EP1155844A2 - Method and device for adjusting the register in a multicolour printing machine - Google Patents

Abstract

The method involves controlling the generation and combination of part color images for register setting so that printing occurs that maintains the register. When a change in toner profile occurs the influence of the toner profile on the register is taken into account directly on implementing the change using existing influencing parameters. Independent claims are also included for the following: an arrangement for implementing the method.

Description

The invention relates to a method for setting the register in a multi-color printing press with several devices for the digital generation of partial color images, whereby the creation and assembly of the Partial color images are controlled so that register-based prints are achieved.

The invention further relates to a device for carrying out the method a multi-color printing machine with several devices for digital generation of partial color images, with at least one controller for achieving register-based Print a register setting that creates and merges the part color images is controlled.

The printing of colored representations, in particular colored images, takes place in that several partial color images are printed on top of each other. These are usually the ones Colors yellow, magenta and cyan as well as black. Special colors are also available if required added. By printing these colors on top of each other you can create all color combinations achieve, the quality of the prints significantly from the register Overprinting the partial color images depends. In digital, for example electrostatic printing is the registration of the overprint achieved by controlling the imaging devices such that the Partial color images in register with each other when transferred to a printing substrate to meet.

A method and a device of the type mentioned at the outset is known from US Pat. No. 5,715. 498 known. There is a correction of register errors by printing and Registration of registration marks proposed. The disadvantage of this technical solution is that when the toner profile is changed by changing the print page a countermeasure is only possible for the following page, because the effect the change in an influencing variable is only recorded when it already has one Has caused register errors. This means that test prints are necessary and time is of the essence lost, which is often uneconomical and therefore unacceptable for short runs. The printing of individual, different printed pages is economical in this way not possible.

The invention is therefore based on the object of a method and a device of the type mentioned in such a way that a change in the toner profile no longer, not even temporarily, due to a change of printed pages leads to a register error.

The object is achieved according to the invention in that a change in the toner profile, the influence of the toner profile on the register by means of existing influencing factors are taken into account immediately when the change is carried out becomes.

The object is achieved according to the invention in that the at least one controller is designed such that it changes the toner profile the influence of the toner profile on the register by means of existing influencing variables taken into account immediately with the implementation of the change.

The advantage of the invention is that when the toner profile is changed a change of print page an impending register error without any Delay is counteracted. There is no longer any need to wait for that to happen changed toner profile in a register error detectable with the help of register marks precipitates, but it is possible that immediately with the print page change counteracted and thus the occurrence of a register error from the outset is prevented, so that test prints of prints and / or registration marks in the Are usually not required. This is economically viable especially for short runs Significance because machine time and often also printing substrates are saved. It is only in relation to the printing of printed pages with changing content possible in this important application area of printing presses with digital To achieve an unprecedented quality standard.

The measure according to the invention enables a register setting of a known type to be optimized so that they do not go first when the toner profile changes "gets out of hand" to be corrected afterwards, but the Register setting remains in the range of tolerable fluctuations, so that at one Change of the toner profile can be continued without interruption. The invention does not exclude the additional consideration of other influencing factors, as far as these have an influence on the register.

A further development of the method provides that as a result of a register correction a change in the toner profile the retroactive influence of the toner profile of the previous one but still in the printing process printed pages on the register of new print page already in the printing process is taken into account. To this The registers of the prints are different when changing the print page with another Image content guaranteed even better. The press can run without any interruption continue printing even if two partial color images are created the print page change takes place in such a way that the new partial color image already is created while the previous partial color image of the previous print page is not yet or has not yet been completely transferred to the print substrate. The registration is therefore also to a large extent in this area of overlap between two printed pages guaranteed and any mutual interference is compensated. This will the cost-effectiveness increased significantly and a printing of printed pages alternating High quality content is possible. With regard to the device, this will achieved that the at least one controller is designed such that it at a Register correction due to a change in the toner profile the retroactive influence the toner profile of the previous one but still in the printing process Print pages on the register of the new print page already in the printing process considered.

Because the printing page change from one printing unit to the next through the machine runs and also within a printing unit on the way from generation to Transfer to the printing substrate is running through the printing unit, these must different machine constellations by means of variable influencing factors for each Printing unit are taken into account.

