EP3153319B1 - Method for controlling the web position - Google Patents

Description

The invention relates to a method and to a printing press for carrying out the method in which the printing material web is brought to a predetermined lateral position before a first printing location by means of an adjusting device and wherein at least one web edge is detected by means of a sensor for controlling the lateral position of the printing material web.

In the case of printing machines which print web-like substrates, it is necessary for the printing substrate web to be brought into a correct lateral position for printing in order to arrange the printed image in the desired position on the printing substrate web before the printing process. This is necessary because deviations over the diameter range can result from the winding of the printing material roll; in some cases, the printing material web also changes the lateral running behavior when it is fed to the printing units under a voltage required for printing. These fluctuations usually vary over a role and are due to variations in the production of the printing material and when winding this on the rollers. In particular, the substrate paper such fluctuations are relatively common.

In this respect, the printing material web is brought by an adjusting device in the desired lateral position after the unwinding of the printing substrate from the Bedruckstoffrolle by an unwinder and kept constant by a control in this lateral position. For the sake of completeness, it should be mentioned that the lateral position lies in the plane spanned by the printing substrate and can be seen at right angles to the web running direction.

Such adjustment are, for example, web control, as this example, from the EP0086270 A1 are known or the adjustment of the web via an adjustment of the entire Bedruckstoffrolle by adjusting the Support arms or clamping cones of the unwinder. The associated control operations are from the prior art such as from the EP0086270 A1 known.

Subsequent to the unwinding operation, the printing material web is printed with at least one printing device at least on one side with at least one printing ink, in which case non-printing form-variable printing processes such as offset printing, gravure printing, flexographic printing or, for example, a screen printing process or printing form variable printing processes such as, for example, the inkjet printing process or toner-based printing processes can be used.

In particular, in the case of multicolored printing of the web, the printed image of the printed printing material web is detected after the at least one printing device by means of one or more sensors in order to change and regulate the parameters influencing the print image so that the printed image meets the required quality criteria. Thus, to ensure the color register, the positions of the individual printing inks and thus of the printing forms are regulated relative to each other. In the color density control, which may require another additional sensor, the color is controlled in such a way that the tonal values of the individual process colors reach the desired value and are kept constant over the production.

The at least one printed substrate web is then for further processing, for example, a folding structure with Längsfalzeinrichtungen and a downstream folding unit, with which the web separated into individual signatures and usually folded, supplied. It is also possible to rewind the printed web, for example.

However, only solutions are known from the prior art, which use separated and usually different from each other sensors for controlling the position of the web by means of an adjustment as well as to control the image values. Thus, especially in multi-lane machines, a very high number of sensors is used.

From the WO 2005/007406 A2 a method is known in which by means of a sensor marks are detected, wherein the detected by a sensor marks a plurality of printed image related to the printing parameters such as color register, diagonal register or fan-out effect can be controlled.

The US 2004/0051061 A1 discloses a method in which, based on detected marks, a plurality of functions can be regulated both with regard to the printed image and the web or strand guidance.

Also from the EP 2 481 585 A1 For example, a method is known in which parameters of a printing machine are regulated by the detection of coded or uncoded marks.

This high number of mostly different sensors for the regulation of the lateral position of the printing substrate and the control of the printed image means on the one hand high investment costs, also there is a high maintenance effort for cleaning and, if necessary, no longer fully functional sensors. In addition, the high number as well as the large number of different built-in sensors makes it difficult to maintain spare parts or binds appropriate means with sufficient stockpiling.

The invention is therefore based on the object to provide a solution with which the number and / or the variety of required sensors can be reduced within a printing press.

This object is achieved by a method according to claim 1 and by a printing machine according to claim 11. The inventive method and the printing machine according to the invention comprises that the sensor for detecting the lateral position of at least one web edge and at least a portion of a printed image, for controlling or regulating the color register and / or the color density and / or the fan-out effect by means of a each associated with the sensor and the adjusting device computing device is detected.

