A binding device includes: an upper teeth portion having at least one teeth row that forms unevenness in a recording material bundle; a lower teeth portion having at least one teeth row that forms unevenness in the recording material bundle and being paired with the upper teeth portion; and at least one holding portion that holds the recording material bundle at a position different from a position where the upper teeth portion and the lower teeth portion have a binding function, when binding processing is performed by the upper teeth portion and the lower teeth portion.

The present apparatus is provided with a placement tray (processing tray) to place sheets to undergo binding processing, and a bind unit that is able to shift along an end edge of sheets on the placement tray and that binds a plurality of sheets as a single bunch, where in the bind unit, a needle bind unit for performing binding processing on a bunch of sheets with a needle and a needleless bind unit for performing binding processing without a needle are provided together in a shift direction of the bind unit, and a length of the needleless bind unit is configured to be shorter than a length of the needle bind unit in the shift direction of the bind unit. By this means, provided is the apparatus capable of miniaturizing the entire apparatus, with the needle bind unit and needleless bind unit provided together.

The present apparatus is provided with a placement tray (processing tray) to place sheets to undergo binding processing, and a bind unit that is able to shift along an end edge of sheets on the placement tray and that binds a plurality of sheets as a single bunch, where in the bind unit, a needle bind unit for performing binding processing on a bunch of sheets with a needle and a needleless bind unit for performing binding processing without a needle are provided together in a shift direction of the bind unit, and a length of the needleless bind unit is configured to be shorter than a length of the needle bind unit in the shift direction of the bind unit. By this means, provided is the apparatus capable of miniaturizing the entire apparatus, with the needle bind unit and needleless bind unit provided together.

The present apparatus includes a placement tray to place sheets to undergo binding processing, and a press bind unit shifting along an end edge of sheets on the placement tray. The press bind unit includes a receiving tooth, and pressing teeth meshing with the receiving tooth to perform press binding on sheets nipped therebetween, and the pressing teeth are provided to shift between a press position for meshing with the receiving tooth, and a retract position spaced apart from the receiving tooth so as to shift the press bind unit along the end edge of sheets with the sheets disposed between the receiving tooth and the pressing teeth. By shifting the pressing teeth to the retract position, it is possible to shift the sheet bind apparatus smoothly along the end edge of a bunch of sheets with the sheets disposed between the receiving tooth and the pressing teeth.

The present apparatus includes a placement tray to place sheets to undergo binding processing, and a press bind unit shifting along an end edge of sheets on the placement tray. The press bind unit includes a receiving tooth, and pressing teeth meshing with the receiving tooth to perform press binding on sheets nipped therebetween, and the pressing teeth are provided to shift between a press position for meshing with the receiving tooth, and a retract position spaced apart from the receiving tooth so as to shift the press bind unit along the end edge of sheets with the sheets disposed between the receiving tooth and the pressing teeth. By shifting the pressing teeth to the retract position, it is possible to shift the sheet bind apparatus smoothly along the end edge of a bunch of sheets with the sheets disposed between the receiving tooth and the pressing teeth.

A sheet processing apparatus includes a first stacking portion on which a sheet conveyed by a conveying portion is stacked, a binding portion which forms, in a sheet bundle stacked on the first stacking portion, a tongue cut out from the sheet, with a part of the tongue attached to the sheet, and a slit, and which binds the sheet bundle by inserting a tip of the tongue of the sheet bundle in the slit of the sheet bundle, and a second stacking portion on which the sheet bundle bound by the binding portion is stacked. In the sheet processing apparatus, a plurality of recessed parts is formed on a guide face of the binding portion, the recessed parts extending in different directions from each other.

A sheet processing apparatus includes a first stacking portion on which a sheet conveyed by a conveying portion is stacked, a binding portion which forms, in a sheet bundle stacked on the first stacking portion, a tongue cut out from the sheet, with a part of the tongue attached to the sheet, and a slit, and which binds the sheet bundle by inserting a tip of the tongue of the sheet bundle in the slit of the sheet bundle, and a second stacking portion on which the sheet bundle bound by the binding portion is stacked. In the sheet processing apparatus, a plurality of recessed parts is formed on a guide face of the binding portion, the recessed parts extending in different directions from each other.

In performing press binding with a pair of pressurizing surfaces opposed to each other with sheets nipped therebetween, one of the pressurizing surfaces is configured to shift to positions relatively to the other pressurizing surface, and a shift section is provided in the pressurizing surface that shifts to positions. An apparatus for applying narrow pressure to a plurality of sheets with a pair of pressurizing surfaces to perform press binding is provided with first and second pressurizing surfaces opposed to each other with sheets nipped therebetween, and a pressurization driver that shifts a position of at least one of the first and second pressurizing surfaces from a waiting position separated to an actuation position for coming into press-contact.

In performing press binding with a pair of pressurizing surfaces opposed to each other with sheets nipped therebetween, one of the pressurizing surfaces is configured to shift to positions relatively to the other pressurizing surface, and a shift section is provided in the pressurizing surface that shifts to positions. An apparatus for applying narrow pressure to a plurality of sheets with a pair of pressurizing surfaces to perform press binding is provided with first and second pressurizing surfaces opposed to each other with sheets nipped therebetween, and a pressurization driver that shifts a position of at least one of the first and second pressurizing surfaces from a waiting position separated to an actuation position for coming into press-contact.

The present invention is to provide a binding processing apparatus that prevents easy unbinding regardless of thickness of a sheet bundle to be bound and that lessens influence of damage on sheets. In the present sheet binding processing apparatus, a pair of pressurizing faces for pressure-nipping a sheet bundle are formed to have tooth forms each having a convex shape and a concave shape, the tooth forms being engaged with each other along a predetermined tooth width, and the tooth forms are shaped so that an engagement depth between a tooth top and a tooth root is varied along a tooth width direction toward a sheet end edge.