An image forming apparatus includes: a pair of first rollers configured to nip a paper sheet in a reference position and convey the paper sheet, the pair of first rollers being pressed against each other; and a control unit configured to control operation of the pair of first rollers to correct a positional deviation in a width direction of the paper sheet, by moving the pair of first rollers from the reference position in the width direction perpendicular to a direction of conveyance of the paper sheet, wherein, the control unit controls the operation of the pair of rollers, to complete a series of operations for the pair of rollers to separate from each other, to return to the reference position, and to be again pressed against each other, before a bottom edge of the paper sheet nipped by the pair of rollers passes through the pair of rollers.

A paper delivery device includes a shift frame movable in a second direction perpendicular or substantially perpendicular to a first direction along which paper is delivered to outside, a driver that moves the shift frame in the second direction, a drive roller with a first outer peripheral surface extending in the second direction and supported by the shift frame such that the drive roller is rotatable about a first shaft parallel or substantially parallel to the second direction, a first driven roller with a second outer peripheral surface extending in the second direction and contactable with the first outer peripheral surface at a first contact position, the first driven roller supported by the shift frame such that the first driven roller is rotatable about a second shaft parallel or substantially parallel to the second direction following the rotation of the drive roller, the first driven roller being rotated in a state where the paper is nipped between the first outer peripheral surface and the second outer peripheral surface thus transporting the paper in the first direction, and a second driven roller with a third outer peripheral surface extending in the second direction and contactable with the first outer peripheral surface at a second contact position downstream of the first contact position in the first direction, the second driven roller being supported by the shift frame such that the second driven roller is rotated about a third shaft disposed parallel or substantially parallel to the second direction following the rotation of the drive roller, the second driven roller being rotated in a state where the paper which is nipped between the first outer peripheral surface and the second outer peripheral surface is nipped by the first outer peripheral surface and the third outer peripheral surface thus transporting the paper in the first direction.

A sheet processing apparatus includes a controller configured to control operations of the pair of aligning members such that a sheet bundle disposed on a first stacking portion is aligned by the pair of aligning members of the pair of aligning members at a position shifted to a side of one aligning member in a width direction perpendicular to the discharge direction of a sheet with respect to a sheet discharge range in which a sheet is discharged at the time of discharging the sheet from a discharge portion, and, before the aligned sheet bundle is discharged to a second stacking portion by a bundle discharge portion, the other aligning member of the pair of aligning members is moved to the outside of the sheet discharge range in the width direction.

An image forming apparatus includes: a pair of first rollers configured to nip a paper sheet in a reference position and convey the paper sheet, the pair of first rollers being pressed against each other; and a control unit configured to control operation of the pair of first rollers to correct a positional deviation in a width direction of the paper sheet, by moving the pair of first rollers from the reference position in the width direction perpendicular to a direction of conveyance of the paper sheet, wherein, the control unit controls the operation of the pair of rollers, to complete a series of operations for the pair of rollers to separate from each other, to return to the reference position, and to be again pressed against each other, before a bottom edge of the paper sheet nipped by the pair of rollers passes through the pair of rollers.

A sheet conveying device includes a correcting portion and a side end detecting portion for detecting a side end of a sheet. The correcting portion includes a first roller whirlable about a first axis in a crossing direction crossing a conveyance direction and a widthwise direction and for correcting a position of the sheet in the widthwise direction, and a second roller disposed at a position different from the first roller in the widthwise direction, whirlable about a second axis in the crossing direction and for correcting the position of the sheet. Based on a detection result of the side end detecting portion, a control portion executes a first control in which the correcting portion corrects the position of the sheet in the widthwise direction and executes a second correcting control in which the correcting portion corrects the position of the sheet after the first correcting control.

A paper delivery device includes a shift frame movable in a second direction perpendicular or substantially perpendicular to a first direction along which paper is delivered to outside, a driver that moves the shift frame in the second direction, a drive roller with a first outer peripheral surface extending in the second direction and supported by the shift frame such that the drive roller is rotatable about a first shaft parallel or substantially parallel to the second direction, a first driven roller with a second outer peripheral surface extending in the second direction and contactable with the first outer peripheral surface at a first contact position, the first driven roller supported by the shift frame such that the first driven roller is rotatable about a second shaft parallel or substantially parallel to the second direction following the rotation of the drive roller, the first driven roller being rotated in a state where the paper is nipped between the first outer peripheral surface and the second outer peripheral surface thus transporting the paper in the first direction, and a second driven roller with a third outer peripheral surface extending in the second direction and contactable with the first outer peripheral surface at a second contact position downstream of the first contact position in the first direction, the second driven roller being supported by the shift frame such that the second driven roller is rotated about a third shaft disposed parallel or substantially parallel to the second direction following the rotation of the drive roller, the second driven roller being rotated in a state where the paper which is nipped between the first outer peripheral surface and the second outer peripheral surface is nipped by the first outer peripheral surface and the third outer peripheral surface thus transporting the paper in the first direction.

A sheet processing apparatus includes a shift unit including a pair of first conveying rollers that nip and convey a sheet and being able to move in a width direction orthogonal to a conveyance direction of the sheet in a state of nipping the sheet; a drive gear configured to transmit a driving force from a drive motor; a rack gear including a rack portion that meshes with the drive gear, the rack gear being configured to receive the driving force from the drive gear via the rack portion and, thereby, move the shift unit in the width direction in a state of nipping the sheet with a pair of first conveying rollers; a guide member configured to guide movement of the shift unit in the width direction; and a supporting member configured to nip the rack gear between the supporting member and the drive gear and support the rack gear, in which the rack gear is rotatable with respect to the shift unit on a plane parallel to the conveyance direction and the width direction.

A sheet conveyance apparatus includes a sheet supporting portion, a feed roller, a first conveyance roller pair for conveying the sheet and moving the sheet in a lateral direction, a second conveyance roller pair, disposed upstream of the first conveyance roller pair, for conveying the sheet and moving the sheet in the lateral direction, and a control unit. The control unit can execute a first mode for conveying a first sheet, the first mode being configured to move a first sheet in the lateral direction, while nipping the first sheet via the first conveyance roller pair and not nipping the first sheet via the second conveyance roller pair, and a second mode for conveying a second sheet, the second mode being configured to move the second sheet in the lateral direction, while nipping the second sheet via the first conveyance roller pair and the second conveyance roller pair.

A medium processing apparatus includes a first conveyor and a second conveyor. The first conveyor is disposed in a conveyance path to convey a medium or multiple media including the medium in a conveyance direction. The second conveyor is disposed in a circulation path that is branched from the conveyance path at a branching point and is merged at a merging point upstream from the branching point in the circulation path in the conveyance direction to circulate the medium. The second conveyor includes a correction roller pair to correct a displacement of the multiple media that are overlaid on each other and circulate together in the circulation path.

A sheet conveyance apparatus includes a first roller pair, a second roller pair, a third roller pair, and a control unit configured to execute a first mode in which skew correction of the sheet is performed by abutting a leading edge of the sheet against the second roller pair in a stopped state, and then the sheet is passed through the third roller pair without abutting the leading edge of the sheet against the third roller pair in a stopped state, and a second mode in which the leading edge of the sheet is passed through the second roller pair without abutting against the second roller pair in the stopped state, and then skew correction of the sheet is performed by abutting the leading edge of the sheet against the third roller pair in the stopped state.