The influencing variables of the toner profiles can be taken into account on the basis of stored Empirical values, through manual input, through the evaluation of digital image data or by automatically recording the toner profiles. Regarding the The device can be provided with at least one memory is the stored empirical values of influencing variables of different toner profiles contains, the at least one controller based on these empirical values controls the creation and assembly of the part color images. However, it is also possible to equip the device with an input device via which the factors influencing various toner profiles can be activated manually. Another alternative is to provide a press control is the stored data from printed pages or the data from several print jobs contains and the consideration of the influencing variables of different toner profiles based on this data. Also a device for automatic recording of the Influencing variables of different toner profiles are possible.

An expedient embodiment of the method provides that the influencing variables different toner profiles according to the extent of the surface coverage of the Total image area by which partial color images are determined. That way it is not necessary to measure the influencing variables again for each printed page, but it is sufficient to measure the area coverage of the entire image area for each partial color image to determine and from this data the influencing variables for all printing units either to calculate or to determine from a prepared tabular file. With regard to the device, it is then provided that the device for determination the influencing variables the toner profiles according to the extent of the surface coverage of the Total image area captured by the sub-color images. It can be provided that the device for recording the influencing variables from the digital image data is designed is. In order to reduce the computing effort, it can be provided that the Evaluation of the digital image data combined areas of several image pixels become.

In essence, the invention has the purpose of correcting an intended one To serve register regulation. The latter can be designed such that it is on the detection is based on register marks, which are printed by the individual printing units become. The invention provides that this correction takes place before a Changing the toner profile can affect the register marks. The device must then be designed in such a way that the at least one controller is designed in this way is that it registers by means of detection of register marks which of printed in the individual printing units and detected by a register sensor and the influencing variables of the toner profiles are taken into account as correction factors, the Correction is made before a change in the toner profile affects the register can.

However, the invention can also be used to correct a register regulation based on the detection of the positions of the part-color image and substrate-carrying elements. With regard to the device, it is then provided that the at least one controller is designed so that it registers by detecting the positions of the Part color image and substrate-carrying elements through position detection elements regulates and takes into account the influencing variables of the toner profiles as correction factors. At The position detection elements can be, for example, rotary angle sensors act.

Of course, it can be provided that other influencing variables that influence the Registers are taken into account when setting the register. It can be for example, paper types, paper thicknesses or other influencing factors. With regard to the device, at least one controller must then be provided is designed to take these other influencing factors into account.

The invention is described below with reference to an embodiment shown in the figure explained.

A multi-color printing press 1 with two printing units 8, 8 'is shown. This is a simplification, normally there are four or more printing units 8, 8 ', ... These have to be considered.

The multicolor printing machine 1 has devices 2, 2 ', ... for digital generation of partial color images 3, 3 '... on image cylinders 9, 9', ... on. Using these facilities 2, 2 ', ... a new image is created for each print, resulting in a new image Such machine is suitable for prints in which the image content and thus the Changes the toner profile from one page to the next. This is the main area of application for the Invention.

Each printing unit 8, 8 ', ... has an image cylinder 9, 9', ... and an image transfer cylinder 10, 10 ', ..., the latter the partial color images 3, 3', ... on the Transfer printing substrates 16. These are in the direction of arrow 29 by one Print substrate carrier 11 transported by the printing press 1. So that the partial color images 3, 3 ', ... are generated by the devices 2, 2', ... in such a way that they are in register are transferred to the printing substrates 16, controls 12, 12 ', ... provided which control the devices 2, 2 ', ... such that picture starts, lines or areas of the partial color images 3, 3 ', ... are coordinated with one another.

Such controls 12, 12 ', ... can be designed so that each printing unit 8, 8 ', ... prints a register mark 7, 7', ... and these register marks 7, 7 ', ... from one Register sensor 18 can be detected. The evaluation of the position of the register marks 7, 7 ', ... then results in the assignment of the partial color images 3, 3 ', ... and it can in the event of deviations such a correction is made that the partial color images 3, 3 ', ... are transferred in register to the printing substrates 16.

Another possibility is that the image cylinders 9, 9 ', ... and if necessary also the image transfer cylinders 10, 10 ', ... with position detection elements 19, e.g. B. are equipped with rotary encoders. Another rotary encoder 19 is provided on the drive roller 23 of the printing substrate carrier 11. By means of these position detection elements 19, the positions of the cylinders 9, 9 ', ...; 10, 10 ', ... and the print substrate carrier 11 assign to each other and it is possible, position shifts to record and correct, so that a register accurate print can be done.

It is true that both the detection of the register marks 7, 7 ', ... and the Position detection a change in the register due to a change in the toner profiles record and correct, but this has the disadvantage that the impact of Changes in the influencing variables 4, 4 ', ... of various toner profiles have already occurred must be in order to be able to grasp and correct them. However, this is an ongoing one Further printing between a previous print page 5 and a new print page 5 'with different image content and therefore different toner profile not possible.

