Illuminable glazing element with dichroic coupling-in element

Abstract

The invention relates to an illuminable glazing element (101), comprising: an optical waveguide (1) having a first and a second surface (I, II), a light coupling-in element (100) arranged on the first surface (I) of the optical waveguide (1), comprising a prismatic film (2) with at least one prismatic surface (2.1, 2.2) which has a plurality of inclined surfaces (F), and a dichroic reflection layer (3) which is applied to the prismatic surface (2.1, 2.2), and a light source (6) for visible light (5), which is arranged facing the second surface (II) of the optical waveguide (1), wherein the light source (6) is oriented such that, during operation, it irradiates the light coupling-in element (100) with light (5) and the emitted light (5) is at least partially coupled into the optical waveguide (1) by way of reflection at the dichroic reflection layer (3).

Description

[0001] SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0002] Illuminated glazing element with dichroic coupling element

[0003] The invention relates to an illuminateable glazing element with a dichroic coupling element, its manufacture and its use.

[0004] Illuminated glazing elements are known as such. They are equipped with a light source whose light is coupled into an optical fiber, usually a glass pane, and propagates due to total internal reflection. Often, the light is coupled back out of the optical fiber by light-diffusing elements, thus achieving illumination. The shape of the light-diffusing elements is freely selectable, so that illuminated surfaces of any shape, for example as patterns, can be created. Illuminated glazing elements of this type are known, for example, from W02014 / 060409 A1 or WO2014 / 167291 A1.

[0005] In the automotive sector, such illuminated glazing elements are particularly interesting as roof panels, but also as windshields or windows in trains or buses. The glazing element is typically designed as a laminated pane, with the light coupled into the inner pane. However, such illuminated glazing elements can also be used for other vehicle windows, as well as for windows in buildings, architecture, or furnishings. The light-diffusing structures create illuminated surfaces that can be used to display aesthetically pleasing shapes and patterns, or to present information, such as directional arrows, status indicators, warnings, price lists, or similar elements.

[0006] Several methods are known for coupling the light from the light source into the optical waveguide formed as a glass pane. The light source (typically a light-emitting diode) can be positioned at the side edge so that the light is emitted into the glass pane via the side edge and thus coupled in. However, such coupling is often impossible, particularly because the side edge of the glass pane is usually ground to increase its mechanical strength, resulting in a cloudy surface. Furthermore, positioning the light source at the edge of the pane is difficult to achieve, as a glass pane with such a light source loses stability. SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0007] Alternatively, the light source can be positioned in a recess in the glass pane (for example, in a feedthrough), so that the light is directed into the glass pane via the side edge of the recess and thus coupled in. However, drilling the recess makes the production of such a glazing element considerably more complex and carries the risk of a comparatively high reject rate due to glass breakage. Another disadvantage is that the pane cannot have an unlimited number of recesses with light sources, which can result in an insufficient amount of light being coupled in.

[0008] US2020241189 A1 proposes coupling light through a main surface of the glass pane. For this purpose, a coupling element is attached to the surface of the glass pane facing away from the light source. The coupling element has sections inclined relative to each other. The coupling element is illuminated by the light source through the glass pane, and the light is reflected at the inclined sections in such a way that it propagates along the surfaces in the glass pane due to total internal reflection. WO2023 / 144282 A1 also describes a reflective structure, preferably a microprism film, attached to one side of the optical waveguide opposite the light source. The structure with inclined surfaces is additionally provided with a reflective coating.

[0009] US 2010 / 300608 A1 concerns the manufacture of an optical system with a cladding. A wedge-shaped optical waveguide made of a material with a first refractive index has a cladding layer.

[0010] US 11852816 B1 discloses a system with a display module and waveguide. The system can be a VR headset containing optical elements that provide the highest possible image resolution. The optical elements can include a diffraction grating, a collimating lens, or a prism.

[0011] However, current approaches to coupling light into optical fibers allow little or no adjustment of the color or polarization of the coupled light. This can lead to undesirable effects, for example, when the light interacts with the environment or when specific colors or polarizations are required for a particular application. Therefore, there is a need for a way to adjust the color or polarization of the light coupled into the glass pane without affecting the light coupling efficiency or the homogeneity of the light distribution.

