DE102007059177A1 - Color mixture composition controlling method for printing machine, involves obtaining optical actual values from light, and producing adjustment color mixture by deviations between actual values and optical desired values - Google Patents

Abstract

The method involves obtaining optical actual values from light (7), where the light has a reciprocal effect with parts of a print image (9) produced on a printing substrate (6) by a printing machine with a color mixture (11). An adjustment color mixture (31) is produced by the deviations between the actual values and optical desired values, where the mixture (31) is mixed with the mixture (11), and changes the proportions of pigments, and color mixtures are made available from different color mixing devices (16, 24). An independent claim is also included for a color mixture composition controlling system comprising a color mixture mixing device.

Description

The The invention relates to a method for controlling the composition a color mixture on at least one printing press, a mixing device for a color mixture and a system for controlling the Composition of a color mixture on at least one printing press.

In Printing presses are printed with inks that are usually off consist of different chemical components.

The Carrier of the color or the intended color impression, which adjust after the printing process to the viewer of the printed image should, is usually colored pigments, such as organic Chromophores, which consist of a combination of carbon, oxygen and nitrogen exist and certain wavelength ranges of the light can be provided. The color impression can also be of long-chain hydrocarbons, so-called polymers are given. The polymer chain comprises chromophoric groups, after the crosslinking process the resulting polymer film the give the desired color impression.

In many inks have several such dyes, so that the later color impression of the viewer of the printed image already by several optically active constituents of an ink is significantly influenced. Further influence on the Color perception of the viewer of course have the print substrate and the solvents of the printing ink, which are common make up a large proportion of the volume of the paint.

To In the prior art, the composition of ink in central facilities ("color kitchen") of the relevant Printer determined.

For this usually are so-called color recipes that the composition specify, before. The colors compiled using the color recipes are brought to the relevant color reservoirs of the printing presses and processed there. It is also known in this context, the Print images to obtain different readings. So is with optical Measuring equipment using the printer "Densitometer" or "Spectrophotometer" calls, light, which interact with the printed image has examined. The interaction usually consists in one Reflection or transmission of light. Light, that any in this context relevant interaction with the printed image has experienced (especially reflection or transmission), is in this Document referred to as remitted light.

When Measurements are light intensities L (of the remitted Light) in a spectral range. In a "densitometric" Measurement will be different narrow spectral ranges of the visible Light (eg nine spectral ranges).

The Densitometer consists of several color filters that light up limit a relevant ink for the measurement. In usually there are four color filters for the inks cyan, Magenta, yellow and black provided. Located behind each color filter a photoelectric sensor (photodiode). The densitometer will among other things for the quantitative measurement of the color density (Volltondichte) used. When measuring light is on a printed measuring surface blasted and then, after passing through a color filter, with a photoelectric sensor (photodiode) of the remission or Transmission value determined. From the measured values can Deviations of the printed measuring surface from a "color standard", such as color deviation, color depth, contrast etc. can be calculated.

The higher-quality "spectrometric" measurement includes usually measured values from the whole spectrum of visible light. This wide spectral range, for example, of 36 sensors measured with narrower spectral ranges.

The Spectrophotometer measures across the entire visible spectrum of light, the remission values of light, that of the measuring surface (usually a printed measuring surface) returned becomes. As a rule, the printing material with suitable - in this case white - light lit.

The Spectrophotometer thus measures the degree of remission of the sample (in percent) the visible spectral range of light (about 400 to 800 nm) and calculated from this remission spectrum with a suitable software the coordinates of the measured color in a color space. The coordinates specify the so-called color location of the color.

The patent application EP 0 228 347 A1 proposes control of the color impression on a material web which uses a spectral color analysis instead of a densitometric color density measurement. Measuring the spectral distribution of the color enables a very accurate correction calculation of the above-described base recipe of the ink by suitable software. However, a procedure shows EP 0 228 347 A1 still disadvantages. So often several correction cycles are necessary until the desired color impression is achieved due to the corrections.

The Object of the present invention is therefore, devices and Propose method, with a faster setting of the Print image is possible, as in the prior art.

According to the invention this object is achieved by the features of claim 1, 16 and 20.

The The present invention has various circumstances Benefit: If at least two color mixing devices are used, then one of these color mixing devices in larger Proximity to one press may be present than the other. In addition, at the one mixing device already anticipated correction colors exist or are expected Correction mixtures be premixed.

The Mixing devices can be used in central mixing devices and decentralized or more decentralized mixing devices be. The central mixing devices are usually used for more printing presses to be responsible than the decentralized. In this case, a mixing device has at least two Paint containers in which color mixtures are preferred, however Basic colors are available. The mixing device has the possibility To supply color components from their containers. This can be done by metering devices, with a mixture of colors or color mixtures in a metering device of the mixing device or only in the ink supply system of the printing machine can be.

A such mixing device can also be mobile. In this case leave her previous components move with her. Is the mixing device mobile and has several dosing taps or downpipes for color mixtures or single colors, see above can be a paint bucket of a printing press from various of these Dosing valves color obtained, the mixing device can be moved so that each filling dosing is located in a filling position to the paint bucket.

decentralized Mixers may have fewer primary colors or more generally contain fewer paint containers than decentralized mixers. So it is advantageous if a decentralized mixing device at least 11 basic colors (basic colors). Another container may contain solvents. The central mixing unit In addition, often also contains spot colors and similar.

The Mobility of a decentralized mixing device can with locomotion how wheels are made. It can drives, auxiliary drives and have steering or Fernlenkeinrichtungen. She can also as Be designed rail vehicle.

Advantageous are controllable paint valves, a control device that controls the paint valves can control, and color lines, which in some way color from a container to a collection point of the printing machine conduct.

A Paint mass detection device is able to measure the mass of Determine color at least in part of the color line system. A color line system of a printing press leads the color from a supply point to the substrate. It usually includes a bucket-like color reservoir, the color is supplied. Furthermore, pipelines are present in the paint line system. At least some of the piping carries paint from the Paint reservoir to other paint containers. In color works are such color containers, often called color pans or Doctor chambers are known available. Especially in gravure printing and flexographic printing have such containers the task of color on the printing process to pass on involved rolls. In flexo printing often a transfer takes place to an anilox roller, which in turn transfers the ink to the printing plate cylinder, which is often called cliché roll in flexographic printing, passes on. Of the Printing plate cylinder transfers the color to the Printing material.