Therefore, the invention provides that the at least one controller 12, 12 ', ... such is designed so that with the help of existing influencing variables 4, 4 ', ... of toner profiles their influence on the register is taken into account immediately.

One possibility of taking into account influencing variables 4, 4 ', ... different Toner profiles consist in that on an input device 14 data from printed pages 5, 5 'can be entered, which are connected via a connection 26 from the input device 14 are forwarded to the controls 12, 12 ', ..., the controls 12, 12', ... based on this data on the printed pages 5, 5 ', ... stored empirical values 6, 6', ... for different toner profiles from memories 13, 13 ', ... and thereby the Get influencing variables 4, 4 ', ... of the same, which are controlled by the controls 12, 12', ... without delay. In this way, the devices 2, 2 ', ... capable of digitally generating partial color images 3, 3', ... without interruption to be made in register.

Experience values 6, 6 ', ... for different toner profiles from the Extent of the total area of an image 24 covered by the individual Partial color images 3, 3 ', ... can be determined. These empirical values 6, 6 ', ... and / or Data for the individual partial color images 3, 3 ', ... for calculating the influencing variables 4, 4 ', ... for the individual printing units 8, 8', ... can be stored in the memories 13, 13 ', ... be filed. To reduce the amount of data regarding the combinations of Individual controls covering the partial color images 3, 3 ', ... can be used by the controls 12, 12 ', ... carry out the necessary calculations. The latter is above all advantageous if the retroactive influence of a previous print page 5 on the subsequent print page 5 'should be taken into account or if - was for simplification is not shown - the retroactive influence of previous printed pages on the following printed pages should be taken into account. This is illustrated by that the image cylinder 9 through the device 2 already with the partial color image 3rd the new print page 5 'is imaged, while on the other image cylinder 9' Partial color image 3, 3 ', ... of the previous print page 5 is processed. Know that Partial color image 3 of the new print page 5 'a different area coverage of the toner application on, as the partial color image 3 of the previous print page 5, so determined the latter the coefficient of friction between the image cylinder 9 and the image transfer cylinder 10. This must be done when imaging the image cylinder 9 with the partial color image 3 of the new print page 5 'are taken into account. Then the partial color image 3 of the new print page 5 'transferred to the image transfer cylinder 10, see above determine the ratios of this new pressure side 5 'the coefficient of friction and thus the position assignments of the image cylinder 9 to the image transfer cylinder 10. In this way, the influencing variables 4, 4 ', ... result as a variable that the must be assigned to the respective machine constellations. Will be one after the other Print pages 5, 5 ', ... are printed with different toner profiles Machine with four printing units 8, 8 ', ... simultaneously four different printing pages 5, 5 ', ... processed and the mutual influence must be taken into account. In accordingly, the circumstances just described must apply to the transfers be taken into account on the printing substrates 16.

The just described determination of the influencing variables 4, 4 ', ... including the However, the previous print page 5 'or print pages are already affected a development of the invention, which different for the printing of printed pages 21 Image content or for small series is important. Even without the latter, it is for other uses are advantageous if a toner profile change is immediate and not first due to their impact on the register that has already occurred can. The above-mentioned determination of the influencing variables 4, 4 ', ... of the toner profiles with the consideration of the mutual repercussions is independent of the Type of availability of the influencing variables 4, 4 ', ... of the toner profiles.

With regard to the determination of the influencing variables 4, 4 ', ... it is possible that the Input device 14 and a connection 27 data from printed pages 5, 5 'to the Press control 15 are given and this via an entered and / or stored data 17 or 21 the influencing variables 4 to be taken into account, 4 ', ... for different toner profiles. The particular advantage of this embodiment is that almost everything is done through data processing, wherein, for example, toner profiles from stored digital image data 17 without let win more. The influencing variables 4, 4 ', ..., which the printing press control 15 from the stored data 21 and / or 17 contains, with the help of a Connection 27 'forwarded to the controls 12, 12', ... Such data 17, 21 can print several pages 5, 5 ', ... or the printed pages 5, 5', ... of several print jobs affect.

