Measuring body with multiple flattenings

Abstract

Measuring body (1) for an optical coating for characterizing an optical layer system, comprising a dome-shaped section (2), wherein the dome-shaped section (2) has several flattenings (7), of which a first flattening (7.a) has a normal 1→ and a second flattening (7.b) has a normal 2→ and the normals n1→ and n2→ have different directions.

Description

Technical FieldThe invention relates to a measuring body for characterizing an optical coating.Prior ArtIn order to monitor coating processes of optical components, planar reference glasses or reference substrates are added to the respective coating process. After the coating process, the optical parameters of the layers formed on the reference substrates are characterized. It is disadvantageous that different configurations of the layer system at different coating angles cannot be detected with a reference substrate. In order to be able to characterize the configurations of the layer system that are produced at different coating angles, a plurality of such reference glasses must be arranged at different angles in the coating installation, which is complicated.It is also known to characterize the layer systems themselves applied to the optical components. For this purpose, complicated optics are required in a measuring arrangement for compensating the refractive power of the coated optical components so that the characteristics of the layer system can be separated. Disadvantages are the complexity of the measuring arrangements, the need for a special measuring arrangement for each component design and the possibility of systematic measurement errors.Object of the InventionIt is the object of the invention to provide a simple method for characterizing an optical coating for different angles of inclination with respect to the main direction, in which method large angles of inclination can also be detected.Solution of the ProblemThe object is achieved by a measurement body according to claim 1, a method for producing the same according to claim 8, a method for characterizing an optical layer system according to claim 9 and the use of a measurement body according to claim 10.Advantages of the InventionThe invention provides a simple method for characterizing an optical coating for different angles of inclination to the principal direction. In this case, large angles of inclination can also be detected. The test specimens according to the invention are simple to produce and use. In addition, they can be easily stored for quality verification of the coating. The characterization of the configurations of the layer system by means of the measurement body can be automated in a simple manner. The characterization can be carried out in a transmitted light and / or reflection arrangement in planar-optical measurement fields.DESCRIPTION OF THE INVENTIONA measurement body according to the invention is described below. Such a measuring body or a plurality of such measuring bodies can be added to a batch of an optical coating process. On the basis of the layer system applied to the measurement body, the layer system can be characterized with respect to at least one physical parameter. It can therefore be a measuring body for an optical coating. The measuring body can also be referred to as a test body.According to the invention, the measuring body has a dome-shaped section. The dome-shaped portion may have an outer side and an inner side. The dome-shaped portion may be formed as a cap of a hollow body. The dome-shaped portion may have a wall thickness. The wall thickness can vary. However, the wall thickness can also be uniform over the dome-shaped section. The dome-shaped portion may be thin-walled. The wall thickness can be less than one fifth, advantageously less than one tenth of the largest outer dimension of the dome-shaped section. The largest outer dimension of the dome-shaped portion may be the diameter or the largest radius of the dome base line described below. The dome-shaped section can have a basic shape of a spherical shell cap (i.e. the cap of a spherical shell), especially a semi-hollow sphere (i.e. a halved hollow sphere). However, it can also be designed as a cap of a polyhedron shell.According to the invention, the dome-shaped portion has a plurality of flats, a first flat having a normal and a second flat having a normal and having the normals and different directions. The flats may advantageously have different angles of inclination with respect to a reference direction, which may be indicated as z-direction. The dome-shaped portion may have a dome base line. This can lie in an xy plane. The directions x, y and z can form a Cartesian coordinate system. The reference direction z can coincide, for example, with the main direction of the material flow of the layer material in the coating process. In this direction, for example, the optical axes of the components to be coated can be aligned. The reference direction z may represent the zenith of the dome-shaped portion.The domed portion can also have at least three, advantageously at least four, particularly advantageously at least five, very particularly advantageously at least six and most advantageously at least seven flattened portions with respectively different normals and / or respectively different inclination angles with respect to the reference direction.Flattening can be understood to mean a point which is planar on the outer side and / or on the inner side (in the sense of "lying in a plane"). In principle, it is possible to make the flattened portions flat only on one side. However, this can lead to the measurement fields having an optical refractive power which can have a disadvantageous effect. Particularly advantageously, the flattened portions can be planar on both sides, i.e. on the inner and outer sides. The outside of the dome-shaped