Method for operating a coating system for the production of layer systems and coating system for the production of layer systems

Abstract

Method for operating a coating system (100) for producing coating systems (10), comprising (i) Coating (S100) a coating system (10) in a coating system (102); (ii) Determining (S102) a spectral actual measurement curve (90) of the layer system (10) in an optical measurement system (104); (iii) Determining (S110) an actual data set (Dat_ist) by fitting a simulation target measurement curve (98) to the actual measurement curve (90); (iv) Determining (S112) actual layer parameters (96) as calculated actual layer parameters (96) from the simulation target measurement curve (98) by simulating the layer system (10) with the actual data set (Dat_ist); (v) Output (S114) of the actual data set (Dat_ist) and the calculated actual layer parameters (96) to at least one decision system (108); (vi) Providing (S118) quality requirement data; (vii) Deciding (S120) on the release (S122, S124) of the shift system (10) in the decision system (108) on the basis of a comparison of at least the actual data set (Dat_ist), the calculated actual shift parameters (96) and the quality requirement data, characterized by the fact that The coating of the layer system (10) in the coating system (102) comprises the deposition of an interferometric layer system (10) on at least one surface (24) of a substrate (22), wherein the layer system (10) comprises a stack (40) of at least four successive layer packages (42, 44, 46, 48, 50), wherein each layer package (42, 44, 46, 48, 50) comprises a pair of first and second single layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), wherein the first single layers (11, 13, 15, 17, 19) each have a first optical thickness (t1) and the second single layers (12, 14, 16, 18, 20) each have a second optical thickness (t2) different from the first optical thickness (t1), wherein a refractive index (n1) of the first individual layers (11, 13, 15, 17, 19) closest to the substrate is greater than a refractive index (n2) of the second individual layers (12, 14, 16, 18, 20) furthest from the substrate of the stack (40), wherein the layer system (10) has a brightness (L*), a chroma (C*) and a hue angle (h) of a residual reflected color, wherein the magnitude of a change (Δh) of the hue angle (h) of the residual reflectance color in an interval of an AOI with limiting values ​​of 0° and 30° with respect to a surface normal (70) on the layer system (10) is less than the magnitude of a change (ΔC*) of the chroma (C*) in the interval of the AOI, wherein, in order to design the layer system (10), the following steps are carried out: - Defining a layer design comprising at least a first material for the high-refractive-index first single layers (11, 13, 15, 17, 19) and a second material for the low-refractive-index second single layers (12, 14, 16, 18, 20), number of desired layer packages (42, 44, 46, 48, 50) with the single layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), starting values ​​of the thickness of the single layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20); - Defining target color values, including brightness (L*), hue (C*) and hue angle (h) at least at the limits for the interval of viewing angle (AOI) with the limits of 0° and 30°; - Performing an optimization procedure to vary the individual layer thicknesses (d_ist_11, ..., d_ist_20) of the individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) until an optimization target is achieved.

Description

State of the art

[0001] The invention relates to a method for operating a coating system for producing layered systems. The invention further relates to a coating system for producing layered systems, a computer program product for a method for operating a coating system, and a data processing system for executing a method for operating a coating system for producing layered systems.

[0002] A coating process implemented in a manufacturing environment, with an underlying coating process, typically exhibits variations from coating batch to coating batch. These variations arise from slight changes in the condition of the coating system, for example, due to deposits of coating material on the walls of the vacuum chamber, operator influences during loading of the coating system with coating material, wear and tear of various components installed in the coating system, and the like.

[0003] Typically, production monitoring tools store reflection curves measured for most coating batches. These curves can be analyzed within the tool with respect to Rm (mean reflectance), Rv (visual reflectance), and their color values, and the corresponding values ​​can be saved. The same applies to other input values ​​such as transmittance, cross-section, etc. For different coating variants, quality-relevant parameters can be indirectly determined, for example, for release purposes.

[0004] Known optical elements with interferometric antireflection coatings, such as those described in WO 2016 / 110 339 A1, typically exhibit a light reflectance of approximately 1%, calculated according to the standard DIN EN ISO 13666:2013-10. The color of the remaining residual reflection can vary considerably depending on the viewing angle. This variation can extend across the entire visual color scale.

[0005] WO 2016 / 110 339 A1 discloses a method for producing layer systems with layers of two material types, in which, using otherwise unchanged materials, a desired optical property of the layer system is specified by defining a parameter multiplied by a reflectivity, by appropriately varying the layer thicknesses of successive high-refractive-index and low-refractive-index layers. In this way, the optical properties of the layer system, ranging from mirrored to antireflective, can be achieved with desired residual colors using unchanged materials.

[0006] From US patent 2015 / 0021168A1, a deposition control device for a deposition apparatus is known, which includes one or more light sources that illuminate the substrate during coating in order to determine the layer thicknesses. A control unit is coupled to the deposition apparatus for feedback control of the deposition process.

[0007] From US Patent 6,217,720 B1, a method for operating a coating system is known in which several layers of at least two material types are produced and the thickness of the deposited layers is determined one or more times during the layer deposition process by optical measurements of the deposited layer and by adjusting theoretical values ​​derived from a model of the deposited layers to the corresponding actual values ​​obtained from the measurements. A process variable is continuously controlled to ensure the homogeneity of the deposited layers so that a valid thickness determination can be made based on the theoretical model.

[0008] From WO 2018 / 127 543 A1, a method for multilayer coating of a substrate is known, in which a test substrate with a programmed physical thickness for at least one layer of the multilayer coating and a design file are provided, which includes a target physical thickness and a target spectral power for the layer of the multilayer coating. The spectral power of the applied layer is measured on the coated test substrate, and the programmed physical thickness is compared with the optical thickness of the applied layer, thereby generating a data set. Disclosure of the invention

[0009] The object of the invention is to provide a method for operating a coating system for the production of layer systems, which includes quality-relevant aspects.

[0010] Further objects of the invention are to specify a coating system as well as a computer program product and a data processing system for carrying out such a method.

[0011] The problems are solved by the features of the independent claims. Favorable embodiments and advantages of the invention become apparent from the further claims, the description, and the drawings.

[0012] The invention is particularly suitable for the production of optical elements. It should be understood that the method according to the invention is neither limited to the production of optical elements and coatings, nor to the deposition of multilayer systems. Likewise, the substrate on which the layer system is deposited can be transparent or opaque, as required.

[0013] Furthermore, the invention can be used for a layer system consisting of a single layer deposited on a substrate and having a layer thickness. This does not preclude the presence of an adhesion promoter layer between the single layer and the substrate and / or the single layer being covered with a protective layer. Any adhesion promoter layer and / or protective layer present has no, or at least no significant, influence on the investigated properties of the layer system with the single layer.

[0014] Alternatively, the layer system can consist of several individual layers deposited on top of each other on a substrate, with each individual layer having a thickness that can be the same or different from the others. Here, too, an adhesion promoter layer can be placed between the individual layer closest to the substrate and the substrate, and / or the layer system can be covered with a protective layer. The adhesion promoter layer and / or protective layer, if present, have no or at least no significant influence on the investigated properties of the layer system with the multiple individual layers.

[0015] Optionally, intermediate layers can also be provided as adhesion promoters between the substrate and the coating system, for example a common coating system such as hard coating, primer coating, buffer coating, etc.

[0016] Unless otherwise stated, the terms used in this disclosure shall be understood in accordance with the standards DIN EN ISO 13666:2013-10 (EN ISO 13666:2012 (D / E)) and DIN EN ISO 11664-4:2012-06 (EN ISO 11664-4:2011) of the German Institute for Standardization eV.

[0017] According to section 4.2 of the standard DIN EN ISO 13666:2013-10, the term visible light, visible radiation, or a visible wavelength range refers to optical radiation that is capable of directly producing a sensation of light in humans. Visible radiation generally refers to a wavelength range from 400 nm to 780 nm.

[0018] Within the scope of this disclosure, visible radiation can preferably refer to a wavelength range of 400 nm or 460 nm to 700 nm, corresponding to the sensitivity maximum of the human eye. This simultaneously increases the design flexibility for the filter properties and slope steepness.

[0019] The term spectral reflectance, reflectance or reflectivity, according to section 15.1 of the standard DIN EN ISO 13666:2013-10, refers to the ratio of the spectral radiant power reflected by the respective material, surface or coating to the incident radiant power for a specific wavelength (λ).

[0020] In this case, reflectivity refers to the reflectivity of the entire coating with its multiple high- and low-refractive-index sublayers, and not to the reflectivity of a single sublayer.

[0021] According to a first aspect of the invention, a method for operating a coating system for producing layer systems is proposed, comprising (i) Coating a layer system in a coating plant; (ii) Determining a spectral actual measurement curve of the layer system in an optical measurement system; (iii) Determining an actual data set by fitting a simulation target measurement curve to the actual measurement curve; (iv) Determining actual layer parameters as calculated actual layer parameters from the simulation target measurement curve by simulating the layer system with the actual data set; (v) Output of the actual data set and the calculated actual layer parameters to at least one decision system; (vi) Providing quality requirement data; (vii) Deciding on the release of the shift system in the decision system on the basis of a comparison of at least the actual data set, the calculated actual shift parameters and quality requirement data.

[0022] The coating of the layer system in a coating system comprises the deposition of an interferometric layer system on at least one surface of a substrate. The layer system comprises a stack of at least four successive layer packages, each layer package comprising a pair of first and second layers. The first layers each have a first optical thickness, and the second layers each have a second optical thickness different from the first. The refractive index of the first layers closest to the substrate is greater than the refractive index of the second layers furthest from the substrate.

[0023] In particular, the interferometric layer system can be designed as a reflection-reducing or reflection-enhancing layer system.

