In an example of the disclosure, service rotation of a drum along a longitudinal axis of the drum is caused. The service rotation is to apply a centrifugal force upon a liquid held by the drum. The centrifugal force pushes gas bubbles in the drum away from a curved surface of the drum and towards the longitudinal drum axis. The gas bubbles evacuate from the drum via an outlet tube positioned adjacent to the longitudinal drum axis. A production rotation of the drum is caused after the service rotation.

In an example of the disclosure, service rotation of a drum along a longitudinal axis of the drum is caused. The service rotation is to apply a centrifugal force upon a liquid held by the drum. The centrifugal force pushes gas bubbles in the drum away from a curved surface of the drum and towards the longitudinal drum axis. The gas bubbles evacuate from the drum via an outlet tube positioned adjacent to the longitudinal drum axis. A production rotation of the drum is caused after the service rotation.

An image forming apparatus, having a casing, a drum unit including first and second lateral walls and first and second photosensitive drums, first and second cartridges supported by the drum unit, first and second operable members, is provided. The first operable member and the second operable member press the first developing cartridge and the second developing cartridge, respectively, in a direction from the first lateral wall toward the second lateral wall to move the first and second developing rollers from the respective contacting positions to respective separated positions. The casing includes a restrictive portion. When the drum unit is attached to the casing, the restrictive portion restricts movement of the drum unit causable by at least one of a pressing action of the first operable member to press the first developing cartridge and a pressing action of the second operable member to press the second developing cartridge.

A toner cartridge according to one example embodiment includes a developer roll and a toner adder roll. First and second drive gears are rotatably connected to and coaxial with the developer roll and toner adder roll, respectively. The toner cartridge includes a drive coupler exposed to receive rotational motion when the toner cartridge is installed in an image forming device. Gear teeth of the first drive gear are directly meshed with gear teeth of the drive coupler of the toner cartridge. The second drive gear is rotatably connected to the drive coupler through a pair of idler gears.

A toner cartridge according to one example embodiment includes a developer roll and a toner adder roll. First and second drive gears are rotatably connected to and coaxial with the developer roll and toner adder roll, respectively. The toner cartridge includes a drive coupler exposed to receive rotational motion when the toner cartridge is installed in an image forming device. Gear teeth of the first drive gear are directly meshed with gear teeth of the drive coupler of the toner cartridge. The second drive gear is rotatably connected to the drive coupler through a pair of idler gears.

An image forming apparatus, having a casing, a drum unit including first and second lateral walls and first and second photosensitive drums, first and second cartridges supported by the drum unit, first and second operable members, is provided. The first operable member and the second operable member press the first developing cartridge and the second developing cartridge, respectively, in a direction from the first lateral wall toward the second lateral wall to move the first and second developing rollers from the respective contacting positions to respective separated positions. The casing includes a restrictive portion. When the drum unit is attached to the casing, the restrictive portion restricts movement of the drum unit erasable by at least one of a pressing action of the first operable member to press the first developing cartridge and a pressing action of the second operable member to press the second developing cartridge.

A roll includes an electrically-conductive shaft; an elastic layer provided on the shaft; and a non-electrically-conductive annular unit that is attached to at least one of ends of the shaft that protrude from end surfaces of the elastic layer in a shaft direction while being in contact with the end surface of the elastic layer. A protruding part that protrudes so as to cut into the end surface of the elastic layer is provided on a part of the annular unit that makes contact with the end surface of the elastic layer, and the protruding part has a thickness smaller than a thickness of the part of the annular unit that makes contact with the end surface of the elastic layer.

A printing apparatus is described comprising a photoconductor for receiving an electrostatic charge pattern corresponding to an image, and one or more developers for applying a colorant to the photoconductor representative of the image. The apparatus further comprises a transfer member for transferring the image from the photoconductor onto a substrate, wherein the transfer member has a substantially grounded potential.

A transfer member for a printing device includes a shaft, a rigid cylindrical core member, mounted on the shaft, an outer layer supported on the rigid cylindrical core member, and optionally a conformable intermediate layer, spacing the cylindrical core member from the outer layer. The outer layer defines an outer surface of the transfer member, and is configured for receiving a toner image thereon. The cylindrical core and outer layer have a same axis of rotation as the shaft. The rigid cylindrical core and/or the conformable intermediate layer, where present may be electrically biased, relative to a photoconductor drum of the printing device.

A printing apparatus is described comprising a photoconductor for receiving an electrostatic charge pattern corresponding to an image, and one or more developers for applying a colorant to the photoconductor representative of the image. The apparatus further comprises a transfer member for transferring the image from the photoconductor onto a substrate, wherein the transfer member has a substantially grounded potential.