Abstract: An image forming apparatus includes an image bearing member, a latent image writing device that emits a plurality of laser beams, two adjacent laser beams of the plurality of laser beams partially overlapping in a sub-scanning direction, respectively, and forming a reference latent image on a surface of the image bearing member by performing repeated scanning of each laser beam on the surface of the image bearing member, a developing device that develops the reference latent image with toner into a reference toner image, and a detecting device that detects the density of the reference toner image. The quantity of light of each laser beam forming a subsequent latent image is adjusted according to the density of the reference toner image detected by the detecting device.

Abstract: An image transferring device for transferring a toner image from an image carrier to a recording medium includes a belt passed over a plurality of rotary bodies for supporting and conveying the recording medium and a cleaning member for cleaning the surface of the belt in contact therewith. A dielectric layer forms the surface of the cleaning member. An image forming apparatus including the above image transferring device is also disclosed.

Abstract: A transfer device for transferring a toner image formed on an image carrier onto a transfer material conveyed on a transfer belt. The transfer device includes a cleaning member having a dielectric surface layer for cleaning a surface of the transfer belt, and a bias application unit for applying to the cleaning member a cleaning bias having an opposite polarity to an electric charge polarity of a toner forming the toner image. Further, specific characteristic values of the dielectric surface layer are set to achieve a higher than predetermined cleaning level, such as setting a volume resistivity of the dielectric surface layer is set to 1E4 ohms/square or more.

Abstract: A toner recycling device of an electrophotographic image forming apparatus conveys collected used toner to a developing device of the image forming apparatus. The toner recycling device includes a powder conveying pump that is driven to convey the collected used toner to the developing device of the image forming apparatus when an integrated value of predetermined numerical values, each based on a number of picture elements of an image to be formed, is equal to or greater than a constant value, and an adding device that adds a predetermined constant value to the integrated value when driving of an image bearing member of the image forming apparatus is detected.

Abstract: An image forming apparatus including a fixing unit, detachably provided in the image forming apparatus, to fix a toner image transferred on a sheet onto the sheet, and a fixing unit falling off preventing device to prevent the fixing unit from falling off of the image forming apparatus. The fixing, unit falling off preventing device includes a first fixing unit supporting member and a second fixing unit supporting member which each support the fixing unit at a predetermined position within the image formate apparatus. The first fixing unit supporting member releases support of the fixing unit upon being depress ed, and the second fixing unit supporting member releases support of the fixing unit upon being rotated in a predetermined direction.

Abstract: In an image forming apparatus, a device for supporting a photoconductive element or image carrier includes an implementation which allows the element to be rapidly and easily dismounted from the apparatus together with its shaft, i.e., without having the shaft pulled out or inserted. Therefore, the device enhances easy replacement of the photoconductive element. The operation is simple because the photoconductive element and shaft do not have to be handled independently of each other.

Abstract: A transfer device comprises a cleaning roller that has a dielectric layer on its surface and cleans the surface of a transfer belt, and transfers a toner image formed on a photosensitive drum onto transfer paper on the transfer belt. A power supply, which applies a cleaning bias of the opposite polarity to an electric charge polarity of the toner that forms a toner image, is provided, and volume resistivity of the dielectric layer is set to 1E3 ohm-cm or more. By specifying characteristic values of the dielectric layer provided on the surface of the cleaning member, the cleaning effect of the dielectric layer can be maintained higher than a predetermined level and the transfer belt can effectively be cleaned.

Abstract: An image forming apparatus capable of collecting toner left on an image carrier after image transfer during an electrophotographic process, and returning the toner to a developing unit for reuse in the form of an air-toner mixture is disclosed. A toner conveying device includes a screw pump and a hopper portion positioned upstream of the screw pump in the intended direction of toner conveyance. When the collected toner accumulating in the hopper portion reaches a preselected amount, the toner conveying device is caused to start and stop operating at a specific timing.

Abstract: In an image forming apparatus, a developing device operable with toner or single component type developer has a hard first developing roller and a soft second developing roller. Fine magnetic N-S poles are formed on the periphery of the first roller. The second roller conveys the toner, electrostatically transferred thereto from the first roller, to an image carrier. The device frees a toner image from deterioration due to toner particles charged to a polarity opposite to an expected polarity. The toner forms a uniform thin layer on the first roller and is uniformly charged. Toner for use with this type of developing device is also disclosed.

Abstract: A toner cartridge removably mounted to an image forming apparatus including a developing device. The toner cartridge includes a plurality of toner outlet openings for replenishing toner to the developing device and a plurality of toner collection openings for collecting the toner from the developing device. Further, the plurality of toner outlet openings and the plurality of toner collection openings are arranged substantially in a single array.

