A drum cartridge includes: a drum frame to which a developing cartridge including a storage medium having an electrical contact surface is detachably attachable; a photosensitive drum; a transfer roller; and a conveying roller. The drum is rotatable about a first axis extending in a first direction and positioned at one end portion of the frame in a second direction. The transfer roller is rotatable about a second axis extending in the first direction and in contact with the drum. The conveying roller is rotatable about a third axis extending in the first direction and separated from the transfer roller in the second direction. A first opening of the frame is positioned between the transfer roller and the conveying roller in the second direction. The electrical contact surface is exposed to an outside through the first opening in a case where the developing cartridge is attached to the frame.

A cartridge includes a shutter that opens and closes when the cartridge is attached and detached to a developing unit or image forming apparatus. The cartridge includes a casing having a chamber with a first opening at one end portion allowing toner to flow out of the casing. The cartridge includes a cover that covers the first opening, movable with the casing and having a second opening allowing toner to flow out of the cover. The shutter is located at the one end portion and has a protrusion further from the one end portion than the cover. The developing unit supports the protrusion when the cartridge is mounted thereon, and the casing pivots with the cover relative to the developing unit between a first position where the shutter closes the second opening and a second position where a third opening of the shutter overlaps the second opening.

An object of this disclosure is to reduce differences in the drawn amount of the parison around the mouth of the toner container, thereby reducing the amount of resin for the toner container and the weight thereof. A powder container includes a cylindrical container body to rotate in a horizontal posture, a cylindrical mouth at a first end of the container body, smaller in diameter than the container body, a conveyor to convey the powder inside the container body toward the mouth, a scooping portion deeper in the container body than the mouth, to lift the powder above a powder inlet of a conveying tube inserted from the mouth and drop the powder to the powder inlet, and a radially inner face continuous with an inner end of the scooping portion, extending in a direction crossing the scooping portion and disposed inward in the radial direction than an outermost face of the container body. The radially inner face extends from the mouth toward a second end of the container body and is not inner in the radial direction than an inner rim of the mouth.

A developing device includes a developer container configured to accommodate a developer containing toner and a carrier; and a feeding screw provided rotatably in the developer container and configured to feed the developer in a predetermined feeding direction, the feeding screw including a rotation shaft, and a first helical blade and a second helical blade which are formed around the rotation shaft and which form a multi-thread helical blade. The feeding screw includes a region in which a plate-like projection portion is provided on the rotation shaft between the first helical blade and the second helical blade. The plate-like projection portion is provided so as to contact an adjacent helical blade on a downstream side with respect to the feeding direction without contacting an adjacent helical blade on an upstream side with respect to the feeding direction.

A developing device includes a developer container configured to accommodate a developer containing toner and a carrier; and a feeding screw provided rotatably in the developer container and configured to feed the developer in a predetermined feeding direction, the feeding screw including a rotation shaft, and a first helical blade and a second helical blade which are formed around the rotation shaft and which form a multi-thread helical blade. The feeding screw includes a region in which a plate-like projection portion is provided on the rotation shaft between the first helical blade and the second helical blade.

The developing device includes a development container, a developer carrier, and a toner trapping mechanism. The development container includes a first conveyance chamber and a second conveyance chamber placed in parallel juxtaposition and communicated with each other at their longitudinal both end portions, and the development container contains a toner-containing developer to be fed to an image carrier. The toner trapping mechanism includes a duct, an air inlet port, a trapping filter, and a fan. The duct is connected to the second conveyance chamber, and allows air present in the second conveyance chamber to flow therethrough. The development container has an air vent opened in the first conveyance chamber and communicated with outside of the development container.

According to an embodiment, a toner cartridge for use with an image forming apparatus includes a body that contains toner and includes an opening through which the toner is supplied the image forming apparatus. A supplying mechanism is provided with the body that discharges the toner from the opening of the body to the image forming apparatus. The body is removably mounted on an mounting unit of the image forming apparatus through a port.

A drum cartridge includes: a drum frame to which a developing cartridge including a storage medium having an electrical contact surface is detachably attachable; a photosensitive drum; a transfer roller; and a conveying roller. The drum is rotatable about a first axis extending in a first direction and positioned at one end portion of the frame in a second direction. The transfer roller is rotatable about a second axis extending in the first direction and in contact with the drum. The conveying roller is rotatable about a third axis extending in the first direction and separated from the transfer roller in the second direction. A first opening of the frame is positioned between the transfer roller and the conveying roller in the second direction. The electrical contact surface is exposed to an outside through the first opening in a case where the developing cartridge is attached to the frame.

Provided is an image forming apparatus in which, while image formation is prevented from being performed, scattered toner that has dropped from a filter and adhered to an outer peripheral surface of a developer carrying member is recovered by a cleaning unit through intermediation of an image bearing member. An absolute value of a perpendicular-magnetic-force gradient of a fixed magnet of the developer carrying member is 4.0 mT/? or less at a position where the fixed magnet faces a central portion of the filter in a rotation direction of a developing sleeve.

A toner container includes containing chambers, a shaft member, rotary members, and stirring members. The containing chambers are arrayed in a first direction and partitioned from each other. The containing chambers contain respective toners of different colors. The shaft member extends in the first direction, passes through the containing chambers, and is rotatable about a rotational axis extending in the first direction. The rotary members are disposed in the respective containing chambers and each have a through-hole extending in the first direction. The rotary members are rotatable in response to rotation of the shaft member in an inserted state of the shaft member in the through-holes. The stirring members are supported by the respective rotary members and each extend in a second direction intersecting the first direction. The stirring members are pivotable in response to rotation of the respective rotary members. The stirring members have different pivoting positions upon pivoting.