The influencing variables 4, 4 ', ... of different toner profiles can, for example, by an automatic detection of the toner profiles can be determined. So can a facility 20 can be designed such that they the toner profiles from digital image data 17th determined. However, it is also possible to close the device 20 with a densitometer 20 ' provided to the influencing variables 4, 4 ', ... or data to calculate them from the to determine images 24 to be printed. For this purpose, the densitometer 20 'detects the entire image 24, which moves according to the arrows 25 for this purpose must become. The determined influencing variables 4, 4 ', ... or data for calculating them can be fed to the controls 12, 12 ', ... via a connection 28. The controls 12, 12 ', ... could also be designed such that they influence the variables 4, 4 ', ... determine, if necessary with the help of in the memories 13, 13 ', ... stored empirical values 6, 6', ....

Another alternative is for a device 20 to transmit the determined data the press control 15 gives, as for example through the connection 28 'is shown. Based on this data, the press control can 15 the influencing variables 4, 4 ', ... different toner profiles also with other influencing variables link to calculate common correction values. This can for example, the type of paper, the paper thickness or other factors with in the calculation of the register should be included. Then the press control gives 15 for example via the connection 27 'influencing variables 4, 4', ... to the controls 12, 12 ', ... further, which are the influencing variables 4, 4', ... different toner profiles or can also be influencing variables, which also other influences mentioned.

So that the controls 12, 12 ', ... the partial color images 3, 3', ... the printing substrates 16 must be able to assign a sensor 22 at the beginning of the print substrate carrier 11 Detection of printing substrates 16 may be arranged, which controls 12, 12 ', ... communicates in which position a printing substrate 16 is on the printing substrate carrier 11 is located.

The list in the embodiment of the FIG. Is not exhaustive and must be not all of the alternatives shown may be provided in the machine, for example it is also possible to have only one input device 14 with a connection 26 to the controls 12, 12 ', ... to provide the stored empirical values 6, 6', ... for get different toner profiles. Alternatively, it can be provided that only the Influencing variables 4, 4 ', ... from stored data 21 and / or 17 by the press control 15 are removed. This can be done automatically or through a Input on the input device 14 take place. Another way that too is possible separately, the determination of influencing variables by means of the described Device 20, 20 '.

Most expedient, however, are all possibilities in one machine illustrated way provided depending on existing data or crucial Influencing factors in the operation of the machine select one or the other alternative to be able to. However, the configurations are only exemplary, other types of wins of influencing variables and processing thereof are conceivable.

Reference list

1

Multicolour printing machine

2, 2 ', ...

Devices for the digital generation of partial color images

3, 3 ', ...

Part color images

4, 4 ', ...

Influencing variables of different toner profiles

4th

Toner profile of the previous print page

4 '

Toner profile of the following print page

5, 5 '

Printed pages

5

previous print page

5 '

following print page

6, 6 ', ...

stored empirical values for different toner profiles

7, 7 ', ...

Register marks

8, 8 ', ...

Printing units

9, 9 ', ...

Image cylinder

10, 10 ', ...

Image transfer cylinder

11

Print substrate carrier

12, 12 ', ...

Control for achieving register-based prints (e.g. the Assigned to printing units)

13, 13 ', ...

Storage

14

Input device

15

Press control

16

Printing substrates

17th

digital image data

18th

Register sensor

19th

Position detection element, e.g. B. Angle of rotation encoder

20th

Device for determining the influencing variables of the toner profiles

20 '

Densitometer

21

Print job data

22

Sensor for the detection of printing substrates

23

Drive roller of the substrate for printing substrates

24th

image

25th

Arrow: movement of the image under the device 20, e.g. B. under the Densitometer 20 '

26

Connection of input device - controls

27

Connection of input device - press control

27 '

Connection of press control - controls (the printing units assigned)

28

Connection device 20, 20 '- controls (the printing units assigned)

28 '

Connection device 20, 20 '- press control

29

Arrow: direction of transport

Claims (22)

