A sheet processing device performs saddle stitching binding a bundle of stacked paper sheets, and includes a stacker section temporarily stacking conveyed paper sheets substantially vertically; a stopper regulating the paper sheets stacked in the stacker section; a first binding section provided in the stacker and saddle-stitching a paper sheet bundle regulated by the stopper at a binding position around a center of the paper sheet bundle in a sheet conveying direction; a folding section folding in half the paper sheet bundle regulated by the stopper; and a conveying section conveying the paper sheet bundle that has been folded in half by the folding section with a back side of the folded paper sheet bundle as a leading end in the conveying direction. The conveying section includes a second binding section binding the folded paper sheet bundle at the back side thereof.

A sheet processing device performs saddle stitching binding a bundle of stacked paper sheets, and includes a stacker section temporarily stacking conveyed paper sheets substantially vertically; a stopper regulating the paper sheets stacked in the stacker section; a first binding section provided in the stacker and saddle-stitching, with a metallic staple, a paper sheet bundle regulated by the stopper at a binding position around a center of the paper sheet bundle in a sheet conveying direction; a second binding section saddle-stitching, without using the metallic staple, the paper sheet bundle being regulated by the stopper at the binding position around the center of the paper sheet bundle in the sheet conveying direction; and a folding section folding in half the paper sheet bundle regulated by the stopper at a folding position at which the paper sheet bundle is bound by the first binding section or second binding section.

A recording material fold enhancing device includes a pressing unit that includes one or more recessed portions and one or more protrusions, and that presses a fold of a recording material; a supporting unit that includes one or more recessed portions and one or more protrusions, and that supports the fold of the recording material; and a driving unit that moves the pressing unit and the supporting unit along a direction in which the fold of the recording material is formed. A portion of the fold of the recording material is interposed between the one or more recessed portions of the pressing unit and the one or more protrusions of the supporting unit, and another portion of the fold of the recording material is interposed between the one or more protrusions of the pressing unit and the one or more recessed portions of the supporting unit.

A sheet processing device includes a plurality of first units and a second unit. The first units each include, as one unit, a pressing member that presses a folding loop, a frame that movably holds the pressing member in a sheet pressing direction, and an elastic member that is disposed between the frame and the pressing member to bias the pressing member in the sheet pressing direction. The second unit supports, as one unit, a plurality of rows of first units such that the first units of each row are arranged, as a pair, so as to be opposed to each other and that an interval between the pairs is reduced stepwise from a downstream side to an upstream side in a moving direction of the second unit.

A sheet pressing device of the present invention includes: a pair of pressing rollers 70 that press, in a fold thickness direction, a fold of a folded sheet bundle BS conveyed in a folded state; and a pressing roller unit 56 that moves the pressing roller pair in a sheet fold direction while supporting the same. The pressing roller pair 70 presses the fold in one of a first region R1 where rollers of the pressing roller pair 70 are brought into pressure contact with each other and a second region R2 adjacent to the first region R1 on an upstream side thereof where rollers of the pressing roller pair 70 are opposed to each other at an interval. With this configuration, it is possible to minimize damage on a sheet end portion and reduce a moving load of the pressing roller pair 70.

A fold-enhancing device includes a pressing member, at least one retaining member, and a moving mechanism. The pressing member presses against a fold line of a recording-medium bundle folded into a booklet shape. The recording-medium bundle is obtained by stacking multiple sheets of recording media. The retaining member retains the recording-medium bundle and is provided at a position located away from the fold line in a direction intersecting the fold line and not in contact with the pressing member. The moving mechanism moves the pressing member and the retaining member in a direction extending along the fold line.

A sheet post-processing device includes a conveying section that conveys a paper sheet; a punch section that punches punch holes in the paper sheet conveyed by the conveying section; a stacker section that stores the paper sheet in which the punch holes are punched by the punch section; a binding section that binds a paper sheet bundle stored in the stacker section with a binding member; and a controller that controls the above sections. The controller selectively performs a ring binding mode and a direct binding mode. The ring binding mode is a mode in which punch holes are punched in the paper sheet by the punch section and then the binding member is made to penetrate the punch holes for binding. The direct binding mode is a mode in which the binding member is directly driven into the paper sheet bundle without punching the punch holes in the sheet.

The present invention is to provide a sheet processing device including: a receiving tray capable of accommodating therein a sheet having, at a part thereof, a protruding portion and a sheet not having the protruding portion in a mixed state; a first binding member that binds the accommodated sheet bundle at a substantially center thereof in a sheet conveying direction; a folding section that folds the sheet bundle bound by the first binding member in two; and a second binding member that binds protruding portions of the sheet bundle folded by the folding section on a fore edge side of the sheet bundle. With this configuration, the fore edge side of the folded and saddle-stitched sheet bundle can be bound by temporary binding. Thus, a sheet processing device capable of ensuring the security of a saddle-stitched sheet bundle can be provided.

A sheet processing apparatus includes: a folding device that folds a sheet bundle which is formed of multiple sheets stacked on each other; and a stapleless binding device including a binding unit that binds the sheet bundle at a position of a portion near a fold line without using a staple, the fold line being formed as a result of the folding device folding the sheet bundle.