Abstract: An image forming apparatus including; an image carrier carrying a toner image; a transfer belt making pressure contact with the image carrier through a sheet of paper and transferring the toner image onto the sheet of paper; a plurality of supporting rollers stretching and supporting the transfer belt; and a transfer roller to which transfer electrical current is applied, as well as making pressure contact of the transfer belt with the image carrier from a back surface of the transfer belt, wherein at least one roller of the supporting rollers is formed in an inverted crown shape with a size of the center portion is smaller than a size of the end portion, and the transfer belt is rotationally driven for a prescribed time without applying transfer electrical current both or in either of before and after transfer of a toner image.

Abstract: A fixing unit is provided with a fixing member to heat a recoding medium and to fix a toner image on the recording medium; a pressure member to press the fixing member to form a nip portion in which a recording medium carrying a toner image is nipped; an auxiliary heating member to heat the surface of the fixing member; and a surface recovery member, arranged at a downstream side of the first auxiliary heating member in a rotational direction of the fixing member, for recovering damage to a surface of the fixing member by making contact with and sliding on the fixing member.

Abstract: Disclosed is an image forming device which can prevent occurrence of damage on the surface of a fixing roller or a fixing belt due to the contact of the end of a sheet with the fixing roller or fixing belt. The image forming device, for transferring a toner image to a sheet fed out from a sheet feed section and fixing the toner image to the sheet by pressing the sheet carrying the toner image at a fixing section, includes a moving section for moving the sheet and or the fixing section in the direction at right angles to the traveling direction of the sheet within a preset moving range, the moving section being controlled based on a preset operation pattern.

Abstract: An image forming apparatus including; an image carrier carrying a toner image; a transfer belt making pressure contact with the image carrier through a sheet of paper and transferring the toner image onto the sheet of paper; a plurality of supporting rollers stretching and supporting the transfer belt; and a transfer roller to which transfer electrical current is applied, as well as making pressure contact of the transfer belt with the image carrier from a back surface of the transfer belt, wherein at least one roller of the supporting rollers is formed in an inverted crown shape with a size of the center portion is smaller than a size of the end portion, and the transfer belt is rotationally driven for a prescribed time without applying transfer electrical current both or in either of before and after transfer of a toner image.

Abstract: A fixing unit is provided with a fixing member to heat a recoding medium and to fix a toner image on the recording medium; a pressure member to press the fixing member to form a nip portion in which a recording medium carrying a toner image is nipped; an auxiliary heating member to heat the surface of the fixing member; and a surface recovery member, arranged at a downstream side of the first auxiliary heating member in a rotational direction of the fixing member, for recovering damage to a surface of the fixing member by making contact with and sliding on the fixing member.

Abstract: Disclosed is an image forming device which can prevent occurrence of damage on the surface of a fixing roller or a fixing belt due to the contact of the end of a sheet with the fixing roller or fixing belt. The image forming device, for transferring a toner image to a sheet fed out from a sheet feed section and fixing the toner image to the sheet by pressing the sheet carrying the toner image at a fixing section, comprises a moving section for moving the sheet and or the fixing section in the direction at right angles to the traveling direction of the sheet within a preset moving range, the moving section being controlled based on a preset operation pattern.

Abstract: Disclosed is a sheet transport device having: a registration roller to transport a sheet after correcting a skew of the sheet; a drive source to drive the registration roller; a frame body; and a rotation resisting body which is connected to the registration roller on one side and is connected to the frame body on the other side, to create a resisting force against a rotation of the registration roller in a sheet transport direction.

Abstract: An image forming apparatus includes: a fixing device that fixes the toner image onto the recording medium by applying heat and pressure; ejection rollers provided away from the fixing device for ejecting the recording medium; a guide provided on at least one part of a recording medium ejection path between the ejection rollers and the fixing device for guiding a conveyance of the recording medium; at least one spur provided on the guide, having a plurality of teeth on a circumference thereof; and a slit formed on the guide so that the plurality of teeth of the spur are protruded on a side of the recording medium ejection path through the slit, wherein the recording medium is conveyed from the fixing device by bringing the plurality of teeth of the spur into contact with a surface of the recording medium.

Abstract: Disclosed is a sheet transport device having: a registration roller to transport a sheet after correcting a skew of the sheet; a drive source to drive the registration roller; a frame body; and a rotation resisting body which is connected to the registration roller on one side and is connected to the frame body on the other side, to create a resisting force against a rotation of the registration roller in a sheet transport direction.

Abstract: An image forming apparatus includes: a fixing device that fixes the toner image onto the recording medium by applying heat and pressure; ejection rollers provided away from the fixing device for ejecting the recording medium; a guide provided on at least one part of a recording medium ejection path between the ejection rollers and the fixing device for guiding a conveyance of the recording medium; at least one spur provided on the guide, having a plurality of teeth on a circumference thereof; and a slit formed on the guide so that the plurality of teeth of the spur are protruded on a side of the recording medium ejection path through the slit, wherein the recording medium is conveyed from the fixing device by bringing the plurality of teeth of the spur into contact with a surface of the recording medium.

