EP3693174B1 - Device and method for printing a print substrate - Google Patents

Description

The invention relates to a device and a method for printing on a print substrate.

background

When printing a material in a printing device or a printing system, the material can be provided as a continuous material on a roll. Alternatively, it can be provided that individual sheets are fed to the printing device one after the other in order to print the sheets individually. When printing continuous material, the continuous material can be separated after printing in order to obtain individual printed sheets.

The document DE 10 2016 102 565 A1 discloses a method and apparatus for producing a singulated sheet for a printing device. In the method, various sheet materials are made available as continuous material in magazine or buffer devices, with a transport path to a material switch, in which the transport paths converge, being arranged downstream of the magazine devices on the output side. Transport devices are provided which are each assigned to one of the transport paths and set up to transport the different sheet materials from the magazine device at least to the material switch. Control signals are received in the transport devices which determine a material selection corresponding to a print job for a selected one of the sheet materials. The transport devices are controlled according to the control signals in such a way that the selected sheet material is transported to the material switch and, in the material switch, moves from the transport path into a feed path into which the transport paths open. The selected sheet material is transported by means of the transport devices via the feed path from the material diverter to a separating device. A single sheet for subsequent printing is produced in the separating device by separating the single sheet from the selected sheet material.

In the document DE 10 2016 102 566 A1 describes a method and a device for printing a single sheet.

The document U.S. 2013/088554 A1 discloses a pallet conveyor. The apparatus includes a forward lane for loading pallets from an upstream portion of the forward lane to a downstream part of the forward line, a return line and a pallet transfer device. The pallet transfer device is configured to simultaneously (1) continuously receive pallets from a downstream portion of the return line and deliver pallets to the upstream portion of the forward line and (2) continuously receive pallets from the downstream portion of the forward line and deliver pallets to an upstream portion of the return line .

The document EP 1 890 884 B1 describes a digital printer with a digital printing unit for digitally printing an image on a printing substrate during relative movement between a print head and the printing substrate and a printing table for holding the printing material during digital printing. The printing table is firmly connected to the digital printing unit during the digital printing of the image on the printing material and is detached from the digital printing unit before and after the digital printing of the image on the printing substrate (3). The printing table (2, 12) can be moved between a printing position, in which it is fixedly attached to the digital printing unit (4, 5), and a printing substrate feeding position, in which it enables the feeding and removal of the printing substrate (3) from the printing table ( 2.12) supported.

The document DE 10 2016 224 313 A1 relates to a device for transporting printing materials on a movable carrier in a printing machine, in which the movable carrier has a device for transmitting electrical energy from a component of the printing machine to the movable carrier.

With the one in the document DE 10 2009 003 443 A1 described method and the corresponding device for printing large-format workpieces is first fixed to a workpiece to be printed on a movable carriage. The carriage is then moved in a feed direction relative to an inking device and a first strip-shaped section is printed on the workpiece. The carriage and/or the inking device is then moved in a direction perpendicular to the feed direction, in order then to move the carriage relative to the inking device and to print a second strip-shaped section on the workpiece. This process can be repeated until the workpiece is completely printed in order to print large-format workpieces.

The document U.S. 2017/253054 A1 discloses a media support unit for supporting a medium on which a printing apparatus prints, comprising a support portion having a support surface for supporting the medium, a heating portion which heats the support portion, and a main body portion on which the support portion is mounted. The thermal conductivity of a mounting portion as part of the main body portion on which the support portion is mounted is lower than the thermal conductivity of the support portion.

In the document DE 10 2010 060 408 A1 an arrangement for controlling the web tension of a printing material web in a printing device is described.

The document EP 2 384 897 A1 describes an inkjet printer having a printing plate which supports a printing medium, a printing means consisting of a carriage, an inkjet head and the like for performing printing on the printing medium supported by the printing plate, a medium feeding device which carries a feeding shaft around which the printing medium is wound in an elongated sheet form and in which the feed shaft is rotatable to feed out the print medium toward the platen, and a media winding device which has the same shape as the media feed device and supports a winding shaft for winding up the print medium and in which the winding shaft is rotatable to wind up the print media that has been fed out from the media feeding device and printed on by the printing device. The media feeding device and the media winding device are arranged bilaterally with respect to the printing plate in a feeding direction of the printing medium so as to be symmetrical in a side view.

The document KR 101 322 166 B1 discloses a high precision feed particularly intended for UV ink jet printing on vinyl.

The document DE 10 2012 105 338 A1 relates to a method for controlling a digital printing system for printing on a continuous recording medium.

In order to print a continuous material, the continuous material must be transported through the printing device or the printing system, whereby the transport movement must be coordinated with the printing process and transport must be ensured under suitable conditions through the entire printing device or the entire printing system, in particular in the area of the printing device responsible components have to meet the requirements that result from the printing process itself.

Summary

The object of the invention is to specify a device and a method for printing on a print substrate with improved positioning of the print substrate. Here, in particular, the positioning of the print substrate is to be improved relative to a print head shuttle.

A device and a method for printing a print substrate according to independent claims 1 and 12 are provided for the solution. Configurations are the subject of dependent subclaims.

