There is provided a binding member. An upper toothed part having projections and recesses for forming irregularities in a bundle of recording materials. 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 a cross section shape of the toothed part, the recesses of the toothed part have depressed areas depressed from virtual lines which are extensions of inclined surfaces of the toothed part.

A thermoplastic film which exhibits elastic-like behavior along at least one axis when stretched or elongated and then released. The thermoplastic film comprises a plurality of raised rib-like elements extending in a direction perpendicular to a main surface of the thermoplastic film. The thermoplastic film further includes a plurality of web areas positioned about the plurality of raised rib-like elements. The plurality of raised rib-like elements and plurality of web areas are arranged in a complex pattern. The complex pattern provides visual and tactile cues as the films are stretched or elongated. The complex pattern can cause the thermoplastic film to have a complex stretch profile.

A thermoplastic film which exhibits elastic-like behavior along at least one axis when stretched or elongated and then released. The thermoplastic film comprises a plurality of raised rib-like elements extending in a direction perpendicular to a main surface of the thermoplastic film. The thermoplastic film further includes a plurality of web areas positioned about the plurality of raised rib-like elements. The plurality of raised rib-like elements and plurality of web areas are arranged in a complex pattern. The complex pattern provides visual and tactile cues as the films are stretched or elongated. The complex pattern can cause the thermoplastic film to have a complex stretch profile.

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.

A binding apparatus includes: a first toothed part including teeth arranged in one direction; and a second toothed part that includes teeth arranged in the one direction and is configured to mesh with the first toothed part and to press a bundle of sheets, wherein at least one first groove is formed between adjacent teeth of the first toothed part, the first groove has cross-sectional areas at central and end portions in a direction orthogonal to the one direction and a direction in which the first and second toothed parts mesh with each other, the one direction and the orthogonal direction are normal to the cross-sectional areas, and the cross-sectional area at the end portion is larger than the cross-sectional area at the central portion.

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.

A thermoplastic film which exhibits elastic-like behavior along at least one axis when stretched or elongated and then released. The thermoplastic film comprises a plurality of raised rib-like elements extending in a direction perpendicular to a main surface of the thermoplastic film. The thermoplastic film further includes a plurality of web areas positioned about the plurality of raised rib-like elements. The plurality of raised rib-like elements and plurality of web areas are arranged in a complex pattern. The complex pattern provides visual and tactile cues as the films are stretched or elongated. The complex pattern can cause the thermoplastic film to have a low force extension.

A sheet processing apparatus includes: a pair of binding members that respectively have a pair of crimping teeth facing each other, which move between binding positions where a sheet bundle is bound and retreat positions retreated from the binding positions; and a pair of regulating members that are arranged close to the binding members and respectively have a pair of regulating pieces which face each other and move between regulating positions where displacement of the sheet bundle bound by the pair of crimping teeth is regulated and retreat positions retreated from the regulating positions, wherein a separation distance between the pair of regulating pieces at the retreat positions of the regulating pieces is longer than a separation distance between the pair of crimping teeth at the retreat positions of the crimping teeth.

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.

There is provided a binding member. An upper toothed part having projections and recesses for forming irregularities in a bundle of recording materials. 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 a cross section shape of the toothed part, the recesses of the toothed part have depressed areas depressed from virtual lines which are extensions of inclined surfaces of the toothed part.