Such a configuration of a printing press has the advantage that the reduced cost of such a printing press can be reduced by the reduced number of sensors installed. Furthermore, the operating costs can be reduced because less effort for the maintenance of the sensors is required.

Furthermore, the expenses for the operator with regard to spare parts stocking are reduced. Although modern sensors, which are usually designed as CCD cameras, a very high operating life and reliability, but especially in systems with many tracks and / or an extremely high required reliability of the systems, as required especially in newspaper printing systems, are in usually stores such sensors as spare parts, thus can be reduced by the present invention, the effort and funds commitment for spare parts inventory.

Since the probability of failure and the error rate generally increases in principle with increasing number of components installed, a higher failure-related availability is also to be assumed due to the smaller number of sensors installed in a printing press according to the invention.

According to a further advantageous embodiment of the invention comes as a sensor camera for the color register control or at least one camera color density control used, but it can also cameras for fan-out control or to capture the print image in so-called inline inspection facilities or other sensors Detecting at least parts of the printed image are used. If a plurality of control loops for controlling various parameters of the print image, such as, for example, the color register or the color density, can be detected with one sensor, then this combined sensor can also be used to detect at least one web edge.

In this case, it is insignificant whether the at least one sensor is embodied as a sensor traversing the web width of the printing material web or as a sensor with a fixed position relative to the printing material web during the detection of the printed image and at least one web edge. In this case, it is only necessary to consider that traversing sensors can not permanently detect a web edge over the web width, so that in this case the position of the web edge is detected only periodically and the position of the web edge can be used to control it. This is due to the fact that a sensor for detecting the printed image for controlling parameters thereof can usually only detect a partial area of the web width. Only in printing machines with a very narrow web width can the entire web width be detected with sufficiently high resolution with one sensor.

Since thus only a partial area of the printing material web and thus of the printed image can thus be detected in the case of sensors having a fixed position during the detection of the printed image and at least one web edge fixed position, in particular in printing presses with a very large web width such as offset or gravure printing machines with only one camera, this is the case possible to detect the web edge to control the lateral position of the substrate web to use a sensor with which the complete web width is detected. Such sensors are usually or in particular in printing presses with a large web width of a plurality of extending in the extension of the web width side by side cameras.

The lateral position of the printing material web can be done either via the definition or regulation of two not directly detectable variables such as the center line of the printing material to the center line of the printing press, but advantageously for this unique and immediately determinable variables such as the location of at least one web edge to another fixed defined reference variable such as the center axis of the printing press or the inner surface of a side wall of a component of the printing press such as a printing device used. Thus, the absolute position of at least one web edge can be used to control the lateral position of the printing material as a controlled variable. This can be determined in absolute terms insofar as the position of the corresponding sensor during detection of the corresponding web edge is known either with respect to the center line of the printing press or with respect to another preferably unchangeable reference point of the printing press such as to an inner surface of the side wall of a printing device, so that by means of the detected deviation of the web edge from the target value of the position of the web edge at any time of the detection of the web edge, the absolute position of this web edge can be determined.

However, it is also possible for the position of at least one web edge to be detected and evaluated relative to a defined print mark to regulate the lateral position of the printing material web. Thus, for example, in the first printing device, a mark, which alternatively can also be used for other purposes such as, for example, the color register or the cut register control, are also printed. On account of the known position of the printing form printing this mark, a reference of the respective web edge to the printing form and thus to the printed image can thus be produced and the position of the printing material edge can be determined for the printed image. As very common in the generation of a Printed product, the position of the printed image to the web edge of importance, this approach may have an advantage over the aforementioned variant, since thus the taking into account the position of the printing plate and thus the print image to a defined reference point of the printing machine is not required.