According to one aspect, an apparatus for printing on a print substrate is provided. The device has a print head shuttle with at least one print head which is set up to apply a printing medium to a print substrate to generate a print image, the print substrate being a web material which can be displaced along a web path in a feed direction, and the print head shuttle on a first side of the printing substrate is arranged. A print table is positioned opposite the printhead shuttle on a second side of the print substrate. The printing table has a holding device which is set up to hold the printing substrate in such a way that a relative movement between the printing table and the printing substrate is prevented for printing. For printing, the print head shuttle is set up to perform a movement in and counter to a shuttle movement direction running transversely to the feed direction of the print substrate, such that the feed movement of the print substrate in the feed direction and the movement of the print head shuttle transverse to the feed direction position the print head shuttle over the print substrate , to create the print image on the print substrate.

According to a further aspect, a method for printing on a print substrate is provided. The method comprises: applying a printing agent to a print substrate, which is a web material that is displaceable along a web path in a feed direction, with at least one print head of a print head shuttle arranged on a first side of the print substrate, for generating a print image; Holding the print substrate, with a holding device of a print table, which is arranged opposite the print head shuttle on a second side of the print substrate, such that a relative movement between the print table and the print substrate is prevented for printing; and when the printing medium is applied to the printing substrate, the print head shuttle is displaced in and counter to a shuttle movement direction running transversely to the feed direction of the print substrate, such that the feed movement of the print substrate in the feed direction and the movement of the print head shuttle transverse to the feed direction provide a positioning of the print head shuttle over the print substrate is used to create the print image on the print substrate.

By arranging the print head shuttle on a side of the web material opposite the printing table, the print substrate can be printed in particular by means of the print head shuttle while it rests on the printing table and is held by the holding device.

The positioning can be improved by distributing the movement components required for positioning the print substrate relative to the print head shuttle to the print head shuttle on the one hand and the print substrate on the other. In particular, the relative positioning in a longitudinal direction, i.e. parallel to the feed direction, is carried out by displacing the print substrate, and the relative positioning in a transverse direction, i.e. transverse to the feed direction, is carried out by displacing the print head shuttle. Advantageously, the print substrate is only moved in the feed direction, while the print head shuttle is moved back and forth transversely to the feed direction.

The print head shuttle can be set up to execute a movement in and counter to a parallel shuttle movement direction running parallel to the feed direction of the print substrate. In other words, provision can be made for the print head shuttle to be displaced not only in the transverse direction but also in the longitudinal direction. The movement of the print head shuttle in the longitudinal direction can be coordinated with the feed movement of the print substrate, in particular the displacement of the print head shuttle in the longitudinal direction and the feed movement of the print substrate can take place at the same speed, so that with simultaneous displacement of the print head shuttle transverse to the feed direction, printing can take place during the feed movement can.

The printing table is set up to perform a feed movement while the holding device holds the print substrate such that the feed movement is transmitted to the print substrate and the print table causes a feed movement of the print substrate along the web path. So the feed movement of the web material can be effected by means of the printing table by being held by the printing table and carried along with the movement of the printing table in the feed direction. The holding device can also be set up to hold the print substrate during a feed movement of the print substrate in such a way that a relative movement between the printing table and the print substrate is prevented during the feed movement. This improves the transport if a relative movement between the printing table and the printing substrate is prevented not only during the printing but also in particular during the feed movement by means of the printing table.

The printing table is set up to move the web material through the printing device in a feed direction, with the printing table being movable in the feed direction and counter to the feed direction. While the web material is held on the printing table by the holding device, the printing table moves in the feed direction from a rear position to a front position and thus pulls the web material, for example from a roll, in the feed direction through the printing device. The holding device can then release the web material so that it is detached from the printing table. The printing table can then move past the web material against the feed direction from the front to the rear position. Contact with the web material can then be established again by means of the holding device, whereupon the movement of the printing table in the feed direction is repeated.

The holding device can comprise a vacuum device which sucks the print substrate onto the printing table by means of a negative pressure or vacuum. The vacuum device can generate a negative pressure and be connected to the environment via channels with a supporting surface of the printing table, so that the printing substrate is sucked onto the supporting surface of the printing table by means of the negative pressure in order to hold the printing substrate. At least a portion of the printing table comprising the support surface may be of a porous material, with the channels connecting the vacuum device to the support surface being provided by the porosity of the material.

The printing table can have a heating device which brings the supporting surface of the printing table to a predetermined temperature. In this way, the printing substrate arranged on the support surface can be brought to a predetermined printing temperature. This can be advantageous for certain materials and possibly printing media and improve the printing result. The heating device can have suitable means for heating the Include support surface, such as electrical heating elements, openings for hot air, etc. In particular, it is preferable to heat the support surface evenly, at least in the area in which the print substrate rests. However, the heating of plastic printing substrate in particular can lead to the expansion of the printing substrate and thus possibly to the formation of creases. Therefore, independently of the heating device, a smoothing device can be provided, for example in the form of a brush, which smoothes the print substrate with the first printing movement of the print head shuttle.

