A post-processing apparatus includes memory and a processor configured to control a curving device that curves a sheet, which is transported to the curving device, by pressing the sheet, control folding processing that is performed on a sheet curved by the curving device, and control, when folding processing is performed such that two ends of a sheet in a transport direction of the sheet face outward in opposite directions after the folding processing has been performed on the sheet, the curving device so as to curve the sheet in plural directions with respect to a transport surface.

A sheet processing apparatus includes: a second conveying roller pair that receives and conveys a sheet conveyed by a first conveying roller pair; a first folding roller pair that forms a first fold on the sheet; and a first rotation unit capable of rotating the second conveying roller pair and the first folding roller pair. One roller of the second conveying roller pair and one roller of the first folding roller pair are a common roller shared therebetween. The second conveying roller pair causes the sheet to be deflected and guided to the first folding roller pair, and the first folding roller pair forms the first fold on the deflected sheet by rotating the first rotation unit in a certain direction in a state in which the sheet is held by the first conveying roller pair and the second conveying roller pair.

A sheet processing apparatus includes: a second conveying roller pair that receives and conveys a sheet conveyed by a first conveying roller pair; a first folding roller pair that forms a first fold on the sheet; and a first rotation unit capable of rotating the second conveying roller pair and the first folding roller pair. One roller of the second conveying roller pair and one roller of the first folding roller pair are a common roller shared therebetween. The second conveying roller pair causes the sheet to be deflected and guided to the first folding roller pair, and the first folding roller pair forms the first fold on the deflected sheet by rotating the first rotation unit in a certain direction in a state in which the sheet is held by the first conveying roller pair and the second conveying roller pair.

A manufacturing method of a structure by which a target member can be easily positioned with high accuracy. In a tilting step, at least one target member is positioned by tilting a positioning table and sliding the target member placed on the positioning table to bring the target member into contact with a locking portion.

A sheet folding apparatus includes a conveyance member to convey a sheet from an ejection member at a first speed lower than a conveyance speed by the ejection member or a second speed substantially same as or higher than the conveyance speed; a registration member; a pair of first and second rollers to rotate in forward and reverse directions; a plurality of folding rollers downstream from the second roller, to rotate in forward and reverse directions to fold the sheet; and circuitry to determine whether the sheet is equal to or smaller than a reference length from an exit position from the ejection member to a folding start position downstream from the pair of the first and second rollers. The circuitry performs first-speed folding when the sheet is equal to or smaller than the reference length and performs second-speed folding when the sheet is longer than the reference length.

A sheet folding apparatus includes a conveyance member to convey a sheet from an ejection member at a first speed lower than a conveyance speed by the ejection member or a second speed substantially same as or higher than the conveyance speed; a registration member; a pair of first and second rollers to rotate in forward and reverse directions; a plurality of folding rollers downstream from the second roller, to rotate in forward and reverse directions to fold the sheet; and circuitry to determine whether the sheet is equal to or smaller than a reference length from an exit position from the ejection member to a folding start position downstream from the pair of the first and second rollers. The circuitry performs first-speed folding when the sheet is equal to or smaller than the reference length and performs second-speed folding when the sheet is longer than the reference length.

A sheet folding processing apparatus suppresses an increase in size and cost of the apparatus and performs folding processing on continuously conveyed sheets. In the sheet folding processing apparatus, a sheet conveyed by a feeding roller pair and hang in a loop shape in a loop forming space is pushed into a nipping portion of a folding roller pair by a pushing plate, so that the sheet is folded in a Z-shape to form a plurality of fold lines. The sheet is conveyed in the conveyance direction until the sheet rear end passes through the feeding roller pair, and after the sheet rear end is stored in a loop forming space by moving the pushing plate from a position for pushing the sheet into a nipping portion to a retracting position, the reinforcing processing of the fold line of the sheet is performed by an additional folding unit.

A sheet folding processing apparatus suppresses an increase in size and cost of the apparatus and performs folding processing on continuously conveyed sheets. In the sheet folding processing apparatus, a sheet conveyed by a feeding roller pair and hang in a loop shape in a loop forming space is pushed into a nipping portion of a folding roller pair by a pushing plate, so that the sheet is folded in a Z-shape to form a plurality of fold lines. The sheet is conveyed in the conveyance direction until the sheet rear end passes through the feeding roller pair, and after the sheet rear end is stored in a loop forming space by moving the pushing plate from a position for pushing the sheet into a nipping portion to a retracting position, the reinforcing processing of the fold line of the sheet is performed by an additional folding unit.

A turnable sheet stopper blocks and passes a sheet conveyed on a sheet guide, and includes a proximal portion, a distal portion connected to the end of the proximal portion, and a folding mechanism that connects the distal portion to the proximal portion. The sheet stopper transitions between first and second positions. In the second position, the proximal and distal portions integrally turn to the downstream side in the sheet conveyance direction to allow the sheet to pass. The sheet stopper transitions from the second position to a third position when a user draws out the sheet from an upstream side. In the third position, the distal portion folds toward the upstream side to allow the sheet to be drawn out. During transition from the second position to the third position, the edge of the distal portion is located on or away from an outer surface of the sheet guide.

An enclosing device to insert an enclosure into an envelope conveyed to an enclosing position includes an envelope conveyor and an enclosing unit. The envelope conveyor conveys the envelope to the enclosing position. The enclosing unit opens a frontage of the envelope such that the enclosure is inserted into the envelope that has reached the enclosing position and includes an opening amount adjuster to adjust an opening amount of the frontage when the enclosure is inserted into the envelope. The opening amount adjuster adjusts the opening amount, depending on a flap length and a body length. The flap length is a length of a flap of the envelope in a conveyance direction in which the envelope is conveyed to the enclosing position. The body length is a length of a body of the envelope in the conveyance direction.