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.

An image forming apparatus is to supply paper sheets on which images are formed to a post-processing apparatus to pressure-bind binding areas of paper sheets bundled. The image forming apparatus includes a conveyor, an image forming device, and a controller. The conveyor conveys a paper sheet. The image forming device discharges liquid ink to the paper sheet conveyed by the conveyor. The controller repeatedly executes a process of: causing the conveyor to convey the paper sheet to a position facing the image forming device; causing the image forming device to discharge the liquid ink to form an image on the paper sheet; and causing the conveyor to convey the paper sheet on which the image has been formed toward the post-processing apparatus. The controller further causes the image forming device to apply the liquid ink to a binding area of at least one of the paper sheets.

A post-processing device includes a paper alignment tray on which a plurality of papers is aligned and a stapleless binder including a stapleless binding portion to compress and bind the plurality of papers and a nozzle in the stapleless binding portion that supplies water vapor to the plurality of papers.

The present invention is to provide a sheet binding apparatus capable of performing stable pressure-bonding binding processing. A sheet binding apparatus includes a moving means configured to move at least one of the first binding portion and the second binding portion to bring the first binding portion and the second binding portion into pressure contact with each other, and a plurality of peeling members configured to apply peeling force in a direction opposite to a pressure-bonding direction to peel off a bound portion of the sheets stuck to the surface when the first binding portion and the second binding portion are separated by the moving means after pressure-bonding binding processing is performed. Here, the peeling force is applied by the plurality of peeling members at different timings.

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.

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.

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 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.