Abstract: Providing a simply-arranged detaching/attaching mechanism and image forming device which allow a transfer supporter device to be detached/attached through a space formed by opening an outer covering, the device includes photosensitive drums, detachable/attachable transfer belt unit, and rail members supporting a transfer belt unit. Each of the rail members includes a rail groove guiding the transfer belt unit, notch and positioning hole determining the position of the transfer belt unit when the belt is in contact with the photosensitive drums, and notch and convex section determining the position of the transfer belt unit when the belt is detached from the photosensitive drums. The transfer belt unit support with respect to the main body of the image forming device, performed by the rail members, is released in response to the action of opening the side cover, so that the transfer belt unit is in a free state.

Abstract: An armored unit includes a side cover and a guide member. When sheet jam operation is carried out, a fixing unit is pulled out with the armored unit, and then is pushed to the rear side. This operation unlocks the lock member provided in the guide member, and a shoulder screw moves in a guide hole. Thus, the fixing unit is moved from the pulled out position toward the rear side and toward the main body of image forming device to be shifted to a receding position. On this account, it is possible to provide an image forming device ensuring sufficient space for removing a jammed sheet by hand with a small opening space.

Abstract: A timer clocks and accumulates time periods during each of which a recording sheet is transported or transfer bias is applied as transfer execution periods. When the accumulated value reaches a predetermined value, the timer outputs a time-up signal to a CPU and then clears the accumulated value. The CPU executes a cleaning operation at the time the time-up signal is inputted from the timer. In the cleaning operation, the CPU causes a high-voltage power source to apply cleaning bias to a transfer electrode roller while causing a high-voltage power source to apply delivery bias to an auxiliary cleaning roller, in order to return toner attracted to the auxiliary cleaning roller to a photosensitive drum via a transfer belt.

Abstract: A transfer belt device includes an endless transfer belt that is tightly stretched by a plurality of rollers and forms a transport path where a recording medium or a developer image is transported facing a monochrome image bearing member and a plurality of color image bearing members arranged in parallel along a fixed direction. In the apparatus, a first transfer unit having a first linking member in which a monochrome-image transfer member is supported that transfers a developer image formed on the monochrome image bearing member onto a recording medium or an outer peripheral surface of the belt, and a second transfer unit having a second linking member in which a plurality of color-image transfer members are supported that transfer developer images formed on the respective color image bearing members onto a recording medium or an outer peripheral surface of the belt, are linked via the first and second linking members.

Abstract: A transfer unit includes: an intermediate transfer belt that (i) holds a toner image that has been transferred, at a primary transfer part, from a photoreceptor drum and (ii) rotates to move a surface holding the toner image; and a secondary transfer belt that comes into contact, at a secondary transfer part, with the intermediate transfer belt. The transfer unit (i) transfers the toner image from the intermediate transfer belt to a sheet conveyed to the secondary transfer part and (ii) includes an intermediate transfer belt cleaning unit that removes and collects toner from the toner image holding surface of the intermediate transfer belt.

Abstract: A transfer belt device includes an endless transfer belt that is tightly stretched by a plurality of rollers and forms a transport path where a recording medium or a developer image is transported facing a monochrome image bearing member and a plurality of color image bearing members arranged in parallel along a fixed direction. In the apparatus, a first transfer unit having a first linking member in which a monochrome-image transfer member is supported that transfers a developer image formed on the monochrome image bearing member onto a recording medium or an outer peripheral surface of the belt, and a second transfer unit having a second linking member in which a plurality of color-image transfer members are supported that transfer developer images formed on the respective color image bearing members onto a recording medium or an outer peripheral surface of the belt, are linked via the first and second linking members.

Abstract: A plurality of photosensitive drums are disposed in a sheet transport direction so as to be in contact with a transfer belt and a transfer voltage for transferring toner images on the photosensitive drums onto a sheet transported by the transfer belt is applied thereto. A sensor for sensing a temperature or humidity in the working atmosphere of the image forming apparatus is provided; when a jam occurs, sheet transportation is ceased at a first stage to thereby enable the sheet in the jam to be removed; at a second stage subsequent thereto, transportation of the sheet is restarted; and the transfer voltage applied onto the transfer belt is controlled based on a measurement result of the sensor.

