SYSTEM OF COATING PLANTS FOR THE PRODUCTION OF LAYER SYSTEMS

Description

State of the art

[0001] The invention relates to a system of coating systems for the production of layer systems, a method for the production of a layer system in at least one coating system and a computer program product for a method for operating at least one coating system.

[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] An economically viable method to minimize variations from coating batch to coating batch is very precise process maintenance, in which the underlying coating process is slightly adjusted from coating batch to coating batch if necessary.

[0004] Such process maintenance requires in-depth know-how and can currently only be successfully carried out by well-trained operators or specialists.

[0005] In the case of coating substrates with a layer system, as is typical in the optical industry, the process is as follows: After an optical substrate has been coated with a layer system, an optical measurement is performed on at least one coated substrate. This measurement records a spectrally resolved signal that represents the optical system consisting of the optical substrate and the applied layer system. In the case of antireflection coatings or mirror coatings, the spectral reflectance or reflectivity of the optical system is determined using a standard spectrometer. The result is a two-dimensional data set consisting of data tuples (for example, wavelength in nanometers, reflectance in %).This recorded data set ("actual system data set") is compared by the operator with a similarly structured target data set, which in the case of antireflection coatings or mirror coatings describes the spectral reflection of the target system.

[0006] In the event of unacceptable deviations in the spectral profile or spectral parameters, such as the color values ​​L*, C*, h* (in the so-called CIELCh color space), the operator must make a correction to the underlying coating process. Typically, the operator will adjust the physical layer thickness to be deposited, at least for a single layer of the coating system, as specified in the coating process. This layer selection is usually based on experience or predefined routines.

[0007] After another coating batch has been produced using this coating process, the operator can determine the effectiveness of his process maintenance by further comparing the actual data set with the target data set and may need to make further phenomenological corrections (not numerically generated) to the coating process.

[0008] This process is often a time-consuming and material-intensive iterative trial-and-error process that can only be performed by skilled operators. This experience-based approach will not always reliably lead to the desired result. Furthermore, experience-driven process maintenance does not always result in consistent layer thickness ratios for identical optical color values. This can lead to unintentional changes in layer properties and thickness ratios.

[0009] Known optical elements with interferometric antireflection coatings, such as those specified in WO 2016 / 110339 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.

[0010] US Patent 2015 / 021168 A1 discloses an inline deposition control device and a coating method for a multi-source coating system for depositing layers onto a substrate. Deposited layers on the substrate are illuminated, and optical measurement signals are acquired with spectral resolution. The measurement signal can include light reflected from the deposited layer and light transmitted through the substrate with the deposited layer. An evaluation unit determines the layer thicknesses based on the measurement signal. A control unit provides feedback control of the layer deposition based on the determined thicknesses.

[0011] EP 3 346 023 A1 describes a method for coating a substrate with multiple layers. A layer with a programmed physical thickness is deposited onto a test substrate. A design file contains the target physical thickness and the spectral result for the layer. A data set is generated by comparing the programmed physical thickness with the optical thickness of the deposited layer.

[0012] General technical background information on the simulation of the reflectivity of multilayer optical systems is revealed in VA Kheraj et al: "Simulation of reflectivity spectrum for non-absorbing multilayer optical films", VA Kheraj et al, Pramana, Vol. 72, No. 6, June 1, 2009 (2009-06-01), pages 1011-1022, XP055689294, IN, ISSN: 0304-4289, DOI: 10.1007 / s12043-009-0081-0. Disclosure of the invention

[0013] The object of the invention is to provide a system of coating systems for the economically optimized operation of one or more coating systems for the production of coating systems.

[0014] Further objectives of the invention are to specify a method and a computer program product.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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 specific thickness. The thicknesses of the individual layers can be the same or different. Here, too, an adhesion promoter layer can be placed between the 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.

[0019] 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 from 2012 and 2011 respectively.

[0020] 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.

[0021] 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.

[0022] 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). 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.

[0023] According to a first aspect of the invention, which is not claimed as such, a method for operating at least one coating system for the production of coating systems is proposed, comprising (i) Acquiring at least one spectral measurement curve with ordinate values ​​and abscissa values ​​as an actual measurement curve on an actual layer system, which consists of one or more individual layers, each with an actual layer thickness of the respective individual layer, wherein the one or more individual layers are produced according to an actual layer data set of the at least one coating system, wherein the actual layer thickness of the respective individual layer of the one or more individual layers includes at least the actual layer thickness of the respective individual layer of the one or more individual layers;(ii) Assigning the actual measurement curve of the actual layer system according to at least one 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 data set layer system formed from one or more individual layers, wherein the target data set includes at least one known target layer thickness of the respective individual layer of the one or more individual layers;(iii) Generating a simulation actual measurement curve by an iterative procedure by varying at least one simulation actual layer thickness of the respective individual layers in at least one spectral interval of the actual measurement curve and obtaining a final simulation actual data set with at least one final simulation actual layer thickness of the respective individual layer of the one or more individual layers, by which the actual measurement curve in the simulation actual measurement curve is at least approximated until a termination criterion is reached;(iv) Generating a simulation target measurement curve by an iterative procedure by varying at least the simulation target layer thickness of the respective single layer in at least one spectral interval of the target measurement curve and obtaining a final simulation target data set with at least one final simulation target layer thickness of the respective single layer of the one or more single layers, by which the target measurement curve is at least approximated in the simulation target measurement curve until a termination criterion is reached, wherein optical differences between the actual measurement curve and the simulation actual measurement curve are correlated, and the simulation actual data set is used for a back-calculation of the simulation target measurement curve to the target measurement curve (92);and (v) providing the final simulation target data set for at least one coating system as a new system data set for the deposition of a further layer system with at least one correction actual layer thickness as the new system actual layer thickness of the respective individual layer, which are determined from the final simulation target layer thickness of the respective individual layer of the one or more individual layers with the final simulation target data set.

[0024] Advantageously, the method according to the invention enables a self-controlling and feedback-based operating mode of coating systems.

[0025] The coating system can be advantageously used to produce layer systems, for example for optical elements.

[0026] The significant points of the curve can be used advantageously to find the appropriate target design of the layer system for a 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The simulation-actual measurement curve includes at least one simulated spectral measurement curve, which preferably represents the best possible agreement with the actual measurement curve performed by the optical measurement.

[0031] 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.

[0032] The simulation target measurement curve includes at least one simulated spectral measurement curve, which preferably represents the best possible agreement between the target measurement curve and the simulation actual measurement curve.

[0033] The simulation target dataset comprises 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 advantageously represent the process parameters for the subsequent coating batch.

[0034] For this purpose, the simulation target data set includes the set calculation parameters of the simulated layer system for the most ideal layers and / or processes possible, material properties such as the most ideal refractive indices and the most ideal deposition conditions possible, as well as system parameters such as coating geometry, layer thickness control, etc.

