A development device may include: a development device body; a developer cartridge detachably attached to the development device body; first and second lavers provided to the development device body, the first lever including an operation part and a first engagement portion and a second lever including a second engagement portion; first and second engaged portions provided to the developer cartridge, the first engaged portion being configured to form a first engagement with the first engagement portion and the second engaged portion being configured to form a second engagement with the second engagement portion; and a first biasing member biasing the first engagement portion to the first engaged portion. When the operation part is operated with a first pressing force, the first engagement is released, and when the operation part is operated with a second pressing force greater than the first pressing force, the first and second engagements are released.

A toner case includes a case main body, a cover, and an agitating member. The case main body is configured to contain a toner and to rotate. The cover is configured to cover an opening part arranged at the case main body and to maintain a rotation stop state when the case main body rotates, the cover having a communication space which communicates with an inside space of the case main body via the opening part. The agitating member is configured to rotate integrally with the case main body and to agitate the toner in the communication space.

The control unit controls supply of toner from the toner container to the developing device. The control unit is capable of executing a normal supply in which toner is supplied from the toner container to the developing device based on a detection result of the toner amount detection sensor, and a toner installation mode in which a larger amount of toner than the normal supply is supplied from the toner container to the developing device. When the toner installation mode is selected, the control unit calculates a toner amount T1 required for executing the toner installation mode and a toner remaining amount T2 in the toner container, and prohibits the execution of the toner installation mode when T1>T2.

A motor control apparatus controls a start/stop operation of a motor and includes a counting unit that performs a count-up or count-down operation from a predetermined initial value with a lapse of time in response to receiving an operation start instruction for the motor; a signal output unit that outputs a first state signal in response to receiving the operation start instruction, and outputs a second state signal only when a result of the counting by the counting unit falls outside a predetermined range; and a drive unit that outputs an ON signal to the motor in response to receiving the first state signal from the signal output unit, and outputs an OFF signal to the motor in response to receiving the second state signal from the signal output unit.

An image forming device is provided with a housing formed with an opening, a cover configured to move between a closing position and an opening position, and a plurality of process cartridges including a first process cartridge and a second process cartridge. The first and second process cartridges respectively include first and second photosensitive drums configured to rotate about first and second drum axes both extending in a first direction. The first and second developing devices are configured to supply toner to the first and second photosensitive drums, respectively. The first and second supplying devices are formed with first and second supply ports through which the toner to be supplied to the first and second developing devices are provided, respectively. Both the first and second supplying ports are opened to outside the housing.

A cartridge includes a shutter that opens and closes when the cartridge is attached and detached to a developing unit or image forming apparatus. The cartridge includes a casing having a chamber with a first opening at one end portion allowing toner to flow out of the casing. The cartridge includes a cover that covers the first opening, movable with the casing and having a second opening allowing toner to flow out of the cover. The shutter is located at the one end portion and has a protrusion further from the one end portion than the cover. The developing unit supports the protrusion when the cartridge is mounted thereon, and the casing pivots with the cover relative to the developing unit between a first position where the shutter closes the second opening and a second position where a third opening of the shutter overlaps the second opening.

In a case where a developer bottle is not attached to a bottle attachment portion, a movable support portion is kept to be at a support position, by an elastic force of a second spring, at which to support the bottle attachment portion to be higher than a reference level in position. In a case where the developer bottle is attached to the bottle attachment portion, a movable arm portion extending from the movable support portion toward an attachment space contacts the developer bottle and is displaced to outside the attachment space, which causes the movable support portion to be displaced from the support position to a release position at which to release a support of the bottle attachment portion. A control portion prohibits an image forming process when the position of the bottle attachment portion is not equal to or lower than the reference level.

An opening/closing mechanism is provided between a powder transport container removably attached to an apparatus housing and a powder receiving container provided in the apparatus housing to receive powder in the powder transport container as a result of a connection port communicating with a discharging port of the powder transport container. The opening/closing mechanism opens and closes the discharging port along with attachment and detachment of the powder transport container, and includes an opening/closing lid that opens the discharging port by being stopped by a part of the powder receiving container when the powder transport container is attached to the apparatus housing, a seal member, and a covering material that is provided on a surface of the opening/closing lid opposed to the seal member and has a protruding piece in contact with an edge portion of the connection port when the powder transport container is attached.

A toner cartridge includes a casing, a feeding member and a pump. the casing includes a toner accommodation chamber accommodating toner, and a toner discharging chamber having a discharge opening for discharging the toner, and a communication port for fluid communication between the toner accommodation chamber and the toner discharging chamber. A part of the feeding member is provided inside the communication port. When a minimum cross-sectional area of the communication port in a plane perpendicular to a toner feeding direction of the feeding member is Asmin, the toner discharging chamber has a cross-sectional area Bs larger than Asmin, and the toner accommodation chamber has a cross-sectional area Cs larger than Asmin.

An image forming apparatus is provided with a setting unit that sets a white toner amount per unit area corresponding to lightness of a recording medium that forms a white image using white toner, and an image forming unit that forms a white image using a white toner amount per unit area which is set by the setting unit and forms a color image using colored toner.