Optical element as sun protection for windows

Abstract

The invention relates to a flat optical element for a window element, wherein the flat optical element comprises a body made of a transparent material, and a plurality of non-transparent micro-lamellas are embedded and / or integrated into the transparent material so as to be slanted by a lamella angle.

Description

[0001] Elements as sun protection for windows

[0002] The invention relates to optical elements for arrangement on windows, window elements and / or glass facades as sun protection or sun glare protection.

[0003] Modern architecture frequently features large windows and glass facades in urban buildings, office buildings, and public buildings, as well as private residential buildings. Today, glass surfaces make up a large portion of the building envelope. Sunlight and daylight radiate through the windows into the rooms during the day, but thermal radiation also causes a high level of heat input, particularly in hotter regions and during the hotter seasons. Air conditioning is necessary to keep rooms at a comfortable temperature. The more heat radiation, the more energy is required for cooling. Direct sunlight through the window elements also leads to unpleasant glare, which is particularly disruptive for office workplaces.

[0004] Blinds, shades, or curtains are often used, either inside or outside windows, to block glare from direct sunlight and reduce heat gain. This often darkens rooms to such an extent that artificial light must be switched on, thus consuming additional energy.

[0005] Mechanical sun glare control solutions for both interior and exterior window surfaces are widespread. However, they have several disadvantages. The mechanical control of the slats is complex and expensive, prone to failure, and requires regular cleaning and maintenance. An indoor device has the disadvantage that the heat radiation is already in the room. Outdoors, the wind causes stability problems. Another major disadvantage of mechanical solutions is that the view from the window surfaces to the outside is significantly obstructed. The large slats divide the view into individual strips and limit the field of vision. Static or passive solar control films (SCF) can significantly reduce heat gain through window surfaces.For example, coatings are used that exhibit high transmission in the visible wavelength range and strong absorption or reflection in the UV and IR wavelength ranges. These coatings can include nanoparticles such as lanthanum hexaborite (Laße), cesium-doped tungsten oxide (CWO), antimony-doped tin oxide (ATO), indium tin oxide (ITO), and vanadium dioxide (VO2). However, the significant heat input through window surfaces caused by direct sunlight in the visible wavelength range is not shielded by the nanoparticle coating.

[0006] WO 03 / 106802 A1 discloses angle-selective shading using a microstructured grid plate with transparent through-holes and intervening non-transparent webs. Publication WO 2022 / 175551 A1 describes microstructured shading elements applied to a carrier film. A disadvantage of the microstructured grid plate or shading elements is the technically achievable ratio of non-transparent to transparent area due to the given width of the shading elements. Even in angular ranges with maximum transparency, transmission is limited by the surface area of ​​the shading elements.

[0007] Publication US 2022 / 0019007 A1 discloses thin shading elements positioned perpendicular to the carrier film with an aspect ratio above 30. The disadvantage of this solution is that the perpendicular alignment of the slats to the surface of the film only allows for symmetrical shading. Shading upwards from the sun is intended, but downward shading severely restricts visibility downwards. The greater the upward shading, the greater the downward view restriction. Furthermore, the use of this solution is severely limited in inclined glass surfaces, for example, in the roof area of ​​buildings.

[0008] US 2018 / 297328 A1 discloses a composite comprising a substrate, a sunscreen layer, and a planarization layer, wherein the substrate has a structured surface comprising a repeating pattern including a valley, a peak, a first sidewall extending at a first angle, and a second sidewall extending at a second angle and meeting the first sidewall at the peak. The sunscreen layer is disposed on the first sidewall, the sunscreen layer is discontinuous, and the planarization layer is adjacent to the sunscreen layer and the substrate. The first angle is in a range of 20° to 45°, and the second angle is in a range of 45° to 100°.

[0009] The object of the invention is to provide an alternative sun protection or glare protection. The aim is to avoid the aforementioned disadvantages, or some of the aforementioned disadvantages, of the mechanical sun protection or glare protection solutions described above. The aim is also to reduce the heat input through windows into buildings caused by solar radiation.

[0010] The above object is achieved by a planar optical element for a window element, wherein the planar optical element comprises a body made of a transparent material, and wherein a plurality of non-transparent micro-lamellae (each arranged adjacently one above the other) are embedded and / or integrated in the transparent material at an angle of inclination by a lamella angle.