As already explained, both web edges can also be detected with one or a plurality of sensors. Since, however, the width of the printing material can vary, which is due, for example, to manufacturing tolerances in the production of Bedruckstoffrollen in varying moisture of the substrate and thus different broadening especially papery substrates or in different behavior during the printing associated Auswalkens the printing material, It may thus come to deviations of the actual position of at least one web edge to the desired position of this web edge.

However, in order to be able to take into account and also to evaluate the possibly occurring fluctuations of the web width in the regulation of the lateral position of the printing material web, the average value of the position of both web edges for controlling the lateral position of the printing material web is preferably used when detecting the position of both web edges of the printing substrate web. This reliably prevents the difference in the web width change from becoming noticeable when the web width is changed, and only when the web edge is in the position to the printed image. Track width variations can thus be averaged out so far that ultimately the position of the print image is averaged out to both web edges.

Particularly when the printing material web is arranged fixedly and also when traversing across the web width, it is possible for the at least one sensor to detect at least one web edge and at least one part of the printed image simultaneously. In the case of a sensor which, for example, consists of a plurality of cameras arranged side by side in the extension of the web width and thus detects the entire web width, it is self-evident that both the print image and at least one web edge are recorded continuously and simultaneously.

Such a solution has the advantage that both at least always a part of the printed image and at least one web edge permanently detected and thus can be permanently and continuously controlled.

But even when traversing across the web width sensors, it is possible as a different alternative that not at least a portion of the printed image and a web edge are detected simultaneously. This is the case in particular if the distance of the printed image to at least one web edge is greater than the detection range of the sensor. In this case, at least one web edge and at least part of the print image are detected alternately by the sensor. Although this ensures no continuous detection of at least the at least one web edge, but is usually sufficient for a regulation of the position of the web edge and thus the regulation of the lateral position of the printing material, as very fast, high-frequency changes the lateral position of the printing material, such as this a so-called tumbling roll caused, can not be corrected by the adjustment above running, so that for the adjustment as a Tragarmverstellung or a web control and discontinuous detection of the controlled variable may be sufficient in principle.

Fig. 1:

Eine Druckmaschine gemäß dem Stand der Technik

Fig. 2:

Dieselbe Druckmaschine der Fig. 1 zur Durchführung des erfindungsgemäßen Verfahrens

Fig. 3:

Eine Draufsicht auf die bedruckte Bedruckstoffbahn bei einer teilweisen Erfassung der Bedruckstoffbahn durch einen Sensor

Fig. 4:

Eine Draufsicht auf die bedruckte Bedruckstoffbahn bei einer vollständigen Erfassung der Bedruckstoffbahn durch einen Sensor

Preferred embodiments of the invention will become apparent from the dependent claims and the description below. Various embodiments of the invention will be described, without being limited thereto, with reference to the drawings. Showing:

Fig. 1:

A printing press according to the prior art

Fig. 2:

The same press of the Fig. 1 for carrying out the method according to the invention

3:

A top view of the printed substrate web at a partial detection of the substrate web by a sensor

4:

A top view of the printed substrate web at a complete detection of the substrate web by a sensor

Fig. 1 shows an embodiment of a printing press 1 with a vertical guidance of the printing material web 2 in the area of the printing devices 7 formed as an offset printing unit according to the prior art. It should be noted, however, that any other embodiment of a printing press, for example, with horizontal web guide or with other than offset printing units running printing devices 7 than in Fig. 1 represented, executed according to the illustrated prior art or is executable. In this respect, the prior art is only at the in Fig. 1 described offset-newspaper printing device described, although this principle applies to other configurations.

The printing material web 2 is unrolled from printing material rolls 5, the printing material roll 5 being held in an unwinder 4 for this purpose. As unwinder 4 so-called reel changers or only dispensers can be executed.

After the unwinder 4 or else integrated into the unwinder 4 and after the unrolling of the printing material web 2 from the printing material roll 5, an adjusting device 6 is arranged, with which the printing material web 2 can be deflected in a direction perpendicular to the web running direction 3. Such adjusting 6 may be designed as a so-called web control or be carried out by adjusting the Bedruckstoffrolle 5 by the support arms or by the Tragkonen.

