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 booklet processing apparatus includes a pressing member and a rotating unit. The pressing member presses a folded portion of a booklet formed to extend in one direction and having the folded portion on the downstream side in the one direction. The pressing member is provided so as to be rotatable about a rotary shaft that extends along the folded portion. The rotating unit rotates the pressing member so as to move a portion of the pressing member that confronts the folded portion downstream in the one direction so that the portion of the pressing member that confronts the folded portion is changed to a different portion.

A square back processing unit performs a square back process on the sheet bundle and includes a pair of clamp portions. The sheet bundle subjected to the square back process by the square back processing unit is discharged to a sheet bundle discharge unit. A cover unit is provided downstream of the square back processing unit in the conveyance direction such that a child access probe according to a safety standard IEC 62368-1 does not reach the pair of clamp portions in a case where the child access probe is inserted from an outside of the sheet processing apparatus.

A conveyance unit conveys the sheet to an accumulation portion. A half-folding processing unit includes a folding roller pair and performs a half-folding process on the sheet bundle. A conveyance roller pair conveys the sheet bundle. A square back processing unit performs a square back process on the sheet bundle and includes a pair of clamp portions. A length of a conveyance path from the folding roller pair to the pair of clamp portions is larger than a half of a length of a long side of a sheet of a maximum size. In a state in which conveyance by the conveyance roller pair of a first sheet bundle to be subjected to the square back process is stopped, the conveyance unit conveys at least one sheet included in a second sheet bundle subsequent to the first sheet bundle toward the accumulation portion.

A sheet processing device includes: a folder that forms a plurality of folds on a sheet such that a fold part and a part with no fold of the sheet overlap with each other; a conveyance unit that conveys the sheen on which the folds are formed by the folder; and a pressing part that presses the fold part of the conveyed sheet in which the fold part and the part with no fold overlap with each other, from a side on which the fold part is located.

A sheet processing apparatus includes a pair of clamp units, a first pressing unit and a second pressing unit. The first pressing unit performs a square back process on a spine of the sheet bundle by moving the first pressing unit in a width direction of the sheet bundle in a state in which the spine of the sheet bundle is pressed toward the pair of clamp units. The second pressing unit performs a pressing process on a folding line of the sheet bundle by moving in the width direction of the sheet bundle while nipping the folding line of the sheet bundle.

A sheet processing apparatus includes a processing unit, a braking mechanism, and, a damper mechanism. The processing unit is movable to a drawn-out position and an accommodated position. The drawn-out position is a position where the processing unit is drawn out from the sheet processing apparatus. The accommodated position is a position where the processing unit is accommodated in the sheet processing apparatus. The braking mechanism acts to brake the processing unit in a case where the processing unit is inserted in a direction from the drawn-out position toward the accommodated position at a speed equal to or higher than a predetermined speed. The damper mechanism absorbs an impact on the braking mechanism in a case where the braking mechanism act, by applying a load to the processing unit moving in the direction from the drawn-out position toward the accommodated position.

A sheet processing device includes a folding unit, a first roller, and a pair of second rollers. The folding unit folds a sheet and forms a fold in the sheet. The pair of second rollers moves in a fold direction and additionally folds the fold. The first roller includes a first large diameter section and a first small diameter section. Each of the pair of second rollers includes a second large diameter section and a second small diameter section. The second large diameter section holds the sheet between the second large diameter section and the first small diameter section. The second small diameter section holds the sheet between the second small diameter section and the first large diameter section.

A mechanism (100a or 100b) for preventing the folding of an intermediate item (300) in a knife folder (200) is disclosed. The mechanism (100a or 100b) includes a deflector (50) that is movable between a non-operating position (50a) and an operating position (50b). When the intermediate item is moving on the folding rollers (230a and 230b) of the knife folder (200), the deflector (50) is moved to the operating position (50b) for deflecting the received intermediate item towards a roller gap (232) of the folding rollers by the deflector end (20) of the deflector. Upon rotating the folding rollers, the intermediate item (300) moves away from the knife folder (200) through the roller gap (232) preventing folding of the intermediate item (300).

A sheet folder includes a conveyor conveying a sheet, a first folding roller and a second folding roller that form a first nip, a third folding roller forming a second nip with the second folding roller, a first guide movable between a first guide posture and a first retracted posture, a second guide movable between a second guide posture and a second retracted posture, and a motor. The motor rotates the second folding roller forward to convey the sheet toward the first nip, reverse to convey the sheet toward the second nip, moves the first guide to arrange in the first guide in the first guide posture or the first retracted posture, and moves the second guide to arrange the second guide in the second guide posture or the second retracted posture.