According to an embodiment, a toner cartridge for use with an image forming apparatus includes a body that contains toner and includes an opening through which the toner is supplied the image forming apparatus. A supplying mechanism is provided with the body that discharges the toner from the opening of the body to the image forming apparatus. The body is removably mounted on an mounting unit of the image forming apparatus through a port.

A developing device includes a developer bearer, a first conveying screw conveying developer from one end to another end of a first conveyance path in a first direction, a second conveying screw conveying the developer in a direction opposite to the first direction in a second conveyance path, and a partition having a first communication port communicating the one end of the first conveyance path and the second conveyance path. A shaft diameter of the first conveying screw from one end to a position away from the first communication port by a first predetermined distance is smaller than a shaft diameter of another portion of the first conveying screw. A shaft diameter of the second conveying screw from one end to a position away from the first communication port by a second predetermined distance is larger than a shaft diameter of another portion of the second conveying screw.

A developing device includes: a developer transport unit that transports a developer containing a toner and a carrier; and a developer discharge unit provided at an end portion on a downstream side along a transport direction of the developer transport unit and including a reverse transport blade that is disposed inside a reversing passage from which a part of the developer is discharged, and rotates around a rotation shaft to transport the developer in a direction opposite to a discharge direction, the developer discharge unit including a magnetic attraction unit magnetically attracting the developer in at least one of the reverse transport blade or the reversing passage.

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 developer container includes: a housing chamber 147 which includes an opening 145 and which houses developer; a stirring member 160 which includes a sheet-like stirring portion 160b and a rotary shaft 160a to which the stirring portion 160b is attached; and a first electrode 143 and a second electrode 144 which are used to detect an amount of the developer and which are arranged with an interval therebetween, where in an area X1 between the first electrode 143 and the second electrode 144 in the housing chamber 147 is positioned below the rotary shaft 160a of the stirring member 160, and the sheet-like stirring portion 160b comes into contact with the area X1 due to rotation of the stirring member 160.

A developer cartridge assembled to a developing device defining therein a developing chamber. The developer cartridge includes a first accommodating portion, and a first agitator. The first accommodating portion accommodates therein a developing agent and is positioned beside the developing device. The first accommodating portion includes a first wall part neighboring the developing device. The first wall part is formed with a first through-hole and a second through-hole. The first through-hole is open diagonally downward from the first accommodating portion to the developing device. The second through-hole is open diagonally upward from the first accommodating portion to the developing device. The first through-hole and the second through-hole allow communication between an interior of the first accommodating portion and the developing chamber. The first agitator is rotatably disposed in the first accommodating portion and in sliding contact with the first wall part in a vertical direction.

According to an embodiment, a developer-supplying container includes a container and a paddle. The container includes an opening for supplying the image forming apparatus with developer contained in the container. The paddle conveys the developer to the opening by rotating within the container. The paddle includes a first arm. The first arm has a shape that is wider on an upstream side in a direction of the rotation of the paddle and narrower toward a downstream side. In addition, the first arm is disposed such that a narrowest portion of the first arm is located at the same position as the opening in a direction of a shaft.

An image forming apparatus includes a housing, a conveyance member, and a sheet member. The housing forms a conveyance path along which toner is conveyed. The conveyance member is supported by the housing. The conveyance member rotates about a rotation axis thereof to convey the toner. The sheet member is disposed on a contact region of the housing where the conveyance member comes in contact with the housing.

An electrophotographic image forming device according to one example includes a toner cartridge having a housing that includes a toner reservoir. An electrical connector on the housing is movable between a retracted position and an operative position. The electrical connector includes an electrical contact for contacting a corresponding electrical contact in the image forming device. The electrical contact is electrically connected to processing circuitry on the housing. The electrical connector and the electrical contact of the toner cartridge move upward toward the top of the housing when the electrical connector moves from the retracted position to the operative position. The electrical contact of the toner cartridge is positioned within a pocket of the electrical connector. The pocket includes an opening that faces upward when the electrical connector is in the operative position permitting the corresponding electrical contact in the image forming device to enter the pocket from above.

A toner container installed in an image forming apparatus includes a toner container main body having a predetermined length and in which toner is accommodated, a discharge port through which the toner is discharged from the toner container main body, a shutter which opens and closes the discharge port, a handle provided on the toner container main body, and a pressed portion provided on the toner container main body and which is pressed by the image forming apparatus to project the handle out from the image forming apparatus.