[0012] The present invention aims to provide an illuminable glazing element with which the color and / or polarization of the coupled light can be flexibly adjusted without impairing the efficiency of the coupled light. Furthermore, the invention aims to provide a manufacturing method and a use for such a glazing element. The glazing element should be flexible, high-quality, and cost-effective to manufacture.

[0013] The object of the present invention is achieved by independent claims 1, 14 and 15. Preferred embodiments are set forth in the dependent claims.

[0014] The illuminateable glazing element according to the invention comprises an optical waveguide with a first and a second surface. These two surfaces are arranged opposite each other. The optical waveguide is therefore disk-shaped or plate-shaped. A light coupling element is arranged on the first surface of the optical waveguide, preferably fixedly attached. The light coupling element comprises a prismatic film, which has at least one prismatic surface. The prismatic surface, in turn, has a plurality of inclined surfaces, which constitute the "prisms" of the prismatic film. Preferably, the prismatic film has no inclined surfaces on the opposite second surface, but is, for example, essentially smooth there. Alternatively, however, both surfaces of the prismatic film can be prismatic surfaces that have inclined surfaces.According to the invention, a dichroic reflective layer is applied to at least one prismatic surface of the prismatic film. Preferably, this reflective layer extends over the entire inclined surfaces of the prismatic surface.

[0015] A light source for visible light is arranged facing the second surface of the optical waveguide. The light source can therefore be located on the second surface. However, it is also possible for further elements to be arranged between the second surface of the optical waveguide and the light source, for example, a glass pane and / or a thermoplastic film. Preferably, however, the light source is arranged on the second surface of the optical waveguide, and in particular, mounted there. According to the invention, the light source is oriented such that, during operation, it illuminates the light coupling element with light, and the emitted light is coupled into the optical waveguide, at least partially, via reflection at the dichroic reflective layer.

[0016] For the purposes of this invention, "optical waveguide" refers to a light-conducting medium, preferably a glass or plastic disc, designed such that light can be coupled into the optical waveguide by utilizing the effect of total internal reflection, and which is also suitable for conducting coupled light. The principle of light conduction by means of total internal reflection is generally known to those skilled in the art and is described in more detail, for example, in WG2008 / 047442A1, JP2011086547A, or JP2015043321A.

[0017] The principle of light transmission can be illustrated using an optical waveguide with two opposing primary surfaces (first surface and second surface). Each primary surface of the optical waveguide represents an interface with the adjacent medium. The first primary surface of the optical waveguide is, for example, the interface with a thermoplastic layer. The second primary surface of the optical waveguide is, for example, the interface with the surrounding atmosphere. Typically, the medium adjacent to the second primary surface (for example, the atmosphere of the room) has a different refractive index than the optical waveguide. In the case that the adjacent medium has a different refractive index than the optical waveguide, this results in a critical angle of total internal reflection, which is determined as α. T= arcsin(— ), where ni is the refractive index of the optically denser medium and n2 is the refractive index of the optically less dense medium. In the case of the interface between an optical fiber and air, the refractive index of the optical fiber is therefore m and the refractive index of the air is n2. If light strikes the interface at an angle of incidence greater than the critical angle, the light is completely reflected (total internal reflection). Therefore, for light to propagate through the optical fiber, the coupled light must be coupled in such a way that it strikes the interface at an angle greater than the respective critical angle.

[0018] When visible light from the light source is irradiated via the second surface of the optical waveguide in the region of the light coupling element, the light propagates through the optical waveguide and, optionally, through elements arranged between the reflective layer (SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT) until it reaches the dichroic reflective layer and is reflected by it. The inclined surfaces provided with the reflective layer are configured such that the light is reflected back to the optical waveguide at least partially, preferably at least 5%, and coupled into it. The light is reflected and coupled into the optical waveguide by the inclined surfaces at an angle suitable for the coupled light to propagate at least partially, preferably predominantly, through the optical waveguide by total internal reflection.The amount of light coupled into the optical waveguide in this way is also affected by the angle at which the light hits the inclined surfaces covered with the reflective layer, and this angle can be adjusted according to requirements.

