An image forming apparatus includes a developing container to store developer, an operation portion, an operation detection portion, a conveyance unit to convey a recording material, a detection unit, a door that is openable and closable, a door detection portion, an agitation member, a drive portion, and a control unit. The control unit controls the drive portion in such a manner that, in a case where the operation detection portion detects movement of the operation portion, a supply agitation operation in which the agitation member agitates the developer stored in the developing container is performed. The control unit controls the drive portion in such a manner that, in a case where, in a state in which the supply agitation operation is being performed, the door detection portion has detected an opened state of the door or the detection unit has detected the recording material, the supply agitation operation is stopped.

An image forming apparatus to which a toner container is detachably mountable includes a mounting portion to which the toner container is detachably mountable and which includes a receiving port for receiving toner supplied from the toner container, a passage for permitting passing of the toner received through the receiving port and provided with a through hole, and a filter portion provided so as to cover the through hole and for permitting passing of air; and an accommodating portion configured to accommodate the toner received through the receiving port. At least a part of the through hole overlaps with the receiving port as viewed in a horizontal direction perpendicular to a direction of gravitation.

An image forming apparatus includes an attachment portion, an attachment detection unit, an output portion, a first cover, a first detection portion, a second cover, and a control unit. A control unit is configured to control opening movement of the first cover to open the first cover linked with movement that the second cover is opened when the output portion outputs information of replacing the developer accommodating container. After the first detection portion detects that the first cover is in a closed state after the first cover has been opened based on information output by the output portion, the first detection portion detects whether the developer accommodating container is attached to the attachment portion or not, and if the first detection portion detects that the developer accommodating container is not attached to the attachment portion, the control unit controls the first cover to open.

A method of converting a CMYW toner printer to a CMYK printer that prints with black toner, comprising the steps: providing a CMYW toner printer; wherein the CMYW toner printer has four starting toner printing cartridges; wherein the four starting toner printing cartridges comprise a white toner printing cartridge, a cyan toner printing cartridge, a magenta toner printing cartridge, and a yellow toner printing cartridge; removing one or more of the four starting toner printing cartridges from the CMYW toner printer, such that there are one or more empty toner cartridge slots; providing a black toner printing cartridge that are each filled with black toner; and installing the black toner printing cartridge into the one or more empty toner cartridge slots.

According to examples, a toner refill apparatus may include a chamber to house a toner, in which the chamber may include an insertion section, the insertion section to be inserted into a refill port of a toner cartridge and including a discharge opening, the refill port including an electrical circuit component. The apparatus may also include a valve mechanism positioned at the discharge opening to control output of the toner from the chamber through the discharge opening, in which an actuator may engage the valve mechanism and may controllably open the valve mechanism. The apparatus may further include an electronic chip to be in electrical communication the electrical circuit component, in which a controller may activate the actuator based on a detection that the electronic chip is in contact with the electrical circuit component.

An image forming apparatus to and from which a replenishment container accommodating toner is attachable includes a replenishment port to allow replenishment of toner from the replenishment container, which is arranged outside of the image forming apparatus, to a developer container therethrough in a state where the replenishment container is attached to the replenishment port, an opening/closing portion to open and close the replenishment port, and a locking member to move between a restricting position in which the locking member restricts movement of the opening/closing portion from the closed position to the open position, and an allowing position in which the movement of the opening/closing portion from the closed position to the open position is allowed. A controller maintains, when the replenishment container is attached to the replenishment port, the locking member in the restricting position in a case where a lifetime of the cartridge is less than a threshold.

A toner container includes a toner accommodating body and a nozzle including an opening configured to form a part of a discharge passageway through which toner may be discharged to outside of the toner container. A shutter is configured to open and close the opening of the nozzle, with the shutter being rotatable about a rotational axis between a first position in which the shutter closes the opening of the nozzle and a second position in which an opening of the shutter aligns with the opening of the nozzle to form the discharge passageway. A projection is positioned at an end portion of the toner container, with the projection including a first surface, a second surface, and a third surface. When the toner container is oriented such that the toner accommodating body is above the nozzle, the nozzle is above the projection, and the projection is at a bottommost side of the toner container, (i) the opening of the nozzle is positioned such that toner may be discharged from a lateral side of the toner container that is above the bottommost side, (ii) the first surface faces downward, (iii) the second surface faces downward, and (iv) the third surface faces upward.

A powder container includes a container body, a spiral projection, and a convex portion. The container body stores powder and is rotatable around an axis of the container body. The spiral projection is inside the container body. The convex portion includes a flat surface portion and protrudes inward from an inner wall surface of the container body. A virtual plane including the flat surface portion passes through the axis.

A first contact portion provided on a first shutter member that opens and closes a receiving port for receiving a developer from a cartridge and a second contact portion provided on the cartridge are configured to contact each other in an attachment and detachment direction of the cartridge so that the first shutter member is in a position at which the receiving port is opened. The first shutter member is urged by a first urging member so that a contacting state between the first contact portion and the second contact portion is maintained until a second shutter member that opens and closes a supplying port of the cartridge closes the supplying port when the cartridge is discharged from the apparatus body.

An example method of operating an image forming apparatus includes measuring a toner concentration supplied to a developing apparatus and increasing a driving speed of the developing apparatus based on the toner concentration not reaching a target toner concentration. The toner concentration is measured in a state where the driving speed of the developing apparatus is increased, and, based on the toner concentration not reaching the target toner concentration based on the driving speed of the developing apparatus being increased, an operating state of the image forming apparatus is determined based on a remaining amount of toner.