[0024] The layer system has a brightness L*, a hue C* and a hue angle h of a residual reflected color, where the magnitude of a change Δh of the hue angle h of the residual reflected color in an interval of a viewing angle with the limiting values ​​of 0° and 30° referred to a surface normal to the layer system is less than the magnitude of a change ΔC* of the hue C* in the interval of the viewing angle.

[0025] The following steps are performed: - Defining a layer design, including at least a first material for high-refractive-index first single layers and a second material for low-refractive-index second single layers, number of desired layer packages with the single layers, starting values ​​of the thickness of the single layers; - Defining target color values, including brightness L*, hue C* and hue angle h, at least at limit values ​​for an interval of a viewing angle with limit values ​​of 0° and 30°; and - Performing an optimization procedure to vary the individual layer thicknesses until an optimization goal is achieved.

[0026] Advantageously, the target color values ​​can be chosen to be the same or similar at the limits of the interval.

[0027] In particular, maximum deviations for the hue angles of different residual reflectance colors can be specified.

[0028] The shift system can advantageously have four or five shift packages; more than five shift packages can also be provided.

[0029] Chromaticity can also be referred to as color saturation. Hue angle can also be referred to as color angle.

[0030] Advantageously, varying the thickness of the sublayers can provide a color-stable layer system whose residual reflected color does not change, or only changes slightly, even with significant changes in the viewing angle. A suitable combination of hue and hue angle can advantageously achieve a color-stable residual reflected color over a wide viewing angle range.

[0031] The first sublayers of the layer packages in the stack, closer to the substrate, can be formed from the same first material. The second sublayers, further away from the substrate, can likewise be formed from the same second material, but different from the first material of the first sublayers.

[0032] It can be provided that in the layer stack furthest from the substrate, a functional layer made of a third material is arranged between the first and second sublayers, exhibiting refractive properties comparable to the second sublayer. For computational purposes, the functional layer can optionally be assigned to the second sublayer. Alternatively, the materials of the first sublayers can vary within the stack. Likewise, it can alternatively be provided that the materials from which the second sublayers are formed vary within the stack.

[0033] Advantageously, the chroma at the upper limit of the viewing angle can have a value of at most 16, and / or the maximum chroma within the viewing angle interval can be at most 16. This allows for the realization of all reflected colors with high color consistency for residual reflection, not just at the edge of the hue angle.

[0034] Advantageously, the method according to the invention enables a self-regulating and feedback-based operating mode of coating systems with regard to quality-relevant aspects.

[0035] The quality requirement data can be loaded, in particular, from a criteria database.

[0036] Optionally, it is also possible to calculate the color values ​​of a residual reflective color of the layer system from the actual measurement curve.

[0037] Advantageously, the coating system can be used to produce layer systems, for example, for optical elements. In this case, the spectral measurement curve comprises the measurement of a spectral reflectance curve over a wavelength range, particularly in the visible spectrum; the simulation target measurement curve corresponds to a simulated spectral reflectance curve in the same wavelength range.

[0038] The field of coatings is increasingly restricted by regulations, which are dictated by standards and patents, among other things. For example, there are numerous patents that protect different characteristics of coatings in the ultraviolet spectral range.

[0039] Both during the development phase of new coatings and later in the product lifecycle during the production of batches of these new coatings, it is essential to monitor compliance with these regulations. This monitoring encompasses not only testing and documenting the test results as before, but also the rejection of coatings during the development phase or of coating batches during the production process if they do not comply with these regulations.

[0040] Advantageously, the inventive method enables such a release decision through a software-based process. This release decision can be made automatically based on stored test routines. These test routines check quality requirement data based on release criteria, which can include, for example, standards, intellectual property rights such as patent applications, utility models, granted patents, etc. The intellectual property rights are based, for example, on claim features. Claim features from which numerical values ​​can be derived can be checked automatically. This software-based quality assurance includes a criteria database in which, for example, standards and / or patent specifications with their numerically representable claim features can be stored.

[0041] However, the release criteria can also advantageously include other features such as compliance with specified optical data based on spectrally verifiable quantities, tolerance parameters, or deviations in coating parameters.

[0042] A completed layer system with a known layer structure can be checked for conformity with the characteristics contained in the criteria database. To check for characteristics that cannot be derived from measurements, such as reflectance measurements on the layer system, or for which data is unavailable, a software-based simulation of the measurement can be performed. Software-based quality assurance includes this simulation step. By comparing the simulation with existing measurements, the reliability of the results can be ensured.

[0043] With a favorable design, the procedure may still include at least one of the following steps (i) Calculating the color values ​​of a residual reflection color of the layer system from the actual measurement curve; (ii) Storing the actual measurement curve and the calculated color values ​​in a storage database; (iii) Loading a target data set of the layer system from a design database and the actual measurement curve into a simulation computer; (iv) Determining the actual data set by fitting a simulation target measurement curve to the actual measurement curve in the simulation computer; (v) Outputting the actual data set and the calculated actual layer parameters to the decision system and to the storage database; (vi) Loading release criteria for layer systems from a criteria database; (vii) Documenting the release decision in the storage database.

[0044] According to an advantageous embodiment of the method according to the invention, the release criteria can include at least permissible and / or impermissible layer parameters, in particular requirements from which requirements are derived which are used for comparison with the actual data set and / or the calculated actual layer parameters and / or the actual measurement curve.

[0045] In this way, regulatory or normative criteria can be included in the approval process. In particular, criteria whose requirements cannot be derived from plant-relevant parameters can be used.

[0046] According to an advantageous embodiment of the method according to the invention, the quality requirement data can include tolerance values ​​for the target data set of a coating system. This makes it possible to produce coating batches with consistent optical measurements, or to make corresponding corrections early on if system parameters change.

[0047] According to an advantageous embodiment of the method according to the invention, the decision regarding the release of the shift system in the decision system can comprise an automatic, software-based release decision, in particular using an artificial intelligence method. Advantageously, the method according to the invention enables release decisions with a high degree of automation through a software-based process. The release decisions can be made automatically based on stored test routines. The test routines can, for example, automatically adapt and further develop themselves based on continuously changing criteria databases.

[0048] According to an advantageous embodiment of the method according to the invention, the decision to coat a layer system in a coating system can be made based on a comparison of at least the target data set and release criteria from the criteria database. Such a release decision can be made early in the design process during development, thereby saving the costs of production that might subsequently go unused.

[0049] According to an advantageous embodiment of the method according to the invention, the calculated actual layer parameters can include reflectance values ​​in wavelength ranges outside the actual measurement curve, particularly in the UV wavelength range, and / or reflectance values ​​at different angles of incidence. This approach is based on derived values ​​for the quality requirement data based on the release criteria. In this way, parameters for a release decision can be included that cannot be directly determined due to equipment limitations or because of overly complex measurements. This enables efficient software-based quality assurance.

[0050] According to an advantageous embodiment of the method according to the invention, the hue angle h can change by a maximum of 15°, preferably by a maximum of 10°, within the interval of the viewing angle with the limit values ​​of 0° and 30°; and / or the magnitude of the change Δh of the hue angle h in a second interval of a viewing angle from 0° up to a limiting viewing angle θ with upper limits between at least 30° and at most 45° with respect to the surface normal to the layer system can be smaller than the magnitude of a change ΔC* of the hue C* in the second interval of the viewing angle, and the magnitude of the hue C* at the limiting viewing angle θ can be at least 2. In particular, the hue angle h in the second interval can change by at most 20°, preferably by at most 15°; and / or the photopic reflectance Rv in the interval of the viewing angle with the limit values ​​of 0° and 30° can be at most 1.5%, preferably at most 1.2%; and / or the scotopic reflectance Rv' in the interval of the viewing angle with the limit values ​​of 0° and 30° can be at most 1.5%, preferably at most 1.2%.

[0051] The color impression of the residual reflection of the optical system remains completely or almost unchanged for an observer over a large range of the viewing angle.

[0052] Advantageously, a color-stable residual reflection color is achieved even with greater variation in the viewing angle.

[0053] Advantageously, the first sub-layers can be made of a high refractive index material.

[0054] Advantageously, the first sublayers can consist of at least one or more of the compounds Ta2O5, TiO2, ZrO2, Al2O3, Nd2O5, Pr2O3, PrTiO3, La2O3, Nb2O5, Y2O3, HfO2, InSn oxide, Si3N4, MgO, CeO2, ZnS and / or their modifications, in particular their other oxidation states and / or mixtures thereof with silanes and / or siloxanes.

[0055] These materials are known as materials with a high classical refractive index for use in optical elements, such as for coating spectacle lenses. However, the higher-refractive-index sublayers can also contain SiO2 or other lower-refractive-index materials, as long as the refractive index of the entire sublayer is greater than 1.6, preferably at least 1.7, particularly preferably at least 1.8, and most preferably at least 1.9.

[0056] Advantageously, the second sub-layers can be made of a low-refractive-index material.

[0057] The lower refractive index sublayers can comprise at least one of the materials MgF₂, SiO₂, SiO₂, or SiO₂ with additions of Al, silanes, or siloxanes in pure form or with their fluorinated derivatives. However, the lower refractive index sublayers can also contain a mixture of SiO₂ and Al₂O₃. Preferably, the lower refractive index sublayers contain at least 80% by weight of SiO₂, and particularly preferably at least 90% by weight of SiO₂.

[0058] Preferably, the refractive index of the low-refractive-index sublayers is at most 1.55, more preferably at most 1.48, and most preferably at most 1.4. These refractive indices are based on standard conditions at a temperature of 25°C and a reference wavelength of 550 nm for the light intensity used.