[0035] 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.

[0036] Using this simulation target dataset, it is possible to conduct a more detailed analysis of the relationships between plant parameters and layer parameters and / or layer properties. For this purpose, it can be advantageous to rely on a statically relevant number of datasets.

[0037] 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.

[0038] Advantageously, the coating process for a layer system can consist of applying one or more single layers. Each single layer is preferably described by a set of parameters that includes the physical or optical layer thickness along with other parameters such as deposition rate, process gas flows, etc. The one or more single layers of the coating process can consist of the materials ZrO₂, TiO₂, Al₂O₃, Ta₂O₅, Si₃N₄, Nd₂O₅, Pr₂O₃, PrTiO₃, La₂O₃, Nb₂O₅, Y₂O₃, Ce₂O₃, Dy₂O₅, HfO₂, SiO₂, MgF₂, ZrF₄, AlF₃, Na₃Al₃F₁₄, Na₃AlF₆, silanes and siloxanes, as well as any mixtures of these materials. All typical coating processes such as PVD, CVD, sputtering and their related processes can be used.

[0039] Using the simulation software, significant spectral points, such as extreme values ​​of the spectral data, selected points like 1% passes (where the reflectance is 1%), a full half-width of a peak in the measurement curve, or similar features, are determined from the spectral data of the actual measurement curve according to an assignment criterion. A comparison is then made with the target measurement curves stored in a database, based on the determined spectral points, to find a target measurement curve that matches the actual measurement curve or to select a target measurement curve with the smallest deviation from the actual measurement curve. Accordingly, all target measurement curves from the database are loaded into the simulation software, and the agreement between the characteristic points of each target measurement curve and the corresponding points of the actual measurement curve is calculated.

[0040] For all spectral points with their respective coordinates, namely wavelength as the abscissa versus intensity as the ordinate, the quotient of the corresponding abscissa of the actual measurement curve to the abscissa of the target measurement curve, as well as the averaged quotient of these determined quotients, is calculated. These averaged quotients are subsequently referred to as scaling factors and apply uniformly to the entire layer system.

[0041] For each of these scaling factors, a virtual spectral data set is generated, which, multiplied by the layer thickness for a single layer or the layer thicknesses for multiple single layers of the target measurement curve and the corresponding scaling factor, yields a first approximation.

[0042] This creates a very favorable starting point for the subsequent optimization process. This scaling factor is stored in the database for further possible analyses.

[0043] Starting with the scaled preliminary layer thickness of the individual layer, or the scaled preliminary layer thicknesses of the multiple layers from the previous step, an optimization process is initiated 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 values ​​then approximate the actual measurement curve to the underlying simulation target measurement curve.

[0044] From the layer thickness(es) obtained in the previous step, which serve as the initial simulation actual layer thicknesses, the quotient is calculated for each individual layer or layer with the corresponding actual layer thickness(es) set on the coating system. This calculation yields the first preliminary simulation data set. This initial preliminary simulation data set is then compared for plausibility at the individual layer level with the target layer thicknesses stored in the target data set. A deviation of + / - 20% per individual layer thickness is acceptable, as this is a first, rough approximation.If there is a larger deviation, the process is restarted from the previous step, this time with a constraint in the optimization procedure, namely that the layer thickness of the single layer, for which the single layer layer thickness was outside the specified range, is restricted to this range.

[0045] Ideally, this restriction is not necessary. If it is, however, the thickness of each individual layer can be limited accordingly.

[0046] After this step, a second preliminary set of layer thicknesses for a single layer or multiple layer thicknesses for multiple single layers is available. If no restriction was necessary, this second simulation actual data set is identical to the first preliminary simulation actual data set.

[0047] The optimization procedure is now applied to each additional 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.

[0048] 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.

[0049] 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.

[0050] These steps are repeated until a termination criterion is reached, for example, until a stable result is obtained after a statistical selection procedure. Preferably, the entire curve can be considered for this purpose, particularly with regard to chi-square deviations and the like.

[0051] If the spectral data of the actual measurement curve are approximated in the best possible agreement, the final simulation actual data set can be generated using one or more simulation actual layer thicknesses.

[0052] The optimization process is now restarted, with the difference that the optimization now takes place between the simulated actual measurement curve and the target measurement curve in order to replicate the spectral data of the target dataset. Furthermore, the simulated actual dataset is now fixed and will no longer be changed.

[0053] At the end of this procedure, one (if the layer system consists of a single layer) or several (if the layer system consists of multiple single layers) simulation target layer thicknesses are available, which generate the simulation target data set. From these one or more simulation target layer thicknesses, the one or more correction actual layer thicknesses are calculated as the next one or more system actual layer thicknesses by calculation with the simulation target data set. These are then set or transmitted to the coating system.

[0054] The advantages of the invention lie in the fact that, in contrast to the prior art approach, the inventive method allows for comprehensive analytical control of the coating process, which is based entirely on numerical calculations.

[0055] Optionally, the inventive method can not only take layer thicknesses into account and correct them, but also, if necessary, monitor other process parameters, such as the condition of a system, the age and / or condition of coating sources, the age and / or condition of measuring devices in the coating systems, the loading status with substrates during coating, and the like.

[0056] The method according to the invention can be applied for the automatic self-optimization of an existing coating process as well as for the automatic self-configuration of new coating processes, such as the commissioning of coating systems. Commissioning, as understood by those skilled in the art, refers to the initial installation or configuration of a new coating process and coating system on a coating system.

[0057] Continuous optimization / monitoring ensures that the layer systems produced in this way, for example optical elements, exhibit the smallest possible deviation from target data.

[0058] In addition, newly introduced parameter sets such as plant data sets and simulation data sets and their monitoring offer new possibilities for coating and plant monitoring.

[0059] The inventive method offers the advantage of cost savings in the production of layered systems, for example, for optical elements. It allows for immediate response / notification of technically caused process deficiencies. For example, in the event of component defects in the coating system, the subsequent batch can be stopped immediately, thus preventing a defective batch. In the case of gradual system or process errors, misalignment can be prevented by immediate and continuous layer correction, indicated by the system-specific correction parameter set. Maintenance of the coating system can be simplified. Individual variations in process control by different personnel can be avoided. Coating-side quality assurance can take place within this self-regulating system and not downstream as before.

[0060] Furthermore, significant cost savings can be achieved in engineering. New processes can be remotely controlled from an external source. A newly introduced set of parameters opens up new avenues for understanding previously unresolved plant, process, and shift-related problems.

[0061] According to an advantageous embodiment of the method according to the invention, the termination criterion can be reached if at least one of the following conditions is met: (i) a stable result is achieved for the assignment criterion using a statistical selection procedure; (ii) a deviation between the actual measurement curve and the simulation actual measurement curve lies within a tolerance range; (iii) a maximum number of iterations has been performed. An optimal result can be advantageously achieved if a stable result is obtained for the allocation criterion using a statistical selection procedure.