[0011] A planar optical element within the meaning of this disclosure has, in particular, a designated inner surface, a designated outer surface, a designated upper side, and a designated underside. It is particularly provided that the designated inner surface and the designated outer surface run parallel or substantially parallel to one another. A designated inner surface of the optical element within the meaning of this disclosure is a surface facing a space delimited by the optical element. The planar optical element within the meaning of this disclosure can be a film or a plate.

[0012] A microlamella can be designed as a thin layer with an approximately cuboid shape with a microlamella length L, a microlamella width w, and a microlamella layer thickness t. The microlamellae are inclined by a lamella angle. An inclined microlamella within the meaning of this disclosure forms a slope relative to a surface normal of the intended outer surface of the optical element. This slope runs from the inner surface of the optical element ("top"), sloping towards the intended outer surface of the optical element ("bottom"). In this case, an edge of the approximately cuboid microlamella, wherein the edge has a length corresponding to the width w of the approximately cuboid microlamella, encloses the lamella angle with the surface normal of the intended outer surface of the optical element, or with a surface normal of the intended outer surface of the optical element, by which the respective microlamella is inclined.The lamella angle by which the respective microlamella is inclined is the angle between one or the surface normal of the intended outer surface of the optical element and an edge of the respective microlamella, which is as long as the width w of the microlamella.

[0013] A slat angle within the meaning of this disclosure is (in terms of magnitude) in particular not less than 1°, in particular not less than 5°, in particular not less than 10°. A slat angle within the meaning of this disclosure is (in terms of magnitude) in particular not greater than 45°, in particular not greater than 30°, in particular not greater than 20°. In a particularly advantageous embodiment, the slat angle is (in terms of magnitude) between 0° and 45°, preferably between 0° and 30°, preferably between 10° and 30°, and particularly preferably between 10° and 20°.

[0014] Alternatively, a microlamella may not be formed as an approximately cuboid-shaped thin layer, but as a curved or otherwise three-dimensionally shaped thin layer.

[0015] In one embodiment of the invention, the respective micro-lamellae are inclined by the same angle. The so-called thin-film micro-lamellae are arranged three-dimensionally in the depth of the planar optical element at a defined angular position.

[0016] Transparent within the meaning of this disclosure can mean, in particular, permeable to light with a wavelength in the visible range. Wavelengths in the visible range are the wavelengths that most people can perceive with the naked eye. Transparent within the meaning of this disclosure can mean, in particular, permeable to light with a wavelength in the infrared range. Transparent within the meaning of this disclosure can mean, in particular, permeable to light with a wavelength in the ultraviolet range.

[0017] Non-transparent within the meaning of this disclosure can mean, in particular, opaque to light in the visible range. Non-transparent within the meaning of this disclosure can mean, in particular, opaque to light with a wavelength in the infrared range. Non-transparent within the meaning of this disclosure can mean, in particular, opaque to light with a wavelength in the ultraviolet range.

[0018] Non-transparent material within the meaning of this disclosure may include light-reflecting and / or light-absorbing material or may consist of light-reflecting or light-absorbing material. Non-transparent material within the meaning of this disclosure may include photovoltaic material or may consist of photovoltaic material.

[0019] Microlamellae within the meaning of this disclosure are, in particular, thin-film microlamellae. A planar optical element within the meaning of this disclosure can be or comprise, in particular, a plate, a curved plate, or a film.

[0020] Microlamellae within the meaning of this disclosure have, in particular, a microlamella width w, a microlamella thickness t, and a microlamella length L. The quotient of microlamella width w and microlamella thickness t, the so-called aspect ratio w / t, is, in particular, not less than 10. The quotient of microlamella width and microlamella thickness, the so-called aspect ratio w / t, is, in particular, less than 30, in particular not more than 25.

[0021] The micro-lamellae can be arranged adjacent to one another, from the bottom of the optical element to the top of the optical element. The micro-lamellae can also be arranged adjacent to one another along the outer surface and / or the inner surface of the optical element. The spacing between the micro-lamellae can be equidistant or different. Alternatively, the micro-lamellae can have a different spacing and / or a different inclination and / or a different geometry in certain areas than in other areas.