[0059] Typical examples of coating materials with different refractive indices are silicon dioxide (SiO2) with a refractive index of 1.46, aluminum oxide (Al2O3) with a refractive index of 1.7, zirconium dioxide (ZrO2) with a refractive index of 2.05, praseodymium titanium oxide (PrTiO3) with a refractive index of 2.1, titanium oxide (TiO2) and zinc sulfide (ZnS), each with a refractive index of 2.3. These values ​​represent average values ​​that can vary by up to 10% depending on the coating process and layer thickness.

[0060] Typical optical glasses have refractive indices between 1.5 and 2.0. Layered materials with refractive indices less than 1.5, such as MgF2 and SiO2, are therefore referred to as low-refractive-index materials when combined with optical glasses, while layered materials with refractive indices greater than 2.0, such as ZrO2, PrTiO3, TiO2, and ZnS, are referred to as high-refractive-index materials when combined with optical glasses.

[0061] The difference in refractive indices between the high-refractive and low-refractive materials of the first and second sub-layers is preferably at least 0.2 to at least 0.5, depending on the coating process and layer thickness.

[0062] The materials used for this type of coating are the typical materials that are applied to a substrate in optics using, for example, PVD processes (PVD = Physical Vapor Deposition) or CVD processes (CVD = Chemical Vapor Deposition).

[0063] According to a favorable design of the optical element, at least the first sublayers can be formed from the same first material and the second sublayers can be formed at least predominantly from the same second material.

[0064] Optionally, the second sublayers can be formed from the same second material and only have a functional layer between the first and second sublayers in the layer package furthest from the substrate. This functional layer can be low-refractive-index and, if necessary, added to the second sublayer for calculation purposes.

[0065] According to an advantageous embodiment of the method according to the invention, a spectral reflectance measurement of the layer system can be carried out in an optical measuring system to determine its actual spectral measurement curve. From the spectral reflectance measurement, suitable further layer parameters can be conveniently determined by simulation calculations.

[0066] According to an advantageous embodiment of the method according to the invention, the calculation of color values ​​of a residual reflection color of the layer system from the actual measurement curve can further include determining a brightness L*, a chroma C* and a hue angle h of the residual reflection color from the actual measurement curve.

[0067] According to an advantageous embodiment of the method according to the invention, determining an actual data set by fitting a simulation target measurement curve to the actual measurement curve in the simulation computer can further include (i) Acquiring at least one spectral measurement curve with ordinate and abscissa values ​​as an actual measurement curve on the layer system, which consists of one or more individual layers with respective actual layer thicknesses, wherein the one or more individual layers are produced according to a target data set of the at least one coating system, wherein the target data set includes at least the actual layer thicknesses of the one or more individual layers assigned to the respective individual layers; (ii) Assigning the actual measurement curve of the layer system according to an assignment criterion, in particular for significant spectral points of the actual measurement curve, to a target measurement curve of a target data set with ordinate values ​​and abscissa values, which is based on a target layer system formed from one or more individual layers, wherein the target data set includes at least one known target layer thickness of the one or more individual layers assigned to the respective individual layer; (iii) Generating a simulation actual measurement curve using an iterative method by varying at least simulation actual layer thicknesses of one or more individual layers in at least one spectral interval of the actual measurement curve and obtaining a final simulation actual data set with at least final simulation actual layer thicknesses assigned to the respective individual layers, by which the actual measurement curve is at least approximated in the simulation actual measurement curve until a stable result is achieved for the assignment criterion according to a statistical selection procedure, wherein the target layer thicknesses are used as the starting values ​​of the simulation actual layer thicknesses; (iv) Generating a simulation target measurement curve by an iterative procedure by varying at least the simulation target layer thickness assigned to the respective single layer of one or more single layers in at least one spectral interval of the target measurement curve and obtaining a final simulation target data set with at least final simulation target layer thicknesses assigned to the respective single layers, by which the target measurement curve is at least approximated in the simulation target measurement curve until a stable result is achieved for the assignment criterion according to a statistical selection procedure; wherein the simulation actual layer thicknesses are used as the initial values ​​of the simulation target layer thicknesses; wherein the iterative procedure is carried out for one or more spectral intervals, each subsequent interval including the preceding interval.

[0068] The significant points of the actual measurement curve can be used advantageously to find the appropriate target design of the layer system for the actual measurement curve of the investigated layer system and then to use it for a first approximation in the form of a horizontal and / or lateral shift of the measurement curve.

[0069] The target data set, including the target measurement curve, contains the target data for the optimal coating. In addition to a spectrally resolved optical measurement, this data can include other target parameters, such as the color values ​​L*, C*, and h* in the visible spectral range, and / or defined, calculable spectral parameters like averaged or weighted transmission and / or reflection values ​​within a user-defined interval. Examples of spectrally calculable parameters include the visible range as well as the IR-A / IR-B and / or UV-A / UV-B ranges.

[0070] Furthermore, the target dataset contains coating-specific spectral intervals, nested from smallest to largest. The largest specified interval represents the maximum spectral viewing range. The number of intervals is freely selectable. The target dataset contains characteristic spectral points that uniquely define the optical layout of the coating.

[0071] The actual measurement curve includes at least the data from the optical measurement performed. The system data set includes at least the actual layer thicknesses of the multiple individual layers set on the coating system if the coating system consists of multiple individual layers, or the actual layer thickness of the single individual layer set on the coating system if the coating system consists of only one individual layer.

[0072] The simulation-actual measurement curve includes at least one simulated spectral measurement curve that represents the best possible agreement with the actual measurement curve performed.

[0073] The simulation actual data set includes at least the simulation actual layer thickness determined in the iterative optimization procedure, either one of the individual layers of the layer system or the simulation actual layer thicknesses of the multiple individual layers of the layer system.

[0074] The simulation target measurement curve includes at least one simulated spectral measurement curve that represents the best possible agreement between the target measurement curve and the simulation actual measurement curve.

[0075] The simulation target dataset includes at least the simulation target layer thicknesses of the multiple individual layers determined in the iterative optimization process, or the simulation target layer thickness of the single individual layer with the best possible agreement with the target measurement curve, calculated using the simulation target dataset. The one or more simulation target layer thicknesses set in this dataset represent the process parameters for the subsequent coating batch.

[0076] For this purpose, the simulation target data set includes the set calculation parameters of the simulated layer system for ideal layers and / or ideal processes, material properties such as ideal refractive indices and ideal deposition conditions, as well as system parameters such as coating geometry, layer thickness control, etc.

[0077] The simulation target dataset correlates, firstly, the optical differences between the actual measurement curve and the simulation actual measurement curve, taking into account system-related deviations, such as morphological and technical variations from coating batch to coating batch, as well as non-system-related deviations, such as handling differences, etc. Secondly, the simulation actual dataset is used to calculate the target measurement curve from the simulation target curve.

[0078] The method according to the invention provides that an actual measurement curve of a layer system, which was deposited on the coating system, is loaded into the simulation software of a simulation computer.

[0079] Starting with the scaled preliminary layer thicknesses of one or more layers from the previous step, an optimization process begins within a restricted spectral interval. This restricted spectral interval is coating-specific and stored in the target data set associated with the target measurement curve as the first possible interval from a list within the target data set. Within this optimization process, the layer thickness of a single layer, if the coating system consists of a single layer, or the layer thicknesses of multiple layers, if the coating system consists of multiple layers, are determined. These thicknesses then approximate the actual measurement curve to the underlying simulation target measurement curve.

[0080] After this step, a second preliminary set of data is available for one or more layer thicknesses. If no restriction was necessary, this second simulation dataset is identical to the first preliminary simulation dataset.

[0081] The optimization procedure is now applied to each subsequent spectral interval from the interval list of the target dataset. The currently running optimization procedure always uses the set of data from the simulation's actual dataset of the previous optimization procedure.

[0082] Typically, a modified simplex algorithm can be used as an optimization method, but other well-known simulation methods may be equally suitable. Simulation software for such optimization methods is commercially available from various vendors, for example, the commercial simulation software "Essential MacLeod" or other well-known simulation software for applications such as the fabrication of optical layers.

[0083] Once all interval iterations have been completed, the spectral data closely approximate the actual measurement curve, resulting in a first final simulation-actual measurement curve and a corresponding set of simulation-actual layer thicknesses. These two parameter sets constitute the simulation-actual dataset, which is temporarily stored.

[0084] These steps are repeated until a stable result is obtained using a statistical selection procedure. Preferably, the entire curve can be considered for this purpose, particularly with regard to chi-square deviations and the like.

[0085] According to an advantageous embodiment of the method according to the invention, the determination of calculated actual layer parameters by simulation of the layer system with the actual data set can further include: providing the final simulation target data set for the at least one coating system as a new system data set for the deposition of a further layer system with at least one or more correction actual layer thicknesses as new system actual layer thicknesses, which are determined from the final simulation target layer thicknesses with the final simulation target data set.

[0086] Once the spectral data of the actual measurement curve are approximated as closely as possible, the final simulation target dataset can be generated using one or more simulated actual layer thicknesses. With this new system dataset, further layer systems can then be produced on the coating system, which more closely match the originally desired target dataset.

[0087] According to a further, particularly independent, aspect of the invention, a coating system is proposed for producing layer systems using a method as described above, comprising at least one coating system for coating a substrate with a layer system for an optical element; a control computer for controlling the coating system and for communicating with a simulation computer; an optical measuring device for determining a spectrally resolved actual measurement curve of the layer system; a simulation computer on which simulation software for optical calculation and optimization of the layer system is installed; a design database for storing target data sets; a storage database for storing actual measurement curves, actual data sets, calculated actual layer parameters, and release decisions; a criteria database for storing release criteria; and a decision system for releasing layer systems.

[0088] The coating system thus comprises all the necessary components required for the effective operation of the coating plant according to the inventive method as described above. This allows a coating plant for the production of a layered system to be operated more efficiently and quickly. This results in considerable potential savings in the operation of the coating plant.