All of the aforementioned reservoirs, containers, lines and rollers which transport the ink to the printing substrate for the printing material are referred to in the present document in their entirety color line system. A color is therefore a color line system that contains the entire amount of that color, assigned.

A accurate determination of the mass of this color is difficult. It is possible, the mass of paint in one or more reservoirs and / or Containers by measuring the weight and / or the measurement to determine the volume. In general, such a measurement right at a paint bucket, which represents the color reservoir take place. Also in a paint tray or even a doctor blade such appears Measurement possible, even if during the printing process Vibrations are to be considered.

It However, it is beneficial to have the mass of paint that is at least in a part of the piping and containers of the paint supply system is appreciated. Here, the volume of the elements concerned be based on.

A (real) mass measurement can be done via a measurement of the Weight and / or via a measurement of the volume (level) the color in the relevant paint reservoir or container be made.

In The rule is the mass determination of a mass detection device due to the addition of such estimates and such measurements be made. In this way, the mass of itself in the supply system (or in parts of the same) located color with justifiable Expense can be determined very accurately.

These Measured values are assigned to a control unit associated with the printing press Evaluation device supplied. Whether this device is physical is present on the press itself or whether it is any Distance to this is subordinated in view of today's information transfer options. Also subordinate is whether the intelligence of this institution at a Place or in several places (central or decentralized Machine control). Above all, it is important that the device has a preferably electrical or electronic contact option with the measuring and control components mentioned in this publication the printing machine has. This contact option should the facility the ability to control and Exchange of information with various functional units of the printing press and give access to such units. If so, then is, the control and evaluation device is considered the printing press assigned.

The Control and evaluation can also the deviation of the optical Actual values which the optical measuring device determines from the optical setpoints, which in the device also in the form of light intensity values stored in selected wavelength ranges are, determine.

at The optical measuring devices may be spectrophotometers Acting on a suitable software is a very accurate one Allow calculation of a correction recipe. Also densitometric measurements can advantageously create a correction color mixture be based on. These measurements can be extrapolated they are also statements about non-measured spectral ranges allow. The quality of densitometric reading and estimation or extrapolation may also from time to time with spectrophotometric Measured values are checked.

advantageous Embodiments of control and evaluation be the optical readings taken by the optical measuring devices be determined at an earlier or later Time of evaluation converted into colorimetric values. The same thing also applies to optical actual and setpoint values.

aid Colorimetric readings can be the visual result of a color review (of a human observer) or a color comparison with a "numerical value" (often called color locus).

by virtue of this deviation and the weight of the color in question In the machine the device calculates the mass and the composition the color that needs to be attached to the desired one To achieve change. Here are the tax and Evaluation in the respective color mixing and metering device existing primary colors and those caused by these colors Effect on light that interacts with these colors known.

advantageously, the device is also the effect of the press processing substrate known.

With Help one implemented in the control and evaluation Software can then be the desired values to the mass and determine the composition of the color. Such computer results, which are determined on the basis of colorimetric nominal values, can also be based on the basic recipe. at the determination and use of the correction recipes is with the mentioned Measures a control process, which the actual values in one or several steps closer to the setpoints possible. Determining the mass of paint in the paint circuit or parts the same is very useful as it monitors in this way can be how much color (from that mixed according to the master recipe Color) is still present on the machine. At least the part of Paint that is not yet on any rolls (ie the color in the pipelines, reservoirs and containers), will most likely be part of a resulting Color mixing after adding the correction color comes about and is therefore for those caused by this color Effect on light relevant. Therefore, the mass measurement of large Use.

Out The above facts also show that it is advantageous may be to measure and measure only the mass of that color appreciate that are not yet on the rollers (ink rollers like anilox rolls and printing plate cylinders).

additionally to the measurement and / or estimation of the amount of color is also the measurement of the viscosity of paint in the feed system advantageous. As already mentioned, the color exists from various constituents, of which especially the color pigments and the solvents are mentioned. The color splitting and evaporation characteristics differ between all Components (between the different pigments among themselves and between the pigments and the solvents) of the paint, so that their composition during processing a color quantum changes. The biggest Differences naturally occur between solvents and pigments. Thus, the proportion of solvents to The color as a result of evaporation greatly lower, which is significant Influence on the density of the color and on the color Light has exerted effect. A measurement of the viscosity usually allows an appropriate conclusion to draw the concentration of color components in the paint and so again with higher accuracy adequate To mix correction colors.

As already mentioned allow the aforementioned process steps the determination or at least adequate estimation the amount and composition of the color, which is related to the printing press located. This is true even if the first or already several Quantum on optionally differently composed correction color have been added as the control and evaluation yes the amount and composition of these correction colors known and it is beneficial to save these. The tax and Evaluation device can then, by adding the attached and the color components still present on the printing machine and optionally by further observation of weight and viscosity, continue to monitor the mass and composition of the resulting paint.

So is it possible, among other things, to record and store, with which color composition has been printed at what time is. It is also possible this original or resulting color composition in direct relation to the (at this time) measured on the substrate colorimetric Values (actual values).

On this way, the machine operator can keep track of gain the color compositions and the respective results.

He can the color compositions with which achieves good results have been, by the mixture of colors according to the assigned resulting recipes, specifically repeat. So can good results by repeating the same procedure at least largely reproduced.

To Mention is still a resulting recipe through the analysis of the resulting color mixture is calculable and that it is advantageous if the appropriate software on the Control and evaluation is installed. As mentioned above the control and evaluation device is the quantity and composition the correction colors known, and advantageous control and evaluation save these. The control and evaluation can thus - as also mentioned above - by adding the attached and the color components still present on the printing machine and if necessary by further observation of the weight and the viscosity continue to monitor the mass and composition of the resulting paint. The different compositions, the control and evaluation then Assign recipes.