portion may be formed convex except for the flat flats. The inside of the dome-shaped portion may be concave except for the flat flats. The flattened portions can thus each be a local deviation from the above-mentioned shape. Represent the basic form. The normals of the flattened portions can have angles of inclination of between 0° and 90° with respect to the reference direction z. Advantageously, the largest of these inclination angles can be at least 60°. Advantageously, the difference between the smallest and the largest of these inclination angles can be at least 60°. Advantageously, the angles of inclination can be multiples of 10° and / or multiples of 15° and / or multiples of 20°. For example, the angles of inclination can be 10°, 30°, 50°, 70° or 0°, 15°, 30°, 45°, 60° or 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°. The term may mean that a normal is associated with the ithplate. The index i can run from 1 to the number k of claddings present. Functionally, a flattening can be understood to mean a measurement field. In a measurement field, the slice system can be characterized subsequently.Advantageously, the first flattened portion can be planar on the outer side, particularly advantageously additionally on the inner side. Advantageously, all the flattened portions can be planar on the outer side, particularly advantageously additionally on the inner side. Advantageously, the first flattened portion can be plane-parallel. This can be understood to mean that in the region of the first flattened portion the inner side is parallel to the outer side. In this sense, a plurality of, particularly advantageously all, flattened portions can be configured plane-parallel. A plane-parallel configuration of the claddings can have the advantage that the characterization of the optical layer system in the transmitted light method is possible more easily. The refractive power of a measurement field formed in this way can be zero. Therefore, compensation of the refractive power can be omitted during the measurement. Alternatively, one or more, particularly advantageously all, flattened portions can be configured in a wedge-like manner. This can be understood to mean that the inside of a flattened portion is planar and has an angle which is different from zero with respect to the outside of the flattened portion. A wedge-shaped configuration can have the advantage that, when characterizing the optical layer system in the reflection method, reflections on the uncoated side of the flattening can have less influence on the measurement result. If a flattened portion is formed in a wedge shape, the normals of the inner side and the outer side can fall apart. In this case, the normal of the side intended for coating can be used as the normal.Advantageously, the flattened portions can be formed with optically smooth surfaces.The flattenings may be bounded by flattening boundary lines. The flattening edge line of a flattening can be understood as an edge of the planar region. The flattening boundary line can be a closed curve and can be formed, for example, as a circle, oval or polygon. Each flattening may also have two flattening margin lines, one on the outside and one on the inside of the dome-shaped portion.The measuring body may have a dome base line. The dome base line may be disposed in an xy plane. Then, a reference direction in a direction perpendicular to the xy plane may be defined. Advantageously, the normals of the flattened portions in an xz plane can be arranged asymmetrically with respect to the reference direction. Thus, redundant angles of inclination can be avoided and the available space on the dome can be used for a finer angle gradation. The dome base line can be a closed curve and can be designed, for example, as a circle, oval or polygon.Advantageously, the measuring body can be characterized in that the dome-shaped section is designed as an icosahedron hollow stump cap. An icosahedron hollow stump cap can be represented geometrically theoretically in such a way that the corners of an icosahedron are truncated. In this case, a surface of pentagonal and hexagonal shapes can be produced in a known manner. These may be regular. The resulting icosahedron stump can be hollowed out as far as its outer shell. A cap can be separated from the resulting icosahedron hollow stump, so that the Ikosaederhohlstumpfkappe is formed, i.e. the cap of a hollow body with the outer surface of an icosahedron stump. Alternatively, an icosahedron hollow stump cap can be considered to be a cap of the surface of an icosahedron stump padded to a certain thickness. Padding can be understood, as is known from CAD technical languages, here in the sense of a geometric extrusion of a surface into a solid body. It should be noted that the considerations set forth in this paragraph do not describe a necessary production method, but serve merely to illustrate the geometry of an icosahedron hollow stump cap. For producing such a measuring body, the production methods shown below may be suitable. Configuring the dome-shaped portion as an icosahedron hollow stump cap can maximize the usable area of the flattened portions. Moreover, owing to the association with the shape of a football, the operating skill of the operator of the coating installation can be increased.Advantageously, the measuring body can also have an edge section. This can follow the dome base line. This rim can serve for the support of the measuring body in a device and / or for the alignment of the measuring body. The edge section can be formed as a brim. The rim can be formed as a hollow cylinder of small height or as a circular ring with finite thickness. The edge section can have a shaped element, for example a recess. As a result, the measuring body can be aligned azimuthally in the coating installation and / or for measuring the optical or mechanical