A developing device includes a developer container configured to accommodate a developer containing toner and a carrier and a feeding screw provided rotatably in the developer container and configured to feed the developer in a predetermined feeding direction. The feeding screw includes a rotation shaft, and a first helical blade and a second helical blade which are formed around the rotation shaft and which form a multi-thread helical blade. The feeding screw includes a region in which a plate-like projection portion is provided on the rotation shaft between the first helical blade and the second helical blade.

A developer container includes a body, an agitating bar, and an agitating film. The body includes a bottom plate; a first side wall; a second side wall facing the first side wall; a developer chamber defined by the bottom plate, the first side wall, and the second side wall, the developer chamber storing developer; and an opening formed in the bottom plate to allow the developer chamber to communicate with an outside of the developer chamber and allow the developer to be supplied from the developer chamber to the outside of the developer chamber. The agitating bar is configured to rotate to agitate the developer stored in the developer chamber. The agitating film is attached to the agitating bar and configured to, when rotation of the agitating bar stops, stop in a state where the agitating film abuts the first side wall and the second side wall.

If a user is not familiar with the operation for the developer supply container, the rotating operation for the developer supply container may be insufficient, so that developer supply container does not reach a predetermined operating position, with the result of abnormal developer supply. by increasing a rotation load of a second gear 6 which is in an operable connection with a drive gear member 12 of the developer receiving apparatus 10 by a function of a locking member 7, the developer supply container 1 mounted to the developer receiving apparatus 10 is rotated toward the supply position. After the developer supply container 1 rotates to the supply position, the locking by the locking member 7 is released, by which the rotation load applied to the second gear 6 is reduced, so that drive transmission, thereafter, to the feeding member 4 for developer supply is smooth.

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 object of this disclosure is to reduce differences in the drawn amount of the parison around the mouth of the toner container, thereby reducing the amount of resin for the toner container and the weight thereof. A powder container includes a cylindrical container body to rotate in a horizontal posture, a cylindrical mouth at a first end of the container body, smaller in diameter than the container body, a conveyor to convey the powder inside the container body toward the mouth, a scooping portion deeper in the container body than the mouth, to lift the powder above a powder inlet of a conveying tube inserted from the mouth and drop the powder to the powder inlet, and a radially inner face continuous with an inner end of the scooping portion, extending in a direction crossing the scooping portion and disposed inward in the radial direction than an outermost face of the container body. The radially inner face extends from the mouth toward a second end of the container body and is not inner in the radial direction than an inner rim of the mouth.

A toner case includes a case main body, first and second agitators, and a transmitting mechanism. The case main body is configured to store a toner. The first and second agitators are configured to rotate and to agitate the toner in the case main body. A transmitting mechanism is configured to transmit rotation to the first and second agitators. The transmitting mechanism stops transmission of the rotation to the second agitator while the transmitting mechanism continues the transmission of the rotation to the first agitator, when driving torque of the second agitator is equal to or more than a first set value.

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 toner container includes a container body, a first bearing portion, and a rotational member. The container body in which toner is stored includes a pair of side walls that face one another across a specific distance. The first bearing portion is provided in an inner surface of at least one side wall of the pair of side walls. The rotational member includes a rotational shaft that is rotatably supported by the first bearing portion. The first bearing portion includes a terminal end portion on one side and an open portion on another side, and further includes a first long groove in which the rotational shaft is inserted, and a projection protruding from a groove bottom surface that extends from the open portion to the terminal end portion of the first long groove.

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 drum cartridge includes: a drum frame to which a developing cartridge including a storage medium having an electrical contact surface is detachably attachable; a photosensitive drum; a transfer roller; and a conveying roller. The drum is rotatable about a first axis extending in a first direction and positioned at one end portion of the frame in a second direction. The transfer roller is rotatable about a second axis extending in the first direction and in contact with the drum. The conveying roller is rotatable about a third axis extending in the first direction and separated from the transfer roller in the second direction. A first opening of the frame is positioned between the transfer roller and the conveying roller in the second direction. The electrical contact surface is exposed to an outside through the first opening in a case where the developing cartridge is attached to the frame.