Abstract: A timer clocks and accumulates time periods during each of which a recording sheet is transported or transfer bias is applied as transfer execution periods. When the accumulated value reaches a predetermined value, the timer outputs a time-up signal to a CPU and then clears the accumulated value. The CPU executes a cleaning operation at the time the time-up signal is inputted from the timer. In the cleaning operation, the CPU causes a high-voltage power source to apply cleaning bias to a transfer electrode roller while causing a high-voltage power source to apply delivery bias to an auxiliary cleaning roller, in order to return toner attracted to the auxiliary cleaning roller to a photosensitive drum via a transfer belt.

Abstract: A junction/disjunction unit of a multicolored image forming apparatus joints/disjoints a transfer material holder with/from an image holder, to switch over between a monochromatic image forming mode which uses a specific image forming unit and a multicolored image forming mode which uses a plurality of image forming units. For switching the image forming mode, a driving unit for driving the junction/disjunction unit also drives an auger provided for conveying toner, which has been recovered by a transfer material holder cleaning unit for recovering toner remaining on the transfer material holder, into a recovery container. Accordingly, a driving force outputted from the driving unit can be effectively utilized, and thereby good cost performance can be realized.

Abstract: To provide a simply-arranged detaching/attaching mechanism and image forming device which allow a transfer supporter device (contacting member) to be detached/attached through a space formed by opening an outer covering, the present invention includes photosensitive drums, detachable/attachable transfer belt unit, and rail members supporting a transfer belt unit. Each of the rail members includes a rail groove for guiding the transfer belt unit, notch and positioning hole for determining the position of the transfer belt unit when the belt is in contact with the photosensitive drums, and notch and convex section for determining the position of the transfer belt unit when the belt is detached from the photosensitive drums. The support of the transfer belt unit with respect to the main body of the image forming device, which is performed by the rail members, is released in response to the action of opening the side cover, so that the transfer belt unit is caused to be in a free state.

Abstract: A plurality of photosensitive drums are disposed in a sheet transport direction so as to be in contact with a transfer belt and a transfer voltage for transferring toner images on the photosensitive drums onto a sheet transported by the transfer belt is applied thereto. A sensor for sensing a temperature or humidity in the working atmosphere of the image forming apparatus is provided; when a jam occurs, sheet transportation is ceased at a first stage to thereby enable the sheet in the jam to be removed; at a second stage subsequent thereto, transportation of the sheet is restarted; and a transport distance of the sheet is controlled based on a printing ratio of an image formed on the sheet.

Abstract: A plurality of photosensitive drums are disposed in a sheet transport direction so as to be in contact with a transfer belt and a transfer voltage for transferring toner images on the photosensitive drums onto a sheet transported by the transfer belt is applied thereto. A sensor for sensing a temperature or humidity in the working atmosphere of the image forming apparatus is provided; when a jam occurs, sheet transportation is ceased at a first stage to thereby enable the sheet in the jam to be removed; at a second stage subsequent thereto, transportation of the sheet is restarted; and the transfer voltage applied onto the transfer belt is controlled based on a measurement result of the sensor.

Abstract: A plurality of photosensitive drums are disposed in a sheet transport direction so as to be in contact with a transfer belt and a transfer voltage for transferring toner images on the photosensitive drums onto a sheet transported by the transfer belt is applied thereto. A sensor for sensing a temperature or humidity in the working atmosphere of the image forming apparatus is provided; when a jam occurs, sheet transportation is ceased at a first stage to thereby enable the sheet in the jam to be removed; at a second stage subsequent thereto, transportation of the sheet is restarted; and a transport distance of the sheet is controlled based on a printing ratio of an image formed on the sheet.

