DE102019103138A1 - Device and method for printing on a print substrate - Google Patents

Abstract

The invention relates to a device and a method for printing on a printing substrate (1). is a web material which is displaceable along a web path. The print head shuttle (5) is arranged on a first side of the print substrate (1), while a printing table (3) is arranged opposite the print head shuttle (5) on a second side of the print substrate (1). A holding device (11) is provided to hold the printing substrate so that a relative movement between the printing table (3) and the printing substrate (1) is prevented for printing. By means of a first and second web tension measuring device (7a, 8a, 7b, 8b), which are arranged along the web path before and after the printing table (3), measurement data are generated which indicate a mechanical web tension of the printing substrate (1) on the respective web tension measuring device specify. Furthermore, a first and a second tensioning device (9a, 9b) are provided, which are arranged along the web path before and after the printing table (3), respectively, in order to set a mechanical web tension of the printing substrate (1).

Description

The invention relates to a device and a method for printing on a printing 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, provision can be made for individual sheets to be fed to the printing device one after the other in order to print the sheets individually. When printing on 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 provided as continuous material in magazine or buffer devices, with a transport path to a material switch, in which the transport paths converge, being located downstream of the magazine devices on the output side. Transport devices are provided which are each assigned to one of the transport paths and are set up to transport the various 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 passes 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 switch to a separating device. In the separating device, a separated sheet is produced for subsequent printing in that the separated sheet is separated from the selected sheet material.

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

To print an endless material, the endless material must be transported through the printing device or the printing system, the transport movement being coordinated with the printing process and transport through the entire printing device or the entire printing system must be ensured under suitable conditions, in particular in the area of the printing The relevant components must 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 a print substrate with an improved transport of a print substrate. In particular, it should be possible to control a web tension of the printing substrate in the device.

To achieve this, an apparatus and a method for printing a print substrate according to independent claims 1 and 13 are created. Refinements are the subject of dependent subclaims.

According to one aspect, an apparatus for printing on a print substrate is provided. The device has a printhead shuttle with at least one printhead which is set up to apply a printing medium to a printing substrate in order to generate a printed image, the printing substrate being a web material which can be displaced along a path, and the printing head shuttle being arranged on a first side of the printing substrate is. A printing table is arranged opposite the printing head shuttle on a second side of the printing 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. The device furthermore has 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 on 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 set a mechanical web tension of the printing substrate, a second web tension measuring device, which is arranged along the web path after the printing table and is set up to generate second measurement data which indicate a mechanical web tension of the printing substrate on the second web tension measuring device, and a second tensioning device which runs along the Web path is arranged after the printing table and is set up to set a mechanical web tension of the printing substrate, as well as a control device. The control device is set up 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 in accordance with the first control data, in such a way that the first tensioning device has a first predetermined web tension of the Causes printing substrate on the first clamping device, and receiving the second measurement data, generating second control data based on the second measurement data and controlling the second clamping device according to the second control data, such that the second clamping device causes a second predetermined web tension of the printing substrate on the second clamping device.

According to a further aspect, a method for printing on a printing substrate is provided. The method comprises: applying a printing medium to a printing substrate, which is a web material which is displaceable along a web path, with at least one print head of a print head shuttle, which is 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; Generating first measurement data with a first web tension measuring device which is arranged along the web path in front of the printing table, the first measurement data specifying a mechanical web tension of the printing substrate on the first web tension measuring device; Receiving the first measurement data in a control device; Generating first control data on the basis of the first measurement data in the control device; Controlling a first tensioning device, which is arranged along the web path in front of the printing table and is set up to change a mechanical web tension of the printing substrate, in accordance with the first control data, in such a way that the first tensioning device causes a first predetermined web tension of the printing substrate on the first tensioning device; Generating second measurement data with a second web tension measuring device which is arranged along the web path after the printing table, the second measurement data specifying a mechanical web tension of the printing substrate on the second web tension measuring device; Receiving the second measurement data in the control device; Generating second control data on the basis of the second measurement data in the control device; and controlling a second tensioning device, which is arranged along the web path behind the printing table and is set up to change a mechanical web tension of the printing substrate, in accordance with the second control data, in such a way that the second tensioning device causes a second predetermined web tension of the printing substrate on the second tensioning device.