[0019] A major advantage of the invention is that it allows the polarization, or color, of the light visible to a user to be adjusted. The dichroic reflective layer enables the light coupling element to split the incident light into two components, each with different properties. For example, the light can be visible only if the driver is not wearing sunglasses, while remaining invisible to a driver wearing sunglasses (reflected light is, for instance, exclusively S-polarized). This can be useful for displaying information or warnings intended only for the driver. The color of the light can also be controlled by the dichroic reflective layer by decomposing the light into its spectral components and reflecting only specific wavelengths.This can be used to compensate for color deficiencies that may arise from processes during light transmission or to achieve different color effects. The solution is also flexible, as the light coupling element with one dichroic reflective layer can be replaced with one with a different dichroic reflective layer. This allows the light properties to be modified depending on the application or preference. Finally, the light source can be inexpensive and simple, since the light properties are primarily controlled by the light coupling element. The light source therefore only needs to provide sufficient brightness and a broad spectral range to produce the desired light.

[0020] In a preferred embodiment, the light coupling medium is applied to the first surface of the optical waveguide by means of an adhesive, for example, an immersion oil layer or an optically clear adhesive layer. The adhesive has an inner and an outer surface. The inner surface of the adhesive is the surface facing the light coupling medium, whereas the outer surface of the adhesive is the surface facing away from the light coupling medium. The adhesive also has a circumferential side surface connecting the inner and outer surfaces.

[0021] The light coupling medium also has an inner and an outer surface. The inner surface of the light coupling medium is the surface facing the adhesive, while the outer surface is the surface facing away from the adhesive. The light coupling medium also has a circumferential side surface connecting the inner and outer surfaces. The inner and outer surfaces of the adhesive and the light coupling medium, respectively, represent the main surfaces of the layer or structure. The main surface is the surface with the greatest extent. The adhesive is applied to the inner surface of the light coupling medium and the first surface of the optical waveguide, or it bonds or connects them together. The inclined surfaces of the prismatic film are considered, in this context, as structuring of the prismatic surface. Therefore, the prismatic surface of the prismatic film is not smooth.The prismatic surface with the dichroic reflective layer can represent the inside or the outside of the light coupling medium, but preferably the inside.

[0022] The inclined surfaces of the prismatic surface are inclined to a straight line that runs along the principal direction of extension of the prismatic film. The inclined surfaces can be inclined at different angles, but preferably the angles of the individual inclined surfaces do not deviate from each other by more than 5°, particularly preferably not by more than 3°, and especially not by more than 1°. The inclined surfaces are preferably arranged at an average angle of at least 30°, particularly preferably at least 45°, and particularly preferably at most 50° to the straight line on the principal direction of extension. In a particularly preferred embodiment, the inclined surfaces are arranged at an average angle of 45° to 48° to the straight line on the principal direction of extension. At such angles, the efficiency of light coupling into the optical waveguide is significantly increased. The aforementioned inclined surfaces are preferably substantially planar.Methods for measuring the angle of inclined surfaces to the line on the principal extension direction are generally known to those skilled in the art. The angles can be determined, for example, using laser scanning microscopes. SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT.

[0023] The term "optically clear adhesive layer" refers to a class of adhesives generally known to those skilled in the art (English: "optical clear adhesives OCA"), which are characterized by particularly good adhesive properties and a high transmittance of visible light. Preferably, the optically clear adhesive refers to an adhesive that has a light transmittance TL of at least 80%, and particularly preferably at least 90%, at an average layer thickness of 100 pm.

[0024] Optically clear adhesives preferably contain acrylic and / or silicone compounds, but may also additionally or independently contain polymers made from butene compounds, particularly preferably polymers made with isobutene and / or 1,3-butadiene. The optically clear adhesive layer is most preferably based on such acrylic, silicone, or butene compounds. In particular, the optically clear adhesive layer consists of such acrylic, silicone, or butene compounds. These materials exhibit improved properties for optical fiber transmission and are simultaneously sufficiently adhesive to bond the light coupling element to an optical fiber.

[0025] In a particularly preferred embodiment of the invention, the adhesive layer is based on or consists of polyacrylate, polyisobutene, and / or synthetic rubber, in particular styrene-butadiene rubber or polyisobutene. These materials exhibit a very constant refractive index over the entire visible spectral range and are very resistant to aging with respect to refractive index and adhesive effect.

