A developing device includes a developing container and a second stirring member. The developing container includes a second feeding chamber and a developer discharge outlet disposed on the downstream side end of the second feeding chamber. The second stirring member includes a second feeding blade, a restricting part for conveying developer in the opposite direction to the second feeding blade, and a discharging blade for conveying the developer in the same direction as the second feeding blade so as to discharge the developer from the developer discharge outlet. The second rotation shaft includes a large shaft diameter part provided with the second feeding blade, a small shaft diameter part provided with the restricting part and the discharging blade, and a shaft diameter changing part positioned at a boundary between the large shaft diameter part and the small shaft diameter part.

An image forming apparatus includes a developing container to store developer, an operation portion, an operation detection portion, a conveyance unit to convey a recording material, a detection unit, a door that is openable and closable, a door detection portion, an agitation member, a drive portion, and a control unit. The control unit controls the drive portion in such a manner that, in a case where the operation detection portion detects movement of the operation portion, a supply agitation operation in which the agitation member agitates the developer stored in the developing container is performed. The control unit controls the drive portion in such a manner that, in a case where, in a state in which the supply agitation operation is being performed, the door detection portion has detected an opened state of the door or the detection unit has detected the recording material, the supply agitation operation is stopped.

A toner case includes a case main body, a cover, and a coil spring. The case main body is rotatable and has a toner containing space in which a toner is contained and an opening through which the toner is discharged from the toner containing space. The cover keeps a rotation stop state when the case main body rotates and has a communication space which communicates with the toner containing space via the opening. The coil spring is fixed to the cover so that at least a part of the coil spring is arranged in the communication space. The coil spring vibrates as the case main body rotates.

A developing cartridge includes a casing to accommodate toner; an agitator to agitate the toner and rotatable about a first axis extending in a predetermined direction, the agitator including one end portion and another end portion in the predetermined direction, the agitator being movable in the predetermined direction between a first position and a second position; a first gear mounted to the one end portion and rotatable along with the agitator; an input gear engaging with the first gear; a second gear mounted to the another end portion and rotatable along with the agitator; a third gear; and a protrusion. The second gear is mounted to the another end portion while the first gear engages with the input gear in the first position. And the second gear is separated from the another end portion while the first gear engages with the input gear in the second position.

A development device includes a development container and a second agitation member. The development container includes a second transport chamber and a developer discharge port which is provided at the end portion of the second transport chamber on a downstream side. The second agitation member includes a second transport blade, a damming member which dams a developer, a regulation portion which transports the developer in a direction opposite to the second transport blade and a discharge blade which discharges the developer from the developer discharge portion. A second rotation shaft includes a large shaft diameter portion on which the second transport blade is provided, a small shaft diameter portion on which the regulation portion and the discharge blade are provided and a shaft diameter change portion. The damming member is arranged between the shaft diameter change portion and the end portion of the second transport blade on the downstream side.

A developing device, including a casing and a seal member is provided. The casing includes a divider wall, dividing a space inside the casing into a container chamber and a developing chamber, and a developing roller. The divider wall includes an opening. The container chamber accommodates a developing agent. The seal member is configured to seal the opening. The seal member includes a ventilation section configured to allow air to pass there-through but restrict the developing agent from passing there-through at least at a part of an area that seals the opening.

A developing device includes a developing container, a developing roller, a supplying roller, a first magnet including a first magnetic pole, a second magnet including a second magnetic pole and a third magnetic pole, a regulating member provided opposed to the third magnetic pole. During non-image formation, an operation in a mode in which the supplying roller is rotated in a direction opposite to a rotational direction of the supplying roller during image formation is executable. With respect to the rotational direction of the supplying roller during the image formation, a position where a magnet flux density of the third magnetic pole in a tangential direction to an outer peripheral surface of the supplying roller is zero is positioned downstream of an upstream end of the regulating member and upstream of the second magnetic pole.

A developing device includes a developing container, a first stirring conveyance member, a second stirring conveyance member, a developer carrying member, a toner concentration sensor, and a scraper. The first stirring conveyance member includes a rotary shaft, a first conveyance blade that is formed on an outer circumferential surface of the rotary shaft and conveys a developer in a first direction, and a second conveyance blade that has the opposite phase to the first conveyance blade and has a lower radial height than the first conveyance blade. The scraper is arranged substantially parallel to the rotary shaft at a position shifted in an axial direction from intersections between the first conveyance blade and the second conveyance blade and has a phase of 45° to 135° with respect to the closest one of the intersections on an upstream side in the first direction.

An assembly for use in an electrophotographic image forming device includes a housing having a reservoir for holding toner. The housing includes a wall having an inner surface forming a boundary of the reservoir and an outer surface opposite the inner surface. A toner agitator is positioned in the reservoir and has a rotatable shaft. The shaft includes an end portion that passes through an opening in the wall. A gear is mounted on the end portion of the shaft outside of the reservoir and is rotatably coupled to the shaft. An annular seal encircles and is in contact with an outer circumferential surface of the shaft. The annular seal is positioned between an inner axial face of the gear and the outer surface of the wall. The inner axial face of the gear contacts the annular seal and presses the annular seal against the outer surface of the wall.

A developing device includes a developer cartridge and a developing unit. The developer cartridge, in some instances, may include a shutter. This shutter may have a wall for closing a developer supply hole, and be movable, with respect to a developer cartridge casing, between an open position where the supply hole is opened by the wall and a closed position where the supply hole is closed by the wall. The shutter may further include a protrusion that is movable with respect to the wall of the shutter between a first position and a second position in an axial direction. The protrusion, in the first position, is engageable with a developing unit and, in the second position, would be disengaged from the developing unit.