After the adjusting device 6, a first sensor 10-1 is arranged, with which at least one web edge 22 of the printing material web 2 is detected. This first sensor 10-1 detects the actual lateral position mostly a web edge 22 of the substrate web, which serves as a controlled variable for controlling the lateral position of the printing material web. This controlled variable is passed via a data line to a computing device 11, a manipulated algorithm from which the manipulated variable for the adjusting device 6 is determined, which is also passed via a data line 12 to the adjusting device 6 and executed there.

Subsequently, the printing material web 2 is printed in at least one printing device 7 at least on one side of the web at least on one side. In the in Fig. 1 illustrated variant, the substrate web 2 is printed on both sides with four inks in the offset printing process.

The printed image 21 of the printed material web 2 thus printed is detected after printing by means of at least one second sensor 10-2. This second sensor 10-2 detects either the printed image 21 printed directly or only special areas of which are designed as pressure control elements 21-1.

In this case, at least one parameter which identifies or influences the printed image 21 is detected by the sensor 10-2. The second sensor 10-2 detects, for example, the color register, ie the arrangement of the individual printing colors relative to one another, hue values such as color density values or the widening of the printed image, the so-called fan-out effect.

Subsequently, the printing material web along the web running direction 3 subsequent components such as the associated Falzaufbau the former 8 and a downstream folding unit 9 is fed and divided there into individual signatures. Since the further processing and post-processing of the printing material web is irrelevant to the method according to the invention, it is unequivocal whether rewinders or other devices are used here.

Fig. 1 shows a multi-lane printing machine 1, wherein at the same time several printing material webs 2 are printed, for example, two printing material webs 2 as in Fig. 1 shown. Thus, according to the number of printing material webs 2, corresponding equipment such as unwinder 4, adjusting devices 6, first sensors 10-1, first computing devices 11-1, printing devices 7, second sensors 10-2, second computing devices 11-2 and other devices, for example to guide the printing material 2 required or suitable, are used.

Thus, it follows that, in particular in the case of multi-track machines, the separate components such as sensors and computing devices for the separate detection and / or regulation of the lateral position of the printing material web 2 and the parameters of the printed image 21 are multiplied by the complexity thereof.

Fig. 2 shows the same printing machine 1 as in Fig. 1 illustrated, however, in one embodiment according to an embodiment of the invention, which is why below only the differences between the in Fig. 2 illustrated printing machine 1 according to an embodiment of the invention and in Fig. 1 shown printing machine 1 according to the prior art.

Thus, in the printing machine 1 of the invention Fig. 2 between the adjusting device 6 and the printing device 7 no longer required a first sensor, the detection of at least one web edge 22 with the same sensor 10, which is arranged after the at least one printing device 7 and thus both the lateral position of at least one web edge 22 and at least a part the print image 21 is detected for controlling or regulating pressure parameters.

Thus, the value of the lateral position of the printing material web 2 as a control variable to the same computing device 11 as the detected pressure parameters for controlling the parameters and properties of the printed image 21 via a data line 12 are passed. The control commands for regulating the lateral position of the printing material web 2, which are calculated by the preferably required computing device 11 for this purpose, are guided to the adjusting device 6 via a data line 12.

The sensor 10 is used in addition to the detection of the web edge 22, for example, for detecting the color register or for detecting the color value such as the color density of the individual process colors. In the case of combination devices for the simultaneous detection of color registers and color values, the position of the web edge 22 can then also be effected with the same sensor 10 as an additional variable.

The sensor 10 can be embodied as a sensor traversing the web width and thus approximately perpendicular to the web running direction 3. Since a traversal of the sensor 10 is usually only required if not the entire print image 21 can be detected at once with the sensor 10, it is thus very probable that the sensor 10 at least a part of the print image 21 and at least one web edge 22 alternating and not permanently recorded.