Out a resulting color composition at a given time can be used to determine resulting color recipes that indicate how one with a color mixture "directly", eg as a basic recipe, to the resulting color composition comes. So can achieve a desired color location "without detours" become.

Generally it is appropriate to use recipes used (except for basic recipes, Correction recipes) to save. Also the associated measurements (v. a visually, but advantageously also mass and viscosity) can get saved. It is also advantageous, various of the aforementioned Repeat measurements at certain intervals.

above was mentioned that the use of the findings already used recipes (basic recipes, correction recipes) and above all the recipes used to provide resulting color mixtures lead, can be beneficial.

Alternatively, however, you can proceed as follows:
The deviations of the colorimetric desired values from the colorimetric actual values, which are recorded as part of a printing process according to the above teaching, are likewise stored. These values are often referred to as ΔK. The various deviations that are measured until a satisfactory result is achieved are added together and to the setpoint. With the help of the color mixing software implemented on the control and evaluation device, a basic recipe is created which is optimized to achieve the resulting (cumulative) color locus and not the desired color locus. The color produced according to this "bypass recipe" is printed.

The methods mentioned for using a resulting color recipe or the bypass recipe are particularly well suited if the other process parameters are as constant as possible for the different orders:
These process parameters include: same press, same anilox rolls, same temperature, etc.

in the The scope of the present document is under Methods of Operation a printing press both a method for processing a print job as well as a method for sequentially processing multiple print jobs Understood. The operation of a printing press encloses here also the order conversion.

at the execution of several orders, where at least a color should cause the same color impression and / or the same set point (color location) in a color space, it is advantageous on "experiences" from previous of these orders to resort to a same color setpoint. To this Experiences include, above all, measured values from these earlier ones Orders. However, these experiences are part of this experience also color mixtures that underlie these color mixtures Color recipes, correction recipes and resulting color recipes.

In With regard to the measured values, especially the deviations of the colorimetric are Actual values to the colorimetric setpoints, which are at earlier When printing was attempted, the colorimetric Target value to achieve with a color mixture, interesting.

As already mentioned elsewhere, it is possible on the basis of given colorimetric nominal values as well as on information to the color values of primary colors (how do the basic colors influence Light) to calculate color recipes with which the underlying Color locus can be calculated relatively accurately. To such bills To be able to perform, the control unit a printing machine with a color calculation software (color formulation software) be charged. The deviation in a color space that arises if with the color mixture based on the calculated recipe is printed, leaves a whole series of inferences to the calculation method itself and to the process parameters.

Therefore, it is advantageous to store the deviation and the process parameters of such printing operations. Especially the deviation is of great interest. If one or more correction cycles are necessary to achieve the desired color location (colorimetric target value of a color) with sufficient accuracy, the other deviations (ΔK ₁ , ΔK ₂ , etc.) are also of interest. The different deviations can be transferred into the coordinates of a color space and be compressed by vectorial addition to a total deviation (ΔK).

In another order, the achievement of the same color locus in the control device is stored, then the total deviation vectorially can be subtracted from the target color location. The resulting difference color location (D = S - ΔK) is then controlled by the Ink Formulation Software as the reference location instead of the target color location.

in the Case of a measurement of the mass of existing on the press Color is possible in the manner already described above, determine exactly with which color mixture which deviation has come about. This measure comes to all the above Devices and methods to good. It is so possible to take into account which deviation due to which Color mixing in the machine came about. Usually you will Set the control components of a press to can perform the procedures. This setting can by implementing software components in appropriate Hardware elements are.

Further Details and embodiments will become apparent from the dependent claims and the objective description.

The individual figures show:

1 A system for providing color mixing

2 A mobile (decentralized) mixing device

3 Another embodiment of the mobile decentralized mixing device

4 An inking unit of a central cylinder flexographic printing machine

5 The course of the spectral light intensity of a color

6 The course of the spectral light intensity of a color

7 The course of the spectral light intensity of a color

8th The course of the spectral light intensity of a color

9 The vector addition in the color space E

10 The vectorial calculation of the target color location S in the color space E

11 Another system for providing color mixing

1 shows a system 1 for providing a color mixture for printing substrate 6 , The system 1 also has the ability to correct the color mixture. The correction can also be carried out during the printing operation.

The printing press 2 has a control device 3 on that over the control line 5 with an optical measuring device 4 connected to the currently printed substrate 6 examined. The light cone 7 indicates this from the printing material web 6 remitted light, which has interacted with the printing material on. From the printing press 2 is only a printing unit 8th shown. Nevertheless, the printing press can 2 have any number of printing units. If that is the case, there are different methods to using the measuring device 4 the print image 9 to investigate. Once special print marks can be examined, which are printed in certain areas of the substrate web. On the other hand, certain selected zones of the print motif, in which a color occurs particularly often, can be examined. However, it is also possible to examine each color sequentially when proofing each color.

The one shown printing unit 8th the printing press 2 gets its color 11 from the paint bucket 10 , its weight from the weighing device 12 is controllable. The weighing device can measure the mass of paint via the control line 14 the control device 3 to transfer. The amount of color that is in the remaining ink delivery system of the press can be estimated. The color lines 13 lead the color to the inking unit / printing unit 8th to. The inflow is from the paint valves 15 regulated.

With a corresponding device of the control device 3 This can be the mass of color constantly 11 in the paint bucket 10 record. It can also measure the readings of the optical measuring device 4 record the optical measurements and the mass values recorded at one time. As long as the control device 3 Knowing the composition of the color in the printing press, it can always determine at which time which color mixture has produced which color values in a color space (E).

To mention is still the viscosity measuring device 22 that constantly measures the viscosity of the ink on the press. Especially in gravure printing and in flexographic printing, it can happen that the ratio of the solvents in the ink to the color pigments changes, which may be due, for example, to different evaporation properties of pigments and solvents. Such a development can be observed quite well by measuring the viscosity, since solvents usually greatly reduce the viscosity. When the viscosity measuring device 22 their readings also in some way to the controller 3 the printing press 2 - or another control device 19 - passes on, are this measuring device values to the actual color I place on the substrate 6 , to the weight of the color 11 at the machine 2 as well as the viscosity of the same 11 to disposal. Based on these measurements, a good overview of the composition and amount of color is given.