The web material can be a film material. The film material can be a plastic film material, for example made of polycarbonate (PC) or polyvinyl chloride (PVC). The sheet material can be a thin sheet material. The thin sheet material can have a material thickness of 100 µm or less. For example, the sheet material can have a thickness of 75 µm. The web material can be provided with a width which corresponds to a desired width of the print image, possibly plus any 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 pulled during operation.

The control device can be configured 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 printing substrate constant along the web path behind the printing table during a printing process. Constant printing conditions can thus be ensured, in which the web tension in front of the printing table and the web tension behind the printing table remain constant.

The control device can be set up to repeatedly receive first and second measurement data and to generate first and second control data during a printing process. For example, the control device can be set up to receive first and second measurement data at a defined frequency and to generate first and second control data, respectively. This allows a first and a second control loop to be provided, the first control loop regulating the web tension in front of the printing table by repeatedly receiving first measurement data and generating first control data as a function thereof in order to set the web tension in front of the printing table, and the second control loop the Controls the web tension behind the printing table by repeatedly receiving second measurement data and generating second control data as a function thereof in order to set the web tension behind the printing table.

In order to generate at least the first or the second control data, the control device can be set up to compare the first or the second measurement data with the first or the second predetermined web tension and to generate first or second control data for a control corresponding in height and direction to the comparison result the first or the second clamping device. The comparison of the first or the second measurement data with the first or the second predetermined web tension can determine a discrepancy between the first or the second comprise second measurement data and the first or the second predetermined web tension. An amount of the deviation and a direction of the deviation can be determined. Thus, the deviation can indicate the difference by which the mechanical web tension of the printing substrate on the first or the second web tension measuring device is above or below the first or the second predetermined web tension.

Control data can be generated from the deviation, which control the first or the second tensioning device, which is suitable to compensate for the deviation and thus to adjust the web tension to the first or the second predetermined web tension. For example, an actuator of the first or the second tensioning device can be controlled in order to adjust the web tension to the first or second predetermined web tension.

The comparison of the first or the second measurement data with the first or the second predetermined web tension can determine that the first or second measurement data correspond to the first or the second predetermined web tension if the amount of the deviation is less than a predetermined threshold value, and that It is established that the first or the second measurement data do not correspond to the first or the second predetermined web tension if the amount of the deviation is greater than the predetermined threshold value. The generation of first or second control data, which lead to a control of the first or the second clamping device corresponding in height and direction to the comparison result, can include generating first or second control data if it is determined that the first or the second measurement data of the first or do not correspond to the second predetermined web tension, and not to generate first or second control data if it is determined that the first or second measurement data correspond to the first or the second predetermined web tension.

Comparing the first or the second measurement data with the first or the second predetermined web tension can comprise comparing at least one characteristic value of the first or second measurement data with the first or the second predetermined web tension. For example, a statistical characteristic value of the first or the second measurement data can be compared with the first or the second predetermined web tension. The statistical characteristic value can be, for example, an average value, a minimum value or a maximum value. The characteristic value can be determined over a measurement period of the first or the second measurement data.

The comparison and the generation of control data can be provided both for the first control data and the first predetermined web tension and for the second control data and the second predetermined web tension.

The first predetermined web tension and the second predetermined web tension can be the same. Alternatively, the first predetermined web tension and the second predetermined web tension can be different. For example, the first predetermined web tension and the second predetermined web tension can be adapted to a respective structure of the printing device in front of and behind the printing table.

At least the first tensioning device or the second tensioning device can be a tensioning roller, which is at least partially wrapped by the printing substrate and which can be moved by means of a drive device along a direction of movement transverse to an axis of rotation of the tensioning roller, such that the tensioning roller can move in a first direction lengthens the web path along the drive direction in order to increase the mechanical web tension of the printing substrate and a movement of the tension roller in a second direction opposite to the first direction shortens the web path along the drive direction in order to reduce the mechanical web tension of the printing substrate. The first and second tensioning devices can be tensioning rollers. In particular, a tensioning pulley can be a so-called dancer.

