A binding processing apparatus includes a pair of pressing members each including a concave-convex portion configured to form a concave part and a convex part in a recording material bundle. The concave-convex portion includes protrusion portions. Aside surface of each protrusion portion is inclined so that the protrusion portion is widened from an apex of the protrusion portion. The side surfaces of the protrusion portions of a first pressing member that is one of the pressing members and the side surfaces of the protrusion portions of a second pressing member that is the other of the pressing members intersect with each other during pressing when viewed in a column direction of the protrusion portions.

A stapleless binding device includes a stapleless binding unit that performs a stapleless binding operation to form irregularities in a sheet stack by making forward and backward movements, a moving unit that relatively moves the stapleless binding unit or the sheet stack in a direction along one side of the sheet stack, and a holding unit that holds the sheet stack during the backward movement of the stapleless binding unit. The holding unit holds the sheet stack during the backward movement of the stapleless binding unit before the moving unit moves the stapleless binding unit or the sheet stack.

A stapleless binding device includes a stapleless binding unit that performs a stapleless binding operation to form irregularities in a sheet stack by making forward and backward movements, a moving unit that relatively moves the stapleless binding unit or the sheet stack in a direction along one side of the sheet stack, and a holding unit that holds the sheet stack during the backward movement of the stapleless binding unit. The holding unit holds the sheet stack during the backward movement of the stapleless binding unit before the moving unit moves the stapleless binding unit or the sheet stack.

A recording-medium binding device includes a first tooth row and a second tooth row. The first tooth row and the second tooth row to be engaged with the first tooth row cooperate with each other to pinch a recording medium batch. The first tooth row and the second tooth row include at least one first region and at least one second region adjacent to the at least one first region. When the first tooth row and the second tooth row are engaged with each other, teeth of the first tooth row and teeth of the second tooth row overlap one another in a tooth height direction by a first engagement overlapping amount in the at least one first region and by a second engagement overlapping amount in the at least one second region. The second engagement overlapping amount is larger than the first engagement overlapping amount.

A recording-medium binding device includes a first tooth row and a second tooth row. The first tooth row and the second tooth row to be engaged with the first tooth row cooperate with each other to pinch a recording medium batch. The first tooth row and the second tooth row include at least one first region and at least one second region adjacent to the at least one first region. When the first tooth row and the second tooth row are engaged with each other, teeth of the first tooth row and teeth of the second tooth row overlap one another in a tooth height direction by a first engagement overlapping amount in the at least one first region and by a second engagement overlapping amount in the at least one second region. The second engagement overlapping amount is larger than the first engagement overlapping amount.

An image forming apparatus including: a printer; a puncher configured to punch the sheet printed by the printer; a binder configured to perform a bookbinding process to form a bound product in which a binding member penetrates punch holes of sheets; a first detector configured to detect a first jam of a sheet in the binder; a second detector configured to detect a second jam of a sheet which occurs upstream of the binder; an annunciator configured to notify information; and a controller configured to cause the annunciator to notify first instruction information for instructing removal of a sheet and the binding member, when the first detector has detected the first jam; and cause the annunciator to notify second instruction information for instructing removal of the second jam when the second detector has detected the second jam and the first detector has not detected the first jam.

An image forming apparatus including: a printer; a puncher configured to punch the sheet printed by the printer; a binder configured to perform a bookbinding process to form a bound product in which a binding member penetrates punch holes of sheets; a first detector configured to detect a first jam of a sheet in the binder; a second detector configured to detect a second jam of a sheet which occurs upstream of the binder; an annunciator configured to notify information; and a controller configured to cause the annunciator to notify first instruction information for instructing removal of a sheet and the binding member, when the first detector has detected the first jam; and cause the annunciator to notify second instruction information for instructing removal of the second jam when the second detector has detected the second jam and the first detector has not detected the first jam.

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.

A sheet processing apparatus includes a conveying portion conveying sheets; a stack portion staking the sheets; a first regulating portion regulating a position of a sheet bundle on the stack portion in a crossing direction; a second regulating portion regulating a position of a sheet bundle in the conveying direction; a first binding device moving in the crossing direction so that the first binding device moves between first and second sides of the sheet processing apparatus and to bind an upstream end portion of a sheet bundle by a staple at a plurality of positions in the crossing direction; a second binding device binding an upstream end portion of a sheet bundle, where the second regulating portion has contacted without a staple; and a controller causing, in a case that the first binding device binds a sheet bundle, the second binding device to be positioned outside the sheet bundle.