[0026] The adhesive preferably has a layer thickness of at least 10 pm, particularly preferably at least 25 pm, most preferably at least 50 pm, and particularly preferably at least 100 pm. At these layer thicknesses, the adhesive essentially completely fills the spaces formed by the inclined surfaces of the prismatic surface, thus preventing additional light refraction (adhesive -> air -> reflective layer) and improving coupling. The layer thickness of the adhesive is preferably not greater than 1000 pm, particularly not greater than 500 pm. Preferably, the layer thickness of the adhesive is never less than 10 pm, and particularly preferably not less than 20 pm. These layer thicknesses have proven to be particularly advantageous with regard to durable adhesion relative to material consumption.Layer thicknesses up to a maximum of 100 pm, preferably up to a maximum of 50 pm (SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT), are particularly preferred, as this prevents local over-thickness, which is especially relevant when using the light coupling element in laminated glass. Unless explicitly stated otherwise, layer thickness specifications within the meaning of the invention generally refer to the average layer thickness over the entire layer.

[0027] If the adhesive is formed as an immersion oil layer, it preferably contains, or consists of, mineral oil, paraffin oil, petrolatum oil, other synthetic oils, and / or mixtures thereof. These oils have a refractive index close to that of mineral glass (e.g., soda-lime glass), so that fewer light rays are refracted at the interface between the glass and air. This ensures higher light coupling. Immersion oils can also reduce chromatic aberration by decreasing the dispersion of light.

[0028] The thickness of the adhesive, the prismatic film, and the dichroic reflective layer can be determined, for example, using micrometers, scanning electron microscopes, or light microscopes, depending on the thickness range. For layers in the nanometer range, as is typical for the reflective layer, X-ray reflectometry (XPR) or a scanning electron microscope (SEM) in combination with a focused ion beam (FIB) can also be used to measure the layer thickness. Methods for determining layer thickness are known to those skilled in the art.

[0029] The prismatic film preferably contains polyethylene terephthalate, polycarbonate, polyethylene, polypropylene, polyacrylate, and / or poly(organo)siloxane, particularly preferably polyacrylate and / or poly(organo)siloxane. The prismatic film most preferably consists of polyethylene terephthalate, polycarbonate, polyethylene, polypropylene, polyacrylate, and / or poly(organo)siloxane, particularly polyacrylate or poly(organo)siloxane. The prismatic film preferably has an average layer thickness of at least 10 µm and at most 200 µm, particularly preferably at least 20 µm and at most 100 µm, and particularly 25 µm and at most 50 µm. The prismatic film is preferably not thinner than 10 µm at any point, and particularly preferably thinner than 20 µm. These layer thicknesses have proven to be particularly advantageous with regard to stability in relation to material consumption.Layer thicknesses up to a maximum of 100 pm, in particular a maximum of 50 pm, SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT are particularly preferred, as this prevents local over-thickness, which is especially relevant when using the light coupling medium in laminated glass.

[0030] In a preferred embodiment of the invention, the prismatic film is a flexible, in particular film-like, polymeric film, which preferably has a substantially flat surface and the structured prismatic surface in the form of inclined planes. However, it is also possible for both surfaces of the prismatic film to be structured. Instead of a flexible film-like film, the prismatic film can also be a rigid plate, i.e., a rigid glass or plastic plate, which is structured on at least one surface with inclined planes or prisms, preferably microprisms, which become reflective surfaces due to the dichroic reflective layer.

[0031] Methods for producing prismatic films, whether as foils or rigid sheets, are generally known to those skilled in the art. Films or sheets structured with inclined surfaces are also commercially available and can be obtained, for example, from 3M Company.

[0032] The prismatic film can be transparent or opaque. If the prismatic surface with the dichroic reflective layer is simultaneously the outer surface of the light coupling element, then the prismatic film preferably has a light transmittance TL of at least 70%, more preferably at least 80%, and more particularly at least 90%.

[0033] The dichroic reflective layer preferably contains at least one metal and / or an alloy. However, a metal-free reflective layer is also possible; for example, such a layer contains or consists of a dielectric stack. Most preferably, the reflective layer contains a metal or an alloy. This increases the reflectivity of the reflective surface. Particularly suitable metals are, for example, silver or aluminum, and alloys thereof. It is understood that, according to the invention, the reflective effect of the reflective structure is achieved largely by the reflective layer on the inclined surfaces. The reflective layer can be a single layer or a stack of several single layers, for example, two or three single layers. SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0034] The dichroic reflective layer preferably contains or consists of gold, silver and aluminum, dielectrics such as silicon dioxide and / or titanium dioxide and / or ceramics.

