Abstract: The invention relates to a method for controlling the transport of sheets through a printing apparatus, in particular a digital printing apparatus. In the method for controlling the transport of sheets through a printing apparatus, a print queue is set by assigning images to respective sheets, prior to feeding the respective sheets into the transport arrangement. The sheets are then fed into the transport arrangement, and it is detecting whether a double sheet feeding has occurred. Superposed double sheets are deflected to a double sheet box, which is arranged upstream of the at least one print module, and at least those sheets following the superposed double sheet in the transport arrangement, for which an image has already been assigned and which are not in a duplex path, are guided to a waste box, which is arranged downstream of the at least one print module. Finally, the print queue is automatically reset and printing is continued without stopping the printing apparatus.

Abstract: Disclosed are a method and a device for measuring a running direction of a substrate web (6). The method for measuring a running direction of a substrate web consists of the substrate web (6) being guided around a measuring roller (12), at least one bearing force of the measuring roller (12) being measured, and the running direction of the substrate web (6) being determined based on the measured bearing force. The device (10) for measuring the miming direction of a substrate web (6) comprises a measuring roller (12), with the substrate web (6) being guided around said measuring roller (12). Furthermore, the device (10) comprises at least one sensor (18a, 18b, 18c) for measuring a bearing force of the measuring roller (12) and comprises an evaluation circuit, said evaluation circuit being connected to the at least one sensor (18a, 18b, 18c) and being suitable for determining an alignment of the substrate web (6) based on the bearing force measured by the sensor (18a, 18b, 18c).

Abstract: Disclosed herein is a method for printing a printing substrate (6), in which the printing substrate (6) is printed with at least one first printing unit (9) and at least one second printing unit (9), said at least one second printing unit, viewed in a transport direction (A) of the printing substrate, being located downstream of the at least one first printing unit. In this method, a reference image is applied by the at least one first printing unit (9) and a location of the reference image is determined in a direction transverse to the transport direction of the printing substrate (6) in a position that is located, viewed in transport direction of the printing substrate, between the at least one first printing unit (9) and the at least one second printing unit (9).

Abstract: A lifting unit and a process for lifting a stack of sheets having at least a first support (20, 120, 220) and at least a second support (22, 122, 222) are described. The first support defines a first con-toured or flat support surface, and the second support defines a second support surface which has a substantially horizontal, flat main surface. In the lifting unit at least one unit is provided for lifting the first and second supports. During operation the supports are lifted such that at least a highest point of the first support is kept elevationally above the second support, the second support is lifted more quickly than the first support, and the substantially horizontal, flat main surface of the second support is kept in its horizontal alignment. The lifting unit is described, in combination with a sheet feeder.

Abstract: A method of printing an image onto a sheet in a printer having at least one print module and a transport arrangement defining a transport path for transporting sheets through the at least one print module is shown. In accordance with the method, a series of constant frame clock signals is generated and a sheet is approximately feed into a frame along the sheet transport path in accordance with the frame clock signal, wherein the frame defines a virtual desired sheet position, which moves with a predetermined speed along the sheet transport path. The sheet is transported along the sheet transport path, an in-track position of the sheet in the sheet transport path is detected and it is determined whether the in-track sheet position matches the frame within predetermined limits.

Abstract: A device and a method for improving the quality of prints using a printing device and system for carrying out a print job with a digital printing machine, preferably with a printing machine that works with a toner, in particular with an electrophotographically operating printing machine, whereby the sheets (1) are preferably printed by recto-printing and verso-printing, whereby the sheets (1) to be printed are divided into batches, and whereby, in the case of batches that are incompletely occupied with sheets (1), the slots of the missing sheets are replaced by an approximately sheet-sized toner field (3) on the transport belt (4) for the sheets.

Abstract: In a sheet conveying device comprising at least one conveying arrangement with a porous conveyor belt that can be moved in a circulating manner, at least one vacuum source and at least one air line whose one end is connected to the vacuum source and whose other end abuts against the porous conveyor belt, a simple and automatic control of the suction pressure for different sheets is achieved by at least one constant pressure controller in the air line in order to essentially maintain constant a pressure differential between the interior space of the air line and its environment.

Abstract: A lifting unit and a process for lifting a stack of sheets having at least a first support (20, 120, 220) and at least a second support (22, 122, 222) are described. The first support defines a first con-toured or flat support surface, and the second support defines a second support surface which has a substantially horizontal, flat main surface. In the lifting unit at least one unit is provided for lifting the first and second supports. During operation the supports are lifted such that at least a highest point of the first support is kept elevationally above the second support, the second support is lifted more quickly than the first support, and the substantially horizontal, flat main surface of the second support is kept in its horizontal alignment. The lifting unit is described, in combination with a sheet feeder.

Abstract: The invention relates to a method and a device for transporting a sheet, in particular after a sheet has been picked off a stack and separated therefrom, preferably for the feeder-side use in a printing machine, wherein the sheet is brought to a transport speed, preferably for transfer to another transport path. The object of the invention is to provide a more controlled method of the aforementioned type and a device allowing this method. In accordance with the invention, considering the method, this object is achieved in that the sheet is initially accelerated to a speed that is greater than the desired transport speed and only later, after a phase of this higher speed, said sheet is slowed to the desired transport speed, in which case the phase of the higher speed is dimensioned such that the affected sheet is in a nominal position at the appropriate time.

Abstract: The invention relates to a printing apparatus and a method for controlling the transport of sheets through a printing apparatus, in particular a digital printing apparatus. The printing apparatus has at least one print module and a transport arrangement defining a direction of transport, arranged for transporting sheets past said at least one print module for printing thereon. In the method for controlling the transport of sheets through the printing apparatus, a print queue is set by assigning images to respective sheets, prior to feeding the respective sheets into the transport arrangement. The sheets are then fed into the transport arrangement, an it is detecting whether a double sheet feeding has occurred.

Abstract: The invention relates to a method and a device for transporting a sheet, in particular after a sheet has been picked off a stack and separated therefrom, preferably for the feeder-side use in a printing machine, wherein the sheet is brought to a transport speed, preferably for transfer to another transport path. The object of the invention is to provide a more controlled method of the aforementioned type and a device allowing this method. In accordance with the invention, considering the method, this object is achieved in that the sheet is initially accelerated to a speed that is greater than the desired transport speed and only later, after a phase of this higher speed, said sheet is slowed to the desired transport speed, in which case the phase of the higher speed is dimensioned such that the affected sheet is in a nominal position at the appropriate time.

Abstract: A device and a method for improving the quality of prints using a printing device and system for carrying out a print job with a digital printing machine, preferably with a printing machine that works with a toner, in particular with an electrophotographically operating printing machine, whereby the sheets (1) are preferably printed by recto-printing and verso-printing, whereby the sheets (1) to be printed are divided into batches, and whereby, in the case of batches that are incompletely occupied with sheets (1), the slots of the missing sheets are replaced by an approximately sheet-sized toner field (3) on the transport belt (4) for the sheets.