However, it is possible with very large web widths to arrange a plurality of traversing sensors 10 over the web width in order to ensure shorter control cycles, in particular for the parameters of the print image 21. In such a case, at least one web edge 22 and at least part of the print image 21 are then continuously detected even with at least one traversing sensor 10. Continuous detection of a web edge 22 has the advantage of a higher control accuracy than an interrupted, non-permanent detection of the position of a web edge 22.

Due to this advantage, at least one sensor 10 can also be executed at a fixed position relative to the printing material web during the detection of the printed image 21 and at least one web edge 22. When changing the web width of the printing substrate 2 of at least one corresponding sensor 10 is moved in the form perpendicular to the web running direction 3, that this can always detect the web edge 22. The displacement can be carried out manually, motorically or presettable to the respective web width.

The at least one sensor 10 can thus either capture only a partial area of the web width, or else the sensor 10 is designed in such a way that the entire web width can be detected simultaneously. Such sensors 10 extending over the web width consist, for example, of cameras arranged side by side in the extension of the web width, preferably CCD cameras, which are interconnected in the form that they represent a detection area.

The lateral position of the printing material web 2 can take place either via the definition or regulation of two variables which can not be directly detected, for example the center line of the printing material web 2 to the center line of the printing press 1, Advantageously, however, clearly determinable variables such as the position of at least one web edge 22 to another fixed reference such as the center axis of the printing machine 1 or the inner surface of a side wall of a component of the printing machine 1 such as a printing device 7 are used. Thus, the absolute position of at least one web edge 22 can be used to control the lateral position of the printing material web 2 as a controlled variable. This can be absolutely determined insofar as the position of the corresponding sensor 10 during the detection of the corresponding web edge either with respect to the center line of the printing machine 1 or with respect to another preferably fixed reference point of the printing press 1 such as to an inner surface of the side wall of a printing device 7 is known, so that thus by means of the detected deviation of the web edge 22 from the desired value of the position of the web edge 22 at any time of detection of the web edge 22, the absolute position of this web edge 22 can be determined.

However, it is also possible that the position of at least one web edge 22 is detected and evaluated relative to a defined print mark for the regulation of the lateral position of the printing substrate 2. Thus, for example, in the first printing device 7, a mark may be printed as part of a print control element 21-1, which may alternatively also be used for other purposes such as, for example, the color register or the cut register control. On account of the known position of the printing form printing this mark, a reference of the respective web edge 22 to the printing form and thus to the printed image 21 can thus be produced and the position of the printing material edge 22 to the printed image 21 can be determined. Since the position of the printed image 21 to the web edge 22 is very important in the production of a printed product, this approach may have an advantage over the aforementioned variant, since thus taking into account the position of the printing plate and thus the printed image 21 to a defined reference point of the printing press 1 is not required.

As already explained, both web edges 22 can be detected with one or a plurality of sensors 10. However, since the width of the Substrate may vary, which is for example due to manufacturing tolerances in the production of Bedruckstoffrollen 5, in varying humidity of the substrate and thus different broadening especially papery substrates or in different behavior during the printing associated Auswalkens the printing material, it may thus Deviations of the actual position of at least one web edge 22 come to the desired position of this web edge 22.

However, in order to be able to take into account and also to evaluate the possibly occurring fluctuations of the web width in the regulation of the lateral position of the printing material web 2, the average value of the position of both web edges 22 for controlling the lateral position of the printing substrate web is preferably determined when the position of both web edges 22 of the printing substrate web is detected used. This reliably prevents the difference of the web width change from this amount being noticeable when the web width changes in the position for print image 21 only at a web edge 22. Track width variations can thus be averaged out so far that ultimately the position of the print image is averaged out to both web edges.

Fig. 3 shows a plan view of the substrate web 2, which is detected by a sensor 10 and the detection range 20 of the sensor 10. As Fig. 3 can be seen, the sensor 10 detects with its detection area 20 both a web edge 22 and a part of the printed image 21. As in Fig. 3 1, a print control element 21-1 is a special part of the print image 21, since it is printed together with the print image 21 with the printing device 7 and the printing form variable or printing form variable printing form.