[0062] If the deviation between the actual measurement curve and the simulation actual measurement curve lies within a tolerance range, at least a satisfactory result can be achieved.

[0063] Once a maximum number of iterations has been performed, the computational effort can be limited.

[0064] According to an advantageous embodiment of the method according to the invention, the target layer thickness of the respective individual layer can be used as the starting value for the simulated actual layer thickness of the respective individual layer. This yields good results for the method. Alternatively or additionally, the simulated actual layer thickness of the respective individual layer can be used as the starting value for the simulated target layer thickness of the respective individual layer. Particularly in combination with the target layer thickness as the starting value for the simulated actual layer thickness of the respective individual layer, the results of the method can be further improved.

[0065] Alternatively or additionally, a predefined layer thickness can be used as the starting value for the simulation target layer thickness of each individual layer. This is advantageous if, for example, empirical data for a suitable layer thickness already exists, or if, when several individual layers are to be deposited, empirical data for suitable layer thicknesses already exists. Furthermore, with a virtually arbitrary starting value for the layer thicknesses, a sufficiently good result for a layer system can be achieved by a correspondingly larger number of iterations.

[0066] According to an advantageous embodiment of the method according to the invention, the generation of the simulation actual measurement curve, or simulation target measurement curve, can further comprise: determining a scaling factor as the mean of quotients of abscissa values ​​of the actual measurement curve, or simulation actual measurement curve and the target measurement curve for abscissa values ​​determined according to the assignment criterion, and scaling the one target layer thickness if the layer system is formed from a single layer, or the several target layer thicknesses if the layer system is formed from several single layers; or the one or more simulation actual layer thicknesses of the one or more single layers with the scaling factor as starting values ​​of the one or more simulation actual layer thicknesses, or one or more simulation target layer thicknesses.

[0067] Accordingly, the simulation actual measurement curve is generated from the actual measurement curve and the target layer thicknesses according to the inventive method in order to determine starting values ​​for the simulation actual layer thicknesses, while the simulation target measurement curve is generated from the simulation actual measurement curve and the simulation actual layer thicknesses in order to determine starting values ​​for the simulation target layer thicknesses.

[0068] This creates the best possible starting point for the subsequent optimization process.

[0069] According to an advantageous embodiment of the method according to the invention, the generation of the simulation actual measurement curve, or simulation target measurement curve, can further comprise: at least for the first interval for each of the several individual layers, if the layer system has several individual layers, or for the single individual layer, if the layer system has only one individual layer: forming a quotient of the corresponding first final simulation actual layer thickness, or the corresponding first final simulation target layer thickness, and the corresponding system actual layer thickness, wherein first simulation actual layer thicknesses, or simulation target layer thicknesses, are generated by scaling the simulation actual layer thicknesses, or simulation target layer thicknesses, with the quotient.

[0070] Accordingly, the simulation actual layer thicknesses are used to generate the simulation actual measurement curve, while the simulation target layer thicknesses are used to generate the simulation target measurement curve.

[0071] In this way, suitable starting values ​​can be generated for further optimization when adjusting simulation actual measurement curves or simulation target measurement curves.

[0072] According to an advantageous embodiment of the method according to the invention, the generation of the simulation actual measurement curve or the simulation target measurement curve can further comprise: Checking the individual first simulated actual layer thickness or multiple simulated actual layer thicknesses, or the simulated target layer thickness of the respective single layer, against at least one criterion, in particular plausibility and / or a specified deviation from the respective target layer thickness of the target measurement curve, and, if at least one criterion is missed, repeating the variation of the simulated actual layer thickness of the respective single layer, or the simulated target layer thickness of the respective single layer, and providing a first final simulated actual layer thickness or simulated target layer thickness of the respective single layer, as well as generating the first simulated actual layer thickness, orSimulation target layer thickness of the respective individual layer(s) of one or more individual layers, wherein a restriction on variation is specified for the individual layer(s) or for those of the several individual layers that have failed to meet the criterion, and provision of a second simulation actual layer thickness, or simulation target layer thickness of the respective individual layer(s) of one or more individual layers.

[0073] Accordingly, the simulation actual layer thicknesses are used to generate the simulation actual measurement curve, while the simulation target layer thicknesses are used to generate the simulation target measurement curve.

[0074] This approach makes it easier to limit the parameters in the optimization process and thus accelerates the determination of the optimized parameter sets.

[0075] According to an advantageous embodiment, the method according to the invention can further comprise: Repeating the steps in one or more further spectral intervals, each subsequent interval including the preceding interval, using the second simulation actual layer thickness or simulation target layer thickness of the respective single layer of the preceding interval as starting values ​​in the following interval, and providing a final simulation actual layer thickness or simulation target layer thickness of the respective single layer of the one or more single layers.

[0076] Accordingly, iterative interval nesting is performed separately for simulation actual layer thicknesses and simulation target layer thicknesses.

[0077] In this way, an effective approximation of the simulation curves to the measured actual curves can be advantageously achieved, whereby the fitting parameters can be successively refined. This reduces the risk of determining an unfavorable minimum in the optimization process.

[0078] According to an advantageous embodiment of the method according to the invention, an optical element can be produced, wherein the optical element comprises a substrate and an interferometrically reflection-reducing layer system on at least one surface of the substrate. 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 having a first optical thickness and the second layers having a second optical thickness different from the first optical thickness, 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, wherein the layer system has a brightness, a hue, and a hue angle of a residual reflectance color, wherein the magnitude of a change in the hue angle of the residual reflectance color in an interval of a viewing angle with the limiting values ​​of 0° and 30° with respect to a surface normal to the layer system is less than the magnitude of a change in the hue in the interval of the viewing angle, wherein the following steps are performed: defining a layer design,including at least one first material for high-refractive-index first layers and a second material for low-refractive-index second layers, the number of desired layer packages with the individual layers, and the initial thickness values ​​of the individual layers; defining target color values, including brightness, hue, and hue angle at least at limit values ​​for an interval of a viewing angle with limit values ​​of 0° and 30°; and carrying out an optimization procedure to vary the individual layer thicknesses until an optimization target is achieved.

[0079] Advantageously, the target color values ​​can be chosen to be the same or similar at the limits of the interval.

[0080] In particular, maximum deviations for the hue angles of different residual reflectance colors can be specified.

[0081] The shift system can advantageously have four or five shift packages; more than five shift packages can also be provided.

[0082] Chromaticity can also be referred to as color saturation. Hue angle can also be referred to as color angle.

[0083] 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.

