Abstract: An image forming apparatus includes: a transfer portion for transferring an image onto a sheet at a transfer nip; a fixing portion for fixing the image on the sheet at a fixing nip; a sheet feeding guide, provided between the transfer portion and the fixing portion, having a sheet guide surface; a sheet detecting portion provided between the transfer portion and the fixing portion; and a controller for controlling a sheet feeding speed of at least one of the transfer portion and the fixing portion depending on an output of the sheet detecting portion so that a feeding attitude of the sheet sandwiched at both of the transfer nip and the fixing nip is maintained in a predetermined feeding attitude. The sheet guide surface of the sheet feeding guide has a most recessed region in a region between the transfer portion and the sheet detecting portion.

Abstract: An image forming apparatus has a fixing unit including a first fixing member and a second fixing member opposing to the first fixing member, a curl correcting unit including a first curl correcting member and a second curl correcting member opposing to the first curl correcting member, a first changing member rotatable about a first rotation center, the first changing member changing a pressure to the sheet by the first fixing member and the second fixing member, and a second changing member rotatable about the first rotation center, the second changing member changing a pressure to the sheet by the first curl correcting member and the second curl correcting member.

Abstract: A drive transmission device includes: a gear, provided with a shaft hole, for transmitting a driving force; a frame to which a fixing shaft for rotatably supporting the gear by engaging with the shaft hole is fixed, wherein during transmission of the driving force, the gear is urged in a radial direction of the shaft hole, and a predetermined region of an outer peripheral surface of the fixing shaft slides on an inner peripheral surface of the shaft hole; and a holding portion, provided in a position closer to a center of the fixing shaft than the predetermined region with respect to a radial direction of the fixing shaft, for holding a lubricant between itself and the shaft hole. The holding portion is disposed only in a position opposite the predetermined region with respect to the center of the fixing shaft.

Abstract: A representative configuration of an image forming apparatus according to the invention includes: an image forming portion; a transfer portion; a fixing portion; a curl correcting unit which is provided on a downstream of the fixing portion in a sheet conveyance direction and includes a first roller and a second roller; a holding portion which movably holds the second roller; a biasing member which applies a force to the holding portion; a door which rotatably holds the first roller, is supported to be opened and closed, and separates the first roller from the second roller by being opened; and a retracting portion which allows the holding portion to be retracted to a position where the second roller deviates from a movement path of the door against a biasing force of the biasing member according to a closing operation of the door.

Abstract: An image forming apparatus includes; an image forming station for forming a toner image on a sheet; a fixing device including a fixing member and a pressing member; an air feeding member for air feeding cooling air toward the pressing member; and a shutter, provided between the air feeding member and the pressing member, for controlling an air feeding region, wherein the image forming apparatus operable selectively in a first mode for feeding the air an entire area with respect to the longitudinal direction of the pressing member, and in a second mode for feeding the air only a non-sheet-passing area when a small size sheet is fed.

Abstract: A conveying portion includes a pair of superimposing rollers and a controller which controls the rotation of the pair of superimposing rollers, wherein the controller controls a rotation of a pair of conveying rollers so that a tail end of a first sheet passes a nip portion between the pair of conveying rollers by conveying the first sheet to the downstream side before a leading end of a third sheet superimposed on a second sheet reaches the nip portion between the pair of conveying rollers nipping the first sheet and the second sheet superimposed on the first sheet.

Abstract: An image forming apparatus that forms a toner image on a recording medium includes an image forming unit that forms an unfixed toner image on a recording medium; a fixing unit that heats the recording medium bearing the unfixed toner image and fixes the unfixed toner image onto the recording medium at a nip portion; a heating member and a pressurizing member that touches the heating member and forms the nip portion therebetween; a first blower that blows air to a non-sheet-passing area of a small-size recording medium in the heating member; and a second blower that blows air to a non-sheet-passing area of a small-size recording medium in the pressurizing member. Upon the temperature of the non-sheet-passing area of the heating member exceeding a threshold temperature, the first blower blows without the second blower blowing, then the two blowers start blowing together.

