According to an aspect of the invention, a developing device includes a developing container that accommodates a two-component developer, a toner concentration detecting unit that detects a toner concentration of the developer by a detecting unit exposed to an inner wall of the developing container, a transport member that is disposed within the developing container and stirs and transport the developer with a transport blade having a pitch that is equal to or less than a size of the detecting unit of the toner concentration detecting unit, and a plurality of gap holding members that is provided at a position facing the toner concentration detecting unit of the transport member and holds a gap such that a tip thereof is abutted against the inner wall of the developing container.

A developer container includes a conveyance member having at least a first sheet member and a second sheet member and configured to convey the developer, a deformation portion provided to contact the first sheet member and configured to elastically deform the first sheet member, and a release portion configured to release elastic deformation of the first sheet member to cause the developer on the first sheet member to fly toward an opening, wherein a containing chamber includes a recessed portion as viewed in a lengthwise direction of the containing chamber and wherein the second sheet member is in contact with a wall inside the recessed portion when the developer on the first sheet member is positioned at the release portion.

A replaceable unit for an electrophotographic image forming device according to one example includes a housing having a toner reservoir. An electrical connector mounted on the housing is movable between a retracted position and an operative position. The electrical connector includes an electrical contact for contacting a corresponding electrical contact in the image forming device. The electrical contact is electrically connected to processing circuitry on the housing. In the retracted position, the electrical connector is tucked into a portion of the housing. In the operative position, the electrical connector is exposed to permit the electrical contact to contact the corresponding electrical contact in the image forming device. A linkage is operatively connected to the electrical connector and includes an engagement surface accessible on an exterior of the housing to receive an actuation force. Movement of the linkage moves the electrical connector between the retracted position and the operative position.

A fluid storage device includes a container and a torsion sensor. The container stores a fluid to be agitated. The torsion sensor has a substrate and detects torsion of the substrate. The substrate has a first end inserted in the container and a second end fixed to the container or a housing.

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 toner case includes a case main body and a rotating member. The rotating member is rotatable around a rotation axis. A side wall of the case main body has a base part, a recess part and a bearing part. The base part is formed so as to cross a direction of the rotation axis. The recess part is recessed inward in the direction of the rotation axis with respect to the base part. The bearing part protrudes outward in the direction of the rotation axis from the recess part and supports one end portion of the rotating member in the direction of the rotation axis. An outer end portion in the direction of the rotation axis of the bearing part is positioned closer to an inner side in the direction of the rotation axis than an outer face of the base part.

A toner cartridge includes a cylinder having an opening and accommodating carbon powder, a transmission member having a pipe portion sleeved onto the cylinder, an end portion and at least one outlet communicating with the opening, a powder guiding member having a main body disposed at the end portion and blades extended from the main body radially, a powder storing cover having a cover body sleeved onto the pipe portion, a powder exiting passage located under the powder guiding member and a powder exit provided on the bottom side of the cover body and communicating with the powder exiting passage, and a spring. As a result, when the blades stir the spring, the carbon powder accumulating in the powder exiting passage can be vibrated, so the carbon powder remaining near the powder exit can be effectively reduced and the powder exit can be prevented from being blocked.

A developer conveying apparatus for conveying a developer that develops an electrostatic latent image includes a rotation unit which rotates around a rotation shaft extending in an axial direction and parallel to a developer conveying direction, a first developer conveying portion which is provided in the rotation unit and which has an opening configured to convey the developer in a first axial direction of the rotation shaft, and a second developer conveying portion which is provided in the rotation unit and which has an opening configured to convey the developer in a second axial direction opposite to the first axial direction. A distance from the rotation shaft to the opening in the first developer conveying portion is different than a distance from the rotation shaft to the opening in the second developer conveying portion.

An electrophotographic image forming device according to one example includes a toner cartridge having a housing that includes a toner reservoir. An electrical connector on the housing is movable between a retracted position and an operative position. The electrical connector includes an electrical contact for contacting a corresponding electrical contact in the image forming device. The electrical contact is electrically connected to processing circuitry on the housing. The electrical connector and the electrical contact of the toner cartridge move upward toward the top of the housing when the electrical connector moves from the retracted position to the operative position. The electrical contact of the toner cartridge is positioned within a pocket of the electrical connector. The pocket includes an opening that faces upward when the electrical connector is in the operative position permitting the corresponding electrical contact in the image forming device to enter the pocket from above.

A developer cartridge assembled to a developing device defining therein a developing chamber. The developer cartridge includes a first accommodating portion, and a first agitator. The first accommodating portion accommodates therein a developing agent and is positioned beside the developing device. The first accommodating portion includes a first wall part neighboring the developing device. The first wall part is formed with a first through-hole and a second through-hole. The first through-hole is open diagonally downward from the first accommodating portion to the developing device. The second through-hole is open diagonally upward from the first accommodating portion to the developing device. The first through-hole and the second through-hole allow communication between an interior of the first accommodating portion and the developing chamber. The first agitator is rotatably disposed in the first accommodating portion and in sliding contact with the first wall part in a vertical direction.