Method for setting the register in a multicolor printing machine (1) with several devices (2, 2 ', ...) for the digital generation of partial color images (3, 3', ...), the creation and combining of the partial color images ( 3, 3 ', ...) is controlled such that register-containing prints are achieved,
characterized in that in the event of a change in the toner profile, the influence of the toner profile on the register by means of existing influencing variables (4, 4 ', ...) is taken into account immediately when the change is carried out. Method according to claim 1,
characterized in that in the event of a register correction as a result of a change in the toner profile, the retroactive influence (4) of the toner profile of the previous print pages (5) which are still in the printing process on the register of the new print pages (5 ') which are already in the printing process is taken into account. The method of claim 1 or 2,
characterized in that the influencing variable (4, 4 ', ...) of the toner profiles is taken into account on the basis of stored empirical values (6, 6', ...). Method according to one of claims 1 to 3,
characterized in that the consideration of the influencing variables (4, 4 ', ...) of the toner profiles is activated by a manual input. Method according to one of claims 1 to 4,
characterized in that the influencing variables (4, 4 ', ...) of the toner profiles are taken into account on the basis of the evaluation of digital image data (17). Method according to one of claims 1 to 4,
characterized in that the influencing variables (4, 4 ', 4 ") are taken into account by automatic detection of the toner profiles. Method according to one of claims 1 to 6,
characterized in that the influencing variables (4, 4 ', ...) of different toner profiles are determined by the partial color images (3, 3', ...) according to the extent of the area coverage of the overall image area. Method according to one of claims 1 to 7,
characterized in that it serves to correct a register regulation based on the detection of register marks (7, 7 ', ...) which are printed by the individual printing units (8, 8', ...), this correction takes place before a change in the toner profile can influence the register marks (7, 7 ', ...). Method according to one of claims 1 to 8,
characterized in that it serves to correct a register control which is based on the detection of the positions of the partial color image and substrate transmitting elements (9, 9 ',... 10, 10', ...; 11). Method according to one of claims 1 to 9,
characterized in that further influencing variables which have an influence on the register are taken into account when setting the register. Device for carrying out a method according to one of claims 1 to 10 with a multicolor printing machine (1) with a plurality of devices (2, 2 ', ...) for the digital generation of partial color images (3, 3', ...), at least one Control (12, 12 ', ...) for achieving register-based prints makes a register setting in which the generation and combining of the partial color images (3, 3', ...) is controlled,
characterized in that the at least one controller (12, 12 ', ...) is designed in such a way that, when the toner profile is changed, the influence of the toner profile on the register is directly influenced by means of existing parameters (4, 4', ...) taken into account with the implementation of the change. Device according to claim 11,
characterized in that the at least one controller (12, 12 ', ...) is designed in such a way that, when a register is corrected as a result of a change in the toner profile, it has the retroactive influence (4) of the toner profile of the previous print page, which is still in the printing process ( 5) on the register of the new print page (5 ') already in the printing process. Device according to claim 11 or 12,
characterized in that it is equipped with at least one memory (13, 13 ', ...) which contains stored empirical values (6, 6', ...) of influencing variables (4, 4 ', ...) of different toner profiles , wherein the at least one controller (12, 12 ', ...) controls the creation and assembly of the partial color images (3, 3', ...) on the basis of these empirical values (6, 6 ', ...). Device according to one of claims 11 to 13,
characterized in that it is equipped with an input device (14) by means of which the influencing variables (4, 4 ', ...) of different toner profiles to be taken into account can be activated manually. Device according to one of claims 11 to 14,
characterized in that a printing press control (15) is provided which contains stored data of print jobs (21) and the influencing variables (4, 4 ', ...) of different toner profiles are taken into account on the basis of this data (21). Device according to one of claims 11 to 15,
characterized in that it is equipped with a device (20, 20 ') for automatically recording the influencing variables (4, 4', ...) of different toner profiles. Device according to claim 16,
characterized in that the device (20, 20 ') for determining the influencing variables (4, 4', ...) detects the toner profiles according to the extent of the area coverage of the overall image area by the partial color images (3, 3 ', ...). Device according to claim 16 or 17,
characterized in that the device (20) for detecting the influencing variables (4, 4 ', ...) is designed from the digital image data (17). Device according to claim 18,
characterized in that areas of a plurality of image pixels are combined in the evaluation of the digital image data (17). Device according to one of claims 11 to 19,
characterized in that the at least one controller (12, 12 ', ...) is designed in such a way that it registers the register by detecting register marks (7, 7', ...) which are used by the individual printing units (8, 8 ', ...) are printed and a register sensor (18) is detected, regulated and the influencing variables (4, 4', ...) of the toner profiles are taken into account as correction factors, the correction being carried out before a change in the toner profile influences the Can have register marks (7, 7 ', ...). Device according to one of claims 11 to 20,
characterized in that the at least one controller (12, 12 ', ...) is designed such that it registers the register by detecting the positions of the partial color image and substrate-carrying elements (9, 9', ...; 10, 10 ', ...; 11) by position detection elements (19) and the influencing variables (4, 4', ...) of the toner profiles are taken into account as correction factors. Device according to one of claims 11 to 21,
characterized in that the at least one controller (12, 12 ', ...) is designed in such a way that it takes further influencing variables which influence the register into account when setting the register.

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