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 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 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: 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 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: 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 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: To correct a bias voltage of each roller upon estimating a toner potential precisely even where toner's characteristics change due to, e.g., changes of environmental condition, changes over time, supplements of the toner, replacement of an EP cartridge, or the like, on an image forming apparatus according to this invention, the toner potential is estimated upon measuring a DB current in a prescribed period from a time that a development starting point on the developing roller starts development to a time that the development starting point comes in contact with a toner supplying roller. Alternatively, where the measured DB current is equal to or less than a fixed amount, a period for a warming-up processing is extended. Alternatively, where the toner is judged as supplemented upon detection of the remaining toner amount, a prescribed warming-up processing is made before the measurement for the DB current.

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.

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: To correct a bias voltage of each roller upon estimating a toner potential precisely even where toner's characteristics change due to, e.g., changes of environmental condition, changes over time, supplements of the toner, replacement of an EP cartridge, or the like, on an image forming apparatus according to this invention, the toner potential is estimated upon measuring a DB current in a prescribed period from a time that a development starting point on the developing roller starts development to a time that the development starting point comes in contact with a toner supplying roller. Alternatively, where the measured DB current is equal to or less than a fixed amount, a period for a warming-up processing is extended. Alternatively, where the toner is judged as supplemented upon detection of the remaining toner amount, a prescribed warming-up processing is made before the measurement for the DB current.

Abstract: Plural guide holes are arranged in a matrix form in a wire guide. Plural print drivers are circularly arranged in plural layers for first print drivers belonging to a layer near to the wire guide and for second print drivers belonging to a layer far from the wire guide. A print wire is provided at each print driver so as to project end thereof from the guide hole of the wire guide when driven. The print wires formed at the first print drivers are inserted in the guide holes of lines located at the edge formed in the wire guide. On the other hand, the print wires formed at the second print drivers are inserted in the guide holes of lines located at the center of the wire guide.

Abstract: A wire driving mechanism for a wire-dot print head employs a piezoelectric element or a magnetostrictive element as a driver (5). To enable printing with a satisfactorily high print quality, the wire driving mechanism employs the extensional force of the driver (5) to pivot two generally parallel levers (3a, 3b) respectively having fixed ends. When the levers (3a, 3b) are pivoted, the free end of each of the levers (3a, 3b) is moved by a displacement which is a multiple of the extension of the driver (5). The respective displacements of the free ends of the levers (3a, 3b) are transmitted by a pair of support members (6a, 6b) to opposite sides of a driving member (8) at positions on different levels with respect to the longitudinal direction of the driving member (8). As a result, the driving member (8) is moved so that a print wire (7) attached to the driving member (8) is advanced in a printing direction.

Abstract: In a method of producing a movable part of a wire-dot print head comprising an armature supported by a plate spring, and a lever having a tip to which print wire is fixed, the armature and the lever are formed of alloys containing identical atoms or alloys easy to diffuse into each other, a bond part of a base part of the lever is inserted in a bond groove in a tip of the armature, and the lever and the armature are heat-treated in vacuum at a temperature not lower than 1100.degree. C. and below the melting points of the lever and the armature, so that the lever and the armature are diffusion-bonded.