The web material can be a foil material. The foil material can be a plastic foil material, for example made of polycarbonate (PC) or polyvinyl chloride (PVC). The web material can be a thin web material. The thin web material can have a material thickness of 100 μm or less. For example, the web material may have a thickness of 75 µm. The web material can be provided with a width which corresponds to a desired width of the printed image, possibly plus the necessary side margins. For example, the web material can be provided with a width of 300 mm to 600 mm. A storage device can be provided, from which the web material is fed to the printing process. For example, the device can comprise a supply roll on which the web material is rolled up and from which the web material is drawn during operation.

The device can also have a first web tension measuring device, which is arranged along the web path in front of the printing table and is set up to generate first measurement data, which indicate a mechanical web tension of the printing substrate at the first web tension measuring device, a first tensioning device, which is arranged along the web path in front of the printing table and is set up to adjust a mechanical web tension of the print substrate, a second web tension measuring device, which is arranged along the web path after the printing table and set up to generate second measurement data, which indicate a mechanical web tension of the print substrate at the second web tension measuring device, and a second tensioning device, which along of the web path is arranged after the printing table and set up to set a mechanical web tension of the printing substrate, and a control device. The control device can be set up to receive the first measurement data, to generate first control data based on the first measurement data and to control the first tensioning device in accordance with the first control data, such that the first tensioning device has a first specified web tension of the printing substrate at the first Clamping device causes, and to receive the second measurement data, to generate second control data on the basis of the second measurement data and to control the second clamping device according to the second control data, such that the second clamping device effects a second predetermined web tension of the printing substrate on the second clamping device.

The control device can be set up to keep the web tension of the print substrate constant along the web path in front of the printing table and to keep the web tension of the print substrate constant along the web path behind the printing table during a printing process. In this way, constant printing conditions can be ensured, in which the web tension in front of the printing table and the web tension behind the printing table remain constant.

The apparatus may include a rejector. The selection device can include a testing device, a packaging device and a document switch. The checking device can be formed with an image recording device and set up to record an image of the print image on the web material, to compare the recorded image of the print image on the web material with comparison image data, to determine the print image as a correct print image when based on the comparison of the print image on the web material with the comparison image data a match between the print image and the comparison image data is determined, and to determine the print image as an incorrect print image if, based on the comparison of the print image on the web material with the comparison image data, there is no match between the print image and the comparison image data is determined.

The making-up device can be set up to make up the web material into individual sheets and the document switch can be set up to direct a made-up sheet onto one of a first transport path and a second transport path, a made-up sheet with a print image which is determined to be a correct print image was, is routed to the first transport path and a made-up sheet with a print image which was determined to be an incorrect print image is routed to the second transport path.

A waste device can be arranged along the second transport path, which destroys a made-up sheet with a printed image that was determined to be an incorrect printed image. This allows reuse of the ready-made bow with a print image determined to be an incorrect print image may be excluded. Alternatively or additionally, sensitive data can be made unrecognizable. For example, the spoilage device can be a cutting device that cuts the made-up sheet with a print image that was determined to be an incorrect print image. The cutter can cut the sheet into strips. Parameters of the cutting device can be adjustable. For example, a strip width of the cut strips can be adjustable. The destroyed sheet, for example the strips to which the sheet was cut, can be collected in a waste container. The second transport route can lead to the scrap container.

The configurations explained in connection with the device for printing on a print substrate can be provided accordingly in the method for printing on a print substrate.

Description of exemplary embodiments

• Fig. 1 eine schematische Übersicht einer Druckvorrichtung zum Bedrucken eines Drucksubstrats;
• Fig. 2 eine schematische Übersicht einer Anordnung eines Drucktischs und eines Drucckopfshuttles in einer Druckvorrichtung;
• Fig. 3 eine schematische Übersicht weiterer Ausgestaltungsoptionen einer Druckvorrichtung; und
• Fig. 4 eine schematische Übersicht einer weiteren Druckvorrichtung zum Bedrucken eines Drucksubstrats.

Further exemplary embodiments are explained in more detail below with reference to drawings. Here show:

• 1 a schematic overview of a printing device for printing a print substrate;
• 2 a schematic overview of an arrangement of a printing table and a print head shuttle in a printing device;
• 3 a schematic overview of further configuration options of a printing device; and
• 4 a schematic overview of a further printing device for printing a printing substrate.

The Fig.1 shows a printing device for printing a printing substrate. The print substrate is a web material 1 on a roll 2 which serves as a storage device for the web material 1 . The web material 1 can be a plastic film. In one example, the web material 1 is a polycarbonate film with a thickness of 75 μm and a width of 600 mm. In a further example, the web material can consist of a different material, for example PVC, have a greater or smaller thickness, for example 100 μm, and/or have a smaller or larger width, for example 300 mm.

The web material is moved in a feed direction 4 through the printing device by means of a printing table 3 . For this purpose, the printing table 3 can be moved in the feed direction 4 and counter to the feed direction 4 . The printing table 3 is designed as a coherent unit or at least moves as a unit in order to support a feed of the web material 1 that is uniform over the width of the web material 1 . The printing table 3 has a holding device by means of which the web material 1 is held. While the web material 1 is held on the printing table 3 by the holding device, the printing table moves in the feed direction 4 from a rear position to a front position and thus pulls the web material 1 from the roll 2 in the feed direction 4 through the printing device. The holding device then releases the web material 1 so that it is detached from the printing table 3 . The printing table 3 then moves against the feed direction 4 past the web material 1 from the front to the rear position and then makes contact with the web material 1 again by means of the holding device, whereupon the movement of the printing table 3 in the feed direction 4 is repeated. A discontinuous advancement of the web material 1 through the printing device is thus provided.