At least the first web tension measuring device or the second web tension measuring device can be a web tension measuring roller which is at least partially wrapped by the printing substrate in such a way that the web tension of the printing substrate causes a transverse force perpendicular to an axis of rotation of the web tension measuring roller, the web tension measuring roller having a force measuring device for measuring the transverse force. The first and the second web tension measuring device can be web tension measuring rollers. The force measuring device can measure a force on a bearing of the axis of rotation of the web tension measuring roller. For example, a force measuring device can comprise strain gauges which are attached to the mounting of the axis of rotation and which detect the force on the mounting of the axis of rotation.

For example, the first web tension measuring device and / or the second web tension measuring device can be a so-called sensor roller system, a so-called block force transducer system and / or a so-called flange force transducer system. With a sensor roller system force transducers can be integrated into the roller body. A block force transducer system can be provided with force sensors and can be configured to receive a bearing of a roller on which a web tension is measured. A flange force transducer system can be set up to accommodate a roller bearing and formed with an inner ring on which force sensors are arranged.

The holding device can comprise a vacuum device which draws the printing substrate onto the printing table by means of a vacuum. The vacuum device can generate a negative pressure and be connected to the environment via channels with a support 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 section of the printing table which comprises the support surface can be made of a porous material, the channels which connect the vacuum device to the support surface being provided by the porosity of the material. The porosity of the material can be a defined porosity. Due to the defined porosity of the material, undefined, statistically evenly distributed channels can be provided, which lead to an even suction and holding of the printing substrate on the support surface. Alternatively, the channels can be provided with a defined grid of bores, for example micro-bores.

The holding device can additionally comprise a gripping device which grips the printing substrate in order to hold it. For example, the gripping device can comprise clamps which clamp the print substrate between the printing table and the clamps and thus grasp and hold it.

The holding device can 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.

The printing table can be set up to carry out a feed movement while the holding device holds the print substrate in such a way that the feed movement is transmitted to the print substrate. As a result, the printing table can bring about a feed movement of the printing substrate along the web path. As an alternative or in addition, one or more feed devices can be provided which cause the print substrate to be fed along the web path. For example, the printing table can bring about a feed movement of the print substrate along the web path, with one or more additional feed devices supporting the feed movement of the print substrate.

The print head shuttle can be set up to carry out a movement for printing in front of and against a module movement direction running transversely to the direction of movement of the print substrate. The feed movement of the print substrate and the movement of the print head shuttle can provide a positioning of the print head shuttle above the print substrate, which enables a print image to be generated on the print substrate. Alternatively or additionally, the print head shuttle can be set up to execute a movement in front of and against a parallel module movement direction running parallel to the direction of movement of the printing substrate.

The device may comprise a rejection device. The separating device can comprise a testing device, a packaging device and a document switch. The test 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 if based on the comparison of the print image a correspondence between the print image and the comparison image data is determined on the web material with the comparison image data, 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 correspondence between the print image and the comparison image data is determined. The assembly device can be configured to assemble the web material into individual sheets and the document switch can be configured to guide 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 defined as a correct print image is directed to the first transport path and a made-up sheet with a print image, which was determined to be an incorrect print image, is directed to the second transport path.

A waste device can be arranged along the second transport path, which destroys a finished sheet with a print image which was determined to be an incorrect print image. As a result, reuse of the made-up sheet with a print image which was determined to be an incorrect print image can be excluded. Alternatively or additionally, sensitive data can be made unrecognizable. For example, the waste device be a cutting device which cuts the finished sheet with a print image which has been determined to be an incorrect print image. The cutting device 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 into which the sheet was cut, can be collected in a reject bin. The second transport route can lead into the reject bin.

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

Figure list

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

In the following, further exemplary embodiments are explained in more detail with reference to drawings. Here show:

• 1 a schematic overview of a printing device for printing on 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
• 4th a schematic overview of a further printing device for printing on a print substrate.

The 1 shows a printing device for printing on a printing substrate. The printing substrate is a web material 1 on a roll 2 , which as a storage device for the web material 1 serves. With the web material 1 it can be a plastic film. In one example it is the sheet material 1 around 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 another material, for example PVC, have a greater or lesser thickness, for example 100 μm, and / or have a smaller or greater width, for example 300 mm.