[0022] The microlamellar spacing d, i.e., the distance between two adjacent microlamellae, is, for example, not more than 2.5 times the width w of the microlamellae (microlamellar width). The microlamellar spacing d, i.e., the distance between two adjacent microlamellae, is, for example, not less than 0.7 times the width of the microlamellae (microlamellar width). It is particularly provided that the width w of the microlamellae (microlamellar width) is not more than 1000 μm. It is particularly provided that the thickness t of the microlamellae (microlamellar thickness) is not more than 10 μm, in particular not more than 5 μm, in particular not more than 2 μm.

[0023] The proportion of the transparent area of ​​the planar optical element in the total area of ​​the planar optical element is particularly large when looking through the planar optical element along the lamellar angle of the micro-lamellae, i.e. looking through in the lamellar direction, due to the small cross-sectional area of ​​the micro-lamellae, and is, for example, more than 80%, in particular more than 90%, in particular more than 95%.

[0024] The planar optical element may comprise markings that identify the intended outer surface, the intended inner surface, the intended upper side and / or the intended lower side of the planar optical element.

[0025] The aforementioned object is also achieved by a method for producing a planar optical element, in particular a planar optical element with one or more of the aforementioned features, wherein a basic structure is produced from a transparent material, said basic structure comprising a plurality of, in particular, wedge-shaped, in particular (approximately) parallel microstructures, wherein material for forming microlamellae is applied to a respective intended upper side or surface of the microstructures. In one embodiment, the material for forming microlamellae is applied to the intended upper sides or surfaces of the microstructures by means of a physical vacuum coating (PVD = Physical Vapor Deposition), for example in a sputtering or vapor deposition process.In a further embodiment, the material for forming microlamellae is applied to the intended top sides or surfaces at an application angle. In a further embodiment, the base structure made of a transparent material with the microlamellae is provided with a cover layer such that the microlamellae are embedded between the base structure and the cover layer. The cover layer can be made of the same or approximately the same transparent material as the base structure.

[0026] In one embodiment, the base structure is created by embossing or hot stamping. In one embodiment, the base structure is made of plastic, for example, PET, PMMA, or PC. In one embodiment, the base structure consists of plastic, for example, PET, PMMA, or PC. In one embodiment, the material of the cover layer is the same as the material of the base structure. In another embodiment, the cover layer is a lacquer layer. The base structure can be created, for example, by UV embossing into a UV-curing lacquer layer, hot stamping, or extrusion. UV embossing is also possible directly on a glass pane.

[0027] The microlamellae, or so-called thin-film microlamellae, are applied using a sputtering or vapor deposition process, for example. This is achieved by oblique sputtering or evaporation. The direction of movement of the atoms in the respective PVD process is aligned at a defined angle to the microstructured surface. In this way, material is deposited atom by atom in a thin film on certain areas of the microstructures, while almost no material is deposited on so-called shadow areas. The geometry of the basic structure allows defined, obliquely positioned microlamellae to be deposited in the form of thin films.

[0028] In a further embodiment, the material of the cover layer has a cover layer refractive index, and the material of the base structure has a base structure refractive index, wherein the base structure refractive index and the cover layer refractive index are the same or substantially the same. In this sense, substantially the same means that the refractive indices differ by no more than 0.05. This creates a virtually invisible interface between the microstructures. This prevents reflections from occurring at the interface.

[0029] Wedge-shaped within the meaning of this disclosure means in particular in the shape of a wedge. A wedge within the meaning of this disclosure is in particular a body in which two side surfaces converge at an acute angle. In a preferred embodiment, the angular width of the wedge is more than twice, in particular not less than 2.5 times, the slat angle. In a preferred embodiment, the angular width of the wedge is not more than four times, in particular not more than three times, the slat angle. A wedge within the meaning of this disclosure can have a blunt tip. A wedge within the meaning of this disclosure can be a triangular prism. A wedge within the meaning of this disclosure can be a regular triangular prism.

[0030] The aforementioned object is also achieved by a window element comprising a glass pane on which a planar optical element having one or more of the aforementioned features or a correspondingly manufactured planar optical element is arranged and / or fixed. In a manufacturing method for producing such a window element, a correspondingly manufactured planar optical element is applied to a glass pane. Alternatively, a base structure is first applied to a glass pane, and the planar optical element is then manufactured according to the aforementioned process steps.

