Provided is an image formation device including a photoreceptor configured to carry a toner image and a developer configured to form the toner image on a surface of the photoreceptor and configured such that the developer is a replaceable development unit, the image formation device including: a development bias application section configured to apply a development bias to between the photoreceptor and the developer; a stabilization control section configured to perform image stabilization control of determining a development bias value to be used in future by changing the development bias while measuring a density of the toner image formed by the developer, thereby obtaining the toner image with a target density; and a life determination section configured to determine expiration of use of the development unit when the development bias value determined by the stabilization control falls outside a preset acceptable range.

A toner conveying device includes a case storing toner; a conveyance member rotatably supported at both ends by the case, including a spiral blade extending along a rotational axis, and configured to rotate to convey the toner inside the case in a predetermined conveying direction; and a pushing member pushed against an outer peripheral portion of the conveyance member in a first direction intersecting with the rotational axis and configured to slide on the outer peripheral portion as the conveyance member rotates. The pushing member is composed of a flexible sheet member and includes a base portion secured at a securing position inside the case and protruding pieces aligned along the rotational axis and protruding from the base portion toward the conveyance member to abut on the outer peripheral portion. An alignment interval between the protruding pieces is different from a pitch of the spiral blade along the rotational axis.

A toner conveying device for conveying toner, comprising: a first conveying portion; and a second conveying portion conveying the toner conveyed from the first conveying portion. The first conveying portion further includes: a first screw which includes a first rotation shaft and a first blade portion, the first screw including an engaging portion and a first protruded portion on a first end portion; and a first conveying passage forming member having a first inner wall face which forms a first conveying passage. The second conveying portion includes: a second screw which includes a second rotation shaft and a second blade portion, the second screw including an engaged portion and a second protruded portion on a second end portion; and a second conveying passage forming member having a second inner wall face which forms a second conveying passage, and which is connected with the first conveying passage forming member.

A processing apparatus including an apparatus housing, powder processing unit for processing powder, a powder recovery unit for recovering discharged powder, a powder discharge unit for transporting and discharging the powder to a discharge portion to be recovered, and a powder receiver. The powder recovery unit is attached to the apparatus housing and the power receiver is positioned below the powder recovery unit on the same side of the apparatus housing that the powder recovery unit is attached to the apparatus housing. When the powder recovery unit is detached from the apparatus housing, the powder receiving unit receives powder discharge falling from the discharge portion.

A drum cartridge includes: a photosensitive drum rotatable about a drum axis extending in an axis direction; a drum cleaner including a cleaning member cleaning a circumferential surface of the photosensitive drum, and a cleaning housing accommodating transfer residual toner removed from the circumferential surface of the photosensitive drum by the cleaning member; a first drum side plate supporting a first end portion of the photosensitive drum; a second drum side plate located distant from the first drum side plate in the axis direction and supporting a second end portion of the photosensitive drum; a pipe located between the first drum side plate and the second drum side plate in the axis direction and extending in the axis direction; and a conveyor device conveying the transfer residual toner from the cleaning housing to the pipe.

A powder collection container accommodates a powder discharged from a discharge port of a powder discharge device including a powder discharger provided with a shutter member that opens and doses the discharge port. The powder collection container includes a moving member that is movable between a first position where the moving member abuts against the shutter member to open the discharge port of the powder discharge device, and a second position where the moving member does not abut against the shutter member and the discharge port of the powder discharge device is not opened.

An image forming apparatus includes a chassis having an opening, a cover, photosensitive members, an intermediate transfer belt, a primary-transfer member, a secondary-transfer roller, a cleaner device, an external-sheet inlet, a waste toner container, a connector, and a conveying roller, which is arranged within the feeding path to feed the recording sheet inserted through the external-sheet inlet in the feeding path. The conveying roller is mounted on the waste toner container and removable from the chassis along with the waste toner container.

A processing apparatus including an apparatus housing, powder processing unit for processing powder, a powder recovery unit for recovering discharged powder, a powder discharge unit for transporting and discharging the powder to a discharge portion to be recovered, and a powder receiver. The powder recovery unit is attached to the apparatus housing and the power receiver is positioned below the powder recovery unit on the same side of the apparatus housing that the powder recovery unit is attached to the apparatus housing. When the powder recovery unit is detached from the apparatus housing, the powder receiving unit receives powder discharge falling from the discharge portion.

A toner conveying device includes a case that can store therein toner to be conveyed, a conveyance member rotatably supported at both ends thereof by the case and configured to rotate to convey the toner inside the case in a conveying direction set in advance, and a pushing member pushed against the conveyance member and configured to slide on an outer peripheral portion of the conveyance member as the conveyance member rotates. The pushing member includes a first sheet member having flexibility and abutting on the outer peripheral portion in a first direction intersecting with a rotational axis direction of the conveyance member to push the conveyance member and a second sheet member having flexibility and abutting on the outer peripheral portion in a second direction, which is different from the first direction, intersecting with the rotational axis direction to push the conveyance member.

A first cartridge support is configured to support a drum cartridge. The first cartridge support is configured to move in a first direction between a first position at which the drum cartridge is mounted on a housing and a second position at which the drum cartridge is detachable. A second cartridge support is configured to support a development cartridge. The second cartridge support is configured to move in the first direction between a third position at which the development cartridge is mounted on the drum cartridge and a fourth position at which the development cartridge is detachable. In a state where the second cartridge support is located at the third position, the second cartridge support is located between the first cartridge support located at the first position and a cover located at a closed position with respect to the first direction.