Typically, a printing process in which an order is processed begins with the provision of color mixtures 21 for the various inking units through the central color kitchen 16 , In this central color kitchen are colors 17 , mainly also primary colors, in suitable containers 18 stored. In the illustrated advantageous embodiment, these color containers are also 18 with weighing devices 12 Mistake. Alternatively, the volume of colors could be 17 be measured with level measuring devices. The weighing and / or level measuring devices can transmit their measured values via a control line 14 the control device 19 the central color kitchen 16 to hand over.

This control device 19 Controlling the "way" in which the color mixtures are composed In the preparation of color recipes, which are based on the color mixtures, it is often attempted to achieve color locations that should arise on the substrate as precisely as possible Color locations and based on the knowledge of the optical properties of the color in the paint containers 18 the color kitchen 16 You can calculate with which mixture of these colors the color point S can be reached. For this purpose, of course, a knowledge of the optical properties of the printing material advantage.

The mentioned computational work can be provided by a software. This can be in the control unit 19 be implemented, so this control unit 19 for calculating a color recipe based on these color set points S is established.

As already mentioned, the printing process generally begins with a primary color mixture which has been produced in the central color kitchen on the basis of a basic recipe - which has been calculated on the basis of color setpoints in the aforementioned manner. However, the basic color mixtures can also be specified by the color manufacturer. This basic color mix 21 will be in a container 20 - Alternatively, in a piping system, not shown - to the printing press 2 brought. With the basic color mixture 21 begins the printing process.

The investigation of the resulting print images 9 with the optical measuring device 4 often shows that the target color locations S deviate from the measured actual values I by a difference ΔK. This circumstance is deplorable, since it comes in many areas on an accurate compliance with the specified color locations. For example, in packaging printing great importance is placed on compliance with such target color locations. Flexographic and gravure printing are leaders in this area, whereby offset printing machines are also used. The printing press 2 So, among other things, it can be a gravure, flexo or offset printing machine.

After the deviation .DELTA.K of the actual value of the color locus from the nominal value of the color locus S has been determined, it can be decided whether and how measures are to be taken in order to bring about a greater agreement between the actual value I and the setpoint value S. This is difficult especially during the current printing operation to a print job. In the in 1 shown embodiment of the system 1 There is next to the central color kitchen 16 , which may well be assigned to several printing presses of a printing company, a decentralized color mixing unit 24 , This color mixing unit 24 can definitely be assigned exclusively to a printing press. In this case, it may even be structurally connected to the printing press. However, it may in turn be intended to provide color, and preferably, correction color to multiple machines.

This can be done by this unit 24 also mobile, so for example as a whole unit on wheels 34 to be movable.

In 1 is shown that the color mixing unit 24 in turn, base color for correction 26 , Paint containers 25 , Weighing equipment 27 as well as color lines 13 and paint valves 28 Has. As a rule, in the decentralized color mixing unit 24 a smaller amount of ink and a lower number of colors are stored than in the central color kitchen 16 , The decentralized color mixing unit 24 is also a control device in this embodiment 23 associated with the color mixing by the decentralized color mixing unit, by the control of color valves 28 or the like. This control device 23 can over the data line 14 , the node 29 and the interface 30 Information about the composition and amount of correction color will be sent. Based on this information, a color recipe emerges, and from the decentralized color mixing device 24 a correction color mixture of the printing press is provided. This process is indicated by the arrow 31 indicated.

The correction color can be brought back to the printing machine with a container, as through the container 20 and the arrow 32 in relation to the basic color mixture 21 is indicated. Again, an unillustrated piping system is available as an alternative. In the case of a mobile decentralized mixing device 35 This can also be attached to the paint buckets 10 the printing press 2 moved up and fill them with a drain cock.

To mention still remains that the dots between the color containers 18 and 25 indicate that their number is usually higher than in 1 shown. Usually N become primary colors 17 be present in the central color kitchen. In a decentralized unit should at least M colors 26 be saved.

In the central color kitchen 16 In addition, individual pigment containers may be provided in which pigments for the individual primary colors 17 are located. By mixing primary color pigments with solvents and other additives, which are not discussed in detail, can be found in the central color kitchen 16 primary colors 17 getting produced.

To mention still remains that by the networking of the control devices 3 . 19 and 23 always useful information can be exchanged. Such is by measuring and / or estimating the amount of color 11 at the printing press 2 , by observing their composition, by the optical measurement on the substrate 6 but also, if necessary, by measuring their 11 Viscosity works well, well known prior to color correction, which composition of the color is printed at a time T on the machine. By adding an at least the control device 23 the decentralized color mixing device 24 known quantity and composition of the correction color changes the composition of the color 11 at the machine 2 considerably. However, this composition after the first correction step is by adding the amounts of the individual color components of the color 11 at the machine 2 and the correction color 31 relatively accurately calculable.

This applies in an adapted form even after further such correction steps. Therefore, it is possible in the manner described, even after to determine relatively accurately any number of correction steps with which color mixture which colorimetric actual value I reaches has been. This knowledge is very helpful if follow-up orders with the same or similar Colors (to be attached to the color locations) to be printed.

2 shows a decentralized mobile color mixing unit 35 , which is the role of the decentralized color mixing unit 24 in 2 could take. The other reference number 35 was awarded here to emphasize that the color mixing unit 35 is mobile while the color mixing unit 24 in the system diagram 1 just be stationary. Otherwise, the functional components carry paint container 25 , Control line 14 , Color line 13 , Control device 23 , Paint valve 28 and interface 30 the same reference numerals as in 1 , The aforementioned functional components are of the frame or the frame 33 on the wheels 36 movable, worn. In addition, with the supports 34 indicated that the aforementioned functional components are supported by the frame. The decentralized mobile unit 35 is able to drive from press to press and deliver correction color there. Here, the decentralized mobile unit is able to detect certain quanta of color in the different paint containers 25 are stored, and thus produce a corresponding correction color mixture and through the color lines 13 leave.