[0084] The first sublayers of the layer packages in the stack, those closest to the substrate, can be formed from the same first material. The second sublayers, those further away from the substrate, can likewise be formed from the same second material, but different from the first material of the first sublayers. It can be provided that in the layer package 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 in the stack can vary. Likewise, it can be alternatively provided that the materials from which the second sublayers are formed vary within the stack.

[0085] According to an advantageous embodiment of the method according to the invention, the hue angle 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 in hue angle in a second interval of a viewing angle from 0° up to a limiting viewing angle with an upper limit between 30° and 45°, relative to the surface normal to the layer system, is less than the magnitude of the change in hue in the second interval of the viewing angle, and the magnitude of the hue at the limiting viewing angle is at least 2, in particular the hue angle in the second interval changes by no more than 20°, preferably by no more than 15°; and / or the photopic reflectance in the interval of the viewing angle with the limit values ​​0° and 30° is at most 1.5%, preferably at most 1.2%; and / or the scotopic reflectance in the interval of the viewing angle with the limit values ​​0° and 30° is at most 1.5%, preferably at most 1.2%.

[0086] The color impression of the residual reflection from the optical system remains completely or almost unchanged for an observer.

[0087] Advantageously, a color-stable residual reflection color is achieved even with greater variation in the viewing angle.

[0088] Advantageously, the first sub-layers can be made of a high refractive index material.

[0089] Advantageously, the first sublayers may consist of at least one or more of the compounds Ta 2 O 5 , TiO 2 , ZrO 2 , Al 2 O 3 , Nd 2 O 5 , Pr 2 O 3 , PrTiO 3 , La 2 O 3 , Nb 2 O 5 , Y 2 O 3 , HfO 2 , InSn oxide, Si 3 N 4 , MgO, CeO 2 , ZnS and / or their modifications, in particular their other oxidation states and / or mixtures thereof with silanes and / or siloxanes.

[0090] 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.

[0091] Advantageously, the second sub-layers can be made of a low-refractive-index material.

[0092] 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 can contain at least 80% by weight of SiO₂, and more preferably at least 90% by weight of SiO₂.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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).

[0098] 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.

[0099] 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.

[0100] According to a further, in particular independent, aspect of the invention, a coating system for producing a layer system, in particular with a method described herein for operating at least one coating system for producing layer systems and / or for example for an optical element, is proposed, comprising at least a coating system for coating a substrate with a coating system; a control computer for controlling the coating system and for communication with a simulation computer; an optical measuring device for determining a spectrally resolved actual measurement curve of the coating system; a simulation computer on which simulation software for optical calculation and optimization of the coating system is installed; a database for storing system data sets; an input device for inputting and controlling the simulation computer and / or the coating system.

[0101] In this way, the coating system comprises all the necessary components required for the effective commissioning and operation of the coating system according to the inventive method as described above.

[0102] This allows for a more efficient and faster commissioning of a new coating system using the inventive method for operating a coating system for the production of a layered system. This results in considerable savings potential during the commissioning of the coating system. Furthermore, the commissioning of the coating system can even be carried out remotely, resulting in further savings potential due to the reduced number of operating personnel required on site.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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".

[0107] The simulation software is installed on the simulation computer.

[0108] 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.

[0109] The software implements the described method according to the invention as a control algorithm. The software interacts with the database and, for example, reads target data sets from the database and saves newly calculated simulation data sets to the database. Furthermore, the software implements at least one arbitrary optimization / fitting algorithm, such as those found in commercially available simulation programs, for example, in "Essential MacLeod".

[0110] The database stores the generated simulation target data sets for each coating system and each coating process, and these can be retrieved at a later time. Additionally, the database contains the corresponding target data sets for all stored coating processes.

[0111] Bidirectional data exchange between the coating system's control computer and the simulation software can be implemented either directly through the simulation software and an existing network connection to the coating system's control computer, or through the use of additional software that handles the data exchange, providing the simulation software with data from the coating system and transferring data back to the coating system. In manual mode, this data exchange occurs through interaction with an operator via an input device.

[0112] According to a further, in particular independent, aspect of the invention, a coating system for producing a layer system, for example for an optical element and / or in particular with a method described here for operating at least one coating system for producing layer systems or as described above, is proposed, comprising a component for applying an artificial aging process to the layer system.

[0113] Advantageously, the coating system produced in the coating plant can also be artificially aged in the same plant to obtain a steady-state measurement curve for determining the spectral properties of the coating system. This results in a high degree of reliability when determining the correct correction layer thicknesses for the new coating systems, since the properties of the coating systems no longer change significantly over time.

[0114] Advantageously, the method using the method according to the first aspect of the invention enables a self-controlling and feedback-based operating mode of coating systems.

[0115] According to a further, in particular independent, aspect of the invention, a coating system for producing a layer system, for example for an optical element, and / or in particular with a method described herein for operating at least one coating system for producing layer systems, or as described above, is proposed, comprising an optical measuring device for determining a spectrally resolved actual measurement curve of the layer system and / or a component for applying an artificial aging process to the layer system.

[0116] Advantageously, an optical measuring device for in-situ determination of the spectral data of the manufactured coating system can be integrated directly into the coating system itself. This eliminates uncertainties during the transfer of the coating system from the system and any potential subsequent modifications to the coating system. This allows for a more direct determination of suitable correction layer thicknesses, whether one (for a single-layer system) or several (for a multi-layer system). Optimization of the system data sets for the coating process can thus be performed more effectively. Furthermore, it is advantageous to integrate a component for artificially aging the manufactured coating system into the coating system.Advantageously, the layer system produced in the coating system can also be artificially aged in the same system in order to obtain a stationary actual measurement curve when determining the spectral properties of the optical element.

[0117] This results in a high degree of certainty when determining the correct one or more correction layer thicknesses for the new layer systems, since the properties of the layer systems no longer change significantly over time.

[0118] Advantageously, the coating system can be operated in a self-controlling and feedback manner using the method according to the first aspect of the invention.

[0119] According to a further, in particular independent, aspect of the invention, a system of coating systems for the production of layer systems, for example for optical elements and / or in particular with a method described here for operating at least one coating system for the production of layer systems or as described above, is proposed, comprising at least one or more coating systems for coating at least one substrate with a coating system; one or more control computers for controlling at least one coating system and for communication with a simulation computer; an optical measuring device for determining a spectrally resolved actual measurement curve of the coating system; a simulation computer on which simulation software for the optical calculation and optimization of the coating system is installed, and which communicates with the control computer of the coating system; a database for storing system data records; and an input device for inputting and controlling the simulation computer and / or the one or more coating systems.

[0120] In such a system of multiple coating lines, the various coating lines can be controlled by a simulation computer, resulting in significant potential savings in the operation of the coating lines. Furthermore, insights and / or data sets obtained from one coating line can be effectively transferred to another.

[0121] According to a further, in particular independent, aspect of the invention, a computer program product is proposed for a method for operating at least one coating system for the production of layer systems, for example for optical elements.

