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 cartridge includes a casing, a developing roller rotatable about an axis extending in a first direction, a developing memory having an electrical contact surface, an agitator, an agitator gear rotatable about an agitator axis together with the agitator, a holder holding the electrical contact surface, and a plate movable between a first position and a second position in a second direction crossing the first direction relative to the casing. The holder is movable relative to the casing in a third direction crossing the first and second directions between a retracted position and an advancing position. The holder is movable from the retracted position to the advancing position in response to a movement of the plate from the first position to the second position. The plate is positioned farther away from the developing roller than the agitator gear and the holder are in the second direction.

A toner cartridge includes: a casing having a first toner accommodating portion and a second toner accommodating portion; an agitator; an auger; a first protrusion positioned at one side in a first direction of the second toner accommodating portion; a second protrusion positioned at another side in the first direction of the second accommodating portion; a memory; and a toner-side electrical contact surface electrically connected to the memory. The toner cartridge is attachable to a drum cartridge by the casing pivotally moving from a first position to a second position relative to the drum cartridge about the first protrusion and the second protrusion. When the casing is at the first position, the toner-side electrical contact surface does not contact a first electrical contact surface of the drum cartridge. When the casing is at the second position, the toner-side electrical contact surface contacts the first electrical contact surface.

An image forming apparatus includes an apparatus body, a developer container, a data recording medium, a contact terminal, a detector, and control circuitry. The developer container is detachably attached in the apparatus body. The data recording medium is on the developer container. The contact terminal is disposed in the apparatus body and contacts the data recording medium. The detector detects a communication failure between the data recording medium and the apparatus body. The control circuitry executes a control mode to vibrate the data recording medium when the detector detects the communication failure.

An image forming apparatus includes an image bearer, a developing device, a fixing device, and circuitry. The developing device contains a developer and develops a latent image on the image bearer with the developer. The developing device includes a stirrer to stir the developer. The fixing device fixes a toner image onto a sheet. The circuitry performs start-up operations after receiving a print start command and before starting a printing operation. The start-up operations includes starting a warm-up operation of the fixing device and starting, during the warm-up operation, a stirring operation in which the stirrer stirs the developer.

A developing cartridge may include: a casing; a developing roller extending in a first direction; a developing-roller gear; a coupling including a coupling gear; a first idle gear; a second idle gear; an agitator; a first agitator gear; and a protrusion. The developing-roller gear, the coupling, the first idle gear, the second idle gear, the first agitator gear, and the protrusion may be positioned at an outer surface of the casing. The protrusion may be positioned between a first axis of the coupling and a third axis of the first agitator gear in a second direction connecting the first and third axes. The protrusion may be positioned outside an addendum circle of the developing-roller gear, an addendum circle of the coupling gear, an addendum circle of the first idle gear, and an addendum circle of the second idle gear. The first agitator gear may be spaced apart from the protrusion in the first direction.

The present disclosure provides a toner cartridge, a method for detecting a remaining toner amount, and an image-forming apparatus. The toner cartridge, installed on an image-forming apparatus, includes a toner hopper, configured to hold toner; a stirring unit, disposed in the toner hopper and configured to stir the toner in the toner hopper; and a detection unit, disposed on the stirring unit and configured to be in contact with the toner during a process of stirring the toner by the stirring unit and output a current signal. A housing of the toner cartridge is disposed with electrical connection contacts, and the detection unit is electrically connected to the image-forming apparatus through the electrical connection contacts. Whether the toner cartridge is short of toner before printed images are defective due to lack of toner is realized, and the detection process is relatively convenient with low detection cost.

In a cartridge, a housing has a developer accommodating portion and includes a first side wall and a second side wall. A coupling member is disposed at a position opposite to the developer accommodating portion with respect to the first side wall. A detection body is disposed at a position opposite to the developer accommodating portion with respect to the second side wall. A first driving force transmission member is positioned at the same side with the coupling member with respect to the first side wall, and transmits driving force from the coupling member to a rotating member. A second driving force transmission member is positioned at the same side with the detection body with respect to the second side wall, and transmits driving force from the rotating member to the detection body.

An example image forming apparatus includes a frame, a first shaft supported by the frame, and a first coupler. The first coupler includes a body coupled to one end of the first shaft and a first protrusion protruding from the body in an axial direction of the first shaft, the first protrusion having a first surface and a second protrusion protruding from the first surface. The second protrusion is to lock with a groove to mount a cartridge on the frame, the first shaft is to provide a rotational force in a first rotational direction to rotate the second protrusion of the first coupler and to insert the second protrusion into the groove to lock with the cartridge, and the first surface of the first protrusion of the first coupler is to contact a second surface to transmit the rotational force to the second coupler in the first rotational direction.

A toner container includes a first rotation member rotatably provided in a container main body, a stirring member rotatably provided in such a way as to be parallel to the first rotation member, a lid member closing an opening portion of the container main body, a first bearing portion provided on an inner surface of the lid member and rotatably supporting a first end portion of a first rotation shaft of the first rotation member, a stirring bearing portion provided on the inner surface of the lid member and rotatably supporting a lid-side end portion of a stirring rotation shaft of the stirring member, a storage concave portion formed on the lid member and recessed from an outer surface of the lid member inward, and a transmission mechanism provided in the storage concave portion to transmit a rotation of the first rotation shaft to the stirring rotation shaft.