[0089] The coating system includes, for example, a vacuum chamber with associated units for coating substrates such as various coating sources, apertures, glass holders, pumps, etc.

[0090] Advantageously, the coating system can be operated in a self-regulating and feedback manner using the method according to the first aspect of the invention.

[0091] The control computer of the coating system manages the coating process and handles communication with the system. For automatic data exchange, this computer can have at least a network connection.

[0092] The optical measuring device can record a spectrally resolved measurement signal that represents the optical element, consisting of the optical substrate and the applied layer system. This so-called actual measurement curve can be provided as a two-dimensional data set, consisting of data tuples, for example, wavelength in nanometers and reflectivity in percent. This data is referred to as "spectral data".

[0093] The simulation software is installed on the simulation computer.

[0094] The simulation software is a computer program that can at least read the data set generated by the optical measuring device. Furthermore, the simulation software can read and output data sets from the coating system. The software works with input from the design database and, for example, reads target data sets from the design database and saves newly calculated simulation data sets in the storage database. The software also implements at least one optimization / fitting algorithm, such as those found in commercially available simulation programs, for example, in "Essential MacLeod".

[0095] The database stores the generated simulation target data sets for each coating system and each coating process, allowing them to be retrieved at a later time. Additionally, the database contains the corresponding target data sets for all stored coating processes.

[0096] The criteria database contains the relevant release criteria according to the latest regulations, patent database searches, specifications based on development and sales considerations, and the like.

[0097] The decision system, which can be designed as a separate processor, makes decisions about releasing the shift system based on a comparison of at least the actual data set, the calculated actual shift parameters and the quality requirement data, and documents the decision in the storage database.

[0098] However, the decision system can also be implemented not as separate hardware, but as a process on the control computer of the coating system.

[0099] According to a further, particularly independent, aspect of the invention, a computer program product is proposed for a method for operating a coating system for producing layer systems, wherein the computer program product comprises at least one computer-readable storage medium which includes program instructions that are executable on a computer system and cause the computer system to execute the method.comprising (i) coating a layer system in the coating system; (ii) determining an actual spectral measurement curve of the layer system in an optical measurement system; (iii) determining an actual data set by fitting a simulation target measurement curve to the actual measurement curve in the simulation computer; (iv) determining actual layer parameters as calculated actual layer parameters from the simulation target measurement curve by simulating the layer system with the actual data set; (v) outputting the actual data set and the calculated actual layer parameters to at least one decision system; (vi) providing quality requirement data; (vii) deciding on the release of the layer system in the decision system based on a comparison of at least the actual data set, the calculated actual layer parameters, and the quality requirement data; (viii) wherein coating the layer system in the coating system comprises,that an interferometric layer system is deposited on at least one surface of a substrate, (ix) wherein the layer system comprises a stack of at least four successive layer packages, each layer package comprising a pair of first and second layers, the first layers each having a first optical thickness and the second layers each having a second optical thickness different from the first optical thickness, (ix) wherein a refractive index of the first layers closest to the substrate is greater than a refractive index of the second layers furthest from the substrate in the stack, (xi) wherein the layer system has a brightness, a chroma, and a hue of a residual reflected color,(xii) wherein the magnitude of a change in the hue angle of the residual reflected color in an interval of a viewing angle with limit values ​​of 0° and 30°, referenced to a surface normal to the layer system, is less than the magnitude of a change in hue in the interval of the viewing angle, wherein, in order to design the layer system, the following steps are performed: (xiii) defining a layer design comprising at least a first material for the high-refractive-index first single layers and a second material for the low-refractive-index second single layers, the number of desired layer packages comprising the single layers, and initial values ​​of the thickness of the single layers; (xiv) defining target color values ​​comprising brightness, hue, and hue angle at least at the limit values ​​for an interval of a viewing angle with limit values ​​of 0° and 30°; (xv) performing an optimization procedure to vary the single layer thicknesses of the single layers,until an optimization goal is achieved.

[0100] The quality requirement data can be loaded, in particular, from a criteria database.

[0101] Optionally, it is also possible to calculate the color values ​​of a residual reflective color of the layer system from the actual measurement curve.

[0102] Furthermore, calculated reflection curves, especially angle-dependent reflection curves, can be generated and used for decision-making. The calculated actual layer parameters can include reflection values ​​in wavelength ranges outside the actual measurement curve, particularly in the UV wavelength range, and / or reflection values ​​at different angles of incidence. This approach is based on derived values ​​for the quality requirement data based on the release criteria. In this way, parameters for a release decision can be included that cannot be directly determined due to equipment limitations or excessively complex measurements.

[0103] The computer program product can provide modular software for operating a coating system for the production of layered systems and make it accessible to a wide variety of data processing systems. The computer program product can be advantageously used as a process recipe program coupled with a control program for the coating system.

[0104] Advantageously, a coating system or a system of coating systems can be operated in a self-controlling and feedback manner using the computer program product and the method according to the first aspect of the invention.

[0105] According to a further, particularly independent, aspect of the invention, a data processing system for executing a data processing program is proposed, which includes computer-readable program instructions in order to execute a method for operating at least one coating system for the production of layer systems, in particular as described above.

[0106] The data processing system can conveniently include the simulation computer as well as the design database, the storage database, the criteria database, and also the control computer of the coating system.

[0107] Advantageously, by means of the data processing system using the method according to the first aspect of the invention, a coating system or a system of coating systems can be operated in a self-controlling and feedback manner. drawing

[0108] Further advantages will become apparent from the following description of the drawings. The figures illustrate exemplary embodiments of the invention. The figures, the description, and the claims contain numerous features in combination. It will be advantageous for those skilled in the art to also consider the features individually and combine them into meaningful further combinations.

[0109] They show, for example: Fig. 1. A process for operating a coating system for producing layer systems for optical elements according to an embodiment of the invention; Fig. 2 a block diagram of a coating system according to an embodiment of the invention; Fig. 3 a table with release criteria according to the inventive method; Fig. 4 an optical element with a layer system of five layer packages on a substrate according to an embodiment of the invention; Fig. 5 a flowchart for determining an actual data set by fitting a simulation target measurement curve to the actual measurement curve according to the inventive method; Fig. 6 Reflectivity curves of a layer system according to the invention at perpendicular incidence of light with a comparison of an actual measurement curve and a target measurement curve in the wavelength range from 280 nm to 800 nm; Fig. 7 an enlarged representation of the reflectivity curves of Fig. 6; Fig. 8 Reflectivity curves of the layer system at perpendicular incidence with a comparison of the target measurement curve and a scaled simulation target measurement curve; Fig. 9 Reflectivity curves of the layer system at perpendicular incidence with a comparison of the target measurement curve and a simulation target measurement curve fitted in a first spectral interval from 380 nm to 580 nm; Fig.10 reflectivity curves of the layer system at perpendicular incidence with a comparison of the target measurement curve and a simulation target measurement curve fitted in a larger spectral interval from 380 nm to 780 nm; and Fig. 11 Reflectivity curves of the layer system at perpendicular incidence with a comparison of the actual measurement curve and a simulation target measurement curve fitted over the entire wavelength range from 280 nm to 800 nm. Embodiments of the invention

[0110] In the figures, similar or equivalent components are numbered with the same reference symbols. The figures merely show examples and are not to be understood as limiting.

[0111] The directional terminology used below, including terms like "left," "right," "above," "below," "in front," "behind," "after," and the like, serves only to improve the understanding of the figures and is in no way intended to limit their generality. The components and elements depicted, their interpretation, and their use may vary according to the considerations of a person skilled in the art and be adapted to the specific applications.

[0112] Fig. Figure 1 shows a process for operating a coating system 100 for producing layer systems 10 for optical elements 80 according to an embodiment of the invention.

[0113] The process comprises, in step S100, the coating of a layer system 10 in a coating system 102. The system components are shown in the Fig. The block diagram of a coating system 100 shown in 2 can be identified.

[0114] Once the coating process is complete, a spectral actual measurement curve 90 of the layer system 10 can be determined in an optical measurement system 104 in step S102. For this purpose, a coated optical element 80 is removed from the coating system and a measurement of its spectral reflectance is taken to record an actual measurement curve 90. The optical element 80, as layer system 10, is, for example, in Fig. 4 specified. An example actual measurement curve 90 is in the Fig. 6 and Fig. 7 shown.

[0115] Optionally, in step S104, color values ​​88 of a residual reflectance color of the layer system 10 can be determined from the actual measurement curve 90, and in step S106, the actual measurement curve 90 and the calculated color values ​​88 can be stored in a database 210. The color values ​​88 of the residual reflectance color are calculated according to the standard from the spectral reflectance data (λ, R(λ)). For example, a brightness L*, a chroma C*, and a hue h of the residual reflectance color are determined from the actual measurement curve.

[0116] In step S108, a target data set Dat_soll of the layer system 10 from a design database 200 and the actual measurement curve 90 are loaded into a simulation computer 106. The actual measurement curve 90 can be loaded as the target curve. Additionally, the design of the completed coating is queried in the design database 200 as a target data set Dat_soll.

[0117] In step S110, an actual data set Dat_ist is determined by fitting a simulation target measurement curve 98 to the actual measurement curve 90 in the simulation computer 106. Such a simulation target measurement curve 98 is, for example, in the Fig. Figures 8 to 10 are shown. The physical single-layer thicknesses of the underlying design of the layer system 10 are varied within appropriate limits until the actual measurement curve 90 is met as closely as possible.

[0118] In step S112, actual layer parameters 96 are determined as calculated actual layer parameters 96 from the simulation target measurement curve 98 by simulating the layer system 10 with the actual data set Dat_ist. The simulation allows for the acquisition of further parameters not accessible from the original reflection measurement as actual measurement curve 90, such as the reflection curve at different angles of incidence, reflection in spectral ranges outside the spectrometer's measurement range, etc. The calculated actual layer parameters 96 can thus include, for example, reflection values ​​in wavelength ranges outside the actual measurement curve 90, particularly in the UV wavelength range, and / or reflection values ​​at different angles of incidence.

