A developing device includes an accommodating member, a developer carrying member, a feeding screw provided with a helical blade, a bearing portion, and a guiding portion including an inclined surface. With respect to the developer feeding direction, a position of an edge of a receiving port of the accommodating member on a bearing portion side is closer to the bearing portion than a most-upstream end of the blade with respect to the developer feeding direction. With respect to the developer feeding direction, a position of a downstream end portion of the inclined surface is remoter from the bearing portion than the most-upstream end of the blade with respect to the developer feeding direction.

A developing device includes a developer carrying member, a first chamber, a second chamber, a first communicating portion, a second communicating portion, and a feeding screw, provided in the second chamber, including a feeding portion having a first helical blade and including a returning portion having a second helical blade in the form of a plurality of threads, the feeding portion and the returning portion being provided so that a boundary portion therebetween opposes the second communicating portion. The first helical blade and the second helical blade satisfy the following relationship: P2P1, where P1 is a pitch, or lead, of the first helical blade and P2 is a lead of the second helical blade.

A transporting member includes a rotating shaft and plural helical blades that helically extend around the rotating shaft and that transport a transport object in a direction of the rotating shaft as the rotating shaft rotates, each helical blade including a downstream side surface at a downstream side in a transporting direction and an upstream side surface at a side opposite to the downstream side surface. A portion of at least one of the helical blades has a gap that enables the transport object to move in the direction of the rotating shaft, and the at least one of the helical blades includes an upstream section that extends upstream in a rotating-shaft rotation direction, in which the rotating shaft rotates, from the gap. The upstream section includes a portion in which an inclination angle of the downstream side surface is less than an inclination angle of the upstream side surface.

A conveying screw configured to convey a toner in an axial direction includes a conveying shaft part and a conveying blade. The conveying shaft part is configured to be rotated around an axis. The conveying blade is spirally formed around an outer circumferential face of the conveying shaft part and configured to convey a toner in a replenishment path. At least one spiral of the conveying blade is formed by two semicircular blade plates which are coupled to in postures inclined in opposite directions to each other. A through hole through which the toner is passed in the axial direction is formed in an area surrounded by the conveying shaft part and the two blade plates.

A developing device includes an accommodating member, a developer carrying member, a feeding screw provided with a helical blade, a bearing portion, and a guiding portion including an inclined surface. With respect to the developer feeding direction, a position of an edge of a receiving port of the accommodating member on a bearing portion side is closer to the bearing portion than a mostupstream end of the blade with respect to the developer feeding direction is. With respect to the developer feeding direction, a position of a downstream end portion of the inclined surface is remoter from the bearing portion than the mostupstream end of the blade with respect to the developer feeding direction is.

A developing apparatus includes a developer container with a discharge port through, a shutter, and a shutter urging member configured to urge the shutter so that the shutter is positioned at the closing position. A fixing member is detachably attached to the developing apparatus and configured to fix the shutter at the closing position so that the shutter is positioned at the closing position and a abutment member disposed on an apparatus body of an image forming apparatus is located, by being pushed by the fixed shutter, at a position moved in an insertion direction of the developing apparatus in a state where the developing apparatus is attached to the apparatus body.

A stirring/conveying member has a rotary shaft rotatably supported in a powder container, a first helical blade formed on the circumferential surface of the rotary shaft and conveying powder in the axial direction by the rotation of the rotary shaft, and a second helical blade formed on the circumferential surface of the rotary shaft to overlap the forming region of the first helical blade, spiraling in the opposite phase to the first helical blade, and having a smaller radial height than the first helical blade. The first helical blade crosses the second helical blade at least at one place in one turn about the rotary shaft. At least one of the radial heights of the first and second helical blades equals zero at the intersection of the first and second helical blades.

A developing apparatus includes a rotatable developer carrying member, a first chamber to supply developer to the developer carrying member, and a second chamber to collect the developer from the developer carrying member. A first conveyance screw in the first chamber conveys the developer in a first conveyance direction, and a second conveyance screw conveys the developer in the second chamber. The second conveyance screw includes a rotary shaft, a first vane portion, and a second vane portion provided downstream of the first vane portion. A developer discharge portion is disposed upstream of the second vane portion in the first conveyance direction and discharges excess developer. The developer discharge portion is disposed in a predetermined area of the second chamber in which the developer is deliverable to a communication portion, and is provided in a bottom portion in the predetermined area of the second chamber.

A toner case includes a case main body, a rotating member, a transmitting member and a cover. The case main body contains a toner. The rotating member is disposed in the case main body and is rotatable around a rotation axis. The transmitting member rotates along an outer face of a side wall of the case main body on one side in a direction of the rotation axis so as to transmit a rotation to the rotating member. The cover covers at least a portion of the transmitting member. The transmitting member has a movable part which moves as the transmitting member rotates. The cover has a hole part through which the movable part is exposed.

A developing device includes a developer container that accommodates an electrostatic image developer including toner containing a toner particle and a zinc stearate particle, a ratio (D.sub.T/D.sub.S) of a volume-average particle size (D.sub.T) of the toner particle to a volume-average particle size (D.sub.S) of the zinc stearate particle being about 1.9 or more; a developer carrier that supplies the toner to an image carrier; a supply conveyor that supplies the electrostatic image developer while conveying the electrostatic image developer; a mixing conveyor that conveys the electrostatic image developer while mixing the electrostatic image developer; and a partition disposed between the supply conveyor and the mixing conveyor. The electrostatic image developer is moved from the supply conveyor to the mixing conveyor through a first passage and is moved from the mixing conveyor to the supply conveyor through a second passage.