[0031] The planar optical element or a corresponding window element can be used in buildings and other applications where angle-selective transparency is required, for example, for glass surfaces in automobiles or other means of transport, such as trains, rail vehicles, aircraft, or ships. The restriction of fields of view by the microlouvres can also be used for glass surfaces inside buildings, for example, to visually demarcate a private area. Another application example is displays where the field of view needs to be restricted. For example, a window element according to the invention can be installed in the construction of a building or means of transport.According to an alternative method for manufacturing a building or a means of transport, a glass pane is installed therein, wherein a planar optical element having one or more of the aforementioned features is applied and / or fixed to the glass pane, for example on the inside of the glass pane.

[0032] The teaching of integrated thin-film micro-louvres disclosed here makes it possible to shade direct sunlight in an angle-selective manner across the entire spectral range of light, particularly in the visible spectrum. Due to the fixed arrangement of the micro-louvres, the transmission properties of the optical element depend on the angle of the incident light.

[0033] The microlouvres can be designed so that window surfaces equipped with the optical element shade direct sunlight while allowing daylight to enter the room at an angle different from that of direct sunlight. The angle of daylight also represents the bright viewing area through the optical element applied to the glass or window surface.

[0034] The (large-)area optical element with integrated microlouvres can be applied to the outside or inside of glass, or to one of the insides of laminated glass. The dimensions, angle, and shape of the microlouvres are fixed within the optical element. They are therefore passive and not mechanically controlled, as is the case with large louvres in external blinds, for example. Maintenance or repairs are therefore unnecessary. The optical elements can be designed into different classes with defined specifications to meet the different requirements of building glass surfaces, such as latitude, location, direction, or inclination.

[0035] Further advantages and details are revealed in the following description of exemplary embodiments. These show:

[0036] Fig. 1A shows an embodiment of a planar optical element in a side view,

[0037] Fig. 1 B the planar optical element according to Fig. 1 A in a view from,

[0038] Fig. 1 C shows the planar optical element according to Fig. 1A in a perspective view,

[0039] Fig. 2 the planar optical element according to Fig. 1A with different viewing angles

[0040] Fig. 3 shows an embodiment of a characteristic field of a planar optical element according to Fig. 1A to illustrate the transmission as a function of the angle of incidence of light at a lamella angle of -20° for different values ​​of the ratio of microlamella width to lamella spacing,

[0041] Fig. 4 shows an embodiment of a characteristic field of a planar optical element according to Fig. 1A for illustrating the transmission as a function of the angle of incidence of light at a micro-lamella width / lamella spacing ratio of 0.8 for different values ​​of the lamella angle,

[0042] Fig. 5A shows an embodiment of a method step for producing the planar optical element according to Fig. 1A,

[0043] Fig. 5B shows an enlarged section of Fig. 5A,

[0044] Fig. 5C shows an embodiment of a further method step for producing the planar optical element according to Fig. 1A,

[0045] Fig. 5D shows an embodiment of a result of the method step according to Fig. 5C,

[0046] Fig. 5E shows an embodiment of a further method step for producing the planar optical element according to Fig. 1A,

[0047] Fig. 5F shows an embodiment of a result of the method step according to Fig. 5E,

[0048] Fig. 6 shows an embodiment of a window element with a planar optical element according to Fig. 1A,

[0049] Fig. 7 shows an embodiment of a building with a window element according to Fig. 6,

[0050] Fig. 8 shows an embodiment of a ship with a window element according to Fig. 6,

[0051] Fig. 9 shows an embodiment of a train with a window element according to Fig. 6,

[0052] Fig. 10 shows an embodiment of an automobile with a window element according to Fig. 6, and

[0053] Fig. 11 an embodiment of an inclined window element with a flat optical element.