The mixing of the different color components can in a Mischeinrich not shown the decentralized mobile unit 35 be made. However, mixing can be done in the paint bucket 10 the printing press 2 be made. The control unit 23 Information about the required correction color is given. Im in 2 This embodiment is done by the interface 30 the decentralized mobile color mixing unit 35 to the interface 37 the printing press 2 that gets the correction color, is docked. In the embodiment shown, the control device shares 3 the printing press 2 the control device 23 the decentralized color mixing device 35 with, with which color mixing which deviations ΔK on the printing material 6 have resulted. The control device 23 the decentralized color mixing device 35 is set with "color formulation software" to calculate the composition and amount of color mixture that can be used for correction 23 Also known, which amounts of correction colors with which optical properties are in the containers 25 the mobile decentralized mixing device. If a color is lacking for creating a correction mixture because it is used up or is not present from the beginning, the control device gives 23 a corresponding signal.

For the execution of the predetermined scope of work, it is advantageous if the optical properties of the printing material 6 the control device 23 be made known.

The above lines have a very "smart" controller 23 described. The way in which the networking of the control devices 3 . 19 and 23 in 1 however, shows that each of the controllers can be tuned to handle these steps if it has the hardware requirements and if the data lines 14 between the control devices 3 . 19 . 23 give this. The interfaces 30 and 37 can be ethernet interfaces. However, it is advantageous, in particular with regard to the mobile decentralized unit 35 if they get their information via radio or mobile phone frequencies (such as UMTS, WLAN, IR, etc). In this case, it can be constantly supplied with information and the docking of the interfaces 30 . 37 eliminated.

Regarding the decentralized color mixing devices 24 and 35 It should be said that these will usually only provide correction color blends. To relieve the central color kitchen 16 However, in exceptional cases they are also a basic color mixture 21 (eg for proofing). To conceptualize the decentralized color mixing devices 24 . 35 is to say that they provide color or color quanta available in any case, but that - as already indicated above - is not said that a real mixing of these color components for correction color mixture or base color mixture necessarily at these decentralized color mixing devices 24 and 35 must take place. Rather, this can, for example, only in the color buckets 10 the printing press concerned 2 be performed.

Especially with regard to the decentralized color mixing devices 24 and 35 is to say that providing any containers or paint lines 13 that lead color mixtures, is not necessarily beneficial. The colors mixed in this way inevitably contaminate the color mixtures for further jobs. Therefore, it is beneficial to the color line 38 in the decentralized color mixing unit 35 Also, mixed color leads to make it interchangeable or easy to clean.

In 3 is another embodiment of a mobile decentralized color mixing unit 35 shown, in their color lines, as downpipes 38 are designed, each only color 24 each from a paint container 25 is directed. Each of these downpipes 38 again has a color valve 28 that from the control device 23 over the control lines 14 can be controlled. The control device 23 controlled with the weighing equipment 27 also the weight of the colors 26 , the interface 30 is an antenna that is suitable for radio and / or (mobile) reception. The attachment of the different functional components on the frame 33 is with the props 34 and the mounting platform 39 shown.

The mobile unit 35 becomes the paint bucket 10 a printing press 2 proceed in such a way that successively one or more downpipes 38 come into their filling position to the paint bucket and the control unit 23 calculated color quanta are delivered.

A solvent tank may also be attached to such a mobile decentralized color mixing unit 35 be provided. However, it is in the illustrated system 1 Also beneficial if such a tank directly on the press 2 is and at a decrease in viscosity at the behest of the control unit 3 the printing press solvent into the relevant paint bucket 10 (As a rule, it is to be assumed from an application of this doctrine on multi-color printing machines, therefore, often more paint buckets 10 at the printing press 2 available).

In 4 becomes an inking unit 8th a central cylinder flexographic printing machine shown. Machines of this type are used in packaging printing and often have eight to twelve such inking units 8th , The scope of the functional components of the inking unit 8th is through the rectangle 44 indicated. The application of the teaching of the present document to such a Zentralzylinderflexodruckmaschine is advantageous. Based on 2 can be the color transport of a paint reservoir, the color of the outside of the printing press is supplied - here the paint bucket 10 - up to the substrate 6 sketch.

The color lines 13 make the connection between the paint bucket 10 and the doctoring chamber 40 ago. In a paint line is color to the doctoring chamber (as indicated by the arrow 46 indicated) and in the other line 13 from the doctoring chamber 40 to the bucket 10 directed (as by the arrow 46 indicated). The color flow in the color lines 13 the printing press from and to the bucket 10 is therefore often referred to as a color cycle, but this is misleading, as well as color from the doctor chamber to the anilox roller 41 , which rotates in the direction indicated by the arrow C, is discharged. The anilox roller 41 Gives the color to the cliché 43 the cliché roller 42 which turns in the direction indicated by arrow B. With the cliché is the substrate 6 printed while that by the cliché roller 42 and impression cylinder 45 defined pressure gap 48 running.

The printing material is further promoted in the direction of rotation A of the impression cylinder, runs on the guide roller 49 over, is from the counterpressure roller 45 lifted off and from the optical measuring device 4 examined. The light cone 7 put that from the print image 9 remitted light.

For the purposes of weighing or determining the color mass or the color volume of the ink in question on the printing machine is in 4 only the weighing device 12 that the weight of the bucket 10 monitored, shown. The color lines 13 could also be weighed. It seems more appropriate to determine their volume and thus to estimate or calculate the volume of the paint in the pipes. The doctoring chamber 40 contains significant color volumes and therefore could be weighed as well. In view of the vibrations prevailing in an inking unit, however, a weighing device was dispensed with at this point and moved in the same way as the volume determination in the color lines.

The on the rollers 41 . 42 or the cliché color in the broadest sense also belongs to the color contained in a color supply system. However, only a fraction of the paint once on one of the rollers returns to the paint bucket 10 so that the volume of this color does not need to be taken into account or only slightly, for example, to close the color composition of the color after a color correction.