In further configurations, additional drive mechanisms can be provided, which support the movement of the web material 1 provided by means of the printing table 3 . For example, driven rollers, over which the web material 1 runs and which move the web material 1 in a supporting manner, can be arranged in front of and/or behind the printing table 3 along a path of the web material 1 . In particular, an assisting drive mechanism may be arranged along the path of the web material 1 behind the printing table 3 to assist movement of the web material 1 away from the printing table 3 .

A print head shuttle 5 is arranged on a side of the web material 1 opposite the printing table 3 . The print head shuttle 5 is arranged opposite the printing table 3 with respect to the web material 1 in such a way that the web material 1 runs between the printing table 3 and the print head shuttle 5, so that it can be printed by means of the print head shuttle 5 while it is lying on the printing table 3 and from the holding device is held. The printing table 3 moves the web material past the print head shuttle 5 in the feed direction 4 . During the movement of the web material, the print head shuttle 5 prints the web material 1.

During the movement through the printing device, the web material 1 runs over a plurality of deflection rollers 6, by means of which the web material 1 is deflected within the printing device. The web material also runs over web tension measuring rollers 7, by means of which a web tension of the web material 1 is measured. Like in the 1 shown, a first web tension measuring roller 7a is arranged along the web path of the web material 1 in front of the printing table. The first web tension measuring roller 7a thus measures the web tension of the web material 1 in front of the printing table 3. By holding the web material 1 by means of the holding device on the printing table 3, a web tension of the web material 1 can occur along the web path of the web material 1 behind the printing table 3, which from the Web tension before the printing table 3 is independent. For this reason, a second web tension measuring roller 7b is arranged along the web path of the web material 1 behind the printing table. The second web tension measuring roller 7b thus measures the web tension of the web material 1 behind the printing table 3. The web tension of the web material 1 causes a respective force on the axes of the web tension measuring rollers 7a, 7b. The respective force on the axis of the web tension measuring rollers 7a, 7b is measured by means of a respective sensor device 8a, 8b of the web tension measuring rollers 7a, 7b. The respective sensor device 8a, 8b of the first 7a and the second 7b web tension measuring roller generates first or second measurement data which indicate the respective web tension of the web material 1 on the first web tension measuring roller 7a or on the second web tension measuring roller 7b.

Furthermore, the web material runs over so-called dancers 9. These are rollers which are movably arranged in order to adjust the tension of the web material 1. Like in the 1 a first dancer 9a can be seen along the path of the web material 1 in front of the printing table. In the example shown, the first dancer 9a can be moved up and down, with a downward movement of the first dancer 9a leading to an increase in the tension of the web material 1 and an upward movement of the first dancer 9a leading to a reduction in the tension of the web material 1 leads. The web tension of the web material 1 in front of the printing table 3 can thus be adjusted by means of the first dancer 9a.

A second dancer 9b is arranged along the path of the web material 1 behind the printing table. The second dancer 9b is also movable up and down in the example shown, with a movement of the second dancer 9b down leading to an increase in the tension of the web material 1 and an upward movement of the second dancer 9b leads to a reduction in the tension of the web material 1. The web tension of the web material 1 behind the printing table 3 can thus be adjusted by means of the second dancer 9b, which is independent of the web tension in front of the printing table 3 at least while the web material 1 is being held by the holding device on the printing table 3.

A control device 10 is connected to the web tension measuring rollers 7a, 7b and the dancers 9a, 9b (not shown) and is set up to receive the first and the second measurement data from the web tension measuring rollers 7a, 7b. In the control device 10, the first measurement data are compared with a first specified web tension. The first specified web tension specifies a desired web tension of the web material 1 along the web path of the web material 1 in front of the printing table. The control device 10 generates first control data corresponding to the comparison result, which are transmitted to the first dancer 9a and lead to a movement of the first dancer 9a. For example, the first control data indicate a small downward movement of the first dancer 9a if the comparison shows that the web tension of the web material on the first web tension measuring roller 7a deviates downwards by a small difference from the first specified web tension and the first control data indicates a larger one Movement of the first dancer 9a upwards when the comparison shows that the web tension of the web material on the first web tension measuring roller 7a deviates by a greater difference upwards from the first predetermined web tension.

The control device 10 is also set up to compare the second measurement data with a second specified web tension. The second predetermined web tension specifies a desired web tension of the web material 1 along the web path of the web material 1 behind the printing table. The control device 10 generates second control data corresponding to the comparison result, which are transmitted to the second dancer 9b and lead to a movement of the second dancer 9b. For example, as explained above with regard to the first dancer 9a, the second control data indicates a small movement of the second dancer 9b downwards if the comparison shows that the web tension of the web material on the second web tension measuring roller 7b has fallen by a small difference downwards from the second predetermined one Web tension deviates and the second control data indicate a greater upward movement of the second dancer 9b if the comparison shows that the web tension of the web material on the second web tension measuring roller 7b deviates upwards by a greater difference from the second predetermined web tension.