Abstract: A transfer unit 5, which has transfer members 51a corresponding to a plurality of image carriers arranged in a sheet transporting direction, for transferring images carried on the image carriers, has rotary fulcrums 50 in the vicinity of an extension of the axis of a transfer member 51a on an upstream side end portion or on an downstream side end portion in the sheet transporting direction so as to be approximately parallel to the axis, and can be rotated on the rotary fulcrums 50 in directions of moving to and from the image carriers. With this image forming apparatus, it is possible to keep stable orientation of the transfer unit while the apparatus is in operation, thereby realizing stable contact/separation movement of the transfer unit.

Abstract: In an image forming device of the present invention, which is a tandem type, electrophotographic image forming device, a first separating/contacting mechanism mechanically lowers/raises the whole of a transfer frame holding the transfer and transport belt unit in association with the opening/closing of a front door, a second separating/contacting mechanism mechanically lowers/raises the right side of the transfer frame in association with the opening/closing of a right side door, and a third separating/contacting mechanism mechanically lowers/raises the left side of the transfer frame in association with the opening/closing of a left side door. Therefore, the handling of a paper jam can be carried out even when power supply is cut off, and the transfer frame can be separated from the photoconductor drums just by opening a door from a plurality of access directions, on a side opened.

Abstract: A junction/disjunction unit 38 of the multicolored image forming apparatus joints/disjoints a transfer material holder with/from an image holder, to switch over between a monochromatic image forming mode which uses a specific image forming unit and a multicolored image forming mode which uses a plurality of image forming units. For switching the image forming mode, a driving unit 39 for driving the junction/disjunction unit 38 also drives an auger 37 provided for conveying toner, which has been recovered by a transfer material holder cleaning unit for recovering toner remaining on the transfer material holder, into a recovery container 36. Accordingly, a driving force outputted from the driving unit can be effectively utilized, and thereby good cost performance can be realized.

Abstract: An armored unit includes a side cover and a guide member. When sheet jam operation is carried out, a fixing unit is pulled out with the armored unit, and then is pushed to the rear side. This operation unlocks the lock member provided in the guide member, and a shoulder screw moves in a guide hole. Thus, the fixing unit is moved from the pulled out position toward the rear side and toward the main body of image forming device to be shifted to a receding position. On this account, it is possible to provide an image forming device ensuring sufficient space for removing a jammed sheet by hand with a small opening space.

Abstract: In an image forming device of the present invention, which is a tandem type, electrophotographic image forming device in which a plurality of photoconductor drums are located in order from one side to the other side of the main unit of the device, and a sheet of paper sequentially passes through the respective photoconductor drums with being supported by a transfer and transport belt unit, so as to transfer a plurality of kinds of toner images onto the sheet of paper, a first separating/contacting mechanism mechanically lowers/raises the whole of a transfer frame holding the transfer and transport belt unit in association with the opening/closing of a front door, a second separating/contacting mechanism mechanically lowers/raises the right side of the transfer frame in association with the opening/closing of a right side door, and a third separating/contacting mechanism mechanically lowers/raises the left side of the transfer frame in association with the opening/closing of a left side door.

Abstract: An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The image forming apparatus further includes a member which charges the transfer paper in a polarity reversed to a polarity of the transfer drum, so that the transfer drum can attract the transfer sheet electrostatically in a satisfactory manner. The image forming apparatus further includes a charge control mechanism for controlling the amount of charges on the photosensitive drum.

Abstract: An image forming apparatus includes a transfer drum which attracts and holds a transfer paper electrostatically. A voltage is applied to a conductive layer provided on an inner side of the transfer drum, and a grounded conductive electrode member is pressed against a dielectric layer provided on an outer side of the transfer drum through the transfer paper. A toner image formed on a photosensitive drum is transferred onto the transfer paper when the transfer paper is wound around the transfer drum and brought into contact with the photosensitive drum. The image forming apparatus further includes an upstream member or layer on the electrode member which charges the transfer paper in a polarity reversed to a polarity of the transfer drum, so that the transfer drum can attract the transfer sheet electrostatically in a satisfactory manner.