[0119] Subsequently, in step S114, the actual data set Dat_ist, the calculated actual layer parameters 96 are output to a decision system 108 and to the storage database 210. The raw data of the spectral reflectance (λ, R(λ,)) and the color values ​​calculated from it are stored in the storage database 210.

[0120] In step S116, release criteria for coating systems 10 are loaded from a criteria database 220 into the decision system 108. In step S118, quality requirement data is provided to the decision system 108, in particular loaded from the criteria database 220 into the decision system 108. The criteria database 220 can contain positive or negative criteria for all coatings.

[0121] The release criteria may include permissible and / or impermissible shift parameters, in particular from which requirements are derived which can be used for comparison with the actual data set Dat_ist and / or the calculated actual shift parameters 96 and / or the actual measurement curve 90.

[0122] The quality requirement data can also include tolerance values ​​for the target data set Dat_soll of a shift system 10.

[0123] Subsequently, in step S120, a release decision (S122, S124) for layer system 10 is made in decision system 108 based on a comparison of at least the actual data set (Dat_ist), the calculated actual layer parameters (96), and the quality requirement data. S122 can, for example, mean accepted, and S124 can mean rejected. The calculated parameters can be compared with target values ​​and defined tolerances. This is followed by an automatic, software-based release decision as to whether the coating batch meets the defined quality requirement data.

[0124] The decision regarding the release of shift system 10 within decision system 108 can therefore expediently include an automated, software-based release decision. In particular, the release can be carried out using an artificial intelligence method.

[0125] The decision S122, S124 is then documented in the filing database 210.

[0126] Alternatively, the decision system 108 can be used to decide in advance, before carrying out a coating in the coating system 102, based on a comparison of at least the target data set Dat_soll and release criteria from the criteria database 220, whether the planned layer system 10 has any chance of receiving a release based on the existing release criteria.

[0127] Fig. Figure 2 shows a block diagram of a coating system 100 according to an embodiment of the invention. The coating system 100 serves to produce a layer system 10 with the in Fig. 1 described procedure.

[0128] The coating system 100 comprises a coating system 102 for coating a substrate 22 with a layer system 10 for an optical element 80, and a control computer 110 for controlling the coating system 102 and for communication with a simulation computer 106.

[0129] The coated optical element 80 can be transferred into an optical measuring device 104 to determine a spectrally resolved actual measurement curve 90 of the layer system 10.

[0130] A design database 200 is used to store target data records Dat_soll of shift systems 10.

[0131] Furthermore, the coating system 100 includes a simulation computer 106 on which simulation software 107 for optical calculation and optimization of the coating system 10 is installed.

[0132] On the simulation computer 106, a computer program product for a method according to the first aspect of the invention for operating at least one coating system 102 for producing layer systems 10 for optical elements 80 is implemented, wherein the computer program product comprises at least one computer-readable storage medium which includes program instructions that are executable on the computer system 106 and cause the computer system 106 to execute the method.

[0133] The computer program product can be considered an independent aspect of the invention, in particular for carrying out a method according to the first aspect of the invention on a simulation computer 106 of a data processing system 124.

[0134] The data processing system 124, which includes at least the simulation computer 106 and the simulation software 107, serves to execute a data processing program which includes computer-readable program commands in order to execute the method for operating the coating system 102 for the production of layer systems 10 for optical elements 80.

[0135] The data processing system 124 can be considered an independent aspect of the invention, in particular for carrying out a method according to the first aspect of the invention with a simulation computer 106.

[0136] A storage database 202 is used to store actual measurement curves 90, actual data records Dat_ist, calculated actual shift parameters 96 and release decisions.

[0137] Finally, the coating system 100 contains a criteria database 220 for storing release criteria, which can be loaded by the decision system 108 to release coating systems 10. The decision system 108 decides whether to release the manufactured coating system 10 based on these release criteria. The criteria database 220 can contain both release criteria and quality requirement data.

[0138] In Fig. Figure 3 shows a table with release criteria according to the inventive method. The table numbers the individual release criteria, for example 1.1, 1.2, 1.3, 1.4. For each criterion, a long text T1-T4 explaining the criterion, a numerically verifiable form N1 to N4, and the requirement R1 to R4 to which the criterion relates are listed.

[0139] For example, the criteria can include individual claim features of a patent specification for an optical application, which are listed in the following example. The individual features, in numerically verifiable form, can be automatically checked using simple comparison algorithms. Claim criterion Feature (full text) Feature (verifiable form) Requirement 1.1 Ophthalmic lens with multilayer system..... At least one low-reflective layer. At least one high-reflective layer. Layer design 1.2 Average reflection factor <1.15% R m < 1,15% Spectral reflection curve 1.3 Light reflection factor < 1% R v < 1,0% Spectral reflection curve 1.4 Coating: at least 3 layers No indium tin oxide (ITO) single layer Layer design

[0140] The Fig. Figure 4 shows an exemplary optical element 80 with a layer system 10 on a substrate 22, for example a spectacle lens, according to an embodiment of the invention. The interferometric layer system 10 is arranged on at least one surface 24 of the substrate 22. Advantageously, the layer system 10 can be produced using a self-regulating and feedback method according to the first aspect of the invention.

[0141] As the bottom layer on the substrate 22, the layer system 10 can, in the usual manner, include a single-layer or multi-layer intermediate layer 30, for example, to improve the adhesion of the stack 40 and / or as scratch protection for the substrate 22. This intermediate layer 30 can, in the usual manner, consist of, for example, substoichiometric refractive metal oxides, chromium, silanes, or siloxanes. The intermediate layer 30 is not relevant for further considerations of the optical properties. Likewise, intermediate layers, such as a conventional coating system like primer coatings and the like, can also be provided as adhesion promoters between the substrate and the layer system.

[0142] On the intermediate shift 30 are in Fig. 5 for example five layer packages 42, 44, 46, 48, 50 of a stack 40 arranged consecutively.

[0143] On the intermediate layer 30, a stack 40 of at least four, in this example five, successive layer packages 42, 44, 46, 48, 50 is arranged, wherein each layer package 42, 44, 46, 48, 50 comprises a pair of first single layers 11, 13, 15, 17, 19 and second single layers 12, 14, 16, 18, 20.

[0144] The layer package 42 closest to the substrate comprises the single layer 11 closer to the substrate and the single layer 12 further away from the substrate, the next layer package 44 the single layer 13 closer to the substrate and the single layer 14 further away from the substrate, the following layer package 46 the single layer 15 closer to the substrate and the single layer 16 further away from the substrate, the layer package 48 following this comprises the single layer 17 closer to the substrate and the single layer 18 further away from the substrate, and the layer package 50 furthest away from the substrate comprises the single layer 19 closer to the substrate and the single layer 20 further away from the substrate.

[0145] Optionally, the layer package 50 furthest from the substrate can have a functional layer 34 between the sublayer 19 closer to the substrate and the sublayer 20 further away from the substrate. This functional layer 34 can, for example, increase electrical conductivity, equalize mechanical stresses, and / or act as a diffusion barrier. It can be made of a low-refractive-index material or alloyed with other metal oxides, such as aluminum. For calculation and simulation purposes of the optical properties, the functional layer 34 can be included in the calculation of the lower-refractive-index sublayer 20 of the uppermost, furthest layer package 50, or, if necessary, for example, if the layer thickness is relatively small, it can be disregarded.

[0146] In each layer package 42, 44, 46, 48, 50, the corresponding first single layers 11, 13, 15, 17, 19 each have a first optical thickness t1 and the corresponding second single layers 12, 14, 16, 18, 20 each have a second optical thickness t2, which differs from the first optical thickness t1 in the respective layer package 42, 44, 46, 48, 50.

[0147] A refractive index n1 of the respective first single layers 11, 13, 15, 17, 19 closest to the substrate is greater than a refractive index n2 of the respective second single layers 12, 14, 16, 18, 20 furthest from the substrate of the stack 40. The layer system 10 has a brightness L*, a chroma C* and a hue angle h of a residual reflected color, wherein the magnitude of a change Δh of the hue angle h of the residual reflected color in an interval of a viewing angle AOI with the limiting values ​​of 0° and 30° with respect to a surface normal 70 on the layer system 10 is smaller than the magnitude of a change ΔC* of the chroma C* in the interval of the viewing angle AOI.

[0148] The layer system is viewed by an observer at a viewing angle AOI of 0° up to a limiting angle, for example 30°, measured from the surface normal 70.

[0149] To design the shift system 10, the following steps are preferably carried out: - Defining a layer design comprising at least a first material for high-refractive-index first single layers 11, 13, 15, 17, 19 and a second material for low-refractive-index second single layers 12, 14, 16, 18, 20, number of desired layer packages 42, 44, 46, 48, 50 with the single layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, starting values ​​of the thickness of the single layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20; - Defining target color values, including brightness L*, hue C* and hue angle h at least at limit values ​​for an interval of an AOI viewing angle with limit values ​​of 0° and 30°; - Performing an optimization procedure to vary the individual layer thicknesses d_ist_11, ..., d_ist_20, until an optimization target is reached.

[0150] Substrate 22, for example, is a plastic, in particular a transparent plastic for a spectacle lens.

[0151] Within the scope of this disclosure, the term spectacle lens refers in particular to a coated spectacle lens in accordance with section 8.1.13 of the standard DIN EN ISO 13666:2013-10, i.e. a spectacle lens onto which one or more surface coatings have been applied, in particular to change one or more of its properties.