variable.Advantageously, the measuring body can be configured stackable. In this case, a plurality of identical measuring bodies can be stacked one above the other, wherein a support for the respective measuring body lying above it can advantageously be provided on the edge section. This makes it possible to prevent the inner side of the dome-shaped section of a measuring body from touching the outer side of the measuring body lying underneath in the stack. In a stackable embodiment, the measuring bodies can be transported and stored more easily.Advantageously, the measuring body can be embodied in one piece. Alternatively, the measuring body can consist of several parts.A method for producing a measurement body can be advantageous, comprising a. producing at least one first molded part having at least one first molded part portion with a plurality of molded part flattened portions, of which a first molded part flattened portion has a normal and a second molded part flattened portion has a normal and the normals and different directions, b. producing a second molded part having at least one second molded part portion, c. providing a moldable measurement body material and / or a deformable measurement body blank, d. injection molding the measurement body material between the first molded part and the second molded part and / or compression molding the measurement body blank between the first molded part and the second molded part.According to the invention, either the first molding part section is of inversely dome-shaped design and the second molding part section is of dome-shaped design or vice versa, i.e. the first molding part section is of dome-shaped design and the second molding part section is of inversely dome-shaped design.Compression molding of the measuring body can be advantageous in particular for thin-walled measuring bodies. The compression molding can advantageously be a deep drawing. In the case of high requirements for the accuracy of the measuring body, however, injection molding can be more suitable as a production method.A moldable measuring body material can be, for example, a granulate or a melt. Such a measuring body material may be suitable in particular for injection molding. A measurement body blank can be, for example, a round blank or a plate. A measuring body blank can be suitable in particular for compression molding, in particular for deep drawing.The mold comprising the first and the second molded part can also be designed in such a way that a plurality of measurement bodies can be produced simultaneously. For this purpose, a plurality of inversely dome-shaped first and dome-shaped second molded part sections can be present.The measuring body can be made of a plastic. A plastic can be understood to mean a polymer. Advantageously, the measuring body can be made of a transparent glass or a transparent plastic. A transparent, i.e. a transparent polymer, can be particularly advantageous. Particularly suitable may be polycarbonate, COP, Zeonex, COC (Topas) or OKP. PMMA may likewise be suitable. Alternatively, the measuring body can be made of a glass. Advantageously, the material of the measuring body can be similar to the material of the components to be coated. Particularly reliable measurement results can then be achieved.In the case of production by compression molding, an elevated temperature, advantageously above a glass transition temperature of the material, can advantageously be used, because a cold measurement body blank could split during the forming process.Advantageously, more than the at least two flattened portions to be provided can be present in the first and / or second molded part in order to produce a measurement body described above with the corresponding number of flattened portions with normal.Advantageously, there can be measuring field inscriptions which identify the individual claddings. These may advantageously be arranged next to the flattened portions. Advantageously, the measuring field inscriptions can be present as negative in one of the molded parts and can be produced simultaneously during the shaping of the measuring bodies in this way.A method for characterizing an optical layer system may be advantageous, comprising a. providing a measuring body having a dome-shaped section which has a plurality of claddings, of which a first cladding has a normal and a second cladding has a normal and the normals and different directions, b. providing a coating installation, c. introducing the measuring body into the coating installation, d. carrying out a coating process by means of the coating installation, wherein an optical layer system is produced on the outer side or on the inner side of the measuring body, wherein a first configuration of the optical layer system is produced on the first cladding and a second configuration of the optical layer system is produced on the second cladding, e. measuring at least one optical and / or mechanical property of the first and of the second configuration of the optical layer system.Advantageously, the dome-shaped section can have more than the at least two flattened portions to be provided, for example a number k, as explained above in the description of the measuring body. Then, in step d, a number k of configurations of the optical layer system can be produced. In step e, at least one optical and / or mechanical property of two or more or all k configurations of the optical layer system can then be measured.An optical layer system in the sense of this invention can comprise one or more optically and / or mechanically active layers. These may include reflection, antireflection or filter layer systems, for example interference filters. The layer system can also comprise at least one hard layer for increasing the scratch resistance of the optical surfaces. The layer system may comprise metallic layers, semiconductor