[0054] Fig. 1A shows - in a side view - an embodiment of a planar optical element 1 or thin-film microlamellae with microlamellae 11 arranged obliquely in a transparent body 10. Fig. 1B shows the planar optical element 1 in a front view, and Fig. 1C shows the planar optical element 1 in a perspective view. Reference numeral 2 denotes a designated outer surface and reference numeral 3 a designated inner surface of the optical element 1. Reference numeral w denotes a or the microlamella width, reference numeral t a or the microlamella thickness, reference numeral d a or the lamella spacing of two adjacent (i.e. arranged adjacent to one another) microlamellae, reference numeral L a or the microlamella length L and reference numeral ö a or the lamella angle.

[0055] Due to the thin-film technology used, the thickness t of the microlamellae (microlamella thickness) is in a range below 10 pm, preferably below 2 pm. The width w of the microlamellae (microlamella width), however, can be designed significantly above 10 pm, preferably above 50 pm. In this way, aspect ratios w / t above 10 are achieved. In this embodiment, the microlamellae are arranged parallel and equidistant from one another.

[0056] In this exemplary embodiment, the micro-lamellae are made of a material that largely absorbs incoming light. The micro-lamellae are each arranged at a lamella angle of δ = -20°, which is measured counterclockwise (and therefore has a negative sign) from the surface normal 7 of the intended outer surface 2 of the optical element 1 to an edge of the respective micro-lamellae with an edge length corresponding to the micro-lamella width w.

[0057] The planar optical element 1 can comprise markings 6 which identify the intended outer surface 2, the intended inner surface 3, a intended upper side 4 and / or a intended underside 8 of the planar optical element 1.

[0058] Fig. 2 shows light rays LS entering the optical element 1 at different angles of incidence. At the top there is a cut-off angle θ1 above which no more light is transmitted (to an observer 5). Light entering the planar optical element 1 at an angle greater than θ1 is largely absorbed by the micro-lamellae. The maximum transmission of light is achieved at an angle of incidence θ2 (for an observer 5) at which the light rays run (approximately) parallel to the inclined micro-lamellae. Towards the bottom there is a cut-off angle θ3 for the angle of incidence below which no more light is transmitted. Light entering the planar optical element 1 at an angle smaller than θ3 is largely absorbed by the micro-lamellae.

[0059] Angle θ1 is measured clockwise (and therefore has a positive sign) from the surface normal 7 of the intended outer surface 2. Angles θ2 and θ3 are measured counterclockwise (and therefore have a negative sign) from the surface normal 7 of the intended outer surface 2.

[0060] Fig. 3 shows an embodiment of a characteristic field of the planar optical element 1 according to Fig. 2 to illustrate the transmission as a function of the angle of incidence of light at a defined slat angle of θ = -20° for different values ​​of the ratio of micro-slat width w / slat spacing d. With a slat position θ = -20°, the maximum transmission is achieved at an angle of incidence θ2 = -30°. At an angle of incidence close to 0°, the transmission of the incident light can be up to 86%, depending on the ratio w / d. Towards upwards, towards positive angles of incidence, the directly incident sunlight is increasingly absorbed, while in the angle of incidence range below -30° (observer 5 looks more downwards), higher transmissions of the incident light continue to occur.

[0061] Fig. 4 shows an embodiment of a characteristic curve field of the planar optical element 1 according to Fig. 2 for illustrating the transmission as a function of the angle of incidence of light at a ratio of micro-lamella width w / lamella spacing d of 0.8 for different values ​​of the lamella angle θ. In the characteristic curve field according to Fig. 4, the angle of incidence θ2 with maximum transmission shifts depending on the angular position of the lamellae. With a horizontal angular position θ = 0°, the transmission characteristic is symmetrical for both upward and downward views. With increasing downward inclination of the lamellae θ < 0°, high transmission values ​​are achieved for horizontal and downward viewing angles, while viewing angles upwards towards the sun, when the sun is high in the sky, have low transmission values. Fig. 5A to Fig.5F show an embodiment of a process chain for producing an optical element 1 with (three-dimensionally integrated micro-lamellae). In the first process step according to Fig. 5A, a film or plate made of a plastic, for example PET, PMMA or PC, is provided with a basic structure having microstructures. This can be done, for example, by UV embossing into a UV-curing lacquer layer, hot stamping or extrusion. UV embossing is also possible directly on a glass pane. Since the micro-lamellae are aligned parallel to one another, the microstructure is also aligned linearly. A typical structural geometry is micro-wedges or microprisms lying parallel to one another, which can have different side angles (i.e. δ and α - δ), where α denotes the angular width or the angular dimension of the respective micro-wedge. Curved side surfaces are also possible, so that curved micro-lamellae can also be produced. Fig.Figure 5B shows an enlarged section of Figure 5A, illustrating the angular width of a micro-wedge, designated by reference symbol a. Reference symbol h denotes the extension of a wedge-shaped structure in the orientation of the surface normal 7 of the intended inner surface 3 and / or the intended outer surface 2 of the planar optical element 1.