[0122] The computer program product can provide the software for controlling and operating coating systems in a modular manner and make it accessible to a wide variety of data processing systems.

[0123] Advantageously, by means of the computer program product, 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.

[0124] According to a further, particularly independent, aspect of the invention, a data processing system for executing a data processing program is proposed, which comprises computer-readable program instructions for executing a method for operating at least one coating system for the production of layered systems, for example, for optical elements and / or, in particular, as described above, or a method for operating at least one coating system for the production of layered systems described herein. The data processing system can advantageously include the simulation computer and the database, as well as the control computer of the coating system.

[0125] 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

[0126] 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. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations. They show, for example:

[0127] Fig. 1 a block diagram of a coating system according to an embodiment of the invention; Fig. 2 a process flow diagram for operating at least one coating system for producing layer systems for optical elements according to an embodiment of the invention; Fig. 3 a flow diagram of the method according to the invention; Fig. 4 a detailed flow diagram of the method according to the invention; Fig. 5 an optical element with a layer system consisting of five layer packages on a substrate according to an embodiment of the invention; 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 view of the reflectivity curves of Fig. 6Fig. 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; 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; Fig. 12 a block diagram of a system of coating systems according to a further embodiment of the invention. Embodiments of the invention

[0128] 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.

[0129] 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.

[0130] Figure 1Figure 1 shows a block diagram of a coating system 100 according to an embodiment of the invention. Advantageously, the coating system 100 can be operated with a self-regulating and feedback control process. The coating system 100 for producing a layer system 10 for an optical element 80 comprises at least one coating unit 108 for coating a substrate 22 with a layer system 10 for an optical element 80.

[0131] The construction of an optical element 80 with a layer system 10 on a substrate 22 is described in Figure 5 depicted.

[0132] Furthermore, the coating system 100 comprises a control computer 110 for controlling the coating system 108 and for communication with a simulation computer 102, an optical measuring device for determining a spectrally resolved actual measurement curve 90 of the coating system 10, a simulation computer 102 on which simulation software 104 for optical calculation and optimization of the coating system 10 is installed, a database 106 for storing system data records DAT, and an input device 114 for input and control of the simulation computer 102 and / or the coating system 108 via manual inputs 120.

[0133] The database 106 is preferably used according to one, in particular independent, aspect for carrying out a method according to the first aspect of the invention.

[0134] The database 106 serves to store plant data records DAT, for a method for operating the coating plant 108 for the production of layer systems 10 for optical elements 80, wherein the plant data records DAT include at least plant data records DAT_n, DAT_n+1, target data records DAT_target, simulation actual data records DAT_actual_sim, and / or simulation target data records DAT_target_sim.

[0135] On the simulation computer 102, a computer program product for a method according to the first aspect of the invention for operating at least one coating system 108 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 102 and cause the computer system 102 to execute the method.

[0136] 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 102 of a data processing system 124.

[0137] The data processing system 124, which includes at least the simulation computer 102 and the simulation software 104, serves to execute a data processing program which includes computer-readable program commands in order to execute the method for operating the coating system 108 for the production of layer systems 10 for optical elements 80.

[0138] 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 102.

[0139] The coating system 108 can optionally include a component 116 for applying an artificial aging process to the layer system 10 in order to ensure stable conditions of the optical element 80 during the spectral measurement of the layer system 10 in the optical measuring device 112, 118.

[0140] In another option, the coating system 108 can also include an optical measuring device 118 for determining a spectrally resolved actual measurement curve 90 of the coating system 10, so that in-situ measurements of the spectral properties of the coating system 10 can be carried out in the coating system 108 itself and direct feedback can be transmitted to the simulation computer 102.

[0141] In Figure 2A sequence of the method according to a first aspect of the invention for operating at least one coating system 108 for producing layer systems 10 for optical elements 80 according to an embodiment of the invention is graphically illustrated and shown in the Figures 3 and 4 described as a flowchart, or as a detailed flowchart in individual steps.

[0142] The method for operating the coating system 108 according to the first aspect of the invention comprises, in the first step S100 (i), the acquisition of at least one spectral measurement curve with ordinate and abscissa values ​​as an actual measurement curve 90 on an actual layer system 10_n, which consists of a sequence of individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 with respective actual system layer thicknesses d_actual_11, ..., d_actual_20. The individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 are produced according to a system data set DAT_n of the coating system 108. The plant data set DAT_n includes at least the plant actual layer thicknesses d_ist_11, ..., d_ist_20 of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.

[0143] In the next step S102, (ii) the actual measurement curve 90 of the actual layer system 10_n is assigned according to an assignment criterion, which may in particular include 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 individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20. The target data set DAT_soll includes at least known target layer thicknesses d_soll_11, ..., d_soll_20 of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 and can be retrieved from the database 106 via the simulation computer 102.

[0144] In a further step S104 (iii) a simulation actual measurement curve 94 is generated according to an iterative procedure by varying at least simulation actual layer thicknesses g_actual_11, ..., g_actual_20 of the 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, by which the actual measurement curve 90 is at least approximated in the simulation actual measurement curve 94. This iterative process is carried out until a termination criterion is reached, for example, until a stable result is achieved for the assignment criterion using a statistical selection procedure (see page 114 and query page 116 in [reference]). Figure 4). For the iterative procedure, the target layer thicknesses d_target_11, ..., d_target_20 are used as starting values ​​for the simulation actual layer thicknesses g_actual_11, ..., g_actual_20.

[0145] In the next step S106 (iv), a simulation target measurement curve 98 is generated using an iterative procedure by varying at least the simulation target layer thicknesses g_target_11, ..., g_target_20 of the 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. This results in a final simulation target data set DAT_target_sim with at least final 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. This iterative process is carried out until a termination criterion is reached, for example, until a stable result is achieved for the allocation criterion using a statistical selection procedure (see S115 and query S117 in [reference]). Figure 4). For the iterative procedure, the initial values ​​of the simulation target layer thicknesses g_target_11, ..., g_target_20 are used, for example, the simulation actual layer thicknesses g_actual_11, ..., g_actual_20.

[0146] In a final step S108 (v), the final simulation target data set DAT_soll_sim for the coating system 108 is provided as a new system data set DAT_n+1 for the deposition of another layer system 10_n+1 with at least correction actual layer thicknesses d_korr_11, ..., d_korr_20 as new system actual layer thicknesses d_ist_11, ..., d_ist_20. These are determined from the final simulation target layer thicknesses g_soll_11, ..., g_soll_20 using the final simulation target data set DAT_soll_sim.