The web tensions upstream and downstream of the printing table 3 can be continuously monitored by repeatedly receiving first and second measurement data and generating corresponding first and second control data. As a result, the web tension in the printing device can be regulated along the web path of the web material 1 both in front of and behind the printing table 3 . For example, the first and the second specified web tension can be the same and the web tension of the web material 1 can be regulated both in front of and behind the printing table 3 in such a way that the same web tension of the web material 1 is achieved in front of and behind the printing table 3 within a predetermined permissible deviation.

The 2 shows an arrangement of a printing table 3 in a printing device, on which a web material 1 is arranged. The web material 1 is fed during a movement of the printing table 3 in a feed direction 4 (from the plane of the drawing in Fig 2 held out) by means of a holding device on the printing table 3, so that the web material 1 is moved along the feed direction 4 through the printing device. In the representation of 2 the holding device is provided with a vacuum device 11 . The vacuum device 11 generates a negative pressure. Here, the vacuum device 11 is connected via channels 12 to a support surface 13 of the printing table 3 with the environment. The web material 1 lies on the support surface 13 of the printing table 3 . To hold the web material 1, the vacuum device 11 generates a negative pressure during the movement of the printing table 3 in the feed direction 4, so that the web material is sucked onto the support surface 13 via the channels 12 and is thus held on the printing table 3.

In order to ensure that the web material 1 is held evenly on the support surface 13 , openings in the channels 12 are distributed over the entire support surface 13 . In the example of 2 For this purpose, the bearing surface 13 consists of a porous material with a defined porosity, which is connected to the vacuum device 11 . The porosity of the material of the bearing surface 13 provides undefined channels 12 which, due to the defined porosity, result in the web material 1 being sucked in and held uniformly on the bearing surface 13 . In alternative configurations, the channels 12 can be provided, for example, with a defined grid of bores, for example micro-bores, in order to ensure that the web material 1 is sucked in and held uniformly on the support surface 13 . Apart from the openings of the channels 12 in the bearing surface 13 or the porosity of the material, the bearing surface 13 of the Printing table 3 designed as a continuous surface. Interruptions in the bearing surface 13 can be provided. However, it is advantageous if the printing table 13 forms a unit and thus the supporting surface 13 is also moved as a coherent unit.

As a further alternative, the holding device may not be provided as a vacuum device 11 . For example, the holding device can be provided by means of one or more grippers which grip the web material 1 and hold it on the support surface 13 of the printing table 3 .

During the movement of the web material 1 on the printing table 3 past the print head shuttle 5, the print head shuttle 5 prints the web material 1 with a printing medium. The print head shuttle has one or more print heads 14 for this purpose. In the representation of 2 the print head shuttle 5 has two print heads 14a, 14b. A print head 14 can comprise a nozzle or a row of nozzles with a plurality of nozzles arranged in a row. The pressure medium can be ejected dropwise through the nozzles. For example, one print head 14 can be used for each desired color or material to be applied.

The print heads 14 are selectively controlled in order to selectively apply printing medium to the web material 1 and thus to generate a desired print image on the web material. In this case, the print head shuttle 5 moves back and forth transversely to the feed direction 4 of the web material 1 , so that the print heads 14 move over the web material 1 . The movement of the printing table 3 along the feed direction 4 thus results in a relative movement of the web material 1 to the print heads 14 in a first printing direction, and the movement of the print head shuttle 5 transversely to the feed direction 4 results in a relative movement of the web material 1 to the print heads 14 in a second Printing direction provided, which is transverse to the first printing direction. By selectively controlling the movement of the printing table 3, the movement of the print head shuttle 5 and the ejection of the printing medium from the print heads 14, a desired print image is thus applied to the web material 1.

Depending on the web material 1 used and the printing medium used, it can be advantageous to bring the web material 1 to a specific temperature for printing. For this purpose, the printing table 3 according to the 2 a heater 15 on. By means of the heating device 15, the support surface 13 of the printing table 3 to a predetermined temperature brought. As a result, the web material 1 arranged on the support surface 13 is heated to a printing temperature for printing.

The print head shuttle 5 also has a smoothing device. In the representations of figures 1 and 2 the smoothing device is a brush 16 which extends along a longitudinal direction which runs parallel to the feed direction 4 . The brush 16 as a functional part of the smoothing device is thus elongated in the longitudinal direction, parallel to the feed direction. It therefore has a greater extent in the longitudinal direction than in other directions. The smoothing device can thus have a smoothing effect transversely to the feed direction 4 when moving over the web material 1 . The brush 16 is as in the 2 shown, based on the direction of movement of the print head shuttle 5 arranged laterally on the print head shuttle 5. The brush 16 is movable up and down relative to the printhead shuttle 5 between first and second positions. In the first position, the brush 16 comes into contact with the support surface 13 so that the brush 16 sweeps across the web material 1 arranged on the support surface 13 of the printing table 3 when the printing shuttle 5 moves transversely to the feed direction 4 . In the second position, the brush 16 is arranged above the printing table 3 in such a way that the brush 16 does not touch either the printing table 3 or the web material 1 when the print head shuttle 5 moves.