The 5 to 8th illustrate the course of the spectral light intensity of a selected color. A special color or color mixture calls for a characteristic course of the spectral intensity of light, which interacts with the ink or with the printing material 6 has, which is printed with the color out. The curve (graph) 50 represents such a characteristic course. A color, which causes such a spectral intensity course of the remittierten light, will leave with the viewer a predominantly blue color impression, since the intensity maxima of the curve 50 range from 380 to 550 nm.

In the 5 to 8th the wavelength in nanometers (nm) on the horizontal axis versus the light intensity L on the vertical axis is plotted in arbitrary units.

The bars 51 are measured values in the first selected wavelength ranges. Measurements in relatively discrete regions are accomplished using measurement devices with wavelength-dependent sensitivity. For this purpose, suitable semiconductor devices are known. Often these are additionally provided with panels for certain areas. Often, only light from limited wavelength ranges is irradiated, so that only remitted light (re-emitted) can be measured in these areas. In 5 a situation is shown in which only a fraction of the spectrum is covered by the measurements. This situation is typical in so-called densitometric measurements. Often, light from nine or less first selected areas in the entire spectral range of visible light (approximately from 380 to 780 nm) is measured (for illustrative purposes in 5 only three in the range between 380 and 550 nm). It is crucial that broad areas 52 of the spectrum of visible light are not investigated in these densitometric measurements. For purposes of this document, these ranges will also become second selected wavelength ranges ( 52 ), which differ from the first wavelength ranges and in which the light intensity L is not measured or even "gaps" 52 called. This is one of the reasons why such measurements according to the prior art only to corrections of Farbdich be used. The density of the ink applied to the printing substrate can be brought about by changing the setting of the rollers involved in the printing process (especially in flexographic printing), by adjusting zone screws (offset printing) or by changing the solvent content of the ink.

A change in the mixing ratio of different color pigments to each other (in a color mixture 11 in an inking unit 8th is used), due to such densitometric measurements is not yet known. In order to change or redefine this mixing ratio of different color pigments (change of the basic recipe or also change of the color mixture on the machine by adding correction color), so-called spectrophotometric measurements are necessary. 6 clarifies the nature of such a measurement. To the small number of first selected spectral ranges 51 additional selected measuring ranges occur 53 added. Both selected areas often cover the entire area to be measured, which extends from 380 to 550 nm. In a spectrophotometric measurement, there are often no "gaps" 55 or 52 between the selected areas 51 and 53 , In this case, the gaps would have 55 in 6 only representational significance.

At the lower horizontal axis 57 is by the juxtaposition of the spectral sensitivity ranges 56 the channels of a spectrophotometer 54 illustrated how such a measurement can be composed ( 8th ). Such spectral sensitivity ranges can be limited to a bandwidth of 10 nm, which then also allows conclusions about the intensity of the remitted light with such a resolution. In this case, 30 to 40 channels would be needed to map the entire spectral range of visible light. Each channel is assigned a semiconductor sensor, possibly with a corresponding aperture and other optical additional devices. The evaluation of the measurement results takes into account high data volumes and causes great computational effort. For these reasons, it is advantageous to extrapolate from densitometric measured values to spectrophotometric measured values and to use the values obtained also for changing or correcting the mixing ratio of different color pigments to one another in a color mixture or a recipe. A first advantageous step is, in general, based on measured values for the spectral light intensity L in the first selected regions 51 , to a light intensity L in at least one wavelength range 52 . 55 in which no measurement is made, to extrapolate and use the extrapolated values, if necessary together with the measured values, to correct the pigment ratio.

This process can be performed more reliably if the "normal" course of the spectral light intensity L of a color or color mixture (at least over a wavelength range), which in the figures through the curve 50 is shown is known. Individual optical values (above all the comparison of the course of the light intensity L in a measured wavelength range to the course of the light intensity L in an unmeasured wavelength range) can also be very helpful.

In this way, it is also possible to carry out a densitometric measurement which determines the spectral light intensity L, for example in only nine first selected regions 51 measures, to extrapolate a complete spectrophotometric measurement, for example, in 6 is shown, if you fill in the gaps 55 mentally fades in to attract.

7 represents a situation in which there is only one gap in the measurement range from 380 to 550 nm 52 is available. Also in the area of this gap can be extrapolated.

8th clarifies the location of the graph 50 in the entire spectrum of visible light and has, as mentioned, the lower horizontal axis 57 on, which is the juxtaposition of the spectral sensitivity ranges 56 a spectrophotometer 54 clarified.

In the 5 and 8th is sketched by the double arrow TB, the transparency range of the color mixture whose color emission behavior by the graph 50 is pictured. The graph 50 This describes the intensity profile of the remitted light, in the areas of the spectrum in which the color mixture in question has a significant degree of remission. An appreciable degree of remission should, as a rule, be a degree of remission for the printer, which is still perceptible to the viewer. Insofar as such an insignificant degree of remission can be uniformly quantified over the entire light spectrum, it is less than 5%, but advantageously less than 2%.

In In the transparency region TB, the color mixture has a larger one Remission degree, that is, the color pigment layer leaves in the reflection and / or transmission of light on or through the substrate through more light.

For the purposes of this document, it is important to note that extrapolating an intensity profile of remitted light 7 - as he uses the graph 50 is shown - also on the basis of a small number (here three) first selected wavelength ranges in which is measured - can be done. On measuring ranges 51 outside the transparency range TB of a particular color mixture can - for the purpose of correcting this color mixture 11 - be completely dispensed with.

9 outlines the situation in a color space E. Starting from an origin point O, which is likely to reflect the color of the printing material, one calculates in a control device 3 . 19 . 23 implemented color mixing software a color recipe, based on a color mixture 21 in a color kitchen 16 is compiled. With this color mixture, a target color location S in a color space (eg LAB, XYZ, LUV, LCH) is to be achieved. The control device 3 . 19 . 23 are the colorimetric properties of the primary colors, the substrate and the mentioned target color location S known in a color space and are based on the preparation of the recipe. With the mentioned color mixture is printed. When measuring with an optical sensor 4 it is found that the actual color location I with the color mixture 21 is reached. There is a deviation ΔK between the actual color location I and the desired color location S. This deviation is given vectorially here in the form of the value ΔK. The specification of the scalar ΔE, which in this case is the magnitude of the vector ΔK, is customary. For the purposes described below, however, the vector ΔK is better.

