A sheet processing apparatus includes a conveying portion; a conveying path for sheets conveyed by the conveying portion; a stack portion where sheets discharged from the conveying path are stacked; a first binding portion moving in a crossing direction crossing the conveying direction; a first regulating portion regulating a position of a sheet bundle stacked on the stack portion; a first guide member guiding the first regulating portion; a second regulating portion regulating a position of a sheet bundle on the stack portion in the crossing direction; a second guide member guiding the second regulating portion; a third regulating portion regulating a position of a sheet bundle on the stack portion in the conveying direction; and a second binding portion binding a corner portion of a sheet bundle without a staple. The first binding portion binds a corner portion of a sheet bundle by a staple.

A sheet processing apparatus includes a conveying portion; a conveying path for sheets conveyed by the conveying portion; a stack portion where sheets discharged from the conveying path are stacked; a first binding portion moving in a crossing direction crossing the conveying direction; a first regulating portion regulating a position of a sheet bundle stacked on the stack portion; a first guide member guiding the first regulating portion; a second regulating portion regulating a position of a sheet bundle on the stack portion in the crossing direction; a second guide member guiding the second regulating portion; a third regulating portion regulating a position of a sheet bundle on the stack portion in the conveying direction; and a second binding portion binding a corner portion of a sheet bundle without a staple. The first binding portion binds a corner portion of a sheet bundle by a staple.

Provided is a binding apparatus enabling easy removal of a sheet bundle, which has been subjected to binding, from clamping teeth. The binding apparatus includes: a sheet placement portion on which sheets are placed; an alignment unit configured to align the sheets placed on the sheet placement portion; a binding member configured to bind the sheets placed on the sheet placement portion by deforming the sheets without using a staple; and a separating member configured to apply a rotational force to the sheets which are bound by the binding member to separate the sheets and the binding member from each other, the alignment unit and the separating member being constructed by different members.

Provided is a binding apparatus enabling easy removal of a sheet bundle, which has been subjected to binding, from clamping teeth. The binding apparatus includes: a sheet placement portion on which sheets are placed; an alignment unit configured to align the sheets placed on the sheet placement portion; a binding member configured to bind the sheets placed on the sheet placement portion by deforming the sheets without using a staple; and a separating member configured to apply a rotational force to the sheets which are bound by the binding member to separate the sheets and the binding member from each other, the alignment unit and the separating member being constructed by different members.

A sheet processing device has a binding unit that applies water to a crimping range of sheets and then crimps the sheets. The sheet processing device includes a processing tray on which sheets are placed, a pair of pressure teeth (pressure teeth and receiving teeth) that crimps the sheets placed on the processing tray at a crimping position with the sheets interposed therebetween, and a water application member (cylinder and piston) that applies water to the crimping position before crimping by the pressure teeth. When the number of sheets placed on the processing tray is equal to or less than a predetermined number, the sheets are crimped by the pressure teeth without water application; while when the number of sheets placed on the processing tray exceeds the predetermined number, the sheets are crimped by the pressure teeth after water application.

A sheet processing device has a binding unit that applies water to a crimping range of sheets and then crimps the sheets. The sheet processing device includes a processing tray on which sheets are placed, a pair of pressure teeth (pressure teeth and receiving teeth) that crimps the sheets placed on the processing tray at a crimping position with the sheets interposed therebetween, and a water application member (cylinder and piston) that applies water to the crimping position before crimping by the pressure teeth. When the number of sheets placed on the processing tray is equal to or less than a predetermined number, the sheets are crimped by the pressure teeth without water application; while when the number of sheets placed on the processing tray exceeds the predetermined number, the sheets are crimped by the pressure teeth after water application.

A mechanism that makes it possible to output a saddle-stitched brochure in a correct page order when a post-processing apparatus that executes a saddle-stitching process by switching back a sheet is caused to execute the saddle-stitching process. Sheets discharged from a printing apparatus are switched back by reverse rotation of a conveying roller pair, and are conveyed into a conveying path for a saddle-stitch bookbinding process. The sheets are accumulated in an accumulation tray for the saddle-stitch bookbinding process. When the saddle-stitch bookbinding process is caused to be executed on the accumulated sheets by the post-processing apparatus, the order of image formation is decided such that the order of pages of images printed on the saddle-stitched sheets becomes correct. The images are printed on the sheets in the decided order of image formation.

A mechanism that makes it possible to output a saddle-stitched brochure in a correct page order when a post-processing apparatus that executes a saddle-stitching process by switching back a sheet is caused to execute the saddle-stitching process. Sheets discharged from a printing apparatus are switched back by reverse rotation of a conveying roller pair, and are conveyed into a conveying path for a saddle-stitch bookbinding process. The sheets are accumulated in an accumulation tray for the saddle-stitch bookbinding process. When the saddle-stitch bookbinding process is caused to be executed on the accumulated sheets by the post-processing apparatus, the order of image formation is decided such that the order of pages of images printed on the saddle-stitched sheets becomes correct. The images are printed on the sheets in the decided order of image formation.

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.

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.