A sheet processing apparatus includes a transport path to guide a sheet transported in a predetermined transport direction, a rotating body pair capable of transporting the sheet in a first direction for nipping the sheet transported to the transport path thereby drawing the sheet to perform folding processing, and in a second direction for switching back the sheet to return to one direction side in the transport direction, a press member for pressing the sheet folded by the rotating body pair in the second direction, and a support portion for supporting the press member, where the support portion is disposed on the side opposite to the rotating body pair with the transport path therebetween and on the other direction side opposite to the one direction side in the transport direction with a nip line for connecting between the nip portion and a front end portion of the folding blade therebetween.

A sheet processing apparatus includes a transport path to guide a sheet transported in a predetermined transport direction, a rotating body pair capable of transporting the sheet in a first direction for nipping the sheet transported to the transport path thereby drawing the sheet to perform folding processing, and in a second direction for switching back the sheet to return to one direction side in the transport direction, a press member for pressing the sheet folded by the rotating body pair in the second direction, and a support portion for supporting the press member, where the support portion is disposed on the side opposite to the rotating body pair with the transport path therebetween and on the other direction side opposite to the one direction side in the transport direction with a nip line for connecting between the nip portion and a front end portion of the folding blade therebetween.

A post-processing apparatus includes memory and a processor configured to control a curving device that curves a sheet, which is transported to the curving device, by pressing the sheet, control folding processing that is performed on a sheet curved by the curving device, and control, when folding processing is performed such that two ends of a sheet in a transport direction of the sheet face outward in opposite directions after the folding processing has been performed on the sheet, the curving device so as to curve the sheet in plural directions with respect to a transport surface.

A post-processing apparatus includes memory and a processor configured to control a curving device that curves a sheet, which is transported to the curving device, by pressing the sheet, control folding processing that is performed on a sheet curved by the curving device, and control, when folding processing is performed such that two ends of a sheet in a transport direction of the sheet face outward in opposite directions after the folding processing has been performed on the sheet, the curving device so as to curve the sheet in plural directions with respect to a transport surface.

A sheet aligning device includes a support member, a regulation member, a regulation member moving mechanism, and an alignment member. The support member supports leading ends of sheets. The regulation member is connected to the support member and is provided to face an inclined tray in such a way as to define a sheet entry space in which the leading ends of the sheets enter. The regulation member moving mechanism is configured to, each time a sheet is conveyed onto the inclined tray, move the regulation member in a separating direction to widen the sheet entry space, and then in an approaching direction to narrow the sheet entry space. The alignment member aligns the sheets by abutting on rear ends of the sheets.

A sheet aligning device includes a support member, a regulation member, a regulation member moving mechanism, and an alignment member. The support member supports leading ends of sheets. The regulation member is connected to the support member and is provided to face an inclined tray in such a way as to define a sheet entry space in which the leading ends of the sheets enter. The regulation member moving mechanism is configured to, each time a sheet is conveyed onto the inclined tray, move the regulation member in a separating direction to widen the sheet entry space, and then in an approaching direction to narrow the sheet entry space. The alignment member aligns the sheets by abutting on rear ends of the sheets.

A sheet stacking device includes a conveyance part and a stopper. The conveyance part includes a tray and a conveyance member. On the tray, sheet stacks are stacked. The conveyance member conveys the sheet stack on the tray. The stopper is located on a downstream side of the tray and prevents the sheet stack from falling from the tray. The stopper has a main plate and an anti-slip member. The main plate is inclined upward. The main plate has a contact face coming into contact with the sheet stack and a bent face bent downward from a downstream side tip end of the contact face. The anti-slip member is provided from a downstream side end portion of the contact face to the bent face. A frictional coefficient between the anti-slip member and the sheet stack is larger than a frictional coefficient between the sheet stack and the contact face.

A sheet stacking device includes a conveyance part and a stopper. The conveyance part includes a tray and a conveyance member. On the tray, sheet stacks are stacked. The conveyance member conveys the sheet stack on the tray. The stopper is located on a downstream side of the tray and prevents the sheet stack from falling from the tray. The stopper has a main plate and an anti-slip member. The main plate is inclined upward. The main plate has a contact face coming into contact with the sheet stack and a bent face bent downward from a downstream side tip end of the contact face. The anti-slip member is provided from a downstream side end portion of the contact face to the bent face. A frictional coefficient between the anti-slip member and the sheet stack is larger than a frictional coefficient between the sheet stack and the contact face.

A sheet processing apparatus is configured to press a fold line that is formed on a sheet. The sheet processing apparatus includes: a sheet supporting unit configured to support the sheet in a pressing direction for pressing the fold line; a pressing unit configured to press the fold line that is formed on the sheet that is supported by the sheet supporting unit; and a pressing-force generating unit configured to generate a pressing force for pressing the sheet supporting unit against the pressing unit at a central part in a direction along which the fold line is formed.

A sheet processing apparatus is configured to press a fold line that is formed on a sheet. The sheet processing apparatus includes: a sheet supporting unit configured to support the sheet in a pressing direction for pressing the fold line; a pressing unit configured to press the fold line that is formed on the sheet that is supported by the sheet supporting unit; and a pressing-force generating unit configured to generate a pressing force for pressing the sheet supporting unit against the pressing unit at a central part in a direction along which the fold line is formed.