Abstract: An image forming apparatus includes an engine controller configured to control an operation of the image forming apparatus; an image processing controller including a constant log storage configured to temporarily store a log of the engine controller; a network controller configured to store the log, which is stored in the constant log storage, in another device via a network or in a storage of the image forming apparatus, according to a command from the engine controller; a communication line configured to communicably couple the engine controller to the image processing controller, and to communicably couple the image processing controller to the network controller; and an exclusive-use communication line configured to communicably couple the engine controller to the network controller, and to be used to report the command from the engine controller to the network controller.

Abstract: An image forming apparatus includes an engine controller configured to control an operation of the image forming apparatus; an image processing controller including a constant log storage configured to temporarily store a log of the engine controller; a network controller configured to store the log, which is stored in the constant log storage, in another device via a network or in a storage of the image forming apparatus, according to a command from the engine controller; a communication line configured to communicably couple the engine controller to the image processing controller, and to communicably couple the image processing controller to the network controller; and an exclusive-use communication line configured to communicably couple the engine controller to the network controller, and to be used to report the command from the engine controller to the network controller.

Abstract: A diagnostic apparatus includes a recording device, an acquisition device, and processing circuitry. The acquisition device acquires first and second diagnostic target data obtained in a manner that an image forming device forms a test pattern on each of a first medium and a second smaller medium with the first medium having a long side in agreement with that of the second medium in a conveying direction and an image reading device reads the first medium and reads the second medium rotated such that the long side of the second medium is different in direction from that of the first medium. The circuitry detects an abnormal area and diagnoses an abnormality factor, with the pattern, the first and second data, and third diagnostic target data obtained by rotating the second data such that the long side of the second medium is identical in direction to that of the first medium.

Abstract: An image forming apparatus includes an image carrier configured to carry an image and a charger to which a direct current voltage overlapped with an AC voltage is applied as a charging bias to charge the image carrier. The charger is positioned in contact or contactlessly with the image carrier. The AC voltage applied to the charger in an adjustment of the AC voltage is not less than twice a charging start voltage Vth at which the image carrier starts to be charged.

Abstract: An image forming apparatus includes an image carrier configured to carry an image and a charger to which a direct current voltage overlapped with an AC voltage is applied as a charging bias to charge the image carrier. The charger is positioned in contact or contactlessly with the image carrier. The AC voltage applied to the charger in an adjustment of the AC voltage is not less than twice a charging start voltage Vth at which the image carrier starts to be charged.

Abstract: An image forming apparatus includes an image carrier configured to carry an image and a charger to which a direct current voltage overlapped with an AC voltage is applied as a charging bias to charge the image carrier. The charger is positioned in contact or contactlessly with the image carrier. A controller performs an adjustment to the AC voltage multiple times to gradually bring the AC voltage to a target value.

Abstract: An image forming apparatus includes an image carrier configured to carry an image and a charger to which a direct current voltage overlapped with an AC voltage is applied as a charging bias to charge the image carrier. The charger is positioned in contact or contactlessly with the image carrier. The AC voltage applied to the charger in an adjustment of the AC voltage is not less than twice a charging start voltage Vth at which the image carrier starts to be charged.

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 image recording apparatus of the type using a single-ingredient type developer, i.e., toner, a latent image is electrostatically formed on a photoconductive drum or similar image carrier. A developing unit has a developing roller for conveying the toner deposited thereon, and an intermediate roller for conveying the toner transferred thereto from the developing roller and depositing it on the latent image to thereby produce a corresponding toner image. An image transfer unit transfers the toner image to a cut sheet. During the development of an area of the image carrier other than a latent image area, at least one of biases assigned to the developing roller and intermediate roller, respectively, 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. As a result, the toner existing on the intermediate roller is collected by the developing roller.

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 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: 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: An image forming apparatus including a developing device having various components with specific relationships between their lengths. There is an image bearing member such as a photoconductive drum or belt having a photosensitive layer. The photosensitive layer has a length A. A first toner transporting roller has two ends, the length between the two ends being defined as B. Additionally, there is a second toner transporting roller, disposed between and contacting both the image bearing member and the first toner transporting roller. The length of the second toner transporting roller being defined as C. The components of the image forming apparatus are constructed such the length of the second toner transporting roller is less than or equal to the lengths of both the first toner transporting roller and the photosensitive layer of the image bearing member. This means that the relationships A>C and B>C may exist. As an alternative, B is approximately equal to C with A being greater than both B and C.

Abstract: A developing apparatus is capable of providing stable charging ability for a developer and stable transfer ability for transferring the developer to a photoreceptor for electronic photography to prevent residual positive images and stain of texture which appear on a toner image. A first toner transfer roller 23 has a core supported to be rotatable and a sheet type insulation layer wound around the outer periphery of the core. The insulation layer is made of elastic rubber in which magnetic material having a specified particle size is uniformly dispersed and the magnetic material is formed with ferromagnetic substance such as magnet and magnetized in advance. The first toner transfer roller 23 attracts toner T by actuating magnetism on the insulation layer since the magnetic material added to the insulation layer is magnetized.

Abstract: In an image forming apparatus, a developing device has a first developer carrier for depositing a developer thereon, a regulating member for regulating the amount of the developer deposited on the first developer carrier, and a second developer carrier having an elastic surface, and contacting the first developer carrier while biting into it by a predetermined amount. The developer is provided with a preselected degree of fluidity. Hence, even when the same portion of the surface of the second developer carrier runs a plurality of times past a position where the two developer carriers contact each other without any developer being fed from the second developer carrier to an image carrier, the first developer carrier can surely strip the developer from the second developer carrier. As a result, a developer on which a predetermined amount of charge is deposited is transferred from the first developer carrier to the second developer carrier. This successfully protects images from defects.

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 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 developing device which includes a first toner transporting roller, a second toner transporting roller to which toner is transported from the first toner transporting roller and an image bearing member such as a photoconductive drum or belt. Seals are located between the circumferential ends of one of the toner transporting rollers and a bottom portion of a toner hopper. When the seals are between the bottom of toner hopper and the first toner transporting roller, the first toner transporting roller is longer than the second toner transporting roller and the circumferential portions of the first toner transporting roller which contact the seals do not contact the second toner transporting roller.