During a printing process, while the printing table 3 is in the rear position, a connection is formed between the web material 1 and the support surface 13 by means of the vacuum device 11 . The according to 2 While the print head shuttle 5 is in a first position in which the print head shuttle 5 and the brush 16 are located to the right of the printing table 3, the brush 16 arranged on the left side of the print head shuttle 5 is brought to the first position. During a subsequent first movement of the print head shuttle 5 over the printing table 3 and the web material 1, the brush 16 sweeps over the web material 1 and thus smoothes out wrinkles and/or bubbles that have formed in the web material 1 during the formation of contact between the bearing surface 13 and the web material 1 and/or during the heating of the web material 1 by means of the heating device 15.

After the brush 16 has been moved across the entire width of the web material 1, the brush 16 is brought to the second position. Thus, during subsequent movements of the print head shuttle 5, during the movement of the printing table 3 from the rear to the front position, the brush 16 does not come into contact with the web material 1. After release of the web material 1 from the printing table 3 and the movement of the printing table 3 from the front to the rear position, a connection is formed again between the web material 1 and the support surface 13 and the brush 16 is moved to the first position. Thus, during the first subsequent movement of the print head shuttle 5 over the web material 1, the web material is smoothed by the brush 16 after each contact is made with the bearing surface 13 of the printing table 3. FIG.

The length of the brush 16 corresponds at least to the length of the support surface 13 of the printing table 3 . Here, as in the 1 recognizable, the length of the brush 16 can be greater than a length of the print head shuttle 5, which can be shorter than the length of the contact surface 13. This ensures that the web material 1 is smoothed by the brush 16 over the entire length on which a contact is made to the support surface 13 of the printing table.

Optionally, a capping station 17 can be provided, which prevents the print heads 14 from drying out. When the printing device is not in use, the print head shuttle 5 is moved into a position in which the print heads 14 are shielded from the environment by the capping station 17 and the print heads 14 are thus prevented from drying out due to evaporation of solvent in the printing medium. Furthermore, a pressure medium tank 18 can optionally be provided for cleaning and/or preparing the print heads 14 for a printing process. The printhead shuttle can be moved to a position in which the printheads 14 are located above the fluid container 18. Pressure medium can then be ejected from the print heads 14 into the pressure medium containers 18 in order to free the print heads 14 of contamination and/or residual pressure medium and/or to remove air from the pressure medium transport paths in the print heads 14 .

Like in the 1 drying devices 19a, 19b are shown along the path of the web material 1 behind the printing table 3 and in the area of the second web tension measuring roller 7b and the second dancer 9b. The printing medium on the web material 1 is dried by means of the drying devices 19a, 19b. For example, the drying devices 19a, 19b can be hot air blowers and/or UV radiators. Different drying devices 19a, 19b can be provided.

The 3 shows further configuration options of a printing device. This can, for example, the printing device from the 1 be. Alternatively, the configuration options according to the 3 in a printing device other than the printing device according to 1 be provided. A printed image testing device 20 is arranged along the movement path of the web material 1 behind the second dancer 9b and the drying devices 19a, 19b. The print image checking device 20 has an image recording device 21 which is set up to record an image of the print image on the web material 1 . In the print image checking device 20, the recorded image of the print image on the web material 1 is compared with comparison image data, which can be, for example, print job data of a print job for printing the print image. If a match between the print image and the comparison image data is determined on the basis of the comparison of the print image on the web material 1 with the comparison image data, the print image is determined as a correct print image. If, based on the comparison of the print image on the web material 1 with the comparison image data, no match is established between the print image and the comparison image data, the print image is determined as an incorrect print image.

A match between the print image and the comparison image data is established when the recorded image of the print image on the web material 1 corresponds to the comparison image data within predetermined limits. If the recorded image of the print image on the web material 1 does not correspond to the comparison image data within the predetermined limits, no match between the print image and the comparison image data is determined. The comparison of the recorded image with the comparison image data can be, for example, a pixel comparison and/or a comparison of characteristic values of the recorded image, for example a contrast value.

A roller drive 22 is arranged behind the testing device 21 to support the movement of the web material 1 along the movement path of the web material 1 . A further dancer 9c for controlling the web tension of the web material 1 is arranged behind the roller drive 22 . The additional dancer 9c can, for example, be controlled by the control device 10 in accordance with the second sensor data. Alternatively, a further web tension measuring roller can be provided, which generates third measurement data, by means of which the control device 10 controls the further dancer 9c.

Along the path of movement of the web material 1 behind the testing device 21 and the additional dancer 9c, there is a finishing device 23 which is set up to finish the web material 1 into individual sheets. For example, the web material 1 can be fed to the finishing device 23 and by means of a cutting device 24 of the assembly device 23 are cut to a predetermined sheet size in order to assemble the web material 1 into individual sheets. The individual sheets are then directed in a document switch 25 to different transport paths 26a, 26b. A transport path 26a leads into a document container 27. Another transport path 26b leads into a reject container 28. Sheets that carry a print image that has been determined as the correct print image are determined as document sheets 29 and are guided by the document switch 25 onto the transport path 26a, the leads into the document container 27. Sheets that carry a print image that was determined to be an incorrect print image are determined as waste sheets 30 and are guided by the document switch 25 onto the transport path 26b, which leads into the waste container 28. In this way, it is possible to sort out printed sheets which have errors in the printed image. The printed image of a waste sheet 30 can then be printed again.