[0152] Such lenses can be particularly advantageously used as eyeglasses (with and without correction), sunglasses, ski goggles, occupational eyeglasses, and eyeglasses in conjunction with head-mounted display devices.

[0153] Within the scope of this disclosure, the term spectacle lens may also include spectacle lens semi-finished products, in particular a spectacle lens blank or spectacle lens semi-finished product as defined in section 8.4.2 of the standard DIN EN ISO 13666:2013-10, i.e. a lens blank or blank with only one optically finished surface.

[0154] Regarding the designs in Fig. 4 The opposite surface 26 of the substrate 22 may optionally have another, similar or identical layer system 10, no coating or merely a protective coating (not shown).

[0155] Preferably, each of the individual layers 11, 13, 15, 17, 19 closest to the substrate is formed from an identical first material. Preferably, the first material is a higher refractive index material with a first refractive index n1.

[0156] Preferably, each of the substrate-remote layers 12, 14, 16, 18, 20 is formed from an identical second material. Preferably, the second material is a low-refractive-index material with a second refractive index n2. The refractive index n1 is greater than the refractive index n2; preferably, the difference between the refractive indices n1 and n2 is at least 0.2, preferably up to at least 0.5.

[0157] The sequence of the first single layers 11, 13, 15, 17, 19 and the second single layers 12, 14, 16, 18, 20 remains the same in stack 40, so that in each layer package 42, 44, 46, 48, 50 the respective first single layer closer to the substrate 11, 13, 15, 17, 19 is always the higher refractive index and the respective second single layer further away from the substrate 12, 14, 16, 18, 20 is always the lower refractive index of the single layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.

[0158] In particular, the higher refractive index single layers 11, 13, 15, 17, 19 may be layers of high refractive index materials and the lower refractive index single layers 12, 14, 16, 18, 20 may be layers of low refractive index materials.

[0159] The layer packages 42, 44, 46, 48, 50 in stack 40 differ only in their respective thickness and / or in the thicknesses of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 in the respective layer package 42, 44, 46, 48, 50.

[0160] The stack 40 is finished in a manner known per se with a top layer 32, which, for example, serves to maintain the layer system 10. The top layer 32 is applied to the last optically relevant single layer 20 of the uppermost layer package 50 of the stack 40 and may, for example, contain fluorine molecules. The top layer 32 typically imparts improved maintenance properties to the stack 40, with characteristics such as water and oil repellency at a surface energy of typically less than 15 mN / m.

[0161] The top layer 32 is not relevant for further considerations of the optical properties of the layer system 10.

[0162] The optical properties of stack 40 of layer system 10 can be simulated computationally using known calculation methods and / or optimization procedures. The layer system 10 is then fabricated with the determined layer thicknesses of the individual sublayers 60, 62 of layer packages 42, 44, 46, 48, 50.

[0163] In the fabrication of optical layer systems 10, the optical properties of the layer system 10 are adjusted during the fabrication of the sublayers 60, 62. For example, the method known from WO 2016 / 110 339 A1, which is briefly outlined below, can be used. With this known method, various optical effects such as mirroring or reflection reduction can be achieved in a material system by changing only the layer thicknesses, while keeping the material used the same. However, other methods are also possible.

[0164] Different reflectivities, particularly for a reflection-reducing effect, can be achieved by varying the layer package thicknesses with identical materials, as described in WO 2016 / 110 339 A1. This is achieved by minimizing or optimizing a parameter σ. The parameter σ is, in turn, a function of the layer thicknesses of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or of the ratios of the optical thicknesses t1, t2 of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 of each of the four layer packages 42, 44, 46, 48 (not shown) or five layer packages 42, 44, 46, 48, 50 according to Fig. 5 in stack 40.

[0165] At a specific wavelength λ, the optical thickness t of a layer, also called FWOT (full wave optical thickness), is determined as follows: t=dλ⋅n where d is the layer thickness, λ is the design wavelength and n is the refractive index of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.

[0166] A reflection-reducing effect by stack 40 can be achieved for a predetermined reflectivity R. m of the stack 40 can be reached when the product of reflectivity R m and the parameter σ is set to less than 1: Rm⋅σ<1

[0167] The reflectivity R m Reflectance, also called reflectance, describes the ratio of reflected to incident intensity of a light ray as an energy quantity. The reflectivity R m It is expediently averaged over the range of light from 380 nm to 800 nm and referenced to 100%.

[0168] Such a condition R m ·σ<1 can be used as a boundary condition for an optimization process of the method for producing the layer system 10.

[0169] The optical thicknesses t1, t2 of the first and second single layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 of the layer packages 42, 44, 46, 48, 50 are determined by determining the parameter σ using an optimization procedure, preferably using variational calculus.

[0170] The thicknesses of the respective individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 are preferred in five layer packages 42, 44, 46, 48, 50 in the stack 40 depending on a quotient v i (with i=1, 2, 3, 4, 5) the first optical thickness t1 of each of the higher refractive index first single layers 11, 13, 15, 17, 19 and the second optical thickness t2 of the lower refractive index second single layers 12, 14, 16, 18, 20 of the respective layer package 42, 44, 46, 48, 50 are formed.

[0171] In an advantageous embodiment, a layer system can be 10 according to Fig.4 of the parameters σ for a stack 40 with five consecutive layer packages 42, 44, 46, 48, 50 from the relationship σ=v1∑i=2nmaxvi to be determined, where i = runs from 2 to nmax = 5.

[0172] The indices i=1, 2, 3, 4, 5 represent the sequence of the layer packages 42, 44, 46, 48, 50 on the substrate 22. Accordingly, v1 represents the layer package 42 closest to the substrate and v5 represents the layer package 50 furthest from the substrate.

[0173] It is known to specify perception-related colors in the so-called CIE-L*a*b* color space (simplified CIELab color space) in Cartesian coordinates, as set out in DIN EN ISO 11664-4:2012-06 (EN ISO 11664-4:2011).

[0174] L* is the CIELab brightness, a*, b* are the CIELab coordinates, C* is the CIELab chromaticity, and h ab the CIELab hue angle.

[0175] The L* axis describes the brightness (luminance) of the color with values ​​from 0 to 100. The L* axis is perpendicular to the a*b* plane at the origin. It can also be called the neutral gray axis, since all achromatic colors (shades of gray) are contained between the endpoints black (L*=0) and white (L*=100).

[0176] Green and red are opposite each other on the a*-axis, while the b*-axis runs between blue and yellow. Complementary colors are positioned 180° apart; gray is located at their midpoint, i.e., at the origin of the coordinate system a*=0, b*=0.

[0177] The a*-axis describes the green or red component of a color, where negative values ​​represent green and positive values ​​represent red. The b*-axis describes the blue or yellow component of a color, where negative values ​​represent blue and positive values ​​represent yellow.

[0178] The a* values ​​range from approximately -170 to +100, and the b* values ​​from -100 to +150, with the maximum values ​​only being reached at medium brightness for certain hues. The CIELab color solid has its greatest extent in the mid-brightness range, but this extent varies in height and size depending on the color range.

[0179] The CIELab hue angle h ab must be between 0° and 90° if both a* and b* are positive, between 90° and 180° if b* is positive and a* is negative, between 180° and 270° if both a* and b* are negative, and between 270° and 360° if b* is negative and a* is positive.

[0180] In the CIE-L*C*h color space (simplified CIELCh color space), the Cartesian coordinates of the CIELab color space are transformed into polar coordinates. The cylindrical coordinates C* (chroma, relative color saturation, distance from the L-axis at the center) and h (hue angle, angle of the hue in the CIELab color circle) are specified. The CIELab lightness L* remains unchanged.

[0181] The hue angle h is derived from the a* and b* axes. h=arctan(b*a*)

[0182] The hue angle h here represents the color of the residual reflection of the interferometric layer system 10.

[0183] The chromaticity C* results from C*=(a*)2+(b*)2

[0184] The chromaticity C* is also referred to as color depth.

[0185] To determine the layer thicknesses d_target_11, ..., d_target_20 of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, an optimization procedure is carried out to vary the individual layer thicknesses d_target_11, ..., d_target_20 until an optimization target is reached. The optimization procedure then continues to vary the individual layer thicknesses d_target_11, ..., d_target_20 until the optimization target (color stability) is achieved.

[0186] The hue angle h can change by at most 15°, preferably by at most 10°, within the interval of the viewing angle AOI with limit values ​​of 0° and 30°. The magnitude of the change Δh of the hue angle h can, in a second interval of a viewing angle AOI from 0° up to a limiting viewing angle θ with upper limits between at least 30° and at most 45° relative to the surface normal 70 on the layer system 10, be smaller than the magnitude of a change ΔC* of the hue C* in the second interval of the viewing angle AOI, and the magnitude of the hue C* can be at least C*=2 at the limiting viewing angle θ. In particular, the hue angle h can change by at most 20°, preferably by at most 15°, in the second interval.

[0187] The photopic reflectance Rv in the interval of the viewing angle AOI with the limit values ​​of 0° and 30° can advantageously be at most 1.5%, preferably at most 1.2%.

[0188] The scotopic reflectance Rv' in the interval of the viewing angle AOI with the limit values ​​of 0° and 30° can advantageously be at most 1.5%, preferably at most 1.2%.

[0189] Fig. Figure 5 shows a flowchart for determining an actual data set Dat_ist by fitting a simulation target measurement curve 98 to the actual measurement curve 90 according to the inventive method.

[0190] The procedure is carried out in the simulation computer 106 and, in step S200, comprises the acquisition of at least one spectral measurement curve with ordinate and abscissa values ​​as an actual measurement curve 90 of the layer system 10, which consists of one or more individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 with respective actual layer thicknesses d_actual_11, ..., d_actual_20. The one or more individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 are produced according to a target data set Dat_target of the coating system 102. The target data set Dat_soll includes at least the actual layer thicknesses d_ist_11, ..., d_ist_20 of the one or more individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 assigned to the respective individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.

