A medium processing apparatus includes a conveyor, a receptacle, an aligner, a crimp binder, and circuitry. The conveyor conveys a medium. The receptacle holds the medium. The aligner contacts a downstream end of the medium and aligns a position of the medium in a conveyance direction of the medium. The crimp binder faces the downstream end of the medium to press and deform a binding position on media of which the position is aligned, to bind the media. The aligner and the crimp binder are movable in a main scanning direction orthogonal to each of the conveyance direction and a thickness direction of the medium. When determining that the aligner overlaps the binding position when the receptacle is viewed in the thickness direction, the circuitry moves the aligner in the main scanning direction away from the binding position and causes the crimp binder to crimp and bind the media.

A sheet processing apparatus includes a binding unit including a first portion and a second portion and configured to nip a sheet bundle between the first portion and the second portion to deform the sheet bundle in a thickness direction to bind the sheet bundle, and a detachment unit configured to push the bound sheet bundle toward the second portion to detach the bound sheet bundle from the first portion.

The present sheet processing apparatus comprises: a pressure tooth part that has a concave-convex surface and pressurizes the sheet bundle; a receiving tooth part that is disposed opposite to the pressure tooth part so as to receive pressurization from the pressure tooth part with the sheet bundle held therebetween; a moving part that reciprocates the pressure tooth part with respect to a receiving surface of the receiving tooth part; and a drive part that drives the moving part that moves the pressure tooth part for crimping of the sheet bundle. The pressure tooth part is divided in the direction crossing the pressurizing direction of the pressure tooth part into a plurality of pressure tooth parts, and the obtained pressure tooth parts are sequentially pressurized for crimping.

A sheet processing apparatus includes a conveying portion, a stack portion on which sheets conveyed by the conveying portion are stacked, a first regulating portion regulating a position of a sheet bundle stacked on the stack portion in a crossing direction, a second regulating portion regulating a position of a sheet bundle on the stack portion in a conveying direction, a first binding device moved in the crossing direction and binding a corner portion of a sheet bundle by a staple, a second binding device binding a corner portion of a sheet bundle without a staple, and a controller positioning the first binding device and binding a corner portion of a sheet bundle by the first binding device. The controller also moves the second binding device and binds a corner portion of a sheet bundle without a staple by the second binding device.

A binding apparatus includes: a set of binding parts configured to press and bind a bundle of recording materials from one side and a remaining side in a thickness direction; a first support part configured to support the bundle of recording materials from the one side by performing rotation toward the bundle of recording materials around a predetermined fulcrum; and a second support part configured to support the bundle of recording materials from the remaining side so as to face the first support part when binding is performed by the set of binding parts.

An image forming apparatus includes: a needleless binding device configured to form a recessed or raised impression as a needleless binding part by performing needleless binding on a bundle of sheets; an environment sensor; and a controller configured to perform, based on a value detected by the environment sensor, control to display a confirmation image requesting a user to make confirmation on the needleless binding prior to execution of the needleless binding.

There is provided a binding member. The binding member includes: an upper toothed part having projections and recesses for forming irregularities in a bundle of recording materials; and a lower toothed part having projections and recesses for forming irregularities in the bundle of recording materials and forming a pair with the upper toothed part. In at least one of the upper toothed part and the lower toothed part, in side surfaces of the recesses of one toothed part, when the upper toothed part and the lower toothed part are engaged, surfaces wide in a direction parallel to the pressing direction of the toothed parts are formed so as to be provided gaps between the upper toothed part and the lower toothed part.

In a cross section shape of the toothed part, in gaps formed between a recesses and a projections when a upper toothed part and a lower toothed part are engaged without a bundle of recording materials, when the distances between the recesses and the projections in a pressing direction of the toothed part at positions where the distances from a center lines of the projections in a direction perpendicular to the pressing direction of the toothed part to the surfaces of the projections in the direction perpendicular to the pressing direction of the toothed part are a distance L1 are H1, and the distances between the recesses and the projections at positions where the distances from the center lines to surfaces of the projections in the direction perpendicular to the pressing direction of the toothed part are H2, a combination of L1 and L2 satisfies H1 is smaller than H2.

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 binding member. The binding member includes an upper toothed part having projections and recesses for forming irregularities in a bundle of recording materials; and a lower toothed part having projections and recesses for forming irregularities in the bundle of recording materials and forming a pair with the upper toothed part. In at least one of the upper toothed part and the lower toothed part, in some of parts of inclined surfaces of the toothed part which form the recesses, second curved surfaces having the centers of curvature on the opposite sides of the inclined surfaces to the centers of curvature of first curved surfaces which form the recesses are formed.