In this pressure control element 21-1 are preferably both the fields and marks for detecting the printing parameters and possibly the marks for detecting the distance between the web edge 22 and printed image 21 included since the pressure control element 21-1 usually removed before completion of the finished printed product by trimming becomes. How out Fig. 3 can be seen, in the example shown, the sensor 10 must traverse about perpendicular to the web running direction 3 on the printing substrate 2 to the entire Print control element 21-1 and / or to capture the entire print image 21. In principle, therefore, both web edges 22 can be detected by the detection area, although not continuously.

Fig. 4 shows an example of a sensor 10, which has a detection area 20 which extends over the entire width of the printing material 2. Thus, the entire pressure control element 21-1 as well as one or both web edges 22 can be detected simultaneously, which leads to a higher control accuracy and control dynamics.

LIST OF REFERENCE NUMBERS

1

press

2

printing material

3

Web direction

4

liquidator

5

printing material

6

adjustment

7

print Setup

8th

formers

9

folding

10

sensor

11

computing device

12

data line

20

detection range

21

print image

21-1

Pressure control element

22

web edge

Claims (11)

1. A method for controlling a lateral position of a printing material web (2), wherein the printing material web (2) is brought to a specified lateral position by means of an adjusting device (6) upstream of a first print position and wherein at least one web edge (22) is detected by means of at least one sensor (10) for controlling the lateral position of the printing material web (2), wherein at least a portion of a print image (21) can also be detected by means of the sensor (10) for detecting the lateral position of at least one web edge (22), in order to monitor or control the color register and/or the color density and/or the fan-out-effect by means of a computing device (11), which is in each case connected to the sensor (10) and to the adjusting device (6).
2. The method according to claim 1, characterized in that the at least one sensor (10) is embodied as at least one sensor, which traverses across the web width.
3. The method according to claim 1, characterized in that the at least one sensor (10) is embodied as a sensor (10) with fixed position to the printing material web (2) during the detection of the print image (21) and at least one web edge (22).
4. The method according to one of claims 2 and 3, characterized in that at least a partial area of the web width is detected by means of the sensor (10).
5. The method according to claim 3, characterized in that the complete web width is detected by means of the sensor (10).
6. The method according to one of claims 1 to 5, characterized in that the detected deviation of the web edge (22) from the setpoint value of the position of the web edge (22) of at least one web edge (22) is detected and evaluated for controlling the lateral position of the printing material web (2).
7. The method according to one of claims 1 to 5, characterized in that the position of at least one web edge (22) relative to a defined printing mark is detected and evaluated for controlling the lateral position of the printing material web (2).
8. The method according to one of claims 1 to 7, characterized in that to consider the web width, the average value of the position of both web edges (22) is detected to control the lateral position of the printing material web (2) in response to the detection of both web edges (22) of the printing material web (2).
9. The method according to one of claims 1 to 8, characterized in that at least one web edge (22) and at least a portion of the print image (21) is detected continuously by means of at least one sensor (10).
10. The method according to one of claims 1 to 8, characterized in that at least one web edge (22) and at least a portion of the print image (21) is alternately detected by means of the sensor (10).
11. A printing press (1), by means of which the lateral position of a printing material web (2) can be controlled, wherein the printing material web (2) is brought to a specified lateral position by means of an adjusting device (6) upstream of a first printing device (7), and wherein at least one sensor (10) detects at least one web edge (22) for controlling the lateral position of the printing material web (2), wherein the sensor (10) also detects at least a portion of a print image (21) for detecting the lateral position of at least one web edge (22), in order to monitor or control the color register and/or the color density and/or the fan-out-effect by means of a computing device (11), which is in each case connected to the sensor (10) and to the adjusting device (6).

Images