The web material is made using a printing table 3 in one feed direction 4th moved by the printing device. The printing table is for this purpose 3 in the feed direction 4th as well as against the feed direction 4th movable. The printing table 3 has a holding device by means of which the web material 1 is held. While the web material 1 by means of the holding device on the printing table 3 is held, the printing table moves in the feed direction 4th from a rear position to a front position, thus pulling the web material 1 off the roll 2 in feed direction 4th by the printing device. The holding device then releases the web material 1 free so this from the printing table 3 is resolved. The printing table 3 then moves against the feed direction 4th on the web material 1 past from the front to the rear position and then again forms contact with the web material by means of the holding device 1 from what is the movement of the printing table 3 in the feed direction 4th repeated. It is such a discontinuous movement of the web material 1 provided by the printing device.

In further refinements, additional drive mechanisms can be provided which the means of the printing table 3 provided movement of the web material 1 support. For example, driven rollers over which the web material 1 runs and which the web material 1 move supportively along a path of the web material 1 in front of and / or behind the printing table 3 be arranged. In particular, an auxiliary drive mechanism can be installed along the path of the web of material 1 behind the printing table 3 be arranged to move the web material 1 from the printing table 3 way to support.

On one of the printing table 3 opposite side of the web material 1 is a print head shuttle 5 arranged. The printing table 3 moves the web material in the feed direction 4th on the print head shuttle 5 past. The print head shuttle prints while the web material is moving 5 the web material 1 .

The web material runs as it moves through the printing device 1 over several pulleys 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 7th , by means of which a web tension of the web material 1 is measured. Like in the 1 shown is a first web tension measuring roller 7a along the path of the web material 1 arranged 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 can be along the path of the web material 1 behind the printing table 3 a web tension of the web material 1 which occur from the web tension in front of the printing table 3 is independent. For this reason there is a second web tension measuring roller 7b along the path of the web material 1 arranged 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 . By means of a respective sensor device 8a , 8b the web tension measuring rollers 7a , 7b is the respective force on the axis of the web tension measuring rollers 7a , 7b measured. The respective sensor device 8a , 8b the first 7a and the second 7b Web tension measuring roller generates first or second measurement data, which shows 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 specify.

Furthermore, the web material runs over so-called dancers 9 . These are rollers that are movably arranged to tension the web material 1 adjust. Like in the 1 a first dancer can be recognized 9a along the path of the web material 1 arranged in front of the printing table. The first dancer 9a is movable up and down in the example shown, with a movement of the first dancer 9a down to an increase in the tension of the web material 1 leads and a movement of the first dancer 9a up to a decrease in the tension of the web material 1 leads. Thus, by means of the first dancer 9a the web tension of the web material 1 in front of the printing table 3 to adjust.

Another dancer 9b is along the path of the web material 1 arranged behind the printing table. The second dancer too 9b is movable up and down in the example shown, with a movement of the second dancer 9b down to an increase in the tension of the web material 1 leads and a movement of the second dancer 9b up to a decrease in the tension of the web material 1 leads. Thus, by means of the second dancer 9b the web tension of the web material 1 behind the printing table 3 set which at least while holding the web material 1 by means of the holding device on the printing table 3 the web tension in front of the printing table 3 is independent.

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

The control device 10 is further set up to compare the second measurement data with a second predetermined web tension. The second predetermined web tension gives a desired web tension of the web material 1 along the path of the web material 1 behind the printing table. The control device 10 generates second control data corresponding to the comparison result, which is sent to the second dancer 9b and to a movement of the second dancer 9b to lead. As above for the first dancer 9a explained, for example, the second control data give 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 deviates by a small difference downwards from the second predetermined web tension and the second control data indicate a greater movement of the second dancer 9b upwards if the comparison shows that the web tension of the web material on the second web tension measuring roller 7b deviates by a greater difference upwards from the second predetermined web tension.

