An apparatus for folding sheets or sheet stacks, including at least two folding/transport rollers, transport device and knife, the transport device defining transport plane E for sheets or sheet stacks fed in transport direction R, knife being movable substantially perpendicularly to and through transport plane E, folding/transport rollers being arranged above transport plane E, oppositely on both sides of knife, axis of rotation A of folding/transport rollers extending substantially perpendicularly to transport plane E, and at least two folding/transport rollers each having, at their end facing toward transport plane E, rounded portion, such that narrowing gap S is formed between the at least two folding/transport rollers, into which gap sheets or sheet stacks can be introduced by means of knife so as to be folded there and at same time conveyed away in transport direction R, and to corresponding method.

A sheet processing apparatus includes a pressing unit including a first pressing member and a second pressing member. The pressing unit is configured to sandwich and press a fold part of a folded sheet bundle between the first pressing member and the second pressing member. The sheet processing apparatus also includes a moving unit configured to move a position pressed by the pressing unit in a direction of a fold of the sheet bundle. A position pressed by the first pressing member on the sheet bundle and another position pressed by the second pressing member on the sheet bundle are shifted with respect to each other in the direction of the fold of the sheet bundle.

A sheet processing apparatus that is capable of properly performing fold line processing at a position depending on a sheet bundle. In a sheet processing apparatus, sheets sequentially received from an image forming apparatus are stacked on a bookbinding processing tray to form a sheet bundle. The sheet bundle is folded at the center thereof, and is conveyed to a processing position. A press unit moves along a fold line portion of the sheet bundle to thereby perform flattening processing for flattening the fold line portion by pressing the fold line portion from a direction orthogonal to a thickness direction. A first pressing strength set by a user using the image forming apparatus and the second pressing strength acquired information on the sheet bundle are compared with each other, and the processing position is determined based on a result of the comparison.

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 folding processing device includes a pressing section that includes a first opposing member and a second opposing member, the first opposing member opposing a folded portion of a folded sheet, the second opposing member opposing the first opposing member with the folded portion interposed therebetween, the pressing section pressing the folded portion by nipping the folded portion by using the first opposing member and the second opposing member; and a guiding section that is disposed upstream from the pressing section in a sheet transport direction, the guiding section nipping the sheet whose folded portion has passed through the guiding section and guiding the sheet to the pressing section.

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.

Provided is a sheet processing device capable of preventing a folded sheet bundle from being opened after pressing to improve accumulating property and aligning property of the sheet bundle. A sheet processing device includes: a pair of sheet pressing members 70 that press a fold of a folded sheet bundle in a thickness direction of the fold; and a moving member 56 that moves the sheet pressing member pair 70 along the fold of the folded sheet bundle. The moving member 56 supports a plurality of rows of the sheet pressing member pairs 70 arranged in a moving direction of the moving member 56. The sheet pressing member pairs 70 press the folded sheet bundle with the intervals therebetween in the respective rows reduced stepwise in the moving direction of the moving member 56.

A medium flattening method, when a medium is transported by being adhered to an adhesive layer which is on a surface of a transport belt, includes detecting a presence or absence of floating being generated in the medium on the transport belt using a sensor, executing a process for flattening to flatten the floating in the medium in the case where the floating exists, and transporting the medium, where the floating is eliminated using the process for the flattening, to a liquid discharge region of a liquid discharge section. The executing of the process for the flattening includes executing the process for the flattening with regard to the medium and liquid discharge with regard to the medium in parallel.

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.