[0147] To generate the simulation actual measurement curve 94 or the simulation target measurement curve 98 in steps S104 and S106, respectively, a scaling factor 122 can be determined in each step S110 and S111. This scaling factor is the mean of the quotients of the abscissa values ​​of the actual measurement curve 90 or the simulation actual measurement curve 94 and the target measurement curve 92 for abscissa values ​​determined according to the assignment criterion. The target layer thicknesses d_target_11, ..., d_target_20 are calculated using this scaling factor 122. or the simulation actual layer thicknesses g_actual_11, ..., g_actual_20 of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 are scaled and determined as starting values ​​of the simulation actual layer thicknesses g_actual_11, ..., g_actual_20, or simulation target layer thicknesses g_target_11, ..., g_target_20.

[0148] To generate the simulation actual measurement curve 94 or the simulation target measurement curve 98 in steps S104 or S106, a quotient 126 can be formed in step S112 or S113, at least for the first interval 82, for each of the individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, from the corresponding first final simulation actual layer thickness g_actual_11, ..., g_actual_20 or the corresponding first final simulation target layer thickness g_target_11, ... , g_target_20 and the corresponding plant actual layer thickness d_actual_11, ..., d_actual_20. The quotient 126 is used to generate initial simulation actual layer thicknesses g_actual_11, ..., g_actual_20, and simulation target layer thicknesses g_target_11, ..., g_target_20, respectively, by scaling the simulation actual layer thicknesses g_actual_11, ..., g_actual_20, and simulation target layer thicknesses g_target_11, ... , g_target_20 with the quotient 126.

[0149] In step S114 or S115, the individual first simulation actual layer thicknesses g_actual_11, ..., g_actual_20 or simulation target layer thicknesses g_target_11, ..., g_target_20 can be checked for at least one criterion, in particular plausibility and / or a specified deviation from the respective target layer thicknesses g_target_11, ..., g_target_20 of the target measurement curve 94. If at least one criterion is not met, the following steps will be performed: varying the simulation actual layer thicknesses g_actual_11, ..., g_actual_20 or simulation target layer thicknesses g_target_11, ..., g_target_20 in steps S104, S106; providing the first final simulation actual layer thicknesses g_actual_11, ..., g_actual_20 or simulation target layer thicknesses g_target_11, ..., g_target_20 in step S108; and generating the first simulation actual layer thickness g_actual_11, ..., g_actual_20 or simulation target layer thickness g_target_11, ...The simulation of g_target_20 is repeated, whereby for individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 that failed to meet the criterion, a restriction on varying S104, S106 is specified. Subsequently, the second simulation actual layer thicknesses g_actual_11, ..., g_actual_20, or simulation target layer thicknesses g_target_11, ..., g_target_20, are provided.

[0150] Steps S104, S106, S112, S113, S114, S115 can be repeated in one or more further spectral intervals 84, 86, wherein each subsequent interval 84, 86 includes the preceding interval 82, 84, and wherein the second simulation actual layer thicknesses g_actual_11, ..., g_actual_20, or simulation target layer thicknesses g_target_11, ..., g_target_20 of the preceding interval 82, 84 are used as starting values ​​in the following interval 84, 86, and final simulation actual layer thicknesses g_actual_11, ..., g_actual_20, or simulation target layer thicknesses g_target_11, ..., g_target_20 are provided.

[0151] The described method for producing a layer system 10 for an optical element 80 can advantageously be carried out such that the iterative process is performed for one or more spectral intervals 82, 84, 86, wherein each subsequent interval 84, 86 includes the preceding interval 82, 84. Furthermore, the described method can also be used for starting up a coating process in at least one coating system 108 for producing a layer system 10 for an optical element 80.

[0152] The Figure 5Figure 1 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 interferometrically reflection-reducing 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.

[0153] As the bottom layer on the substrate 22, the layer system 10 can, in the usual manner, have 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, for example, of substoichiometric refractive metal oxides, chromium, silanes, or siloxanes. The intermediate layer 30 is not relevant for further considerations of the optical properties.

[0154] On the intermediate shift 30 are in Figure 5 for example, five layer packages 42, 44, 46, 48, 50 of a stack 40 arranged consecutively.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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 ​​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.

[0160] 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.

[0161] To design the layer 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, comprising brightness L*, chroma C* and hue angle h at least at limit values ​​for an interval of a viewing angle AOI 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.

[0162] Substrate 22, for example, is a plastic, in particular a transparent plastic for a spectacle lens.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] Regarding the designs in Figure 5 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).

[0167] 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.

[0168] 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.

[0169] The order 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] The top layer 32 is not relevant for further considerations of the optical properties of the layer system 10.

[0174] 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.

[0175] 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 / 110339 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.

[0176] 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 / 110339 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 Figure 5 in pile 40.

[0177] At a specific wavelength λ, the optical thickness t of a layer, also called FWOT (full wave optical thickness), is determined as follows: t = d λ ⋅ 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.

[0178] A reflection-reducing effect by the stack 40 can be achieved for a predefinable reflectivity R m of the stack 40 if the product of reflectivity R m and the parameter σ is set to less than 1: R m ⋅ σ < 1

[0179] The reflectivity Rm, also called reflectance, describes the ratio of reflected to incident intensity of a light beam as an energy quantity. The reflectivity Rm is conveniently averaged over the wavelength range of light from 380 nm to 800 nm and referenced to 100%.

[0180] Such a condition R m ·σ<1 can be applied as a boundary condition for an optimization process of the method for producing the layer system 10.

[0181] 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.

[0182] Preferably, the thicknesses of the respective individual layers 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 in five layer packages 42, 44, 46, 48, 50 in the stack 40 are determined depending on a quotient vi (with i=1, 2, 3, 4, 5) of the first optical thickness t1 of each of the higher refractive index first individual layers 11, 13, 15, 17, 19 and the second optical thickness t2 of the lower refractive index second individual layers 12, 14, 16, 18, 20 of the respective layer package 42, 44, 46, 48, 50.

[0183] In an advantageous embodiment, a layer system can be 10 according to Figure 5 the parameter σ for a stack 40 with five consecutive layer packages 42, 44, 46, 48, 50 from the relationship σ = v 1 ∑ i = 2 nmax v i to be determined, where i = runs from 2 to nmax = 5.

[0184] 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, v 1 represents the layer package 42 closest to the substrate and v 5 represents the layer package 50 furthest from the substrate.

[0185] 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).

[0186] L* is the CIELab brightness, a*, b* are the CIELab coordinates, C* is the CIELab hue, and h ab is the CIELab hue angle.

[0187] 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).

[0188] 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.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 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.

[0193] The hue angle h is derived from the a* and b* axes. h = arctan b * a *

[0194] The hue angle h here represents the color of the residual reflection of the reflection-reducing layer system 10.

[0195] The chromaticity C* results from C * = a * 2 + b * 2

[0196] The chromaticity C* is also referred to as color depth.

[0197] 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.

[0198] 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 limit values ​​of 30° and 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 Θ = 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.