It can continuously monitor the web tension in front of and behind the printing table 3 take place by repeatedly receiving first and second measurement data and generating corresponding first and second control data. This enables the web tension in the printing device to be regulated along the web path of the web material 1 both in front of and behind the printing table 3 , be provided. For example, the first and the second predetermined web tension can be the same and the web tension of the web material 1 both in front of and behind the printing table 3 be regulated in such a way that in front of and behind the printing table 3 the same web tension of the web material 1 is reached within a specified 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 railway material 1 becomes during a movement of the printing table 3 in one feed direction 4th (from the drawing plane of the 2 out) by means of a holding device on the printing table 3 held so that the web material 1 along the feed direction 4th is moved by the printing device. In the representation of the 2 is the holding device with a vacuum device 11 provided. The vacuum device 11 creates a negative pressure. Here is the vacuum device 11 via channels 12th to a support surface 13th of the printing table 3 connected to the environment. The railway material 1 lies on the support surface 13th of the printing table 3 on. For holding the web material 1 creates the vacuum device 11 during the movement of the printing table 3 in the feed direction 4th a negative pressure so that the web material over the channels 12th to the support surface 13th sucked in and so on the printing table 3 is held.

To ensure that the web material is held evenly 1 on the support surface 13th openings in the channels are to be ensured 12th over the entire support surface 13th distributed. In the example of the 2 is the contact surface 13th for this purpose made of a porous material with a defined porosity, which with the vacuum device 11 connected is. Due to the porosity of the material of the support surface 13th are undefined channels 12th provided, which due to the defined porosity to a uniform suction and holding of the web material 1 on the support surface 13th to lead. In alternative configurations, the channels 12th For example, it can be provided with a defined grid of bores, for example micro-bores, in order to suck in and hold the web material evenly 1 on the support surface 13th to guarantee.

As a further alternative, the holding device cannot be used as a vacuum device 11 be provided. For example, the holding device can be provided by means of one or more grippers that hold the web material 1 grab and on the support surface 13th of the printing table 3 hold.

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

The print heads 14th are selectively controlled to selectively apply pressure medium to the web material 1 to apply and thus generate a desired print image on the web material. The print head shuttle moves here 5 across the direction of feed 4th of the web material 1 back and forth so that the printheads are 14th over the web material 1 move. It is thus due to the movement of the printing table 3 along the feed direction 4th a relative movement of the web material 1 to the print heads 14th in a first printing direction and by the movement of the print head shuttle 5 across the feed direction 4th a relative movement of the web material 1 to the print heads 14th provided in a second printing direction 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 14th thus creates a desired print image on the web material 1 upset.

Depending on the web material used 1 and the pressure medium used, it can be advantageous to use the web material 1 to bring to a certain temperature for printing. To this end, the printing table 3 according to the 2 a heater 15th on. By means of the heating device 15th becomes the supporting surface 13th of the printing table 3 brought to a predetermined temperature. This will do this on the support surface 13th arranged web material 1 heated to a printing temperature for printing.

The print head shuttle 5 further comprises a smoothing device. In the representations of the 1 and 2 the smoothing device is a brush 16 which extends along a longitudinal direction which is parallel to the advancing direction 4th runs. The brush 16 is like in the 2 shown, based on the direction of movement of the print head shuttle 5 on the side of the print head shuttle 5 arranged. The brush 16 is relative to the printhead shuttle 5 movable up and down between a first and a second position. In the first position the brush steps 16 with the supporting surface 13th in contact so that the brush 16 when the module moves 5 across the direction of feed 4th about that on the support surface 13th of the printing table 3 arranged web material 1 deletes. The brush is in the second position 16 so above the printing table 3 arranged that the brush 16 when the print head shuttle moves 5 neither the printing table 3 nor the web material 1 touched.

When printing is performed while the printing table is 3 is in the rear position by means of the vacuum device 11 a connection between the web material 1 and the support surface 13th educated. According to the 2 on the left side of the print head shuttle 5 arranged brush 16 while the printhead shuttle 5 is in a first module position in which the print head shuttle 5 and the brush 16 to the right of the printing table 3 are arranged, brought into the first position. During a subsequent first movement of the print head shuttle 5 over the printing table 3 and the web material 1 strokes the brush 16 over the web material 1 and thereby smooths wrinkles and / or bubbles in the web material 1 while making contact between the support surface 13th and the web material 1 and / or during the heating of the web material 1 by means of the heating device 15th may have arisen.

After the brush 16 across the entire width of the web material 1 moved the brush 16 brought into the second position. During subsequent movements of the print head shuttle 5 , while the printing table is moving 3 from the rear to the front position, the brush occurs 16 thus not in contact with the web material 1 . After loosening the web material 1 from the printing table 3 and the movement of the printing table 3 from the front to the rear position there is again a connection between the web material 1 and the support surface 13th trained and the brush 16 moved to the first position. Thus, after each contact is made with the support surface, the web material 13th of the printing table 3 during the first subsequent movement of the print head shuttle 5 over the web material 1 through the brush 16 smoothed.

