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.

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.

A developing cartridge includes: a casing, a developing roller, a first agitator, a supply roller, and a second agitator. The casing is configured to accommodate toner. The developing roller is rotatable about a developing roller rotation axis extending in a first direction. The first agitator is configured to agitate the toner. The first agitator is rotatable about a first agitator rotation axis extending in the first direction. The supply roller is positioned between the first agitator and the developing roller. The supply roller is rotatable about a supply roller rotation axis extending in the first direction. The second agitator is positioned between the supply roller and the first agitator. The second agitator is rotatable about a second agitator rotation axis extending in the first direction. A rotation locus of the second agitator is positioned outside of a rotation locus of the first agitator.

A developing device includes a developer carrying member for developing an electrostatic image with a developer, a developer container including a developer accommodating portion, a developing opening, and a developing chamber, and a developer supplying member that includes a shaft member, a first feeding member, and a second feeding member. The first feeding member has a length L1 measured in an axial direction of the developer carrying member and has a rotational radius R1 measured from a rotation center of the shaft member, and the second feeding member has a length L2. When a length of the developing opening is L3, a shortest length from the developing opening to the shaft member is L4, and a length from the developer carrying member to the shaft member is L5, the following relationships are satisfied: L1<L3<L2, and L4<R1<L5.

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.

A developing cartridge includes: a casing, a developing roller, a first agitator, a supply roller, and a second agitator. The casing is configured to accommodate toner. The developing roller is rotatable about a developing roller rotation axis extending in a first direction. The first agitator is configured to agitate the toner. The first agitator is rotatable about a first agitator rotation axis extending in the first direction. The supply roller is positioned between the first agitator and the developing roller. The supply roller is rotatable about a supply roller rotation axis extending in the first direction. The second agitator is positioned between the supply roller and the first agitator. The second agitator is rotatable about a second agitator rotation axis extending in the first direction. A rotation locus of the second agitator is positioned outside of a rotation locus of the first agitator.

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.

A developing cartridge includes: a casing, a developing roller, a first agitator, a supply roller, and a second agitator. The casing is configured to accommodate toner. The developing roller is rotatable about a developing roller rotation axis extending in a first direction. The first agitator is configured to agitate the toner. The first agitator is rotatable about a first agitator rotation axis extending in the first direction. The supply roller is positioned between the first agitator and the developing roller. The supply roller is rotatable about a supply roller rotation axis extending in the first direction. The second agitator is positioned between the supply roller and the first agitator. The second agitator is rotatable about a second agitator rotation axis extending in the first direction. A rotation locus of the second agitator is positioned outside of a rotation locus of the first agitator.

A print material cartridge (215) that includes a reservoir to maintain an amount of print material (Toner) therein; an agitator (230) formed within the reservoir to fragment clumps of print material present in the reservoir; and a tab (235) mechanically coupled to the agitator via a gear system (240), the tab extending out of a housing of the print material cartridge to activate the agitator as the print material cartridge is being interfaced with a printing device (205, 410).