A sheet processing apparatus includes a binding portion binding a plurality of sheets stacked on a sheet stacking portion as a bundle by deforming the sheets without a staple. The sheet processing apparatus further includes a moving member moving the sheet bundle bound at a binding position by the binding portion from the binding position and a restricting member restricting the move of the sheet bundle such that a distance between the sheet bundle and the moving member is kept to be less than a predetermined distance in moving the sheet bundle by the moving member.

A binding processing apparatus includes: a pressure-applying member pair that has multiple projections arranged side-by-side and applies pressure to a sheet stack by pressing the projections against the sheet stack; and an advancing-and-retracting part that causes at least one of the pressure-applying members in the pressure-applying member pair to move toward or away from the other pressure-applying member. A pitch of the projections in each pressure-applying member is from 1.2 mm to 1.5 mm, and a height of the projections is from 0.55 mm to 0.75 mm, and a load per unit area applied from each pressure-applying member to the sheet stack when the pressure-applying member applies pressure to the sheet stack is from 42 N/mm.sup.2 to 94 N/mm.sup.2.

According to an aspect of the present invention, there is provided a sheet processing device including a first teeth portion, a second teeth portion that clamps and binds a sheet bundle with the first teeth portion, a first support portion supporting the first teeth portion, a shaft, and a second support portion supporting the second teeth portion. The second support portion includes first and second arm members integrally supported to be capable of swinging around the shaft between a binding position in which the second teeth portion clamps and binds the sheet bundle with the first teeth portion and a standby position in which the second teeth portion is apart from the first teeth portion. The second arm member is provided over the first arm member so as to cover a part of the first arm member.

A staple-less binding unit including a pair of upper and lower teeth binds a sheet bundle which is discharged to an intermediate processing tray by a sheet discharge portion and whose one edge abuts against a rear edge stopper. A control portion switches a binding mode of the staple-less binding unit that implements the binding process on the sheet bundle in a first binding mode of binding the sheet bundle without any staple such that the pair of upper and lower teeth bite across an edge of the sheet bundle and in a second binding mode of binding the sheet bundle without any staple such that the pair of upper and lower teeth do not bite across any edge of the sheet bundle.

A post-processing device includes a stacking portion on which media are stacked; a staple binding device that binds the media together by using a staple and that is movable between staple binding positions at which the staple binding device binds the media together and a supply position that is in a front section in a width direction of the media and at which staples are suppliable to the staple binding device; and a stapleless binding device that binds the media together without using a staple and that is movable between a stapleless binding position at which the stapleless binding device binds the media together and a retracted position that is in the front section. When the stapleless binding device is moved to the retracted position, the staple binding device and the stapleless binding device do not interfere with each other irrespective of a position of the staple binding device.

A sheet processing apparatus includes a first binding unit configured to bind a sheet bundle; a second binding unit with greater number of bindable sheets than number of bindable sheets of the first binding unit; and a number-of-sheets determining unit configured to determine whether number of to-be-bound sheets exceeds the number of bindable sheets of the first binding unit. The first binding unit moves to a binding position, and if the number-of-sheets determining unit determines that the number of to-be-bound sheets exceeds the number of bindable sheets of the first binding unit, the first binding unit moves away from the binding position. When the number-of-sheets determining unit determines that the number of to-be-bound sheets exceeds the number of bindable sheets of the first binding unit, the second binding unit moves to the binding position.

A staple-less binding unit including a pair of upper and lower teeth binds a sheet bundle which is discharged to an intermediate processing tray by a sheet discharge portion and whose one edge abuts against a rear edge stopper. A control portion switches a binding mode of the staple-less binding unit that implements the binding process on the sheet bundle in a first binding mode of binding the sheet bundle without any staple such that the pair of upper and lower teeth bite across an edge of the sheet bundle and in a second binding mode of binding the sheet bundle without any staple such that the pair of upper and lower teeth do not bite across any edge of the sheet bundle.

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 binding operation unit including a first tooth-shaped member that has plural arrayed teeth, a second tooth-shaped member that has plural arrayed teeth and binds sheets by biting the first tooth-shaped member to clamp the sheets in cooperation with the first tooth-shaped member, and a link structure that opens and closes the first tooth-shaped member and the second tooth-shaped member to perform a binding operation, and two side frames that are arranged to hold the binding operation unit therebetween and to support the binding operation unit on both sides of the binding operation unit.

An embossing group includes: a first embossing roller and at least one embossing unit associated with the first roller. The embossing unit includes a second embossing roller, a third embossing roller, and a sleeve surrounding the second roller and the third roller by coupling them. The sleeve faces the first roller and is configured to contact the first roller. The embossing unit and the first roller are configured to emboss at least one paper sheet wound between the first roller and the embossing unit.