[0191] In step S202, the actual measurement curve 90 of the layer system 10 is assigned according to an assignment criterion, in particular for significant spectral points of the actual measurement curve 90, to a target measurement curve 92 of a target data set DAT_target with ordinate values ​​and abscissa values, which is based on a target data set layer system 10_target, formed from one or more individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20. The target data set DAT_soll includes at least one known target layer thickness d_soll_11, ..., d_soll_20 assigned to the respective individual layer 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 of one or more individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.

[0192] In step S204, a simulation actual measurement curve 94 is generated iteratively by varying at least the simulation actual layer thicknesses g_actual_11, ..., g_actual_20 of one or more individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 in at least one spectral interval 82 of the actual measurement curve 90. This results in a final simulation actual data set DAT_actual_sim with at least final simulation actual layer thicknesses g_actual_11, ..., g_actual_20 assigned to the respective individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, by which the actual measurement curve 90 is at least approximated in the simulation actual measurement curve 94. This process continues until a stable result is achieved for the allocation criterion using a statistical selection procedure.

[0193] The target layer thicknesses d_target_11, ..., d_target_20 are used as the starting values ​​for the simulation actual layer thicknesses g_actual_11, ..., g_actual_20.

[0194] In step S206, a simulation target measurement curve 98 is generated according to an iterative procedure by varying at least the simulation target layer thickness g_target_11, ..., g_target_20 assigned to the respective single layer 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 of one or more single layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 in at least one spectral interval 82 of the target measurement curve 92. This results in a final simulation target dataset DAT_soll_sim with at least the final simulation target layer thicknesses g_soll_11, ..., g_soll_20 assigned to the respective individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, by which the target measurement curve 92 is at least approximated in the simulation target measurement curve 98. This is carried out until a stable result is achieved for the assignment criterion using a statistical selection procedure. The initial values ​​of the simulation target layer thicknesses g_soll_11, ... are used., g_soll_20 uses the simulation actual layer thicknesses g_ist_11, ..., g_ist_20.

[0195] This iterative procedure is performed for one or more spectral intervals 82, 84, 86, with each subsequent interval 84, 86 including the preceding interval 82, 84.

[0196] Determining calculated actual layer parameters 96 by simulating the layer system 10 with the actual data set Dat_ist can expediently in step S208 further include providing the final simulation target data set DAT_soll_sim for the at least one coating system 102 as a new system data set Dat_ist+1 for the deposition of a further layer system 10_n+1 with at least one or more correction actual layer thicknesses d_korr_11, ..., d_korr_20 as new system actual layer thicknesses d_ist_11, ..., d_ist_20, which are determined from the final simulation target layer thicknesses g_soll_11, ..., g_soll_20 with the final simulation target data set DAT_soll_sim.

[0197] Fig. Figure 6 shows reflectivity curves of a layer system 10 according to the invention with a comparison of an actual measurement curve 90 (solid line) and a target measurement curve 92 (dotted line) in the wavelength range from 280 nm to 800 nm; Fig.Figure 7 shows an enlarged representation of the reflectivity curves of Fig. 6. The target measurement curve 92 was determined by comparing extreme values ​​from database 106 to the actual measurement curve 90. A strong peak shift in the lower wavelength range between 280 nm and 380 nm is visible, as can be seen in the enlarged representation in Fig. 7 in the wavelength range of 380 nm and 680 nm.

[0198] In Fig.Figure 8 shows reflectivity curves of the layer system 10 with a comparison of the target measurement curve 92 (dotted line) and a scaled simulation target measurement curve 98 (solid line). This resulted in a horizontal shift of the simulation target measurement curve 98. The entire layer system 10 was scaled, i.e., the vector that preserves all physical layer thicknesses g_soll_11, ..., g_soll_20 of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 representing the layer system 10 was multiplied by a scaling factor 122, i.e., each individual layer 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 was made thicker or thinner by the same scaling factor 122.

[0199] Fig.Figure 9 shows reflectivity curves of the layer system 10 with a comparison of the target measurement curve 92 and a simulation target measurement curve 98 fitted in a first spectral interval 82 from 380 nm to 580 nm. The simplex algorithm was used for the iterative optimization procedure. The algorithm was started with the optimization goal of mapping the simulation target measurement curve 98 from the previous step as closely as possible to the target measurement curve 92 in the interval 380 nm to 580 nm by changing the physical layer thicknesses g_target_11, ..., g_target_20. This results in a very good approximation of the two measurement curves 92 and 98 in the selected interval 82.

[0200] In Fig.Figure 10 shows reflectivity curves of the layer system 10, comparing the target measurement curve 92 with a simulation target measurement curve 98 fitted over a larger spectral interval 84 from 380 nm to 780 nm. This time, a simplex optimization was applied over the larger interval 84 from 380 nm to 780 nm. Layer thickness relationships were not considered. In the lower wavelength range around 400 nm, the quality of agreement between the two measurement curves 92 and 98 is slightly worse, while it is better in the upper wavelength range from 580 nm to 680 nm.

[0201] Fig.Figure 11 shows reflectivity curves of the layer system 10 with a comparison of the target measurement curve 92 and a simulation target measurement curve 98 fitted over the entire wavelength range as interval 86 from 280 nm to 800 nm. This time, a simplex optimization was applied in the larger interval 86 from 280 nm to 800 nm. Layer thickness relationships were not taken into account. The quality of the agreement between the two measurement curves 92 and 98 has deteriorated slightly in the mid-wavelength range from 480 nm to 580 nm, but is on average better over the entire wavelength range from 280 nm to 800 nm.

