller controls to apply a first developing voltage to a developer bearing member when the first region in which a first surface potential has been formed faces a developer bearing member and apply a second developing voltage lower than an absolute value of the first developing voltage to the developer bearing member when the second region in which a second surface potential has been formed faces the developer bearing member.

An image forming apparatus includes a first container to accommodate liquid developer for replenishment to a developing container, and a second container to accommodate carrier fluid containing a charge control agent for replenishment to the first container. The concentration of the charge control agent in the carrier fluid accommodated in the second container is between equal to or more than 10 wt % and equal to or less than 20 wt %. A driving unit is driven so as to replenish the charge control agent accommodated in the second container to the first container, and a control unit controls the driving unit based on image coverage of an output image so that a concentration of the charge control agent in the liquid developer accommodated in the first container becomes a predetermined value.

An electrostatic printer comprises a charging unit, a photoconductor member, an imaging unit, a developer unit and a controller. The charging unit is to charge the photoconductor member to a charged voltage. The imaging unit is to generate a latent electrostatic image on the photoconductor member by discharging areas of the charged photoconductor member. The developer unit is to develop a toner image on the photoconductor member using a developer voltage. The controller is to change the developer voltage, and to change the charged voltage dependent on the change of the developer voltage.

An example method of controlling a printing process in accordance with aspects of the present disclosure includes controlling an optical density of a printed image such that the optical density is increased for a predetermined portion of a leading edge of a page.