A development device including: a developer bearing; a regulation portion; a magnetic field generation member that is provided inside of the developer bearing member, the magnetic field generation member having: a development pole; a first magnetic pole; and a second magnetic pole; wherein the magnetic field generation member has a region satisfying |(Br(θa)−Br(θc))/10|<0.3, wherein Br(θa) is a magnetic flux density in a normal direction relative to the surface of the developer bearing member on a position shifted by −5° from a point nearest to the regulation portion on the developer bearing member around a center of the developer bearing member, and Br(θc) is the magnetic flux density around the developer bearing member on a position shifted by +5° from the point nearest to the regulation portion on the developer bearing member.

An image forming apparatus (1) includes a casing (21) having a toner conveyance path (34); a screw (24) conveying a toner in the toner conveyance path (34) in a predetermined conveyance direction; and a downstream side bearing (25) rotatably supporting a downstream side end portion of the screw (24) in the conveyance direction, wherein the screw (24) includes: a shaft (51) extending in the conveyance direction; and a spiral fin (52) provided around an outer circumferential face of the shaft (51), the shaft (51) has a downstream side insertion part (54) inserted into the downstream side bearing (25), and the downstream side insertion part (54) has an outer diameter larger than an outer diameter of a downstream side end portion of the fin (52) in the conveyance direction.

A toner conveying device includes a toner replenishing tube extended upwardly/downwardly, a loosening member reciprocating upwardly/downwardly inside the replenishing tube, a toner conveying tube, a conveying member and a converting part. The conveying tube is extended in a crossing direction with the replenishing tube and communicates the replenishing tube and a toner containing part. The conveying member is arranged rotatably inside the conveying tube to convey a toner from the toner containing part to the replenishing tube. The converting part converts rotating movement of the conveying member to reciprocating movement of the loosening member. The loosening member includes a straight line portion and a protruded portion. The straight line portion is engaged with the conveying member via the converting part and extended downwardly along the replenishing tube. The protruded portion is continued from a lower end of the straight line portion, and bent and protruded in the crossing direction.

A powder transport device includes: a rotation shaft rotatably supported in a container chamber that contains powder; and plural blade members detachably attached to the rotation shaft, the blade members including spiral blades configured to transport the powder in an axial direction of the rotation shaft in response to the rotation shaft rotating.

Toner cartridge includes a housing, an agitator, an auger, a first protrusion, and a second protrusion. The housing includes a first toner accommodating portion having and a second toner accommodating portion. The auger is rotatable about a second axis extending in a first direction and is configured to convey toner from a first toner accommodating portion to the second toner accommodating portion. The first protrusion is positioned at a first side of the second toner accommodating portion. The first protrusion extends in the first direction. The second protrusion is positioned at a second side of the second toner accommodating portion and extends in the first direction.

A developer transport device includes a transport path through which a developer is transported from a developer container to a developing device; an inlet portion that is disposed at an upstream end of the transport path in a developer transport direction and into which the developer falls freely from an outlet opening of the developer container; a transport member that is disposed in the transport path and that transports the developer by rotating; and a rotation control unit that causes, if the transport member has not been driven for a predetermined period, the transport member to rotate in a backward direction that is opposite to a forward direction in which the transport member rotates when supplying the developer to the developing device.

A toner storage device includes a toner storage case that stores toner, and a stirring paddle rotatably supported in the toner storage case and includes at least one stirring blade that stirs the toner stored in the toner storage case, and a rotating shaft that rotates the at least one stirring blade, wherein the toner storage case includes a first supporting portion that rotatably supports an end of the rotating shaft of the stirring paddle, a second supporting portion that rotatably supports an other end of the rotating shaft, and a tapered portion that is tapered toward the first supporting portion.

A third communicating portion is disposed downstream of the first communicating portion and upstream of the second communicating portion in the first direction. The third communicating portion is disposed above a rotational axis of a first conveyance screw and a rotational axis of a second conveyance screw in a vertical direction. The third communicating portion is configured to allow air inside the developing container to move between the first chamber and the second chamber. An opening portion for discharging the air inside the developing container outside the developing container is disposed above the second chamber in the vertical direction.

In one embodiment, a toner container comprises a toner container body in which toner is stored, a cover portion configured to cover the toner container body, and a projection. The projection is provided in the vicinity of a rear end portion in a longitudinal direction of the cover portion or a longitudinal direction of the toner container body, and projecting toward a rear side of the toner container.

In one embodiment, a toner container comprises a toner container body in which toner is stored, a cover portion configured to cover the toner container body, and a projection. The projection is provided in the vicinity of a rear end portion in a longitudinal direction of the cover portion or a longitudinal direction of the toner container body, and projecting toward a rear side of the toner container.