Claims

[1] Method for operating a coating system (100) for producing coating systems (10), comprising (i) Coating (S100) a coating system (10) in a coating system (102); (ii) Determining (S102) a spectral actual measurement curve (90) of the layer system (10) in an optical measurement system (104); (iii) Determining (S110) an actual data set (Dat_ist) by fitting a simulation target measurement curve (98) to the actual measurement curve (90); (iv) Determining (S112) actual layer parameters (96) as calculated actual layer parameters (96) from the simulation target measurement curve (98) by simulating the layer system (10) with the actual data set (Dat_ist); (v) Output (S114) of the actual data set (Dat_ist) and the calculated actual layer parameters (96) to at least one decision system (108); (vi) Providing (S118) quality requirement data; (vii) Deciding (S120) on the release (S122, S124) of the shift system (10) in the decision system (108) on the basis of a comparison of at least the actual data set (Dat_ist), the calculated actual shift parameters (96) and the quality requirement data, characterized by , that The coating of the layer system (10) in the coating system (102) comprises the deposition of an interferometric layer system (10) on at least one surface (24) of a substrate (22), wherein the layer system (10) comprises a stack (40) of at least four successive layer packages (42, 44, 46, 48, 50), wherein each layer package (42, 44, 46, 48, 50) comprises a pair of first and second single layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), wherein the first single layers (11, 13, 15, 17, 19) each have a first optical thickness (t1) and the second single layers (12, 14, 16, 18, 20) each have a second optical thickness (t2) different from the first optical thickness (t1), wherein a refractive index (n1) of the first individual layers (11, 13, 15, 17, 19) closest to the substrate is greater than a refractive index (n2) of the second individual layers (12, 14, 16, 18, 20) furthest from the substrate of the stack (40), wherein the layer system (10) has a brightness (L*), a chroma (C*) and a hue angle (h) of a residual reflected color, wherein the magnitude of a change (Δh) of the hue angle (h) of the residual reflectance color in an interval of an AOI with limiting values ​​of 0° and 30° with respect to a surface normal (70) on the layer system (10) is less than the magnitude of a change (ΔC*) of the chroma (C*) in the interval of the AOI, wherein, in order to design the layer system (10), the following steps are carried out: - Defining a layer design comprising at least a first material for the high-refractive-index first single layers (11, 13, 15, 17, 19) and a second material for the low-refractive-index second single layers (12, 14, 16, 18, 20), number of desired layer packages (42, 44, 46, 48, 50) with the single layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), starting values ​​of the thickness of the single layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20); - Defining target color values, including brightness (L*), hue (C*) and hue angle (h) at least at the limits for the interval of viewing angle (AOI) with the limits of 0° and 30°; - Performing an optimization procedure to vary the individual layer thicknesses (d_ist_11, ..., d_ist_20) of the individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) until an optimization target is achieved. [2] Method according to claim 1, furthermore characterized by the steps (i) Calculating (S104) color values ​​(88) of a residual reflection color of the layer system (10) from the actual measurement curve (90); (ii) Storing (S106) the actual measurement curve (90) and the calculated color values ​​(88) in a storage database (210); (iii) Loading (S108) a target data set (Dat_soll) of the layer system (10) from a design database (200) and the actual measurement curve (90) into a simulation computer (106); (iv) Determining (S110) the actual data set (Dat_ist) by fitting the simulation target measurement curve (98) to the actual measurement curve (90) in the simulation computer (106); (v) Output (S114) of the actual data set (Dat_ist) and the calculated actual layer parameters (96) to the decision system (108) and to the storage database (210); (vi) Loading (S116) release criteria for shift systems (10) from a criteria database (220); (vii) Documenting the decision on release (S122, S124) in the filing database (210). [3] Method according to claim 2, characterized by , that the release criteria include at least permissible and / or impermissible shift parameters, in particular from which requirements are derived which are used for a comparison with the actual data set (Dat_ist) and / or the calculated actual shift parameters (96) and / or the actual measurement curve (90). [4] Method according to any one of claims 2 to 3, characterized by , that the quality requirement data include tolerance values ​​for the target data set (Dat_soll) of the shift system (10). [5] Method according to any one of the preceding claims, characterized by , that the decision on the release of the shift system (10) in the decision system (108) includes an automatic, software-based release decision, in particular using an artificial intelligence procedure. [6] Method according to any one of claims 2 to 5, furthermore characterized by Deciding on the coating of the layer system (10) in the coating system (102) based on a comparison of at least the target data set (Dat_soll) and release criteria from the criteria database (220). [7] Method according to any one of the preceding claims, characterized by, that the calculated actual layer parameters (96) include reflection values ​​in wavelength ranges outside the actual measurement curve (90), especially in the UV wavelength range, and / or reflection values ​​at different angles of incidence. [8] Method according to any one of the preceding claims, characterized by , that the hue angle (h) in the interval of the viewing angle (AOI) with the limit values ​​of 0° and 30° changes by at most 15°, preferably by at most 10°; and / or wherein the magnitude of the change (Δh) of the hue angle (h) in a second interval of a viewing angle (AOI) from 0° up to a limiting viewing angle (θ) with upper limits between at least 30° and at most 45° with respect to the surface normal (70) to the layer system (10) is less than the magnitude of a change (ΔC*) of the hue (C*) in the second interval of the viewing angle (AOI) and the magnitude of the hue (C*) at the limiting viewing angle (θ) is at least 2, in particular wherein the hue angle (h) in the second interval changes by at most 20°, preferably by at most 15°; and / or wherein the photopic reflectance (Rv) in the interval of the viewing angle (AOI) with the limit values ​​of 0° and 30° is at most 1.5%, preferably at most 1.2%; and / or wherein the scotopic reflectance (Rv') in the interval of the viewing angle (AOI) with the limit values ​​of 0° and 30° is at most 1.5%, preferably at most 1.2%. [9] Method according to any one of the preceding claims, characterized by , that to determine the actual spectral measurement curve (90) of the layer system (10) in the optical measurement system (104) a spectral reflectance measurement is carried out on the layer system (10). [10] Method according to any one of claims 2 to 9, characterized by , that the calculation of the color values ​​(88) of the residual reflective color of the layer system (10) from the actual measurement curve (90) further includes that the brightness (L*), the chroma (C*) and the hue angle (h) of the residual reflective color is determined from the actual measurement curve (90). [11] Method according to any one of claims 2 to 10, characterized by, that determining the actual data set (Dat_ist) by fitting the simulation target measurement curve (98) to the actual measurement curve (90) in the simulation computer (106) further includes (i) Acquiring (S200) at least one spectral measurement curve with ordinate values ​​and abscissa values ​​as an actual measurement curve (90) on the layer system (10) which consists of the several individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) with respective actual system layer thicknesses (d_actual_11, ..., d_actual_20), wherein the several individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) are produced according to the target data set (DAT_target) of the coating system (102), wherein the target data set (DAT_target) contains at least the values ​​corresponding to the respective individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) assigned actual layer thicknesses (d_ist_11, ..., d_ist_20) of the several individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20); (ii) Assigning (S202) the actual measurement curve (90) of the layer system (10) according to an assignment criterion, in particular for significant spectral points of the actual measurement curve (90), to a target measurement curve (92) of the target data set (DAT_target) with ordinate values ​​and abscissa values, which is based on a target layer system (10_target) formed from several individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), wherein the target data set (DAT_target) includes at least one known target layer thickness (d_target_11, ..., d_target_20) assigned to the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) of the several individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) includes; (iii) Generating (S204) a simulation actual measurement curve (94) according to an iterative procedure by varying at least simulation actual layer thicknesses (g_actual_11, ..., g_actual_20) of the several individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) in at least one spectral interval (82) of the actual measurement curve (90) and obtaining a final simulation actual data set (DAT_actual_sim) with at least final simulation actual layer thicknesses (g_actual_11, ..., g_actual_20) assigned to the respective individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), by which the actual measurement curve (90) in the The simulation actual measurement curve (94) is at least approximated until a stable result is achieved for the assignment criterion according to a statistical selection procedure, whereby the target layer thicknesses (d_target_11, ..., d_target_20) are used as the starting values ​​of the simulation actual layer thicknesses (g_actual_11, ..., g_actual_20); (iv) Generating (S206) the simulation target measurement curve (98) by an iterative procedure by varying at least one of the simulation target layer thicknesses (g_target_11, ..., g_target_20) assigned to the respective individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) of the several individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) in at least one spectral interval (82) of the target measurement curve (92) and obtaining a final simulation target data set (DAT_target_sim) with at least final values ​​for the respective individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) assigned simulation target layer thicknesses (g_target_11, ..., g_target_20), by which the target measurement curve (92) is at least approximated in the simulation target measurement curve (98) until a stable result is achieved for the assignment criterion according to a statistical selection procedure; wherein the initial values ​​of the simulation target layer thicknesses (g_target_11, ..., g_target_20) are the simulation actual layer thicknesses (g_actual_11, ..., g_ist_20) are used, wherein the iterative procedure is carried out for one or more spectral intervals (82, 84, 86), with each subsequent interval (84, 86) including the preceding interval (82, 84). [12] Method according to claim 11, characterized by , that the determination of calculated actual layer parameters (96) by simulation of the layer system (10) with the actual data set (Dat_ist) further includes providing (S208) the final simulation target data set (DAT_soll_sim) for the coating system (102) as a new system data set (Dat_ist+1) for the deposition of another layer system (10_n+1) with at least one or more correction actual layer thicknesses (d_korr_11, ..., d_korr_20) as new system actual layer thicknesses (d_ist_11, ..., d_ist_20), which are determined from the final simulation target layer thicknesses (g_soll_11, ..., g_soll_20) with the final simulation target data set (DAT_soll_sim), wherein the plant data set (Dat_ist) includes at least the actual layer thicknesses (d_ist_11, ..., d_ist_20) of the several individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) of the coating system (10) set at the coating system (102). [13] Coating system (100) for producing coating systems (10) by a method according to at least one of the preceding claims, comprising at least - a coating system (102) for coating a substrate (22) with a layer system (10) for an optical element (80), - a control computer (110) for controlling the coating system (102) and for communication with a simulation computer (106), - an optical measuring device (104) for determining a spectrally resolved actual measurement curve (90) of the layer system (10), - the simulation computer (106) on which simulation software (107) for optical calculation and optimization of the layer system (10) is installed, - a design database (200) for storing target data records (Dat_soll), - a storage database (210) for storing actual measurement curves (90), actual data records (Dat_ist), calculated actual shift parameters (96) and release decisions, - a criteria database (220) for storing release criteria, - a decision system (108) for the release of shift systems (10). [14] Computer program product for a method for operating at least one coating system (100) for producing layer systems (10) according to any one of claims 1 to 12, wherein the computer program product comprises at least one computer-readable storage medium comprising program instructions that are executable on a computer system (106) and cause the computer system (106) to execute the method according to at least claim 1, comprising (i) Coating (S100) a coating system (10) in a coating system (102); (ii) Determining (S102) a spectral actual measurement curve (90) of the layer system (10) in an optical measurement system (104); (iii) Determining (S110) an actual data set (Dat_ist) by fitting a simulation target measurement curve (98) to the actual measurement curve (90); (iv) Determining (S112) actual layer parameters (96) as calculated actual layer parameters (96) from the simulation target measurement curve (98) by simulating the layer system (10) with the actual data set (Dat_ist); (v) Output (S114) of the actual data set (Dat_ist) and the calculated actual layer parameters (96) to at least one decision system (108); (vi) Providing (S118) quality requirement data; (vii) Deciding (S120) on the release (S122, S124) of the shift system (10) in the decision system (108) on the basis of a comparison of at least the actual data set (Dat_ist), the calculated actual shift parameters (96) and the quality requirement data, (viii) wherein the coating of the layer system (10) in the coating system (102) comprises depositing an interferometric layer system (10) on at least one surface (24) of a substrate (22), (ix) wherein the layer system (10) comprises a stack (40) of at least four successive layer packages (42, 44, 46, 48, 50), each layer package (42, 44, 46, 48, 50) comprising a pair of first and second single layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), wherein the first single layers (11, 13, 15, 17, 19) each have a first optical thickness (t1) and the second single layers (12, 14, 16, 18, 20) each have a second optical thickness (t2) different from the first optical thickness (t1), (x) where a refractive index (n1) of the first single layers (11, 13, 15, 17, 19) closest to the substrate is greater than a refractive index (n2) of the second single layers (12, 14, 16, 18, 20) furthest from the substrate of the stack (40), (xi) wherein the layer system (10) has a brightness (L*), a chroma (C*) and a hue angle (h) of a residual reflection color, (xii) wherein the magnitude of a change (Δh) of the hue angle (h) of the residual reflectance color in an interval of an AOI with limit values ​​of 0° and 30° with respect to a surface normal (70) to the layer system (10) is less than the magnitude of a change (ΔC*) of the hue (C*) in the interval of the AOI, wherein, in order to design the layer system (10), the following steps are carried out: (xiii) - Defining a layer design comprising at least a first material for the high-refractive-index first single layers (11, 13, 15, 17, 19) and a second material for the low-refractive-index second single layers (12, 14, 16, 18, 20), number of desired layer packages (42, 44, 46, 48, 50) with the single layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), initial values ​​of the thickness of the single layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20); (xiv) - Defining target colour values, including brightness (L*), hue (C*) and hue angle (h) at least at the limits for the interval of viewing angle (AOI) with the limits of 0° and 30°; (xv) - Performing an optimization procedure to vary the individual layer thicknesses (d_is_11, ..., d_is_20) of the individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) until an optimization target is achieved. [15] Data processing system (124) for executing a data processing program comprising computer-readable program instructions to execute a method for operating at least one coating system (100) for producing layer systems (10) comprising the steps according to at least claim 1.

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