[0062] In the second process step (Fig. 5C), the microlamellae 11 are applied to the surfaces of the microstructures using a sputtering or vapor deposition process (both PVD processes, physical vapor deposition). This is done by oblique sputtering or evaporation. The direction of movement of the atoms in the PVD process is aligned at a defined angle to the microstructured surface. In this way, a thin film of material is deposited atom by atom on specific areas of the respective microstructure, although no material is deposed in a thin film on so-called shadow areas. The geometry of the microstructures can thus be used to create defined, obliquely positioned microlamellae in the form of thin films.

[0063] The material and surface of the micro-louvres can be selected so that the incident light rays are predominantly absorbed or reflected. Metals such as aluminum or silver can be used as reflective materials. Thin films such as black aluminum or deep black DLC (diamond-like carbon) can be used as absorbing materials.

[0064] Fig. 5D shows the intermediate product with applied microlamellae. In a further process step in Fig. 5E, a film or plate with an intermediate lacquer layer is laminated onto the microstructure. The lacquer layer fills the microstructure, including the microlamellae, completely and without air inclusions, and the film or plate ensures a flat surface. A UV-curing, highly transparent acrylic lacquer, for example, is used as the lacquer. Ideally, the same lacquer is used for the microstructuring and the subsequent filling of the microstructures. The refractive indices of the materials used for the base structure with the microstructure and the cover layer are the same or almost the same in this embodiment. This way, no reflections occur at the interface.

[0065] Fig. 6 shows an embodiment of a window element 20, which is composed of a glass pane 21 with a planar optical element 1 mounted thereon according to Fig. 1A. Fig. 7 shows an embodiment of a building 30 with a window element 20. Fig. 8 shows an embodiment of a ship 40 with a window element 20, Fig. 9 shows an embodiment of a train 50 with a window element 20, and Fig. 10 shows an embodiment of an automobile 60 with a window element 20.

[0066] Fig. 11 discloses an embodiment of a tilt angle relative to the horizontal 222 <p geneigt verbauten Fensterelements 200 mit einem flächigen optischen Element 201 auf einer Glasscheibe 210. Für ein derartig eingebautes Fensterelement 200 ist bei der Bestimmung des Lamellenwinkels der Mikrolamellen des flächigen optischen Elements der Verkippungswinkel <p des Gebäudes zu berücksichtigen, um eine bestimmte Transmission des einfallenden Lichts zu erreichen.

[0067] The use of the described flat optical elements on windows and glass facades ensures pleasant daylight in rooms and prevents glare from direct sunlight. In the hot season, when the sun is high in the sky, the sun's rays are dimmed. This reduces the heat buildup in rooms, so less energy is needed to cool them. In the cooler season, when the sun is lower in the sky, more sunlight enters the rooms. The invention enables sustainable energy savings and more energy-efficient building technology.

[0068] The elements or objects in the figures are drawn for simplicity and clarity and are not necessarily to scale. For example, the sizes of some elements are exaggerated relative to others to improve understanding of the embodiments of the present invention. Fig. 1A, Fig. 1B, Fig. 1C, Fig. 2, Fig. 5A, Fig. 5B, Fig. 5C, Fig. 5D, Fig. 5E, Fig. 5F, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Fig. 10 and Fig. 11 are oriented, shown or drawn with the intended top side up and the intended bottom side down.

