There is provided a sheet post-processing apparatus capable of performing eco-stapling processing to prevent a decrease in binding force by the thickness of a sheet with a simple arrangement by changing a stapling count depending on the grammage and size of a sheet and the number of sheets in consideration of the change in binding force caused by the sheet size.

There is provided a sheet post-processing apparatus capable of performing eco-stapling processing to prevent a decrease in binding force by the thickness of a sheet with a simple arrangement by changing a stapling count depending on the grammage and size of a sheet and the number of sheets in consideration of the change in binding force caused by the sheet size.

An apparatus for folding sheets or sheet stacks, including at least two folding/transport rollers, transport device and knife, the transport device defining transport plane E for sheets or sheet stacks fed in transport direction R, knife being movable substantially perpendicularly to and through transport plane E, folding/transport rollers being arranged above transport plane E, oppositely on both sides of knife, axis of rotation A of folding/transport rollers extending substantially perpendicularly to transport plane E, and at least two folding/transport rollers each having, at their end facing toward transport plane E, rounded portion, such that narrowing gap S is formed between the at least two folding/transport rollers, into which gap sheets or sheet stacks can be introduced by means of knife so as to be folded there and at same time conveyed away in transport direction R, and to corresponding method.

A sheet processing device includes: a stacking unit configured to stack a plurality of sheets to obtain a sheet bundle; a stitched-sheet number acquiring unit configured to acquire a number of sheets in the sheet bundle, which is a target to be stitched; a permanent stitching unit configured to permanently stitch the sheet bundle; a temporary stitching unit configured to be capable of temporarily stitching a plurality of areas of the sheet bundle; a selecting unit configured to select any one of the permanent stitching unit and the temporary stitching unit to be used; and a stitching-process control unit configured to, when the temporary stitching unit is selected by the selecting unit, control the temporary stitching unit so as to change a number of areas that are stitched by the temporary stitching unit.

A sheet processing device includes: a stacking unit configured to stack a plurality of sheets to obtain a sheet bundle; a stitched-sheet number acquiring unit configured to acquire a number of sheets in the sheet bundle, which is a target to be stitched; a permanent stitching unit configured to permanently stitch the sheet bundle; a temporary stitching unit configured to be capable of temporarily stitching a plurality of areas of the sheet bundle; a selecting unit configured to select any one of the permanent stitching unit and the temporary stitching unit to be used; and a stitching-process control unit configured to, when the temporary stitching unit is selected by the selecting unit, control the temporary stitching unit so as to change a number of areas that are stitched by the temporary stitching unit.

A sheet binding device includes a first tooth-shaped member that has plural arranged teeth, and a second tooth-shaped member that has plural arranged teeth, bites the first tooth-shaped member to clamp and bind sheets in cooperation with the first tooth-shaped member, and is tilted relative to the first tooth-shaped member from a beginning of biting to a completion of biting.

A sheet binding device includes a first tooth-shaped member that has plural arranged teeth, and a second tooth-shaped member that has plural arranged teeth, bites the first tooth-shaped member to clamp and bind sheets in cooperation with the first tooth-shaped member, and is tilted relative to the first tooth-shaped member from a beginning of biting to a completion of biting.

Provided is a stapler device installed to staple a bundle of papers processed and discharged from an image forming apparatus or a post-processing apparatus. The stapler device includes a stapler, and a moving unit installed to allow the stapler to reciprocate in a direction intersecting with a discharge direction of the bundle of papers. The moving unit may rotate the stapler outwardly such that a bundle of papers inserted from the outside in addition to the discharged bundle of papers is stapled in at least one end position of a range of the reciprocating movement.

A binding unit includes a pressing portion that binds a recording material bundle, which includes a first pressing portion pressing against the recording material bundle in order to bind the recording material bundle and a second pressing portion facing the first pressing portion, an extruding portion that is separately formed from the second pressing portion, and extrudes the second pressing portion toward the first pressing portion, and a driving source that drives the extruding portion, in which the extruding portion is connected to the pressing portion, the pressing portion retracts to a downstream side in a direction where a recording material enters when the recording material enters, and the driving source does not operate in conjunction with movement of the reaction of the pressing portion.

A binding unit includes a pressing portion that binds a recording material bundle, which includes a first pressing portion pressing against the recording material bundle in order to bind the recording material bundle and a second pressing portion facing the first pressing portion, an extruding portion that is separately formed from the second pressing portion, and extrudes the second pressing portion toward the first pressing portion, and a driving source that drives the extruding portion, in which the extruding portion is connected to the pressing portion, the pressing portion retracts to a downstream side in a direction where a recording material enters when the recording material enters, and the driving source does not operate in conjunction with movement of the reaction of the pressing portion.