Abstract: An image forming apparatus includes a development unit having a first wireless communication part, a developer cartridge having a second wireless communication part and an antenna part that communicates with the first and second wireless communication parts. When the first and second wireless communication parts are respectively accommodated in holding parts, the first wireless communication part is closer to the antenna part than the second wireless communication part is, and the second wireless communication part and the first wireless communication part oppose each other.

Abstract: An image forming apparatus includes a development unit having a first wireless communication part, a developer cartridge having a second wireless communication part and an antenna part that communicates with the first and second wireless communication parts. When the first and second wireless communication parts are respectively accommodated in holding parts, the first wireless communication part is closer to the antenna part than the second wireless communication part is, and the second wireless communication part and the first wireless communication part oppose each other.

Abstract: A development device includes a developer carrier, a restriction member to control a layer thickness of the developer on the developer carrier, first and second developer supply members being in contact with the developer carrier. Each of the developer supply members is configured to rotate at a speed having a constant ratio to a rotation speed of the developer carrier. The second developer supply member and the restriction member are arranged in this order downstream of the first developer supply member in a rotating direction of the developer carrier. A peripheral speed (a speed of the outer peripheral surface) of the second developer supply member is set to be slower than that of the first developer supply member.

Abstract: A developer holding apparatus holds a developer material therein. A rotatable member is disposed within the developer holding apparatus. The rotatable member includes a rotational shaft and an agitating portion. The agitator is offset relative to the rotational shaft and extends in a first direction parallel to the rotational shaft. The agitating portion includes a first portion and a second portion. The first portion includes a first dimension in a second direction substantially perpendicular to the first direction and the second portion includes a second dimension in a third direction substantially parallel to the second direction. The second dimension is smaller in width than first dimension.

Abstract: A development device includes a developer carrier, a restriction member to control a layer thickness of the developer on the developer carrier, first and second developer supply members being in contact with the developer carrier. Each of the developer supply members is configured to rotate at a speed having a constant ratio to a rotation speed of the developer carrier. The second developer supply member and the restriction member are arranged in this order downstream of the first developer supply member in a rotating direction of the developer carrier. A peripheral speed (a speed of the outer peripheral surface) of the second developer supply member is set to be slower than that of the first developer supply member.

Abstract: A developer holding apparatus holds a developer material therein. A rotatable member is disposed within the developer holding apparatus. The rotatable member includes a rotational shaft and an agitating portion. The agitator is offset relative to the rotational shaft and extends in a first direction parallel to the rotational shaft. The agitating portion includes a first portion and a second portion. The first portion includes a first dimension in a second direction substantially perpendicular to the first direction and the second portion includes a second dimension in a third direction substantially parallel to the second direction. The second dimension is smaller in width than first dimension.

Abstract: A developer holding apparatus holds developer therein. The developer is discharged through a discharging opening. An agitator includes shaft portions and an agitating portion. A bearing member includes a bearing hole formed therein. One of the shaft portions is rotatably received in the bearing hole. The bearing hole has a larger diameter than the shaft portions. A hollow body is rotatable in the developer holding apparatus and the agitator rotates in the hollow body.

Abstract: An image forming unit includes an image forming unit main body; and a developer storage unit detachably attached to the image forming unit main body. The image forming unit main body includes a developer retaining space for retaining developer and a supply opening for supplying developer to the developer retaining space. The developer storage unit includes a discharge opening for discharging developer to the developer retaining space. The image forming unit main body further includes a movable member moving relative to the discharge opening and the supply opening.

Abstract: A toner cartridge is detachably attached to an image forming apparatus and supplies toner to the image forming apparatus. The locking mechanism is positioned either at a locking position or at a non-locking position. Shortly after the toner cartridge has been attached to the image forming apparatus, the locking mechanism is at a non-locking position. When a user operates a driving member of the toner cartridge after the toner cartridge has been attached to the image forming apparatus, the operating lever engages the locking mechanism to cause the locking mechanism to move to a locking position. When the locking mechanism is at the locking position, the locking mechanism limits the driving member to move relative to the engagement portion, so that the toner cartridge is not allowed to be detached from the image forming apparatus.

Abstract: A toner cartridge extends in a longitudinal direction, and is detachably attached to an image drum unit. A memory element is electrically connected to an electrical terminal. The toner cartridge includes a first end portion on which the electrical terminal is disposed and a second end portion longitudinally opposite to the first end portion. An engagement portion is formed on the outer surface of the toner cartridge in the vicinity of the first end portion. When the toner cartridge is attached into the image drum unit, the second end portion engages the image drum unit, and the engagement portion engages the image drum unit such that the toner cartridge is urged against the image drum unit.

Abstract: A toner cartridge and a developing unit are used in an image forming apparatus. The toner cartridge includes a toner chamber, an inner shutter, and an outer shutter. The toner chamber holds toner therein and has an opening through which the toner is discharged into the developing unit. The inner shutter is disposed in the toner chamber and is rotatable relative to the toner chamber to close and open the opening. The outer shutter has an engagement portion, is mounted to an outer surface of the toner chamber, and is movable either to a closing position where said outer shutter closes the opening or to an opening position where the outer shutter opens the opening. When the toner cartridge is moved into the developing unit, the engagement portion is guided in a guide groove formed in the developing unit to move relative to the toner chamber from the closing position to the opening position.