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.

An image forming apparatus includes a cartridge storage portion that is installed in an image forming apparatus main body, and a toner cartridge that is configured so as to be able to be inserted into and removed from the cartridge storage portion. The cartridge storage portion has a storage opening that receives the toner cartridge, and has a gap between an end part of the toner cartridge and the storage opening, through which the end part of the toner cartridge is not able to be held, when the toner cartridge is stored in the cartridge storage portion.

An image forming apparatus includes a cartridge storage portion that is installed in an image forming apparatus main body, and a toner cartridge that is configured so as to be able to be inserted into and removed from the cartridge storage portion. The cartridge storage portion has a storage opening that receives the toner cartridge, and has a gap between an end part of the toner cartridge and the storage opening, through which the end part of the toner cartridge is not able to be held, when the toner cartridge is stored in the cartridge storage portion.

One or more toner bottles are provided for supplying toners to development apparatuses. The toner bottles each include bottle portions and displacement sensors. The bottle portions accommodate the toners and are rotated by a drive force of a drive source. The displacement sensors are positioned on sides of the bottle portions and detect deflection amounts of the sides of the bottle portions to determine how much toner is remaining in each toner bottle.

An image forming apparatus includes a cartridge storage portion that is installed in an image forming apparatus main body, and a toner cartridge that is configured so as to be able to be inserted into and removed from the cartridge storage portion. The cartridge storage portion has a storage opening that receives the toner cartridge, and has a gap between an end part of the toner cartridge and the storage opening, through which the end part of the toner cartridge is not able to be held, when the toner cartridge is stored in the cartridge storage portion.

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 cartridge includes a casing accommodating toner and provided with a toner discharge opening, a fan, a closing member capable of shifting between a closed position and an open position for opening a passage. The toner cartridge also includes a drive receiving member for receiving a driving force from outside of the toner cartridge and for transmitting the driving force toward the fan and the closing member by rotation thereof. The closing member periodically moves between the closed position and the open position by receiving the driving force.

[Task] To further develop the photosensitive member unit.

[SOLUTION] A photosensitive member unit capable of being mounted to a main assembly of an image forming apparatus includes a photosensitive member rotatable about a rotational axis thereof, a first gear portion, and a second gear portion having a plurality of teeth. The first gear portion is a helical gear portion including a helical tooth which is twisted in a first circumferential direction about the rotational axis of the photosensitive member as a distance from the photosensitive member measured along the rotational axis of the photosensitive member increases. Between the first gear portion and the photosensitive member with respect to a direction of the rotational axis of the photosensitive member, the second gear portion is disposed. Between the first gear portion and the second gear portion with respect to the direction of the rotational axis of the photosensitive member, a gap is provided, wherein the teeth of the second gear portion include a tooth which has (i) a first projecting portion extending at least in the direction of the rotational axis of the photosensitive member and (ii) a second projecting portion disposed at a position which is downstream of at least a part of the first projecting portion in the first circumferential direction and which is closer to the first gear portion in the direction of the rotational axis of the photosensitive member than at least a part of the first projecting portion.

A process cartridge mountable on an image forming apparatus includes a photoconductive drum, a developing unit including a developing roller and a toner storage unit. The toner storage includes a first toner storage chamber, a second toner storage chamber located above the first toner storage chamber, a first toner conveying member located in the first toner storage chamber and configured to convey the toner in the first toner storage chamber upward toward the second toner storage chamber in an area wider than the toner discharge outlet in the first direction, and a second toner conveying member located in the second toner storage chamber and configured to convey, in the first direction, the toner in the second toner storage chamber toward the toner discharge outlet.

A process cartridge mountable on an image forming apparatus includes a photoconductive drum, a developing unit including a developing roller and a toner storage unit. The toner storage includes a first toner storage chamber, a second toner storage chamber located above the first toner storage chamber, a first toner conveying member located in the first toner storage chamber and configured to convey the toner in the first toner storage chamber upward toward the second toner storage chamber in an area wider than the toner discharge outlet in the first direction, and a second toner conveying member located in the second toner storage chamber and configured to convey, in the first direction, the toner in the second toner storage chamber toward the toner discharge outlet.