A developer supply container 1 is detachably mountable to a developer receiving apparatus including a developer receiving portion 11 provided with a receiving port 11a for receiving a developer, a portion-to-be-engaged 11b a displaceable integrally with the developer receiving portion 11. The developer supply container 1 includes an engaging portion 30 and a discharging portion provided with a shutter opening 4j for discharging the developer accommodated in a developer accommodating portion. The engaging portion 30 is provided at only one side with respect to a predetermined direction crossing with a mounting direction of the developer supply container 1 in the crossing with a displacing direction of the developer receiving portion 11. The engaging portion 30 engages with the portion-to-be-engaged 11b with a mounting operation of the developer supply container 1 to bring the receiving port 11a in the communication with the shutter opening 4j.

An attached portion of an image forming apparatus includes a rotating member of which at least a part is exposed outside the image forming apparatus when the developer container is attached, and a rotation restricting mechanism that is movable between a restricting position to restrict rotation of the rotating member and an allowable position to allow rotation of the rotating member, and includes a restricting member that is at the restricting position when the developer container is not attached. The developer container is attached to the attached portion so that the discharging portion engaging portion and the shutter engaging portions are engaged with the frame engaged portions and the rotating member engaged portions respectively when the container shutter is in the close state, and the restricting member moves from the restricting position to the allowable position when the developer container is attached to the attached portion.

Examples of a print a print particle replenishment device are described. In some examples, a print particle replenishment device includes a rotating member to rotate about a central axis of the print particle replenishment device. In some examples, the rotating member includes an opening offset from the central axis. In some examples of a print particle replenishment device, a nozzle is offset from the central axis, where the nozzle is to slide with respect to an interior plane of the rotating member to align with the opening to transfer print particles through the nozzle and opening when in an open position. In some examples, a print particle replenishment device includes an extension that protrudes with respect to the opening to engage a port cover of a host device to move the port cover to open a port for replenishment at rotation.

An electrostatic image developing toner includes toner particles containing a binder resin and a release agent. In sections of the toner particles in which the sections of the toner particles have an area St in total and, among sections of domains of the release agent, sections of domains having long diameters of 10 nm or more and 500 nm or less have a total area Sa and sections of domains having long diameters of 1500 nm or more and 3000 nm or less have a total area Sb, an area fraction Sa/St is 2% or more and an area fraction Sb/St is 20% or more.

An example operation method of an image forming apparatus includes determining a state of a toner refill operation of injecting toner from a toner reload kit (TRK) into a cartridge in the image forming apparatus, based on completion of injecting toner from the TRK into the cartridge, controlling the TRK to store information indicating a toner refill completion in a memory of the TRK, based on completion of injecting toner from the TRK into the cartridge, updating information of an amount of remaining toner of the cartridge based on an amount of the toner injected into the cartridge from the TRK, and based on the information indicating the toner refill completion being stored in the memory of the TRK, unlocking a locking apparatus in the image forming apparatus so the TRK may be removed from the cartridge.

An electrostatic charge image developing toner includes a toner particle that contains a pyrazolotriazole-based dye and a zirconium oxide particle.

A toner cartridge includes a container accommodating toner and including a discharge opening. A pump is configured to alternately generate (i) a first air flow from outside to inside of the toner cartridge and (ii) a second air flow from inside to outside of the toner cartridge, with the pump being configured to supply the toner from the discharge opening to outside of the toner cartridge with the second air flow. The cartridge also includes a rotational force receiving portion configured to receive a rotational force from outside of the toner cartridge, with the rotational force receiving portion being configured to drive the pump with rotation of the rotational force receiving portion.

A developer supply container is detachably mountable to a developer receiving apparatus, the developer receiving apparatus including a developer receiving portion provided with a receiving port for receiving a developer and including a portion-to-be-engaged of displacing integrally with the developer receiving portion. The developer supply container includes a discharging portion provided with a shutter opening for discharging the developer accommodated in the developer accommodating portion, and an engaging portion. The engaging portion engages with the portion-to-be-engaged with a mounting operation of the developer supply container to displace the developer receiving portion so as to bring the receiving opening into fluid communication with the shutter opening. The engaging portion includes a curved portion having an angle relative to a mounting direction of the developer supply container, the angle decreasing with approach toward an upstream side in the mounting direction.

A drum cartridge includes: a photosensitive drum rotatable about an axis extending in a first direction; a first drum frame to which a developing cartridge is attachable; and a second drum frame having an outer surface; and a memory having an electrical contact surface. The first drum frame is at one end portion of the drum cartridge in a second direction and the second drum frame is at another end portion of the drum cartridge in the second direction. The electrical contact surface is positioned at the outer surface of the second drum frame and is movable in a predetermined direction relative to the second drum frame.

A powder storage device includes a container housing and a powder storage. The container housing is configured to allow the powder container to rotate around a rotation axis α. When the powder container is rotated from an installing position to a predetermined position in a peeling-off rotation direction around the rotation axis α, a supply port moves to a position corresponding to a receiving port, a bonder in which the sealer adheres to the powder container is peeled off, and thus the supply port and the receiving port are interconnected.