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

Optionally, a capping station 17th be provided which a drying out of the print heads 14th prevented. When the printing device is not in use, the print head shuttle 5 moved into a position in which the print heads 14th through the capping station 17th are shielded from the environment and thus dry out the printheads 14th is prevented by evaporation of the solvent of the pressure medium. Furthermore, a pressure medium container can optionally be used 18th for cleaning and / or preparing the printheads 14th be provided for a printing process. The print head shuttle can be moved to a position in which the print heads move 14th above the pressure medium tank 18th are located. Then can from the print heads 14th Pressure medium in the pressure medium container 18th ejected around the the printheads 14th to free from impurities and / or pressure medium residues and / or to remove air from transport routes of the pressure medium in the print heads 14th remove.

Like in the 1 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 Drying facilities 19a , 19b arranged. By means of the drying devices 19a , 19b becomes the pressure medium on the web material 1 dried. For example, it can be with the drying devices 19a , 19b be hot air blowers and / or UV lamps. Different drying devices can be used 19a , 19b 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 design options according to the 3 in a different printing device than the printing device according to FIG 1 be provided. Along the path of movement of the web material 1 behind the second dancer 9b and the drying facilities 19a , 19b is a printed image checking device 20th arranged. The print inspection device 20th has an image pickup device 21st on, which is set up an image of the print image on the web material 1 record. In the print inspection device 20th becomes the recorded image of the printed image on the web material 1 compared with comparison image data, which can be, for example, print job data of a print job for printing the print image. If based on the comparison of the printed image on the web material 1 a correspondence between the print image and the comparison image data is determined with the comparison image data, the print image is determined to be a correct print image. If based on the comparison of the printed image on the web material 1 If no correspondence is found between the print image and the comparison image data using the comparison image data, the print image is determined to be an incorrect print image.

A correspondence between the print image and the comparison image data is established when the recorded image of the print image is on the web material 1 corresponds to the comparison image data within predetermined limits. Corresponds to the recorded image of the printed image on the web material 1 the comparison image data is not within the predetermined limits, no correspondence is found between the print image and the comparison image data. 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.

To support the movement of the web material 1 is along the path of movement of the web material 1 behind the testing device 21st a roller drive 22nd arranged. Behind the roller drive 22nd is another dancer 9c to control the web tension of the web material 1 arranged. The other dancer 9c can for example from the control device 10 can be controlled according to 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 the other dancer 9c drives.

Along the path of movement of the web material 1 behind the testing device 21st and the other dancer 9c is a finishing device 23 arranged, which is set up, the web material 1 to be assembled into individual sheets. For example, the web material 1 the finishing device 23 are fed and by means of a cutting device 24 the finishing device 23 cut to a predetermined sheet size to fit the web material 1 to be assembled into individual sheets. The individual sheets are then placed in a document switch 25 on different transport routes 26a , 26b steered. One way of transport 26a leads into a document holder 27 . Another way of transportation 26b leads into a reject bin 28 . Sheets that carry a print image that has been determined to be the correct print image are called document sheets 29 determined and by the document switch 25 on the transport route 26a into the document tray 27 leads. Sheets that carry a print image that has been determined to be an incorrect print image are called waste sheets 30th determined and by the document switch 25 on the transport route 26b directed into the reject bin 28 leads. In this way, print sheets which have errors in the print image can be sorted out. The print image of a waste sheet can then be reprinted 30th respectively.

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

It can be provided that the print image comprises several individual print images. In this case, each individual print image can be determined as a correct individual print image or 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 marking which identifies the individual print image as an incorrect individual print image. In this case the document switch 25 omitted and all the individual sheets can be transported over the transport route 26a the document tray 27 are fed.

Alternatively, the document switch 25 be provided and set up, print sheets with a print image which comprises a number of individual print images identified as incorrect individual print images, which exceeds a predetermined maximum number of incorrect individual print images, via the transport path 26b the reject bin 28 feed and other sheets over the transport route 26a the document tray 27 feed.