Some time later, an order is processed on the same printing press, in which the same target color location S is to be achieved with the same inking unit. Advantageously, the color mixtures were 21 , as well as the deviation ΔK stored for this purpose.

The following calculation examples of the vector diagrams in the 9 and 10 , should be in a sense equal pitch color space, for example, in the LAB color space done.

In the present embodiment, the value -ΔK is vectorially added to the target color location S. The result is point S ', which represents an auxiliary target color location. It is advantageous, instead of the Solifarbortes S the Hilfsssollfarbort S 'of the control device 3 . 19 . 23 to be specified as target color location. The control device 3 . 19 . 23 then calculates a color recipe, which is actually intended to reach the auxiliary target color location S ', but with the inking unit in question 8th the target color location S is achieved relatively well.

In a further embodiment of this teaching, it may be advantageous if different successively occurred deviations .DELTA.K, .DELTA.K ₁ , .DELTA.K ₂ , .DELTA.K ₃ ... Are used in the manner described for determining a Hilfsollfarbortes S '. The determination of the auxiliary target color location S 'can then take place according to the following formula: S → '= S → - ΔK → ΔK → = | ΔK → | · (S → - I →)

This is in 10 shown.

In 11 is another similar system 1 for providing a color mixture for printing substrate 6 , as in 1 shown. The same reference numerals are used, so that only the differences between the figures or systems must be shown at this point. In contrast to 1 is in 11 in addition a station 60 for the spectrophotometric investigation of parts of the substrate web 6 intended. At this station is a spectrophotometer 54 present, the parts of the printing substrate 58 examined spectrophotometrically and thereby measured values, as in the 6 and 8th are indicated. The parts of the printing material web are usually not "inline", that is in the printing press 2 during operation (= running substrate web) examined, since in this case, enormous amounts of data would be incurred in a short time, since the optical components of the spectrophotometer 54 should have certain qualities. In the future, however, it would seem desirable to also inline (running substrate web 6 , running machine 2 ) to be measured spectrophotometrically. In relation to the 5 to 8th However, densitometric readings can be taken by the optical measuring device 4 be approximated to spectrophotometric measurements. On this basis, correction recipes for one of the two mixing devices 16 and 24 to be won (actually central color kitchen 16 and decentralized mixing device 24 ).

As a rule, one will form two control circuits with the devices mentioned. With a color mixture 21 from the central color kitchen 16 is printed. The recipe, this color mixture 21 zugrun can be specified by the customer or the paint manufacturer. However, it can also be obtained by the optical examination of a template. This one becomes a spectrophotometer 54 in preference to a densitometer.

The color mixture created on the basis of the recipe 21 gets to the printing press 2 brought in the paint bucket 10 filled in and it is printed. The resulting color grades are on the current substrate 6 measured. Is the optical measuring device 4 a densitometer, its measured values are approximated in a manner that makes the results of the approximation usable at least in certain wavelength ranges of the remitted light, such as spectrophotometric measured values. In spectral ranges not measured by the densitometer 52 of the remitted light 7 the measured values are approximated and used to determine an actual color location I. Is this Istfarbort 7 in a target area around the target color location (which is often represented as a circle or a ball with a certain radius having the length .DELTA.E _Soll ), the printing operation is not stopped, but it is a correction color mixture 31 Created the paint bucket 10 is also added. In general, this correction color mix 31 from the decentralized color mixing device 16 to be created.

At regular or irregular intervals, a further, additional determination of the Istfarbortes I by a spectrophotometer 54 be performed. For this purpose, after a change of a pressure roller (in sheet-fed press by removing a sheet) substrate 58 be removed and in the station 60 to be examined. Especially if an offline measurement (substrate 58 outside the printing press 2 ) can be determined with sufficient accuracy when the relevant printing material section 58 has been printed, the function of the densitometer and the quality of the approximation can be checked.

The arrow 59 symbolizes in the 11 the transportation or transport of the printing material 58 in the station 60 , The spectrophotometer 54 is via the control line 14 in an advantageous embodiment with the other intelligent components of the system, but at least with the control device 19 connected.

LIST OF REFERENCE NUMBERS 1 system to provide a color mixture 2 press 3 control device the printing press 4 optical measuring device 5 control line 6 substrate 7 light cone 8th Printing / inking 9 print image 10 paint bucket 11 Color / color mixing 12 weighing device 13 paint line 14 control line 15 paint valves 16 (Central) color kitchen 17 Colours (Basic colors) 18 Container for the colors 17 19 control device 20 Container for the basic color mixture 21 21 Basic color mixing 22 Viscosity measuring device 23 control device a (decentralized) mixing device 24 (Decentralized) mixing device 25 ink pool the (decentralized) mixing device 26 Basic color for correction with a (decentralized) mixing device 24 27 weighing a (decentralized) mixing device 28 Color valve of a (decentralized) mixing device 24 29 junction 30 interface 31 Arrow "Transport the correction color mixture to the press "/ correction color, Correcting color mixing 32 Arrow "Transport the basic color mixture to the printing machine " 33 frame the mobile unit 34 Support the mobile unit 35 decentralized, mobile color mixing device 36 bikes 37 interface the printing press 38 downspouts 39 mounting plates 40 blade chamber 41 anilox roller 42 cliché roller 43 cliche 44 rectangle 45 Impression cylinder 46 arrow (Color conveying direction) 47 arrow (Color conveying direction) 48 nip 49 guide roll 50 Curve / graph, optical values 51 First selected areas 52 Not measured (wavelengths) areas ("gaps") 53 additional selected measuring ranges 54 spectrophotometer 55 (Performing) Gap between measuring ranges 56 spectral Sensitivity range of a "channel" of a spectrophotometer 57 "Lower horizontal axis " 58 section of the substrate 59 Arrow "Transport of / information about the section of the printing material 60 station for spectrophotometric examination 61 Color supply system S color coordinates, Color setpoint, target color location I Istfarbort S ' Hilfssollfarbort K correction vector O origin TB transparent Area L intensity

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0228347 A1 [0012, 0012]

