A sheet processing apparatus includes a rotatable pressing member, a guide, and a contact member. The rotatable pressing member includes a pressing portion that is disposed in a predetermined range in a rotation direction of the pressing member to press a folded portion of a sheet. The guide is disposed opposite the pressing member. The contact member contacts the guide and is rotatably disposed at at least one end of the pressing member in an axial direction of the pressing member.

A sheet discharge apparatus includes a first tray for stacking sheets, and a sheet bundle forming unit that forms a sheet bundle on the first tray. The sheet bundle forming unit forms a first sheet bundle on the first tray, and forms a second sheet bundle on the first sheet bundle to be offset from the first sheet bundle. When forming each of the first sheet bundle and the second sheet bundle on the first tray, the sheet bundle forming unit divides sheets constituting each of the sheet bundles into a plurality of sets and discharges the sheets in a plurality of times for each sheet bundle. A number of sheets included in a first sheet set of the first sheet bundle is set smaller than a number of sheets included in a first sheet set of the second sheet bundle.

A sheet processing apparatus includes a first sheet conveyance path, a second sheet conveyance path that branches from the first sheet conveyance path at a branch portion on the first sheet conveyance path and merges with the first sheet conveyance path at a merging portion, and a control unit. The control unit controls a guide unit so as to guide a first sheet conveyed first in the sheet bundle to be processed by a sheet processing unit to the second sheet conveyance path, and guide a second sheet following the first sheet to the first sheet conveyance path to merge the first and second sheets in an overlapping manner at the merging portion, and guide at least one of sheets following the second sheet among a plurality of sheets constituting the sheet bundle to the second sheet conveyance path.

The present invention is to provide a sheet discharge device capable of preventing the lowermost sheet on a tray from being displaced. A present sheet post-processing device includes a first tray for stacking a sheet, a processing tray that temporarily stacks conveyed sheets until a number of the sheets reaches a predetermined number, and a discharge mechanism that discharges the sheets stacked on the processing tray onto the first tray. A sheet bundle forming unit divides, when forming a first sheet bundle on the first tray, sheets constituting the first sheet bundle into a plurality of sets and discharges the sheets a plurality of times for each set. At this time, a number of sheets included in a sheet set to be discharged at the first time is smaller than a maximum number of sheets included in sheet sets to be discharged at the second and subsequent times.

A post-processing device for processing a sheet includes a post-processing section for post-processing a sheet; a buffer section for temporarily staying a plurality of sheets at an upstream of the post-processing section; and a conveying section for conveying, one by one, the plurality of sheets stayed at the buffer section to the post-processing section.

A sheet processing apparatus includes a roller pair configured to convey a sheet, a sheet bundle conveyer configured to convey a sheet bundle to the roller pair, and circuitry configured to cause the sheet bundle conveyer to contact leading edges of sheets of the sheet bundle to the roller pair and cause the roller pair to rotate in reverse to align the leading edges of the sheets of the sheet bundle.

A post-processing device for processing a sheet includes a first post-processing section and a second post-processing section, for processing a sheet; a buffer section for temporarily staying a sheet transferred from a carry-in port; a first conveying section for conveying a sheet at the buffer section to the first post-processing section; and a second conveying section for conveying a sheet at the buffer section to the second post-processing section.

A sheet processing apparatus includes a folding device to fold a sheet and a fold-enhancing device to press a folded portion of the sheet folded by the folding device to perform enhanced folding processing on the sheet whose trailing edge has exited the folding device.

A sheet processing apparatus includes an entry portion, a sheet conveyance path extending from the entry portion, a skew correction roller pair that contacts a leading edge of a sheet conveyed in a predetermined direction from the entry portion to correct skew of the sheet, and a receiving path. The skew correction roller pair conveys the skew-corrected sheet in a direction opposite the predetermined direction. The receiving path branches from the sheet conveyance path from the entry portion to the skew correction roller pair to receive the sheet conveyed in the direction opposite the predetermined direction.

A sheet processing apparatus includes conveyers to convey a sheet. The conveyers include a registration conveyer which a plurality of sheets is to sequentially contact and is configured to bend a preceding sheet contacting the registration conveyer toward a direction in which the preceding sheet does not obstruct an entry of a following sheet to the registration conveyer when the conveyers overlay and convey the plurality of sheets after the plurality of sheets sequentially contacts the registration conveyer.