A developer cartridge may include: a first gear having a small-diameter gear portion and a large-diameter gear portion; and a second gear including: a first columnar portion centered on a second axis; a second columnar portion having a smaller diameter than the first columnar portion; a first engagement portion extending along a portion of a peripheral surface of the first columnar portion and engageable with the small-diameter gear portion; a second engagement portion extending along a portion of a peripheral surface of the second columnar portion and positioned closer to a housing than the first engagement portion in an axial direction and engageable with the large-diameter gear portion; and a protruding portion protruding in the axial direction and rotatable together with the first engagement portion and the second engagement portion. The second engagement portion may engage the large-diameter gear portion after the first engagement portion engages the small-diameter gear portion.

A drum cartridge includes a drum cover movable relative to a photosensitive drum between a first position at which the drum cover covers a part of a circumferential surface of the photosensitive drum and a second position at which the drum cover does not cover the part of the circumferential surface. The drum cover is located at an opposite side of a toner cartridge with respect to the photosensitive drum in a state where the toner cartridge is attached to the drum cartridge and the drum cover is located at the second position. The drum cover is located at the first position in a state where the drum cartridge is attached to a drawer and the drawer is located at a pulled-out position and located at the second position in a state where the drum cartridge is attached to the drawer and the drawer is located at an accommodated position.

An image forming apparatus includes first and second image bearing members, first and second developing members. The controller controls to execute first and second controls based on an image information in a case that the first developing member is separated from the first image bearing member when an operation in which the image is sequentially transferred to a transferred member from the first and second image bearing members is terminated. The first developing member is started to separate from the first image bearing member in the first control after an end of an image forming area on the first image bearing member in a moving direction passes through the first transfer position, and in the second control after the end of the image forming area on the first image bearing member in the moving direction passes through the developing position and before the end of the image forming area reaches the first transfer position.

A toner includes: toner base particles including a binder resin, a colorant, an inorganic filler, and a release agent; and an external additive. An average circularity of the toner is 0.974 or more but 0.985 or less. A surface roughness parameter Sz of a surface of the toner is 200 nm or more but 500 nm or less, the surface roughness parameter Sz being measured with an atomic force microscope (AFM).

An example device can include a reserve print materials container, an access port coupled to the reserve print materials container to receive, from a replenishment device, print materials directly to the reserve print materials container in-situ, and a main print materials container coupled to the reserve print materials container to receive print materials from the reserve print materials container.

A developing cartridge may include: a casing for accommodating developer therein; a developing roller rotatable about an axis extending in a first direction and positioned at one side of the casing in a second direction; a storage medium having an electric contact surface; and a holder movable relative to the casing in the second direction with the electric contact surface between a first position and a second position, the holder having an outer surface at which the electric contact surface is positioned.

A developer storage container includes a container wall, a substrate member having first and second surfaces, and a storage portion provided on the container wall and storing the substrate member. The storage portion includes an outer surrounding wall provided on the container wall, a first support portion disposed inside the outer surrounding wall and supporting the first surface of the substrate member, and a second support portion disposed inside the outer surrounding wall and connected to the container wall. The second support portion supports the first surface of the substrate member. A lid portion is fixed to the outer surrounding wall and has an opening through which the substrate member is exposed. The lid portion contacts the second surface of the substrate member. The lid portion includes first and second protrusions protruding in a second direction perpendicular to a first direction from the substrate member to the container wall. A distance between the first and second protrusions in the second direction is shorter than a length of the substrate member in the second direction. The outer surrounding wall has a through-hole disposed so as to face the second support portion.

A developer container includes a casing having a developer accommodating chamber and a waste-developer accommodating chamber, conveying member, a conveying-member accommodating unit, and a supporting member. The conveying member conveys waste developer in a longitudinal direction of the waste-developer accommodating chamber. The conveying-member accommodating unit accommodates the conveying member therein and has a first opening and a second opening. The first opening is provided in an upstream end portion and allows the waste developer to move from outside of the conveying-member accommodating unit to the inside of the conveying-member accommodating unit. The second opening allows the waste-developer to move from the inside of the conveying-member accommodating unit to the waste-developer accommodating chamber. The supporting member is provided on the casing. The supporting member supports the conveying-member accommodating unit such that the conveying-member accommodating unit is movable in directions perpendicular to the longitudinal direction relative to the casing.

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 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.