An image forming apparatus includes an apparatus body including an image forming unit, a unit detachably attached to the apparatus body, a first rotary member provided in the unit, a second rotary member provided in the apparatus body and configured to be coupled with and decoupled from the first rotary member by being moved in a rotation axial direction of the first rotary member, and a restriction member provided in the apparatus body and movable to a first position and a second position. The restriction member includes an engaging portion configured to engage with the second rotary member and is configured to move the second rotary member by the engaging portion so that the second rotary member is decoupled from the first rotary member along with a move of the restriction member from the first position to the second position.

A powder transporting device includes: a circulation path that receives and accommodates a developer from multiple toner cartridges filled with the developer, and along which the accommodated developer is transported while circulating; a first supply port that allows the developer to be fed onto the circulation path; a transport path that merges with the circulation path at a portion of the circulation path upstream from the first supply port to allow the developer to be transported therealong into the circulation path; a second supply port through which the developer is fed to the transport path; a detector that detects the developer accommodated in the circulation path; a first transporter that transports the developer in the circulation path at a first transport speed; and a second transporter that extends along the transport path in the circulation path, and that transports the developer into the circulation path at a second transport speed higher than the first transport speed.

According to one embodiment, the image forming apparatus includes a developing device and a control unit. The developing device includes a rotator for rotating to cause a developer contained in a container to flow, and performs development using the developer. The control unit has a first control for rotating the rotator in a first direction during development. The control unit has a second control that rotates the rotator in a second direction opposite to the first direction at a predetermined timing when development is not performed. When the second control is performed a plurality of times during a predetermined period, the control unit gradually reduces an interval at which the second control is performed.

A developing apparatus includes: a housing that accommodates developer and has a plurality of constituent parts; a vibrator that vibrates parts, which are two or more of the plurality of the constituent parts and to which scattered toner may adhere, as vibrated portions; an adjuster provided for at least one of the vibrated portions and the vibrator so as to adjust and match natural frequencies of the two or more of the vibrated portions; and a hardware processor that controls the vibrator.

A developing apparatus includes: a housing that accommodates developer and has a plurality of constituent parts; a vibrator that vibrates parts, which are two or more of the plurality of the constituent parts and to which scattered toner may adhere, as vibrated portions; an adjuster provided for at least one of the vibrated portions and the vibrator so as to adjust and match natural frequencies of the two or more of the vibrated portions; and a hardware processor that controls the vibrator.

An image forming apparatus includes an apparatus body including an image forming unit, a unit detachably attached to the apparatus body, a first rotary member provided in the unit, a second rotary member provided in the apparatus body and configured to be coupled with and decoupled from the first rotary member by being moved in a rotation axial direction of the first rotary member, and a restriction member provided in the apparatus body and movable to a first position and a second position. The restriction member includes an engaging portion configured to engage with the second rotary member and is configured to move the second rotary member by the engaging portion so that the second rotary member is decoupled from the first rotary member along with a move of the restriction member from the first position to the second position.

A developing cartridge can be detachably installed on a drum cartridge in an image forming apparatus, where a mounting cavity is provided on the drum cartridge and a photosensitive drum and a first groove wall are provided in the mounting cavity. The developing cartridge includes: a casing having a first side and second side arranged oppositely along a first direction, where the casing can be installed in the mounting cavity along a second direction; a developing roller rotatably arranged in the casing, where the rotation axis of the developing roller is parallel to the first direction; and a separator including a force-receiving part, where a first inclined surface is formed on the force-receiving part, and the first inclined surface receives a separation force provided by the image forming apparatus and drives the casing to move in a direction away from the photosensitive drum.