The 4th shows another printing device for printing on a printing substrate. In the embodiment according to 4th the printing device has two dancers 9a , 9b , but no third dancer. In this embodiment example comprises a roll unwinding module 40 the role 2 , the first web tension measuring roller 7a with the sensor device 8a , the first dancer 9a and the associated pulleys 6 . According to the embodiment shown, it comprises a printing module 41 the printing table 3 , the printhead shuttle 5 and the brush 16 . A drying module 42 comprises the second web tension measuring roller 7b with the sensor device 8b , the second dancer 9b who have favourited drying facilities 19a , 19b and the associated pulleys 6 . An image processing module 43 comprises the print image checking device with the image pickup device 21st and optionally the bad marking device 31 . The drying module 42 and the image processing module 43 can be combined to form a drying and image processing module. According to the 4th The embodiment shown includes a packaging module 44 the roller drive 22nd , the finishing device 23 with the cutting device 24 , the document switch 25 , the transport routes 26a , 26b , the document tray 27 as well as the reject bin 28 .

The features disclosed in the above description, the claims and the drawing can be of importance both individually and in any combination for the implementation of the various designs.

List of reference symbols

1

Railway material

2

role

3

Printing table

4th

Feed direction

5

Print head shuttle

6

Pulleys

7a, 7b

Web tension measuring roller

8a, 8b

Sensor device

9a, 9b, 9c

dancer

10

Control device

11

Vacuum device

12th

channels

13th

Support surface

14a, 14b

Print heads

15th

Heating device

16

brush

17th

Capping station

18th

Pressure medium tank

19a, 19b

Drying device

20th

Testing device

21st

Image capture device

22nd

Roller drive

23

Assembly device

24

Cutting device

25

Document switch

26a, 26b

Transport routes

27

Document tray

28

Reject bin

29

Document sheet

30th

Waste sheets

31

Bad marking device

40

Roll unwind module

41

Print module

42

Drying module

43

Image processing module

44

Assembly module

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102016102565 A1 [0003]
• DE 102016102566 A1 [0004]

Claims (13)