Abstract: According to this invention, in a manual feed apparatus having an opening/closing tray which can be stored in an image forming apparatus main body by swing operation, and a feedout member which feeds a sheet stacked on the opening/closing tray, the opening/closing tray is swingably connected to a vertically movable support member which is restricted to be movable in a vertical direction, and the apparatus includes a vertically movable unit which moves the vertically movable support member in the vertical direction.

Abstract: According to this invention, in a manual feed apparatus having an opening/closing tray which can be stored in an image forming apparatus main body by swing operation, and a feedout member which feeds a sheet stacked on the opening/closing tray, the opening/closing tray is swingably connected to a vertically movable support member which is restricted to be movable in a vertical direction, and the apparatus includes a vertically movable unit which moves the vertically movable support member in the vertical direction.

Abstract: A color image forming apparatus is provided wherein toner images formed on a plurality of image carriers are primarily transferred onto an intermediate transfer object, and then, are secondarily transferred onto a recording sheet. The color image-forming apparatus includes an intermediate transfer member, a longitudinal direction of which is arranged in substantially a vertical direction, and onto which toner images formed on image carriers are sequentially transferred in such a manner that the toner images overlap relative to each other so as to form a color toner image on the intermediate transfer member. In addition, a transferring device is provided to transfer the color toner image formed on the intermediate transfer member onto a transfer sheet. The intermediate transfer member and the image carriers are integrated into a rack, and the rack is drawable in substantially a horizontal direction with respect to a mainframe of the color image-forming apparatus.

Abstract: The present invention concerns a color image forming apparatus wherein toner images formed on a plurality of image carriers are primarily transferred onto an intermediate transfer object, and then, are secondarily transferred onto a recording sheet.

Abstract: The present invention concerns a color image forming apparatus wherein toner images formed on a plurality of image carriers are primarily transferred onto an intermediate transfer object, and then, are secondarily transferred onto a recording sheet.

Abstract: The present invention concerns a color image forming apparatus wherein toner images formed on a plurality of image carriers are primarily transferred onto an intermediate transfer object, and then, are secondarily transferred onto a recording sheet.

Abstract: A sheet feeder for feeding a sheet from a sheet stacker. The sheet feeder includes: a main body of the sheet stacker for holding plural stacked sheets; a movable bottom plate, provided on the bottom portion of the main body and supported bivotally on an axis, for supporting the plural stacked sheets; a lifting lever for lifting the movable bottom plate; and plural pickup rollers, aligned on an axis in a direction perpendicular to a sheet feeding direction, for having a pressure contact with a sheet of the plural stacked sheets on the movable bottom plate, and for feeding the sheet from the main body in the sheet feeding direction. In the sheet feeder, a protruded portion is formed either on the movable bottom plate or on the lifting lever so that a contact portion where the movable bottom plate comes in contact with the lifting lever is of a point contact, and the contact portion is provided at the center of the closest two of the pickup rollers in the direction of their axis.

Abstract: A sheet conveyer for conveying a sheet so that an image of a document is duplicated on both sides of the sheet by an image forming machine such as a photocopy machine. The sheet conveyer has; a first conveyance path for conveying the sheet to an image forming section of the image forming machine; a second conveyance path for conveying the sheet from the image forming section to a tray; the tray for holding the sheet; a third conveyance path for conveying the sheet from the tray to the image forming section; and, a pair of nip rollers, located at the vicinity of the tray, for holding the sheet conveyed through the second conveyance path, and forwarding the sheet into the third conveyance path; in which the sheet conveyance apparatus has a first mode that the sheet is forwarded into the third conveyance path by the nip rollers without being placed on the tray, and a second mode that the sheet is once placed on the tray and forwarded into the third conveyance path by the nip rollers.

Abstract: An image forming apparatus such as a copier or a printer for forming an image of a document on a recording paper. The image forming apparatus includes a paper feed tray for holding the recording paper; a conveyance unit for conveying the recording paper from the paper feed tray; a image forming section for forming a toner image of the document onto the recording paper; a fixing unit for fixing the toner image on the recording paper; a detector for detecting a paper jam between the units, and for generating a detection signal; a locking member with a solenoid for locking one of the units in another; a controller for controlling the locking member according to the detection signal so that both of the units are resisted from being removed separately when the paper jam occurs between the units.

Abstract: A document feeding apparatus having a conveyor belt which moves documents along a platen glass plate of a photoreproducing machine, first and second rollers which support the conveyor belt, a driving source connected to the first roller, and a member for driving the second roller so that it prevents the conveyor belt from slackening. In preferred forms of the device, the first roller is connected to the second roller by a one-way clutch and the line speed of the first or second roller on the document feed side is greater than the line speed of the first or second roller on the discharge side.