An image forming apparatus determines whether crease processing at a plurality of portions set on the sheet includes crease processing on two, front and back surfaces of the sheet; determines, if it is determined that crease processing includes crease processing on the two surfaces of the sheet, whether a connected post-processing apparatus that performs crease processing on a sheet can perform crease processing on the two, front and back surfaces of the sheet by one feeding; and controls, if it is determined that the connected post-processing apparatus cannot perform crease processing on the two surfaces by one feeding, to change, to one of the front and back surfaces of the sheet based on attribute information of the sheet, a surface to be processed in crease processing at the plurality of portions.

A sheet folding apparatus for folding a sheet is provided with a hold member that holds a transported sheet in a substantially cylindrical shape, a shift member that presses the outer circumferential surface of the sheet of the substantially cylindrical shape held by the hold member to make a substantially flat shape, and a discharge section that further presses the sheet made the substantially flat shape by the shift member, while discharging in a direction crossing a transport direction. By this means, it is possible to provide a relatively compact sheet folding apparatus.

An image forming apparatus determines whether crease processing at a plurality of portions set on the sheet includes crease processing on two, front and back surfaces of the sheet; determines, if it is determined that crease processing includes crease processing on the two surfaces of the sheet, whether a connected post-processing apparatus that performs crease processing on a sheet can perform crease processing on the two, front and back surfaces of the sheet by one feeding; and controls, if it is determined that the connected post-processing apparatus cannot perform crease processing on the two surfaces by one feeding, to change, to one of the front and back surfaces of the sheet based on attribute information of the sheet, a surface to be processed in crease processing at the plurality of portions.

Folding information and printing surface information, included in content information of a sealed letter creation job, are compared with content printing conditions stored in a storage section, and an appropriate condition (a conveyance path after printing, execution/non-execution of image rotation, and printing page order) is selected such that the position of a window of a windowed envelope is aligned with the position of specifying information printed on a print sheet P to be a content when the print sheet P is enclosed in the envelope. A convey section and a printing section are controlled based on the selected content printing condition.

A sheet processing apparatus includes a conveyance roller pair that rotates in a certain direction to convey a sheet, a first normal-reverse rotation roller pair that is capable of rotating in a normal direction and a reverse direction and rotates to convey the sheet, a first driver that drives the first normal-reverse rotation roller pair to rotate, and a first driving force transmitter that transmits a driving force of the first driver for rotating the first normal-reverse rotation roller pair in a first specific direction to the conveyance roller pair so as to rotate the conveyance roller pair in the certain direction, and blocks a driving force of the first driver for rotating the first normal-reverse rotation roller pair in the direction opposite to the first specific direction from being transmitted to the conveyance roller pair.

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 method operates a facility, which serves for the continuous production of multiple gang runs for forming individual signatures or signature packs from which type-specific print products are made in a downstream print further processing machine. An endless web is the basis for the formation of these multiple gang runs. The endless web, in the non-folded state, is imparted complementary handling by facility-internal means according to the following criteria: i) in a 2-gang run, the individual signatures or the folded signature packs are only deflected in a second longitudinal air folding station disposed downstream of the first longitudinal air folding station; and ii) in a 3 or 4-gang run, the individual signatures or the folded signature packs are additionally folded in a second longitudinal air folding station disposed downstream of the first longitudinal air folding station.

A sheet processing device includes an upstream device, a downstream device, and a controller as circuitry. The upstream device includes multiple rollers to convey a sheet in a conveyance direction and perform a sheet processing. The downstream device is downstream from the upstream device in the conveyance direction. The downstream device includes a sheet sensor to detect the sheet. The controller controls a timing to rotate the multiple rollers of the upstream device to perform the sheet processing in response to a detection of the sheet by the sheet sensor.