Abstract: An image forming apparatus including a housing, a toner cartridge, and a drum unit. The drum unit is movable through the opening between an accommodated position where the drum unit is positioned in the housing and a pulled-out position where the drum unit is pulled out of the housing. The drum unit includes a photosensitive drum and a developing unit. The photosensitive drum is rotatable about a first axis extending in a second direction. The developing unit includes a magnetic roller, a developer container, a first auger and a second auger. The magnetic roller is positioned between the toner cartridge and the photosensitive drum. The magnetic roller faces a surface of the photosensitive drum. The developer container is formed with an inlet allowing the toner to be replenished from the toner cartridge. The first auger is positioned in the developer container. The second auger is positioned in the developer container.

Abstract: A drum unit includes a photosensitive drum, a developing unit, a toner cartridge, a connector and a relay board. The photosensitive drum is rotatable about a first axis extending in an axial direction. The developing unit includes a magnetic roller, a developer container, a conveyer member and a toner sensor. The developer container accommodates therein carrier, and has an inlet. The conveyer member is positioned in the developer container, and configured to convey toner and the carrier from the inlet toward the magnetic roller. The toner cartridge accommodates therein toner and is attachable to the developer container to replenish toner in the developer container through the inlet. The connector is electrically connected to an image forming apparatus. The relay board electrically connects the toner sensor to the connector. The relay board is configured to transmit a detection signal from the toner sensor to the image forming apparatus.

Abstract: A developing cartridge is attachable to a drawer that is movable in a first direction relative to a main housing of an image forming apparatus. The developing cartridge includes: a casing having a toner chamber; and a developing roller positioned at one end of the casing in a second direction and rotatable about an axis extending in a third direction. The casing includes: a recessed portion recessed from an outer surface of the casing toward the developing roller; a first wall extending in the second direction; and a first boss positioned inside the toner chamber. The recessed portion is positioned at a center in the third direction of another end of the casing in the second direction. The first wall and the second wall form the toner chamber. The first boss extends from the first wall to be connected to the second wall.

Abstract: A toner cartridge includes: a casing; a conveyer member rotatable about an axis; a shutter rotatable about the axis between a closed position and an open position; a toner coupling rotatable about the axis; a planet carrier rotatable about the axis with the toner coupling; a planetary gear rotatable about a pin of the planet carrier and rotatable about the axis in accordance with the rotation of the planet carrier; and a ring gear meshing with the planetary gear and rotatable about the axis with the shutter. When the shutter moves from the closed position to the open position, the planetary gear is not rotatable about the pin and is rotatable about the axis with the ring gear. In a state where the shutter is at the open position, the planetary gear is rotatable about the pin and is rotatable about the axis relative to the ring gear.

Abstract: A drum cartridge attachable to and detachable from a main frame of an image forming apparatus includes: a photosensitive drum; a drum frame; and a drum contact. The photosensitive drum is rotatable about a drum axis extending in a first direction. A toner cartridge including a storage medium having an electrical contact surface is attachable to and detachable from the drum frame. In a state where the toner cartridge is attached to the drum frame, the drum contact is movable in the first direction between: a separated position in which the drum contact is positioned away from the electrical contact surface; and a contacting position in which the drum contact is in contact with the electrical contact surface. The drum contact moves from the separated position to the contacting position in accordance with attachment of the drum cartridge to the main frame.

Abstract: An image forming apparatus including a housing, a toner cartridge, and a drum unit. The drum unit is movable through the opening between an accommodated position where the drum unit is positioned in the housing and a pulled-out position where the drum unit is pulled out of the housing. The drum unit includes a photosensitive drum and a developing unit. The photosensitive drum is rotatable about a first axis extending in a second direction. The developing unit includes a magnetic roller, a developer container, a first auger and a second auger. The magnetic roller is positioned between the toner cartridge and the photosensitive drum. The magnetic roller faces a surface of the photosensitive drum. The developer container is formed with an inlet allowing the toner to be replenished from the toner cartridge. The first auger is positioned in the developer container. The second auger is positioned in the developer container.

Abstract: A drum unit includes a photosensitive drum, a developing unit, a toner cartridge, a connector and a relay board. The photosensitive drum is rotatable about a first axis extending in an axial direction. The developing unit includes a magnetic roller, a developer container, a conveyer member and a toner sensor. The developer container accommodate therein carrier, and has an inlet. The conveyer member is positioned in the developer container, and configured to convey the toner and the carrier from the inlet toward the magnetic roller. The toner cartridge accommodate therein toner and is attachable to the developer container to replenish the toner in the developer container through the inlet. The connector is electrically connected to the image forming apparatus. The relay board electrically connects the toner sensor to the connector. The relay board is configured to transmit a detection signal from the toner sensor to the image forming apparatus.

Abstract: An image forming apparatus including a housing, a toner cartridge, and a drum unit. The drum unit is movable through the opening between an accommodated position where the drum unit is positioned in the housing and a pulled-out position where the drum unit is pulled out of the housing. The drum unit includes a photosensitive drum and a developing unit. The photosensitive drum is rotatable about a first axis extending in a second direction. The developing unit includes a magnetic roller, a developer container, a first auger and a second auger. The magnetic roller is positioned between the toner cartridge and the photosensitive drum. The magnetic roller faces a surface of the photosensitive drum. The developer container is formed with an inlet allowing the toner to be replenished from the toner cartridge. The first auger is positioned in the developer container. The second auger is positioned in the developer container.

Abstract: An image forming apparatus includes a controller capable of performing a printing control and a cleaning control. In the printing control, developer images carried on the image carriers are transferred toward the opposing surface or a recording sheet by applying a transfer current between each of the image carriers and the transfer device. In the cleaning control, developer collected by the cleaning rollers is transferred toward the image carriers and the transfer device and collected by the cleaning device by applying a transfer current between each of the image carriers and the transfer device and switching an electric field established between the image carrier and the corresponding cleaning roller. The controller is configured to control the transfer current such that an average absolute value of the transfer current in the cleaning control is smaller than that in the printing control.