[0199] The photopic reflectance Rv in the interval of the viewing angle AOI with the limit values ​​0° and 30° can advantageously be at most 1.5%, preferably at most 1.2%.

[0200] The scotopic reflectance Rv' in the interval of the viewing angle AOI with the limit values ​​0° and 30° can advantageously be at most 1.5%, preferably at most 1.2%.

[0201] In the Figures 6 to 11 The reflectivity curves for perpendicular light incidence are shown as actual measurement curves 90 together with target measurement curves 92, or simulation actual measurement curves 94.

[0202] Figure 6 Figure 1 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; Figure 7 shows an enlarged representation of the reflectivity curves of Figure 6The 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 Figure 7 in the wavelength range of 380 nm and 680 nm.

[0203] In Figure 8The reflectivity curves of the layer system 10 are shown with a comparison of the target measurement curve 92 (dotted line) and a scaled simulation target measurement curve 98 (solid line). A horizontal shift of the simulation target measurement curve 98 has thus occurred. 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.

[0204] Figure 9Figure 1 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.

[0205] In Figure 10Reflectivity curves of the layer system 10 are shown, 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.

[0206] Figure 11Figure 1 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.

[0207] Figure 12Figure 1 shows a block diagram of a system 200 of coating systems 108 according to a further embodiment of the invention. The system 200 can also be considered as an independent system that can be operated with a self-regulating and feedback control process according to the first aspect of the invention.The system 200 of coating systems 108 for the production of layer systems 10 for optical elements 80 comprises two coating systems 108 for coating a substrate 22 with a layer system 10 for an optical element 80, a control computer 110 for each coating system 108 for controlling a coating system 108 and for communication with a simulation computer 102, an optical measuring device 112 per coating system 108 for determining a spectrally resolved actual measurement curve 90 of the layer system 10, and a simulation computer 102 on which simulation software 104 for the optical calculation and optimization of the layer system 10 is installed, and which communicates with the control computers 102 of the coating systems 108. Furthermore, the system 200 includes a database 106 for storing plant data records DAT, an input device 114 for input and control of the simulation computer 102 and / or the coating systems 108.With such a system 200 of coating systems 108 it is advantageously possible to control several coating systems 108 via a simulation computer 102 and to initiate and / or optimize the coating processes for the production of optical elements 80 with layer systems 10.

Claims

1. System (200) of coating apparatuses (108) for producing coating systems (10), comprising at least - one or more coating installations (108) for coating a substrate (22) with a coating apparatus (10), - one or more control computers (110) for controlling at least one coating apparatus (108) and for communicating with a simulation computer (102), - an optical measuring device (112) for determining a spectrally resolved actual measurement curve (90) of the coating system (10), - a simulation computer (102) on which simulation software (104) for the optical calculation and optimization of the coating system (10) is installed and which communicates with the control computer (102) of the coating apparatus (108), - a database (106) for storing apparatus data records (DAT), - an input device (114) for inputting and controlling the simulation computer (102) and / or the one or more coating apparatuses (108), wherein the system, in particular the one or more coating apparatuses (108), is / are designed to execute a method for operating at least one of the coating apparatuses (108) for producing coating systems (10), which comprises (i) Recording (S100) at least one spectral measurement curve with ordinate values and abscissa values as an actual measurement curve (90) on an actual layer system (10_n), which consists of one or more individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), each with an actual layer thickness (d_ist_11, ..., d_ist_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), wherein the one or more individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) are produced according to an apparatus data set (DAT_n) of the at least one coating apparatus (108), wherein the apparatus data set (DAT_n) contains at least the apparatus actual layer thickness (d_ist_11, ..., d_ist_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) of the one or more individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20); (ii) Assigning (S102) the actual measurement curve (90) of the actual layer system (10_n) according to at least one 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_soll) with ordinate values and abscissa values, which is based on a target data set layer system (10_soll) formed from one or more individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), wherein the target data set (DAT_soll) has at least one known target layer thickness (d_soll_11, ..., d_soll_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) of the one or more individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20); (iii) generating (S104) a simulation actual measurement curve (94) according to an iterative method by varying at least one simulation actual layer thickness (g_ist_11, ..., g_ist_20) of the respective individual layer (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_ist_sim) with at least one final simulation actual layer thickness (g_ist_11, ..., g_ist_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) of the one or more 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), until a termination criterion is reached (S116); (iv) Generating (S106) a simulation target measurement curve (98) according to an iterative method by varying at least the simulation target layer thickness (g_soll_11, ..., g_soll_20) of the respective individual layer (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_soll_sim) with at least one final simulation target layer thickness (g_soll_11, ..., g_soll_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) of the one or more 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), until a termination criterion is reached (S116), whereby optical differences between the actual measurement curve (90) and the simulation actual measurement curve (94) are correlated, and the simulation actual data set (DAT_ist_sim) is used for a recalculation of the simulation target measurement curve (98) to the target measurement curve (92) ; (v) Providing (S108) the final simulation target data set (DAT_soll_sim) for the at least one coating apparatus (108) as a new apparatus data set (DAT_n+1)for depositing a further layer system (10_n+1) with at least one corrected actual layer thickness (d_korr_11, ..., d_korr_20) as the new apparatus actual layer thickness (d_ist_11, ..., d_ist_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), which is calculated from the final simulation target layer thickness (g_soll_11, ..., g_soll_20) of 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) with the final simulation target data set (DAT _soll_sim).

2. System according to claim 1, wherein the system is configured to perform the method, which further comprises determining that the termination criterion is met when at least one of the following conditions is satisfied: (i) a stable result is achieved for the assignment criterion according to a statistical selection procedure; (ii) a deviation between the actual measurement curve (90) and the simulation actual measurement curve (94) is within a tolerance range; (iii) a maximum number of iterations has been performed.

3. System according to claim 1 or 2, wherein the system is configured to perform the method, wherein the start value of the simulated actual layer thickness (g_ist_11, ..., g_ist_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) is used as the start value of the simulation actual layer thickness (g_ist_11, ..., g_ist_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20); and / or wherein the system is designed to execute the method, wherein the start value of the simulation target layer thickness (g_ist_11, ..., g_ist_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) is used as the start value of the simulation target layer thickness (g_ist_11, ..., g_ist_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20); and / or wherein the system is designed to execute the method, wherein a predetermined layer thickness of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) is used as the start value of the simulation target layer thickness (g_soll_11, ..., g_soll_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20).

4. System according to one of the preceding claims, wherein the system is designed to generate (S104, S106) the simulation actual measurement curve (94) and simulation target measurement curve (98), further comprising determining (S110) a scaling factor (122) as the mean value of quotients from abscissa values of the actual measurement curve (90) or simulation actual measurement curve (94) and the target measurement curve (92) for abscissa values determined according to the assignment criterion, and scaling the target layer thickness (d_soll_11, ..., d_soll_20); or the simulated actual layer thickness (g_ist_11, ..., g_ist_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) with the scaling factor (122) as start values for the simulated actual layer thickness (g_ist_11, ..., g_ist_20) or the simulated target layer thickness (g_soll_11, ..., g_soll_20) of 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).

