A stirring device includes a stirrer configured to stir a stirred object, at least another component of the stirring device, and a coating layer. The coating layer is disposed on at least one of a contact part of the stirrer that contacts the at least another component and a contacted part of the at least another component contacted by the stirrer.

A developer accommodating unit for accommodating a developer for image formation includes a flexible container provided with an opening 35a for permitting discharge of the developer, a frame for accommodating the flexible container and for accommodating the developer to be discharged from the flexible container, and an urging member 21 for urging a developer accommodating bag toward the frame for accommodating the developer accommodating bag 16. By this, it is possible to satisfactorily effect discharge of the developer from the flexible developer accommodating bag 16.

A developing device includes a rotatable sleeve for carrying a developer including a magnetic material to develop a latent image on an image bearing member, a developer chamber, a rotatable stirring member provided inside the chamber to stir the developer while being in contact with at least a part of an inner surface of the chamber and a magnet generating a magnetic field in at least a part of a contact region between the stirring member and the inner surface. A magnetic flux density of the magnetic field at a first position in the contact region generated by the magnet is different from that in a second position which is adjacent to the first position in a rotational axis direction of the sleeve.

A powder container includes a rotator and a coil disposed adjacent to the rotator. The rotator is configured to rotate in a predetermined direction. The coil is configured to be rotated by contact with the rotator and divided into a plurality of divided coil portions along a rotation center of the coil in an axial direction of the coil. A plurality of coil centers of the plurality of divided coil portions is eccentric relative to the rotation center.

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.

Providing a toner cartridge capable of restraining toner from leaking through an opening, and improving labor efficiency for assembling the cartridge. The toner cartridge (process cartridge 1) includes a developing frame having a storage chamber configured to store therein toner and formed with an opening to discharge the toner out of the storage chamber, a shaft rotatably supported to the developing frame; and an agitation sheet positioned in the storage chamber and having a base end portion supported to the shaft, the agitation sheet being rotationally movable along with rotation of the shaft. The developing frame includes a first wall formed with the opening, and a second wall configured to support the agitation sheet by nipping the agitation sheet positioned to close the opening between the first wall and the second wall, the second wall permitting the agitation sheet to contact with the first wall and contacting with the agitation sheet through an elastic member.

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 powder conveying device includes a first conveyor, a first conveyance passage, a fall passage, a second conveyor, and a second conveyance passage. The first conveyor conveys powder in a substantially horizontal direction and is disposed in the first conveyance passage. The powder output from an outlet port of the first conveyance passage is to fall in the fall passage. The second conveyor conveys the powder in the substantially horizontal direction and is disposed in the second conveyance passage that has an inlet port to receive the powder falling in the fall passage. When viewed in a cross section orthogonal to a powder conveyance direction, a cross-sectional area of a space that is not occupied by the first conveyor in the first conveyance passage is larger than a cross-sectional area of a space that is not occupied by the second conveyor in the second conveyance passage.

A powder container includes a powder storage configured to store powder and having side walls with through-holes; a hollow member including a hollow part; held parts disposed at both ends of the hollow member in an axial direction of the hollow member; a coil configured to be held by the hollow member; holders configured to hold the held parts of the hollow member; and a piercing shaft configured to be inserted into the hollow part of the hollow member from outside of the powder container through one of the through-holes.

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.