Optionally, a bad marking device 31 can be provided, which is arranged along the movement path of the web material 1 behind the testing device 21 and in front of the finishing device 23 . The bad marking device 31 is set up to provide a print image which was determined as an incorrect print image with a mark which characterizes the print image as an incorrect print image. For example, the bad marking device 31 can include a print head for this purpose.

Provision can be made for the print image to include a plurality of individual print images. In this case, each individual print image can be determined as a correct individual print image or an incorrect individual print image, and the bad marking device 31 can be set up to provide each individual print image determined as an incorrect individual print image with a mark, which identifies the individual print image as an incorrect individual print image. In this case, the document switch 25 can be omitted and all the individual sheets can be fed to the document container 27 via the transport path 26a.

Alternatively, the document switch 25 can be provided and set up to transport printed sheets with a print image that includes a number of individual print images marked as incorrect individual print images that exceeds a predetermined maximum number of incorrect individual print images via the transport path 26b feed reject bin 28 and feed other sheets to the document bin 27 via the transport path 26a.

The 4 shows a further printing device for printing a printing substrate. In the configuration according to 4 the printing device has two dancers 9a, 9b, but no third dancer. In this exemplary embodiment, a roll unwinding module 40 includes the roll 2, the first web tension measuring roller 7a with the sensor device 8a, the first dancer 9a and the associated deflection rollers 6. According to the embodiment shown, a printing module 41 includes the printing table 3, the print head shuttle 5 and the brush 16. A drying module 42 includes the second web tension measuring roller 7b with the sensor device 8b, the second dancer 9b, the drying devices 19a, 19b and the associated deflection rollers 6. An image processing module 43 includes the print image checking device with the image recording device 21 and optionally the bad marking device 31 Drying module 42 and the image processing module 43 can be combined to form a drying and image processing module. According to the in the 4 In the embodiment shown, a finishing module 44 comprises the roller drive 22, the finishing device 23 with the cutting device 24, the document switch 25, the transport paths 26a, 26b, the document container 27 and the scrap container 28.

The features disclosed in the above description, the claims and the drawing can be important both individually and in any combination for the realization of the various embodiments.

Reference List

1

web material

2

role

3

printing table

4

feed direction

5

printhead shuttle

6

pulleys

7a, 7b

web tension measuring roller

8a, 8b

sensor device

9a, 9b, 9c

dancer

10

control device

11

vacuum device

12

channels

13

bearing surface

14a, 14b

printheads

15

heating device

16

brush

17

capping station

18

pressure fluid tank

19a, 19b

drying device

20

testing device

21

image pickup device

22

roller drive

23

packaging facility

24

cutting device

25

document switch

26a, 26b

transport routes

27

document container

28

reject bin

29

document sheet

30

waste sheet

31

Bad marking device

40

roll unwind module

41

pressure module

42

drying module

43

image processing module

44

assembly module

Claims (13)

1. A device for printing on a printing substrate (1), comprising

   - a print head shuttle (5) with at least one print head (14a, 14b) which is configured to apply a printing medium to a printing substrate (1) in order to generate a print image, wherein the printing substrate (1) is a web material (1) which can be displaced along a web path in a feed direction (4), and the print head shuttle (5) is arranged on a first side of the printing substrate (1); and

   - a printing table (3) with a supporting surface (13) which is arranged opposite the print head shuttle (5) on a second side of the printing substrate (1), wherein the printing table (3) comprises a holding device (11) which is configured to hold the printing substrate (1) during the feed movement of the printing substrate (1), in such a manner that a relative movement between the printing table (3) and the printing substrate (1) during the feed movement is prevented;

   wherein

   - in order to print, the print head shuttle (5) is configured to execute a movement in and against a shuttle movement direction running transversely to the feed direction (4) of the printing substrate (1), in such a manner that through the feed movement of the printing substrate (1) in the feed direction (4) and the movement of the print head shuttle (5) transversely to the feed direction (4), a positioning of the print head shuttle (5) over the printing substrate (1) is provided in order to produce the print image on the printing substrate (1); and