5. System according to one of the preceding claims, wherein the system is designed to generate (S104, S106) the simulation actual measurement curve (94) and simulation target measurement curve (98), respectively, further comprising at least for the first interval (82) for one or each of the multiple individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), forming (S112) a quotient (126) from the corresponding first final simulation actual layer thickness (g_ist_11, ..., g_ist_20) or the corresponding first final simulation target layer thickness (g_soll_11, ..., g_soll_20) and the corresponding actual layer thickness of the apparatus (d_ist_11, ..., d_ist_20), wherein a first actual simulation layer thickness (g_ist_11, ..., g_ist_20) or a target simulation layer thickness (g_soll_11, ..., g_soll_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) by scaling the simulation actual layer thickness (g_ist_11, ..., g_ist_20), or simulation target layer thickness (g_soll_11, ..., g_soll_20) of 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) with the quotient (126).

6. System according to claim 5, wherein the system is designed to generate (S104, S106) the simulation actual measurement curve (94) and simulation target measurement curve (98), further comprising checking (S114) the individual first simulation actual layer thicknesses (g_ist_11, ..., g_ist_20) or the one simulation target layer thickness (g_soll_11, ..., g_soll_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) against at least one criterion, in particular plausibility and / or a specified deviation from the respective target layer thickness (g_soll_11, ..., g_soll_20) of the target measurement curve (94), and, if the at least one criterion is not met, Repeat varying (S104, S106) the simulated actual layer thickness (g_ist_11, ..., g_ist_20) or the simulated target layer thickness (g_soll_11, ..., g_soll_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) and providing (S108) a first final simulation actual layer thickness (g_ist_11, ..., g_ist_20) or simulation target layer thickness (g_soll_11, ..., g_soll_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) and generating the first simulated actual layer thickness (g_ist_11, ..., g_ist_20) or simulated target layer thickness (g_soll_11, ..., g_soll_20), whereby for the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) of the one or more individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) that has failed to meet the criterion, a restriction is specified for variation (S104, S106), and providing a second simulation actual layer thickness (g_ist_11, ..., g_ist_20) or simulation target layer thickness (g_soll_11, ..., g_soll_20) of 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).

7. System according to one of claims 5 to 6, wherein the system is designed to repeating the steps (S104, S106, S112, S113, S114, S115) in one or more further spectral intervals (84, 86), each subsequent interval (84, 86) including the preceding interval (82, 84), wherein the second simulation actual layer thickness (g_ist_11, ..., g_ist_20) or simulation target layer thickness (g_soll_11, ..., g_soll_20) of the respective individual layer (11, 12, 13, 14, 15, 16, 17, 18, 19, 20) of the preceding interval (82, 84) are used as start values in the following interval (84, 86) and provision of a final simulation actual layer thickness (g_ist_11, ..., g_ist_20) or simulation target layer thickness (g_soll_11, ..., g_soll_20) of 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).

8. System according to any one of claims 1 to 7, wherein the system is designed such that an interferometrically reflective layer system (10) is deposited on at least one surface (24) of a substrate (22), wherein the layer system (10) comprises a stack (40) of at least four consecutive layer packages (42, 44, 46, 48, 50), each layer package (42, 44, 46, 48, 50) comprising a pair of first and second individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), wherein the first individual layers (11, 13, 15, 17, 19) have a first optical thickness (t1) and the second individual layers (12, 14, 16, 18, 20) have a second optical thickness (t2) that differs from the first optical thickness (t1), wherein a refractive index (n1) of the respective first individual layers (11, 13, 15, 17, 19) closer to the substrate is greater than a refractive index (n2) of the respective second individual layers (12, 14, 16, 18, 20) of the stack (40) farther from the substrate, wherein the layer system (10) has a brightness (L*), a chroma (C*) and a hue angle (h) of a residual reflection color, wherein the amount of change (Δh) in the hue angle (h) of the residual reflection color in an interval of a viewing angle (AOI) with the limits 0° and 30° relative to a surface normal (70) to the layer system (10) is smaller than the amount of change (ΔC*) in the chroma (C*) in the viewing angle interval (AOI), wherein the following steps are performed: - Defining a layer design comprising at least a first material for high-refractive first individual layers (11, 13, 15, 17, 19) and a second material for low-refractive second individual layers (12, 14, 16, 18, 20), number of desired layer packages (42, 44, 46, 48, 50) with the individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20), starting values for the thickness of the individual layers (11, 12, 13, 14, 15, 16, 17, 18, 19, 20); - Defining target color values, comprising brightness (L*), chroma (C*) and hue angle (h) at least at limit values for an angle of view (AOI) interval with limit values of 0° and 30°; - Performing an optimization process to vary the individual layer thicknesses (d_ist_11, ..., d_ist_20) until an optimization target is achieved.

9. System according to claim 8, wherein the system is designed such that the hue angle (h) in the viewing angle interval (AOI) with limit values of 0° and 30° changes by a maximum of 15°, preferably by a maximum of 10°; and / or wherein the system is designed such that the amount of change (Δh) in the hue angle (h) in a second viewing angle (AOI) interval from 0° to a limit viewing angle (Θ) with an upper limit value between 30° and 45° relative to the surface normal (70) on the layer system (10) is smaller than the amount of a change (ΔC*) in the colorfulness (C*) in the second interval of the viewing angle (AOI) and the amount of chromaticity (C*) at the limit 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 system is designed such that the photopic reflectance (Rv) in the viewing angle (AOI) interval with the limit values 0° and 30° is at most 1.5%, preferably at most 1.2%; and / or wherein the system is designed such that the scotopic reflectance (Rv') in the viewing angle (AOI) interval with the limits 0° and 30° is at most 1.5%, preferably at most 1.2%.

10. Method for producing a coating system (10) in at least one coating apparatus (108) using a method in a system (200) according to one of the preceding claims, wherein the coating system (10) is produced based on a final simulation target data set (DAT_soll_sim) for the coating apparatus (108).

11. Coating apparatus (108) for producing a coating system (10), with a method in a system (200) according to at least claim 1, comprising at least one of the following (i) a component (116) for applying an artificial aging process to the coating system (10), (ii) an optical measuring device (118) for determining a spectrally resolved actual measurement curve (90) of the coating system (10).

12. Computer program product for a method for operating at least one coating apparatus (108) for producing coating systems (10), wherein the computer program product comprises at least one computer-readable storage medium comprising program instructions executable on a computer system (102) and causing the computer system (102) to perform a method in a system (100) according to at least claim 1.