Device for printing a print substrate (1), with - A print head shuttle (5) with at least one print head (14a, 14b), which is set up to apply a printing medium to a print substrate (1) in order to generate a print image, the print substrate (1) being a web material which can be displaced along a web path , and the print head shuttle (5) is arranged on a first side of the print substrate (1); - A printing table (3), which is arranged opposite the print head shuttle (5) on a second side of the printing substrate (1), with a holding device (11) which is set up to hold the printing substrate (1) in such a way that for printing a relative movement between the printing table (3) and the printing substrate (1) is prevented; - a first web tension measuring device (7a, 8a) which is arranged along the web path in front of the printing table (3) and is set up to generate first measurement data which indicate a mechanical web tension of the printing substrate (1) on the first web tension measuring device; - A first tensioning device (9a) which is arranged along the web path in front of the printing table (3) and is set up 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 after the printing table (3) and is set up to generate second measurement data which indicate a mechanical web tension of the printing substrate (1) on the second web tension measuring device; - A second tensioning device (9b) which is arranged along the web path after the printing table (3) and is set up to set a mechanical web tension of the printing substrate (1); and - A control device (10) which is 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 (9a) in accordance with the first control data, in such a way that the first tensioning device (9a) applies a first predetermined web tension of the printing substrate (1) to the first tensioning device (9a) causes; and - to receive the second measurement data, to generate second control data based on the second measurement data and to control the second tensioning device (9b) in accordance with the second control data, in such a way that the second tensioning device applies a second predetermined web tension of the printing substrate (1) to the second tensioning device (9b) causes. Device according to Claim 1 , characterized in that the web material is a film material. Device according to Claim 1 or 2 , characterized in that the control device (10) is set up to keep the web tension of the printing substrate (1) constant along the web path in front of the printing table (3) during a printing process and the web tension of the printing substrate (1) along the web path behind the printing table ( 3) to keep constant. Device according to at least one of the preceding claims, characterized in that the control device (10) is set up to repeatedly receive first and second measurement data and to generate first and second control data during a printing process. Device according to at least one of the preceding claims, characterized in that the control device is set up - to generate at least the first or the second control data to compare the first or the second measurement data with the first or the second predetermined web tension and - to add first or second control data generate, which lead to a control of the first or the second clamping device corresponding in height and direction to the comparison result. Device according to at least one of the preceding claims, characterized in that the first predetermined web tension and the second predetermined web tension are the same. Device according to at least one of the preceding claims, characterized in that at least the first tensioning device (9a) or the second tensioning device (9b) is a tensioning roller which is at least partially wrapped around by the printing substrate (1) and which by means of a drive device along a transverse to A direction of movement extending along an axis of rotation of the tensioning roller is movable such that a movement of the tensioning roller in a first direction along the drive direction extends the web path in order to increase the mechanical web tension of the printing substrate (1) and a movement of the tensioning roller in a second direction opposite to the first direction Direction along the drive direction shortens the web path in order to reduce the mechanical web tension of the printing substrate (1). Device according to at least one of the preceding claims, characterized in that at least the first web tension measuring device (7a, 8a) or the second web tension measuring device (7b, 8b) is a web tension measuring roller around which the printing substrate (1) is at least partially wrapped, such that the Web tension of the printing substrate (1) is a transverse force perpendicular to an axis of rotation Caused web tension measuring roller, wherein the web tension measuring roller has a force measuring device for measuring the transverse force. Device according to at least one of the preceding claims, characterized in that the holding device (11) comprises a vacuum device which sucks the printing substrate (1) onto the printing table (3) by means of a vacuum. Device according to at least one of the preceding claims, characterized in that the holding device (11) is set up to hold the printing substrate (1) during a feed movement of the printing substrate (1), such that a relative movement between the printing table (3) and the printing substrate (1) is prevented during the feed movement. Device according to at least one of the preceding claims, characterized in that the printing table (3) is set up to perform a feed movement while the holding device (11) holds the print substrate (1) in such a way that the feed movement is transferred to the print substrate (1) . Device according to at least one of the preceding claims, characterized by a separation device, comprising: - a test device (20) with an image recording device (21) which is set up, - recording an image of the print image on the web material, - the recorded image of the print image on the To compare web material with comparison image data, - to determine the print image as a correct print image if a correspondence between the print image and the comparison image data is determined based on the comparison of the print image on the web material with the comparison image data, and - the print image as to determine an incorrect print image if no correspondence is found between the print image and the comparison image data on the basis of the comparison of the print image on the web material with the comparison image data; - A converting device (23) which is set up to convert the web material into individual sheets; and - a document switch (25) which is set up 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 was determined to be a correct print image , is directed onto the first transport path (26a) and - a made-up sheet with a print image, which was determined to be an incorrect print image, is directed onto the second transport path (26b). A method for printing on a printing substrate (1), comprising: - Applying a printing medium to a printing substrate (1), which is a web material which is displaceable along a web path, with at least one print head of a print head shuttle (5), which is arranged on a first side of the print substrate (1), for generating a Print image; - Holding the printing substrate (1), with 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 way that a relative movement between the printing table for printing (3) and the printing substrate (1) is prevented; - Generation of first measurement data with a first web tension measuring device (7a, 8a), which is arranged along the web path in front of the printing table (3), the first measurement data indicating a mechanical web tension of the printing substrate (1) on the first web tension measuring device (7a, 8a) ; - Receiving the first measurement data in a control device (10); - Generating first control data on the basis of the first measurement data in the control device (10); - Control of a first tensioning device (9a) which is arranged along the web path in front of the printing table (3) and is set up to change a mechanical web tension of the printing substrate (1), in accordance with the first control data, such that the first tensioning device (9a) has a first predetermined web tension of the printing substrate (1) is effected on the first tensioning device (9a); - Generating second measurement data with a second web tension measuring device (7b, 8b), which is arranged along the web path after the printing table (3), the second measurement data indicating a mechanical web tension of the printing substrate (1) on the second web tension measuring device (7b, 8b) ; - Receiving the second measurement data in the control device (10); - Generating second control data on the basis of the second measurement data in the control device (10); and - Control of a second tensioning device (9b), which is arranged along the web path behind the printing table (3) and is set up to change a mechanical web tension of the printing substrate (1), according to the second control data, such that the second tensioning device (9b) has a causes a second predetermined web tension of the printing substrate (1) on the second tensioning device (9b).

Images