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.

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.

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.

There is provided a binding processing device including:

a first pressing member including a convex portion formed by a curved surface with a curvature and protruding toward a sheet bundle; and

a second pressing member including a concave portion formed by a curved surface with a curvature and configured to be combined with the convex portion through the sheet bundle, the second pressing member configured to press the sheet bundle sandwiched between the first and second pressing members, wherein

in a state where the convex portion of the first pressing member and the concave portion of the second pressing member are combined with each other, a gap is formed between the convex portion and the concave portion in a cross section of the first and second pressing members along a pressing direction, and

the gap has a volume larger than a volume of the sandwiched sheet bundle.

There is provided a binding processing device including:

a first pressing member including a convex portion formed by a curved surface with a curvature and protruding toward a sheet bundle; and

a second pressing member including a concave portion formed by a curved surface with a curvature and configured to be combined with the convex portion through the sheet bundle, the second pressing member configured to press the sheet bundle sandwiched between the first and second pressing members, wherein

in a state where the convex portion of the first pressing member and the concave portion of the second pressing member are combined with each other, a gap is formed between the convex portion and the concave portion in a cross section of the first and second pressing members along a pressing direction, and

the gap has a volume larger than a volume of the sandwiched sheet bundle.

A recording-medium binding device includes a first tooth row that includes teeth arranged in a tooth arrangement direction and a second tooth row that includes teeth, that is to be engaged with the first tooth row, and that cooperates with the first tooth row to bind recording media by pinching a batch of the recording media. In the tooth arrangement direction, the first and the second tooth rows have first and second ranges. In the first range, an engaging height is a first engaging height, and a width of an effective tooth top is a first effective tooth top width. In the second range, the engaging height is a second engaging height that is smaller than the first engaging height, and a width of an effective tooth top is a second effective tooth top width that is larger than the first effective tooth top width.