Abstract: An intake system-draining structure for an engine to remove water or other liquids that may collect on the surface of an intake manifold. The intake system-draining structure has several plate-like members that are disposed between branch pipes of an intake manifold positioned in the dust chamber of an air cleaner. A pair of communication members connects the branch pipes with the dust chamber. A water drain hole portion is formed through one of the plate-like members. The plate-like member with the water drain hole portion is positioned lower than the other plate-like members to efficiently drain water.

Abstract: In an electrophotographic image forming apparatus of the type using single-ingredient type high resistance toner, a developing roller or similar toner conveyor roller is covered with a dielectric layer which is comparatively thick at opposite end portions than at an intermediate portion. A conductive or semiconductive elastic layer underlies the dielectric layer. With the above configuration, the dielectric layer is prevented from coming off the roller. This, coupled with the fact that the elastic layer does not contact a photoconductive element, eliminates current leaks and thereby extends the life of the roller and photoconductive element.

Abstract: In a cleaning device and a eveloping device installed in an electrophotographic device, a cleaner and toner magazine (CTM) has a cleaning unit including a cleaning blade for removing a toner left on a photoconductive element after image transfer and a waste toner tank for collecting it, and a developing unit accommodating a fresh toner tank storing a fresh toner. The waste toner tank and fresh toner tank are connected together such that the fresh toner tank is movable relative to the developing device independently of the waste toner tank.

Abstract: An object of the present invention is to provide a microcomputer capable of checking the data stored in a read only memory (ROM) integrally formed therein even without using any additional testing device, but an external ROM. In the test mode, a test signal TS to be fed to an external terminal 15 is set to a logic "1". By this operation, the output signal of a register 13 is fed to the address terminal A of the internal ROM 16 by way of a selector 14. Further, the data read out from the ROM 16 is outputted to a register 18 through a selector 17. On the other hand, by connecting the external ROM 30, in which a test program is stored, to an address terminal 21 and a data terminal 22. The CPU 11 can carry out the test program stored in the external ROM 30. By reading and comparing the data stored in the ROM 16 and the data stored in the external ROM 30 to be compared by the test program, the data in the ROM 16 can be checked.

Abstract: In an image forming apparatus, a developing device operable with toner or single component type developer has a hard first developing roller and a soft second developing roller. Fine magnetic N-S poles are formed on the periphery of the first roller. The second roller conveys the toner, electrostatically transferred thereto from the first roller, to an image carrier. The device frees a toner image from deterioration due to toner particles charged to a polarity opposite to an expected polarity. The toner forms a uniform thin layer on the first roller and is uniformly charged. Toner for use with this type of developing device is also disclosed.

Abstract: In an electrophotographic recording apparatus of the type using a single-ingredient type developer, i.e., toner, a developing device has a developing roller for conveying the toner deposited thereon, and an intermediate roller for conveying the toner transferred theretofrom the developing roller and depositing it on a latent image electrostatically formed on an image carrier to thereby produce a corresponding toner image. During the development of an area of the image carrier other than a latent image area, a bias assigned to the developing roller is switched over to thereby form an electric field different in direction from an electric field assigned to the formation of the toner image between the two rollers. Further, before the rotation of the image carrier is stopped, the bias assigned to the developing roller is again switched in order to form the electric field for the formation of the toner image between the rollers. As a result, a toner layer is formed on the intermediate roller.

Abstract: In an image forming apparatus using a corona discharge type charging device and a contact type image transferring device, a toner deposited on a photoconductive element in the form of a black stripe is prevented from being transferred to the image transferring device; otherwise, the toner would be transferred from the image transferring device to the rear of the following recording medium. Because the toner forming the black stripe is limited to the toner charged to a polarity opposite to an expected polarity, toner consumption ascribable to the stripe is reduced.

Abstract: A developing device for an electrophotographic image forming apparatus and a toner cartridge for replenishing a fresh toner to the developing device are disclosed. A toner is circulated between a toner cartridge and a hopper so that an additive included in the toner existing in the developing device is adequately distributed throughout the developing device. This prevents the concentration of additive in the toner from differing at the ends of the hopper with respect to the center of the hopper. This ensures that images are produced with constant toner density.

Abstract: In an image forming apparatus, a developing device operable with toner or single component type developer has a hard first developing roller and a soft second developing roller. Fine magnetic N-S poles are formed on the periphery of the first roller. The second roller conveys the toner, electrostatically transferred thereto from the first roller, to an image carrier. The device frees a toner image from deterioration due to toner particles charged to a polarity opposite to an expected polarity. The toner forms a uniform thin layer on the first roller and is uniformly charged. Toner for use with this type of developing device is also disclosed.

Abstract: In a cleaning device and a developing device installed in an electrophotographic device, a cleaner and toner magazine (CTM) has a cleaning unit including a cleaning blade for removing a toner left on a photoconductive element after image transfer and a waste toner tank for collecting it, and a developing unit accommodating a fresh toner tank storing a fresh toner. The waste toner tank and fresh toner tank are constructed integrally with each other and connected together such that the fresh toner tank is movable to the developing device.