A toner container includes a toner accommodating body, a nozzle in fluid communication with the toner accommodating body, and a shutter configured to open and close the opening of the nozzle. A projection is positioned at an end portion of the toner container in a direction of the rotational axis, the projection having an inner peripheral surface facing towards the rotational axis. 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 projection includes (ii-i) a first surface facing downward, (ii-ii) a second surface facing downward, and (ii-iii) a third surface facing upward, with the first surface, the second surface, and the third surface being positioned outside the inner peripheral surface of the projection and inside the opening of the nozzle in the direction perpendicular to the rotational axis, (iii) the first surface extends such that a distance in the direction of the rotational axis from the first surface to the toner accommodating body decreases along the first surface in the first rotational direction, (iv) the second surface extends such that a distance in the direction of the rotational axis from the second surface to the toner accommodating body decreases along the second surface in the first rotational direction, (v) a distance, measured along a line that is perpendicular to the rotational axis, from the rotational axis to at least a part of the first surface is less than a distance, measured along a line that is perpendicular to the rotational axis, from the rotational axis to a part of the second surface that is closest from the rotational axis, and (vi) at least a part of the third surface is above an uppermost part of the second surface.

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.

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.

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 image forming apparatus, to which a supply container storing a developer is detachably attachable and which forms an image on a recording material, includes a photosensitive member that rotates, an optical box, a developer bearing member, and a developer container including a supply port for receiving the developer to be supplied from the supply container. The optical box irradiates the photosensitive member with light and forms an electrostatic latent image on the photosensitive member. The developer bearing member bears the developer and develops the electrostatic latent image by supplying the developer to the photosensitive member. The developer container stores the developer to be borne by the developer bearing member. When viewed in a rotation axial direction of the photosensitive member, a region where the optical box is located and at least a part of a region where the supply port is located overlap each other in a horizontal direction.

A toner container includes a toner accommodating body, a nozzle in fluid communication with the toner accommodating body, and a shutter configured to open and close the opening of the nozzle. A projection is positioned at an end portion of the toner container in a direction of the rotational axis, the projection having an inner peripheral surface facing towards the rotational axis. 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 projection includes (ii-i) a first surface facing downward, (ii-ii) a second surface facing downward, and (ii-iii) a third surface facing upward, with the first surface, the second surface, and the third surface being positioned outside the inner peripheral surface of the projection and inside the opening of the nozzle in the direction perpendicular to the rotational axis, (iii) the first surface extends such that a distance in the direction of the rotational axis from the first surface to the toner accommodating body decreases along the first surface in the first rotational direction, (iv) the second surface extends such that a distance in the direction of the rotational axis from the second surface to the toner accommodating body decreases along the second surface in the first rotational direction, (v) a distance, measured along a line that is perpendicular to the rotational axis, from the rotational axis to at least a part of the first surface is less than a distance, measured along a line that is perpendicular to the rotational axis, from the rotational axis to a part of the second surface that is closest from the rotational axis, and (vi) at least a part of the third surface is above an uppermost part of the second surface.

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 image forming system includes a toner container and an image forming apparatus to which the toner container is detachably mountable. The image forming apparatus includes a mounting portion to which the toner container is detachably mountable. The toner container includes an accommodating portion configured to accommodate toner, a discharge portion provided with an opening for discharging the toner in the accommodating portion to outside of the toner container, a rotatable member rotatable, relative to the discharge portion, about a rotational axis in a first rotational direction and a second rotational direction that is opposite to the first rotational direction, and a projection provided below the opening of the discharge portion, the projection having inner peripheral surface such that, when the toner container is oriented in a predetermined direction in which the rotational axis extends in a direction of gravity and at least a part of the discharge portion is below the accommodating portion, the inner peripheral surface faces inward in a radial direction of an imaginary circle centered on the rotational axis.

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 and 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.

An example toner refill cartridge includes a body to accommodate toner and having a toner discharge hole, a shutter being rotatable between a first position at which the toner discharge hole is closed and a second position at which the toner discharge hole is opened, a coupler to rotate by receiving an external rotational force, an agitation member to rotate and agitate the toner by receiving a rotational force from the coupler, and a connection member to selectively transmit a rotational force of the coupler to the shutter.