Abstract: Provided is a sheet conveying apparatus including: a pair of rollers which includes an upper roller and a lower roller and conveys a sheet in a nipping manner; a driving unit which independently drives the upper roller and the lower roller; a conveying unit which is disposed at the upstream of the pair of rollers in the sheet conveying direction and conveys the sheet to the pair of rollers; an overlapping unit which is provided between the pair of rollers and the conveying unit and overlaps a subsequent sheet on a precedent sheet in the conveying direction; and a control unit which controls the driving unit, wherein the control unit controls the driving unit so that: the upper roller and the lower roller are driven before a leading end of the precedent sheet conveyed by the conveying unit reaches the pair of rollers and the driving of the upper roller and the lower roller is stopped before a tail end of the precedent sheet passes the pair of rollers; the pair of rollers is driven again before a leading end of

Abstract: An image forming apparatus includes: a transfer portion for transferring an image onto a sheet at a transfer nip; a fixing portion for fixing the image on the sheet at a fixing nip; a sheet feeding guide, provided between the transfer portion and the fixing portion, having a sheet guide surface; a sheet detecting portion provided between the transfer portion and the fixing portion; and a controller for controlling a sheet feeding speed of at least one of the transfer portion and the fixing portion depending on an output of the sheet detecting portion so that a feeding attitude of the sheet sandwiched at both of the transfer nip and the fixing nip is maintained in a predetermined feeding attitude. The sheet guide surface of the sheet feeding guide has a most recessed region in a region between the transfer portion and the sheet detecting portion.

Abstract: An image forming apparatus includes: a fixing portion for fixing an image formed on a recording material; and a guide member for guiding the recording material. The guide member is provided at an entrance to the fixing portion and at an end portion with respect to a direction perpendicular to a feeding direction of the recording material The guide member is moved when the guide member is pushed by the recording material.

Abstract: A representative configuration of an image forming apparatus according to the invention includes: an image forming portion; a transfer portion; a fixing portion; a curl correcting unit which is provided on a downstream of the fixing portion in a sheet conveyance direction and includes a first roller and a second roller; a holding portion which movably holds the second roller; a biasing member which applies a force to the holding portion; a door which rotatably holds the first roller, is supported to be opened and closed, and separates the first roller from the second roller by being opened; and a retracting portion which allows the holding portion to be retracted to a position where the second roller deviates from a movement path of the door against a biasing force of the biasing member according to a closing operation of the door.

Abstract: A controller controls operations of a sheet conveying portion and a sheet feeding portion in such a manner that an operation for feeding a preceding sheet by the sheet feeding portion is started after a downstream portion of a subsequent sheet conveyed by the sheet conveying portion is overlapped an upstream portion of the preceding sheet stacked on the stacking portion, and the downstream edge of the preceding sheet is caused to abut against the reference member by the sheet feeding portion in a state where the upstream portion of the preceding sheet and the downstream portion of the subsequent sheet are maintained in an overlapped state.

Abstract: A controller controls operations of a sheet conveying portion and a sheet feeding portion in such a manner that an operation for feeding a preceding sheet by the sheet feeding portion is started after a downstream portion of a subsequent sheet conveyed by the sheet conveying portion is overlapped an upstream portion of the preceding sheet stacked on the stacking portion, and the downstream edge of the preceding sheet is caused to abut against the reference member by the sheet feeding portion in a state where the upstream portion of the preceding sheet and the downstream portion of the subsequent sheet are maintained in an overlapped state.

Abstract: With representative configurations of the sheet processing apparatus and the image forming apparatus according to the present invention, the sheet processing apparatus which includes an intermediate stacking portion in which a sheet is temporarily placed, an aligning portion which supports a part of a lower surface of the sheet stacked in the intermediate stacking portion and which presses a lateral surface end portion of a sheet width direction to align the sheet, and a stapler which processes the sheet aligned by the aligning portion, includes a sheet supporting member which can support the lower surface of the sheet conveyed while sheet stacked in the intermediate stacking portion is processed and a sheet discharging member which presses the rear end of the sheet processed by the stapler and discharges the sheet to the stack tray.

Abstract: With representative configurations of the sheet processing apparatus and the image forming apparatus according to the present invention, the sheet processing apparatus which includes an intermediate stacking portion in which a sheet is temporarily placed, an aligning portion which supports a part of a lower surface of the sheet stacked in the intermediate stacking portion and which presses a lateral surface end portion of a sheet width direction to align the sheet, and a stapler which processes the sheet aligned by the aligning portion, includes a sheet supporting member which can support the lower surface of the sheet conveyed while sheet stacked in the intermediate stacking portion is processed and a sheet discharging member which presses the rear end of the sheet processed by the stapler and discharges the sheet to the stack tray.