[0069] List of reference symbols

[0070] 1 flat optical element

[0071] 2 intended exterior surface

[0072] 3 intended inner surface

[0073] 4 intended top side

[0074] 5 viewers

[0075] 6 Marking

[0076] 7 Surface normals

[0077] 8 intended subpage

[0078] 10 transparent body

[0079] 11 micro-lamella

[0080] 12 Top coat (paint layer)

[0081] 14 Basic structure (microstructured film or plate, e.g. made of plastic)

[0082] 20, 200 window element

[0083] 21 , 210 glass pane

[0084] 30 buildings

[0085] 40 Ship or watercraft

[0086] 50 train

[0087] 60 automobiles

[0088] 101 planar optical element

[0089] 120 Window element 141 wedge-shaped structure (wedge, triangular prism)

[0090] 201 planar optical element

[0091] 222 Horizontal d Distance between two adjacent microlamellae h Extension of the wedge-shaped structure or microstructure

[0092] L Microlamellar length t Microlamellar thickness w Microlamellar width a Angle width, angle dimension ß Application angle

[0093] 01 Cut-off angle

[0094] 02 Angle of maximum transmission

[0095] 03 Cut-off angle

[0096] 6 slat angles <p Verkippungswinkel

[0097] LS light beam

Claims

1. A planar optical element (1) for a window element (20), wherein the planar optical element (1) comprises a body (10) made of a transparent material, and wherein a plurality of non-transparent micro-lamellae (11) are embedded and / or integrated in the transparent material at an angle (6) to which they are inclined.

2. Planar optical element (1) according to claim 1, characterized in that the microlamellae (11) are designed as thin-film microlamellae with a lamella thickness (t) of less than 10 pm, in particular less than 2 pm, and wherein the aspect ratio (w / t) is not less than 10.

3. Flat optical element (1) according to claim 1 or 2, characterized in that the amount of the lamella angle (6) is greater than 0° and less than 45°, in particular not greater than 30°.

4. Flat optical element (1) according to claim 1 or 2, characterized in that the amount of the lamella angle (6) is not less than 10° and not greater than 30°, in particular not greater than 20°.

5. Method for producing a planar optical element (1), in particular a planar optical element (1) according to one of the preceding claims, characterized in that a basic structure (14) is produced from a transparent material, which basic structure comprises a multiplicity of, in particular parallel, microstructures (141), wherein material for forming microlamellae (11) is applied to a respective intended upper side of the microstructures (141).

6. Method according to claim 5, characterized in that the microstructures are wedge-shaped.

7. Method according to claim 5 or 6, characterized in that, in order to form microlamellae (11), material is applied to a designated upper side of the Microstructures are applied using a sputtering or vapor deposition process.

8. Method according to one of claims 5 to 7, characterized in that the material for forming microlamellae (11) is applied at an application angle.

9. Method according to one of claims 5 to 8, characterized in that the basic structure (14) with the microlamellae (11) is provided with a cover layer (12) in such a way that the microlamellae (11) are embedded between the basic structure (14) and the cover layer (12).

10. The method according to claim 9, characterized in that the transparent material of the base structure has a first refractive index and the transparent material of the cover layer has a second refractive index, wherein the first refractive index is equal to or approximately equal to the second refractive index.

11. Window element, characterized in that it has a glass pane (21) on which a planar optical element (1) according to one of claims 1 to 4 or a planar optical element (1) produced according to a method according to one of claims 5 to 10 is arranged and / or fixed.

12. A method for producing a window element (20), characterized in that a planar optical element (1) is produced according to a method according to one of claims 5 to 10, wherein the planar optical element (1) is applied to a glass pane (21).

13. A method for producing a window element (20), characterized in that a basic structure (14) is applied to a glass pane (21), which comprises a plurality of wedge-shaped, in particular parallel, microstructures, wherein material for forming microlamellae (11) is applied to a respective intended upper side of the microstructures (141), and wherein the basic structure (14) with the microlamellae (11) is provided with a cover layer (12) in such a way that the microlamellae (11) are embedded between the basic structure (14) and the cover layer (12).

14. Building (30) or means of transport (40, 50, 60), characterized in that it comprises a window element (20) according to claim 11 or a window facade with a plurality of window elements according to claim 11.

15. A method for producing a building (30) or a means of transport (40, 50, 60) which comprises at least one glass pane, characterized in that an optical element (1) according to one of claims 1 to 4 or a planar optical element (1) produced according to the method according to one of claims 5 to 10 is arranged, applied and / or fixed on the glass pane, in particular on the inside of the glass pane.

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