   - the printing table (3) is configured to move the web material (1) along the web path in a feed direction (4), wherein the printing table (3) is movable in the feed direction (4) and also against the feed direction (4).
2. The device according to claim 1, characterized in that the print head shuttle (5) is further configured to perform a movement in and against a parallel shuttle movement direction running parallel to the feed direction (4) of the printing substrate (1).
3. The device according to claim 1 or 2, characterized in that the printing table (3) is configured to perform a feed movement, while the holding device (11) holds the printing substrate (1) in such a manner that the feed movement is transferred to the printing substrate (1) and the printing table (3) brings about a feed movement of the printing substrate (1) along the web path.
4. The device according to at least one of the preceding claims, characterized in that the holding device (11) comprises a vacuum device, which is configured to draw the printing substrate (1) onto the printing table (3) by means of negative pressure, in order to hold the printing substrate (1).
5. The device according to at least one of the preceding claims, characterized in that the printing table (3) has a heating device (15) which is configured to bring the supporting surface (13) of the printing table (3) to a predetermined temperature.
6. The device according to at least one of the preceding claims, characterized in that the device is configured for a web material which has a thickness of 100 µm or less, preferably a thickness of 75 µm.
7. The device according to at least one of the preceding claims, characterized in that the device is configured for a web material (1) which is a film material.
8. The device according to claim 7, characterized in that the device is configured for a film material which is a plastic film material, which preferably comprises polycarbonate (PC) or polyvinyl chloride (PVC).
9. The device according to at least one of the preceding claims, characterized by

   - a first web tension measuring device (7a, 8a), which is arranged along the web path upstream of the printing table (3) and is configured to generate first measurement data which indicate a mechanical web tension of the printing substrate (1) at the first web tension measuring device (7a, 8a),

   - a first tensioning device (9a) which is arranged along the web path upstream of the printing table (3) and is configured to set a mechanical web tension of the printing substrate (1);

   - a second web tension measuring device (7b, 8b) which is arranged along the web path downstream of the printing table (3) and is configured to generate second measurement data which indicate a mechanical web tension of the printing substrate (1) at the second web tension measuring device (7b, 8b);

   - a second tensioning device (9b) which is arranged along the web path downstream of the printing table (3) and is configured to set a mechanical web tension of the printing substrate (1); and

   - a control device (10) which is configured

   - to receive the first measurement data, to generate first control data on the basis of the first measurement data and to control the first tensioning device (9a) in accordance with the first control data, in such a manner that the first tensioning device (9a) effects a first predetermined web tension of the printing substrate (1) at the first tensioning device (9a); and

   - to receive the second measurement data, to generate second control data on the basis of the second measurement data and to control the second tensioning device (9b) in accordance with the second control data, in such a manner that the second tensioning device (9b) effects a second predetermined web tension of the printing substrate (1) at the second tensioning device (9b).
10. The device according to claim 9, characterized in that the control device (10) is configured to keep the web tension of the printing substrate (1) constant along the web path upstream of the printing table (3) and to keep the web tension of the printing substrate (1) constant along the web path downstream of the printing table (3) during a printing process.
11. The device according to at least one of the preceding claims, characterized by a sorting device comprising:

    - a testing device (20) comprising an image recording device (21) which is configured

    - to record an image of the print image on the web material (1),

    - to compare the recorded image of the print image on the web material (1) with comparative image data,

    - to determine the print image as a correct print image if a comparison of the print image on the web material (1) with the comparative image data shows that the print image and the comparative image data correspond, and

    - to determine the print image as an incorrect print image if a comparison of the print image on the web material (1) with the comparative image data shows that the print image and the comparative image data do not correspond;

    - a finishing device (23) which is configured to tailor the web material (1) into individual sheets; and

    - a document diverter (25) which is configured to guide a finished sheet onto one of a first transport path (26a) and a second transport path (26b), wherein

    - a finished sheet with a print image which has been determined as a correct print image is guided onto the first transport path (26a) and

    - a finished sheet with a print image which has been determined as an incorrect print image is guided onto the second transport path (26b).
12. A method for printing on a printing substrate (1), comprising:

    - applying a printing medium to a printing substrate (1), which is a web material (1) which is displaceable in a feed direction (4) along a web path, by means of at least one print head (14a, 14b) of a print head shuttle (5), which is arranged on a first side of the printing substrate (1), in order to generate a print image;

    - holding the printing substrate (1) during the feed movement of the printing substrate (1) by means of a holding device (11) of a printing table (3) which is arranged opposite the print head shuttle (5) on a second side of the printing substrate (1), in such a manner that a relative movement between the printing table (3) and the printing substrate (1) is prevented during the feed movement for printing; and

    - displacing the print head shuttle (5) during the application of the printing medium to the printing substrate (1) in and against a direction of shuttle movement running transversely to the feed direction (4) of the printing substrate (1), in such a manner that through the feed movement of the printing substrate (1) in the feed direction (4) and the movement of the print head shuttle (5) transversely to the feed direction (4), a positioning of the print head shuttle (5) above the printing substrate (1) is provided, in order to produce the print image on the printing substrate (1),

    wherein the printing table (3) moves the web material (1) along the web path in a feed direction (4) and the printing table (3) moves in the feed direction (4) and against the feed direction (4).
13. The method according to claim 12, characterized by at least one of the following steps during the application of the printing medium to the printing substrate (1):

    - displacement of the printing substrate (1) along the web path, wherein the printing table (3) performs a feed movement while the holding device (11) holds the printing substrate (1), in such a manner that the feed movement is transferred to the printing substrate (1) and the printing table (3) brings about a feed movement of the pressure substrate (1) along the web path; and

    - displacement of the print head shuttle (5) in, and against, a parallel shuttle movement direction running parallel to the feed direction (4) of the pressure substrate (1).

Images