A recording material processing apparatus includes: first teeth that are used for binding processing of a recording material bundle; second teeth configured to move toward the first teeth and to press the recording material bundle positioned between the first teeth and the second teeth; a first metal block configured to support the first teeth; and a second metal block configured to support the second teeth.

A recording medium processing apparatus includes first teeth that are used for binding processing of a recording medium bundle; second teeth that move toward the first teeth and press the recording medium bundle located between the first teeth and the second teeth; and a control unit that moves the second teeth toward the first teeth to press the second teeth against the first teeth in a state in which there is no recording medium bundle between the first teeth and the second teeth.

A recording medium processing apparatus includes first teeth that are used for binding processing of a recording medium bundle; second teeth that move toward the first teeth and press the recording medium bundle located between the first teeth and the second teeth; a position detection unit that detects a position of the second teeth; and a control unit that controls movement of the second teeth on the basis of the position detected by the position detection unit.

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.

A binding processing apparatus includes: a pressure-applying member pair that has multiple projections arranged side-by-side and applies pressure to a sheet stack by pressing the projections against the sheet stack; and an advancing-and-retracting part that causes at least one of the pressure-applying members in the pressure-applying member pair to move toward or away from the other pressure-applying member. A pitch of the projections in each pressure-applying member is from 1.2 mm to 1.5 mm, and a height of the projections is from 0.55 mm to 0.75 mm, and a load per unit area applied from each pressure-applying member to the sheet stack when the pressure-applying member applies pressure to the sheet stack is from 42 N/mm.sup.2 to 94 N/mm.sup.2.

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.

A binding member is provided and includes: upper teeth having a tooth form configured to form a convex-concave portion on a recording material bundle; and lower teeth having a tooth form configured to form the convex-concave portion on the recording material bundle, and paired with the upper teeth. At least one of the upper teeth and the lower teeth includes: a first tooth row having a first tooth form having a first shape suitable for binding a first binding number of sheets; and a second tooth row having a second tooth form having a second shape suitable for binding a second binding number of sheets which is smaller than the first binding number of sheets.

A recording-medium binding device includes first and second tooth groups. The first tooth group includes first and second tooth rows. The second tooth group includes third and fourth tooth rows. The third tooth row to be engaged with the first tooth row forms, together with the first tooth row, a first tooth row pair. The fourth tooth row to be engaged with the second tooth row forms, together with the second tooth row, a second tooth row pair. A second engaging height in the second tooth row pair is smaller than a first engaging height in the first tooth row pair. A second effective tooth top width in the second tooth row pair is larger than a first effective tooth top width in the first tooth row pair.