layers, and / or dielectric layers. The layer system can comprise organic and / or inorganic layers. The layer system can comprise layers with incorporated particles, for example nanoparticles.When manufacturing the optical layer system on a component with a curved surface, for example an optical lens, the angles of inclination of the normal to the reference direction z can be location-dependent. During the production of the optical layer system, the latter can be formed differently depending on the angle of inclination. The different configurations can differ, for example, with regard to the layer thicknesses. At a larger angle of inclination, for example, a smaller layer thickness can occur than at a smaller angle of inclination. With the aid of the measuring body, the different configurations of the layer system for different normals can be easily detected.The optical property can be, for example, the transmission or the reflection at a specific wavelength, a transmission or reflection spectrum over a specific wavelength range, the determination of the Brookfield angle, the determination of the degree of polarization in the case of oblique incidence of light or the like. The optical property can also be, for example, the surface density of defects of the layer system, the scattering of light, the light absorption or the destruction threshold of the layer system. The mechanical property can be, for example, the abrasion, scratch, abrasion or adhesion strength of the layer system. Characterization can be done by a non-destructive or destructive measurement. A plurality of optical or mechanical properties can also be characterized in each case. It may be advantageous to perform destructive measurements only after the completion of non-destructive measurements.Advantageously, the measuring body can be introduced into the coating plant in such a way that the outer side of the dome-shaped section is coated. For this purpose, the reference direction z of the measuring body can be arranged opposite to the main direction of the material flow of the layer material in the coating process. Alternatively, the measuring body can be introduced into the coating plant in such a way that the inner side of the dome-shaped section is coated. For this purpose, the reference direction z of the measuring body can be arranged in the main direction of the material flow of the layer material in the coating process. Advantageously, the flattened portions can be designed such that they are each planar on the side to be coated. A plane-parallel or wedge-shaped configuration of the flattened portions can be particularly advantageous.It may be advantageous to use a measuring body according to the invention to control the result of an optical coating of components. The components can be optical components, for example lenses, mirrors or prisms.The figures show the following: FIG. 1 shows a first exemplary embodiment in a first illustration. FIG. 2 shows the first exemplary embodiment in a second illustration. FIG. 3 shows the first exemplary embodiment in an xy-view. FIG. 4 shows the first exemplary embodiment in a sectional illustration AA. FIG. 5 shows the first exemplary embodiment in an xz view. FIG. 6 shows the first exemplary embodiment in a sectional illustration BB. FIG. 7 shows a second exemplary embodiment. FIG. 8 shows a third exemplary embodiment. FIG. 9 shows a stack of measuring bodies in a sectional illustration. FIG. 10 shows a fourth exemplary embodiment. FIG. 11 shows molded parts of a mold for producing a measuring body. Fig. 12 shows the mold having a cavity.Exemplary EmbodimentsThe invention is explained below using exemplary embodiments.FIG. 1 shows a first exemplary embodiment in a first illustration. FIG. 2 shows the first exemplary embodiment in a second illustration. A measuring body 1 is shown having a dome-shaped section 2 with an outer side 5 and an inner side 6. The dome-shaped section has a basic shape of a spherical shell cap (i.e. the cap of a spherical shell), in a specific embodiment of a semi-hollow sphere (i.e. a halved hollow sphere). The measuring body has an edge section 4 designed as a brim.FIG. 3 shows the first exemplary embodiment in an xy-view. The positions of the sectional planes AA and BB are given here. In this figure, the first flattening 7.a, the second flattening 7.b, a third flattening 7.c, a fourth flattening 7.d, a fifth flattening 7.e, a sixth flattening 7.f and a seventh flattening 7.g are indicatedFIG. 13 shows the first exemplary embodiment in a sectional illustration AA. The dome-shaped portion 2 has flattened portions 7. Each of the flattened portions has a flattened normal 11 on the outer side 5, the first flattened portion 7.a having a normal and the second flattened portion 7.b having a normal and having the normals and different directions. The flattened portions are plane-parallel. The flattenings are bounded on the outside by flattening margin lines 8 and on the inside by flattening margin lines 9.The dome-shaped portion has a dome base line 12. This lies in an xy plane. The directions x, y and z form a Cartesian coordinate system. The direction z may be considered as a reference direction 10. It may represent the zenith of the dome-shaped portion.FIG. 5 shows the first exemplary embodiment in an xz view.FIG. 6 shows the first exemplary embodiment in a sectional illustration BB.In a first variation, not shown in the figure, the inside of the dome-shaped portion is designed as a spherical surface throughout. This means that the flattened portions are formed as flat locations only on the outer side.In a second variation, not shown in the figures, the outside of the dome-shaped portion is designed as a spherical surface throughout. This means that the flattened portions are formed as flat locations only on the inner side.FIG. 7 shows a second exemplary embodiment. This is