An image forming system includes a toner container and an image forming apparatus, the toner container including a first toner containing portion, a container base portion having a discharge port for discharging toner, and a container shutter that is moved between open and closed positions and includes an engaged portion, wherein the image forming apparatus includes a main body base portion that detachably attaches the toner container and has a receiving port for receiving the toner and, a second toner containing portion, a movable member that is moved between first and second positions and includes an engaging portion that engages with the engaged portion, a regulating member that is moved between a regulation position and a regulation release position, and an urging member that urges the movable member to move from the first position to the second position when the regulating member is located at the regulation release position.

A toner cartridge includes: a casing having a first toner accommodating portion and a second toner accommodating portion; an agitator; an auger; a first protrusion positioned at one side in a first direction of the second toner accommodating portion; a second protrusion positioned at another side in the first direction of the second accommodating portion; a memory; and a toner-side electrical contact surface electrically connected to the memory. The toner cartridge is attachable to a drum cartridge by the casing pivotally moving from a first position to a second position relative to the drum cartridge about the first protrusion and the second protrusion. When the casing is at the first position, the toner-side electrical contact surface does not contact a first electrical contact surface of the drum cartridge. When the casing is at the second position, the toner-side electrical contact surface contacts the first electrical contact surface.

An image forming apparatus includes a toner container, a storage part, a cover and an opening/closing mechanism. The toner container includes a shutter. The cover is movable between a closed position for closing the storage part and an opened position for opening the storage part. The opening/closing mechanism closes a supply port by rotating the shutter in accordance with an opening operation for moving the cover to the opened position and opens the supply port by rotating the shutter in accordance with a closing operation for moving the cover to the closed position, in a state where the toner container is attached to the storage part. The toner container includes an interference portion which interferes with the opening/closing mechanism to prevent the toner container from being attached to the storage part in a case where the cover is not moved to the opened position normally.

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.

A developer container includes a pouch, a communication member, and a cap. A marking including an arrowhead part and a parting line are formed on an outer peripheral surface of the cap. A rear end of the arrowhead part is disposed between a first position that is a position 45° upstream from a reference position in a direction of rotation and a second position that is a position 45° downstream in the direction of rotation. The rear end of the arrowhead part overlaps the parting line.

A developer supply container includes a developer accommodating body configured to contain developer and a developer discharging body in fluid communication with the developer accommodating body. The developer discharging body has a discharge opening configured to form at least a part of a discharge passageway through which developer may be discharged to outside of the developer supply container. A track is positioned at a side of the developer discharging body. A cover is attached to the developer discharging body, with the cover being configured to cover the developer discharging body and the track, with the cover including a front wall that crosses a rotational axis of the developer accommodating body, and with the front wall being provided with a slit.

A developer supply container is detachably mountable to a developer receiving apparatus including a developer receiving portion provided with a receiving opening for receiving a developer, and a portion-to-be-engaged 11b integrally displaceable 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. An operation portion 21 displaces the developer receiving portion to bring the receiving opening into communication with the shutter opening by engagement between the engaging portion 21d and the portion-to-be-engaged 11b by a predetermined operation executed after the developer supply container is mounted to a predetermined position of the developer receiving apparatus.

A developer storage container includes a storage portion, a communication portion, and a gear portion. The storage portion conveys developer stored therein in a conveying direction parallel to a rotation axis by being rotated around the rotation axis in a specific direction. The communication portion has a tubular shape coaxial to the rotation axis and extending in the conveying direction from an end of the storage portion on a downstream side in the conveying direction, includes an inner peripheral part that gradually increases its diameter in the conveying direction, and connects the storage portion to an opening portion that has an opening facing the conveying direction. The gear portion is provided for an outer peripheral part of the communication portion and receives a rotational driving force supplied from the outside.

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.

A toner container includes an elongated container main body, a toner discharge port, a first rotation member configured to convey the toner toward the toner discharge port, a support plate provided in the container main body and disposed in such a way as to face the wall surface, and an opening and closing member provided between the wall surface and the support plate and supported by the support plate in such a way as to be able to move between a closing position and an opening position. The support plate includes a first opening portion formed at a position corresponding to the toner discharge port and larger than the toner discharge port in size, and a film member attached to the support plate in such a way as to cover the first opening portion and including a second opening portion formed at a position corresponding to the toner discharge port.