Claims (20)

Method for controlling the composition of a color mixture ( 11 . 31 ) for at least one printing machine ( 2 ), - at the optical actual values (I) of light ( 7 ), wherein the light at least with parts of the printed image ( 9 ), which the printing press ( 2 ) on a printing substrate ( 6 ) with a color feed system ( 61 ) of the printing machine ( 2 ) color mixture ( 11 ), has undergone an interaction, and in which, due to the deviations of the optical actual values (I) from optical nominal values (S), at least one correction color mixture ( 31 ) generated in the color feed system ( 61 ) of the printing machine ( 2 ) color mixture ( 11 ) and there ( 61 ) the proportions of the colored pigments to each other characterized in that the color mixtures used in the process ( 11 . 31 ) of different color mixing devices ( 16 . 24 ) to be provided. Method according to the preceding claim, characterized in that - the first color mixing device ( 16 ) a color kitchen ( 16 ), which is used to provide color ( 11 ) for a first number (N) of printing presses ( 2 ) is used, and that second color mixing device ( 24 ) a decentralized mixing device ( 24 ), which is used to provide color ( 11 ) for a second number (M) of printing presses ( 2 ), the first number (N) of printing presses ( 2 ) greater than or equal to the second number (M) of printing presses ( 2 ). Method according to the preceding claim, characterized in that the second decentralized mixing device ( 24 ), which provide color ( 11 ) for a second number (M) of printing presses ( 2 ), a single press ( 2 ) assigned. Method according to one of the preceding claims, characterized in that the composition of the color mixture on at least two printing presses ( 2 ) and that at least one of the color mixing devices ( 16 . 24 ) between at least two printing presses ( 2 ) is moved to these printing machines ( 2 ) To supply color mixtures. Method according to the preceding claim, characterized in that the color mixing device ( 24 ) between at least two printing presses ( 2 ) is moved to these printing machines ( 2 ) To supply color mixtures, a color delivery system ( 61 ) of an inking unit ( 8th ) of the printing machine ( 2 ) supplies different color components, and that these color components only in the color supply system ( 61 ) mix. Method according to one of the preceding claims, characterized in that at least one of the measurements with which optical actual values (I) are obtained is a densitometric measurement which only measures the light intensity (L) in first selected wavelength ranges ( 51 ), the subareas ( 51 ) of the transparent area (TB) of the relevant color mixture ( 11 ) are included. Method according to one of the preceding claims, characterized in that from the densitometric measured values ( 51 ) Estimates of the light intensity (L) in second selected wavelength ranges ( 52 ), which differ from the first wavelength ranges ( 51 ) and in which the light intensity (L) is not measured, are derived. Method according to the preceding claim, characterized in that optical values ( 50 ), which in the interaction of light with the used color ( 11 ) or the color components used in an earlier measurement, are taken into account in the estimation. Method according to one of the two preceding claims, characterized in that in the estimation at least parts of a curve ( 50 ), the curve ( 50 ) the spectral intensity (L) of the remitted light ( 7 ), which is due to the interaction of light with the color ( 11 ) or the color components used in a wavelength range. Method according to one of the four preceding claims, characterized in that the densitometric measured values of the preparation of correction mixtures ( 31 ). Method according to one of the five preceding claims, characterized in that at least one of the measurements with which optical actual values (I) are obtained is a spectrophotometric measurement, the measurements of the light intensity (L) in all wavelength ranges ( 51 . 52 ) of the region of the transparent region of the respective color mixture. Method according to the preceding claim, characterized in that spectrophotometric measured values of the production of basic mixtures ( 21 ). Method according to one of the two preceding claims characterized in that spectrophotometric measured values are used be to the quality of the densitometric readings and / or to assess the estimate. Method according to one of the preceding claims, characterized in that to provide the correction color mixture ( 31 ) less different varieties of primary color ( 26 ) are used as for the production of the basic color mixture ( 21 ). Method according to one of the preceding claims, characterized in that at least on one of the following devices measurements of the color mass and / or the color volume are made and that these results are taken into account in the preparation of the color mixtures: - to color containers ( 18 ) of the central color kitchen ( 16 ) - on paint containers ( 10 ) at least one printing machine ( 2 ) - on paint containers ( 25 ) of the decentralized mixing device Mixing device ( 24 ) for providing color mixtures for at least one printing machine ( 2 ) containing at least two paint containers ( 25 ) and dosing devices ( 13 . 38 . 28 ) characterized in that the mixing device with locomotion means ( 36 ) - preferably wheels ( 36 ) - Is provided. Mixing device ( 24 ) according to the preceding claim, characterized in that the mixing device ( 24 ) with a control and evaluation device ( 23 ) Is provided. Mixing device ( 24 ) according to the preceding claim, characterized in that at least a part of the metering devices ( 13 . 38 . 28 ) of the mixing device ( 24 ) with the control and evaluation device ( 23 ) of the mixing device ( 24 ) is controllable. Mixing device ( 24 ) according to the preceding claim characterized by interfaces ( 30 ) to external control components ( 3 . 19 ), which provide data on the at least one printing press ( 2 ) required color mixtures ( 11 . 31 ) are transferable. System ( 1 ) for controlling the composition of a color mixture for at least one printing machine ( 2 ), - which ( 1 ) at least one optical measuring device ( 4 . 54 ), with the optical actual values (I) of light can be recorded, wherein the recordable light at least with parts of the printed image ( 9 ), which with the at least one printing machine ( 2 ) on a printing substrate ( 6 ) with a color feed system ( 61 ) of the printing machine ( 2 ), has interacted, and which ( 1 ) Components ( 16 . 24 . 35 ), with which ( 16 . 24 . 35 ) due to the deviations of the optical actual values (I) from optical nominal values (S) at least one correction color mixture ( 31 ) which can be generated in the ink feed system ( 61 ) of the printing machine ( 2 ) color mixture ( 11 ) to change the local ( 61 ) Quantitative ratios of the color pigments to one another are characterized by at least two different color mixing devices ( 16 . 24 ), with whom ( 16 . 24 ) each color mixtures ( 11 . 31 ) are available.