characterized in that the dome-shaped section 2 is designed as an icosahedron hollow stump cap 3. In this case, adjacent claddings 7(a-e) may be contiguous with common portions of the cladding boundary lines 8. In this embodiment, there is no edge portion. The measuring body 1 has only the dome-shaped portion 2. In a variation of the exemplary embodiment which is not illustrated in the figure, an edge section of the measuring body is provided in addition to the dome-shaped section.FIG. 8 shows a third exemplary embodiment. Here, the measuring body is made thinner-walled. This allows the material requirement to be reduced. Disposal of the measuring bodies can be more cost-effective.FIG. 9 shows a stack of measuring bodies in a sectional illustration. The stack shown contains two measuring bodies. As desired, more measuring bodies can be stacked one above the other, the stack then becoming correspondingly higher.FIG. 10 shows a fourth exemplary embodiment. Here, measurement field inscriptions 14 are provided, which indicate the inclination of the normal to the cladding to the reference direction z.FIG. 11 shows molded parts of a mold for producing a measuring body. The mold 15 comprises a plurality of molded parts A first molded part 16 is shown having a first inversely dome-shaped molded part section 17 which has molded part flattened portions 18. A first 18.a, second 18.b and third flattening 18.c of the shaped part are designated. Also shown is a second mold part 19 having a dome-shaped second mold part portion 20.Fig. 12 shows the mold having a cavity. The cavity 21 is located between the first molded part 16 and the second molded part 19 and enables shaping during the production of the measurement body, for example by injection molding or compression molding.The reference numerals used uniformly in all figures are as follows: 1 measurement body 2 dome-shaped section 3 icosahedron hollow stump cap 4 edge section 5 outer side 6 inner side 7 flattening a first b second c third d fourth e fifth f sixth g seventh 8 flattening edge line outer side 9 flattening edge line inner side 10 reference direction 11 flattening normal 12 dome base line 13 stack 14 measurement field marking 15 mold 16 first molded part 17 first molded part section 18 molded part flattening a first b second c third 19 second molded part 20 second molded part section 21 cavity

Claims

Measuring body (1) for an optical coating for characterizing an optical layer system, having a dome-shaped section (2), wherein the dome-shaped section (2) has a plurality of claddings (7), of which a first cladding (7.a) has a normal n 1→ and a second cladding (7.b) has a normal n 2→ and the normals n 1→ and n 2→ have different directions.Measuring body (1) according to claim 1, characterised in that the first flattened portion (7.a) is plane-parallel or wedge-shaped.Measuring body (1) according to one of the preceding claims, characterized in that it has a dome base line (12), and the dome base line (12) is arranged in an xy plane and a reference direction (10) can be defined in a direction perpendicular to the xy plane, and the normals n k → (11) of the flattened portions (7) in an xz plane are arranged asymmetrically with respect to the reference direction (10).Measuring body (1) according to one of the preceding claims, characterized in that the domed portion (2) is designed as an icosahedron hollow stump cap (3).Measuring body (1) according to one of the preceding claims, characterized in that it also has an edge section (4) designed as a brim.Measuring body (1) according to one of the preceding claims, characterized in that it is formed in one piece.Measuring body (1) according to one of the preceding claims, characterized in that it is produced from a glass or a transparent plastic.Method for producing a measuring body (1) comprising a. producing at least one first shaped part (16) having at least one first shaped part section (17) having a plurality of shaped part claddings (18), of which a first shaped part cladding (18.a) has a normal n 1→ and a second shaped part cladding (18.b) has a normal n 2→ and the normals n 1→ and n 2→ have different directions, b. producing a second shaped part (19) having at least one second shaped part section (20), wherein the first shaped part section (17) is formed in an inversely dome-shaped manner and the second shaped part section (20) is formed in a dome-shaped manner or vice versa, c. Providing a moldable measuring body material and / or a deformable measuring body blank. d. Injection molding the measuring body material between the first molded part (16) and the second molded part (19) and / or compression molding the measuring body blank between the first molded part (16) and the second molded part (19).Method for characterizing an optical layer system, comprising a. providing a measuring body (1) with a dome-shaped section (2) which has a plurality of claddings (7), of which a first cladding (7.a) has a normal n 1→ and a second cladding (7.b) has a normal n 2→ and the normals n 1→ and n 2→ have different directions, b. providing a coating installation, c. introducing the measuring body (1) into the coating installation, d. carrying out a coating process by means of the coating installation, wherein an optical layer system is produced on the outer side (5) or on the inner side (6) of the measuring body (1), wherein a first configuration of the optical layer system is produced on the first cladding (7.a) and a second configuration of the optical layer system is produced on the second cladding, e. measurement of at least one optical and / or mechanical property of the first and the second configuration of the optical layer system.Use of a measuring body (1) according to at least one of Claims 1 to 7 for controlling the result of an optical coating of components.

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