[0035] In a preferred embodiment, the dichroic reflective layer comprises, in addition to a metallic layer, for example, a silver or aluminum layer, an adhesive layer, wherein the adhesive layer is applied directly to the inclined surfaces and the metallic layer is applied to the adhesive layer. The adhesive layer improves the adhesion of the metallic layer and thus also its aging resistance. The adhesive layer can contain nickel, chromium, titanium oxide, silicon nitride, and / or nickel-chromium alloys. Preferably, the adhesive layer consists of nickel, chromium, titanium oxide, silicon nitride, and / or nickel-chromium alloys. These materials significantly improve the adhesion of the dichroic reflective layer to the reflective structure. The adhesive layer preferably has a thickness of 1 nm to 100 nm, more preferably 5 nm to 70 nm, and particularly preferably 10 nm to 50 nm.At these layer thicknesses, a particularly good ratio of adhesion to material consumption is achieved. The thickness and composition of the dichroic reflective layer determine the colors that are reflected and transmitted.

[0036] Preferred designs for materials and layer thicknesses of the dichroic reflective layer:

[0037] • A gold layer with a thickness of 50 nm reflects green light and allows red and blue light to pass through.

[0038] • A silver layer with a thickness of 30 nm reflects blue light and allows red and green light to pass through.

[0039] • Titanium dioxide with a thickness of 70 nm and a layer of silicon dioxide with a thickness of 130 nm reflect green light and allow red and blue light to pass through.

[0040] These are just a few examples, and there are many other ways to produce dichroic reflective layers with different materials and layer thicknesses.

[0041] The dichroic reflective layer on the inclined surfaces preferably has a reflectance for visible light of at least 70%, particularly preferably at least 80%, and especially at least 90%.

[0042] The term "reflectivity" is used in accordance with ISO 9050:2003 3.4. Reflectivity is measured at an angle of incidence of 8° to the surface normal. Regarding the reflectivity of the dichroic reflective coating, the SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT standard applies.

[0043] The surface normal refers to the normal to the principal surface of the prismatic film. The principal surface is defined as a surface oriented parallel to the principal direction of extension of the prismatic film. The spectral range from 380 nm to 780 nm was used to characterize the reflection properties.

[0044] Reflectance describes the proportion of the total incident radiation in a specified spectral range that is reflected. Reflectance always refers to a specific spectral range, for example, the visible spectrum from 380 nm to 780 nm or the ultraviolet range. It is expressed as a percentage (relative to 100% incident radiation) or as a dimensionless number from 0 to 1 (normalized to the incident radiation). Plotted against wavelength, it forms the reflection spectrum. The values ​​for reflectance and reflection spectrum refer to a reflection measurement with a light source that emits uniformly across the considered spectral range at a normalized radiation intensity of 100%.

[0045] In a preferred embodiment of the invention, the prismatic film is a microprism film. The inclined surfaces of the reflective structure are configured as a plurality of microprisms. The microprisms act primarily as reflective prisms, reflecting the incident light in a direction that depends on the inclination angle of the prism surfaces and the angle of incidence of the light. Microprism films are commercially available and can be purchased or manufactured in-house. The inclined surfaces are in the micrometer range. The edge length of the individual microprisms is preferably from 10 pm to 250 pm, more preferably from 20 pm to 100 pm, for example, approximately 30 pm.

[0046] Refractive indices are generally specified within the scope of the present invention with reference to a wavelength of 589 nm, unless explicitly stated otherwise. Methods for determining refractive indices are known to those skilled in the art. The refractive indices specified within the scope of the invention can, for example, be determined by ellipsometry, using commercially available ellipsometers. If the refractive index refers to a coating or layer comprising several individual layers in a layer stack, the refractive index specified is the effective refractive index across all layers. The effective refractive index describes the average optical density of a medium through which the light wave propagates / onto which it strikes. The effective refractive index takes into account the different refractive indices of the individual layers of the layer stack.Unless otherwise stated, the specification of layer thicknesses or thicknesses refers to the geometric thickness of a layer.

[0047] In a preferred embodiment A of the glazing element, the light coupling element is arranged on the optical waveguide such that the prismatic surface provided with the dichroic reflective layer faces the optical waveguide. The prismatic surface with the dichroic reflective layer is therefore the inner side of the light coupling element. A major advantage of this arrangement is that the light does not have to propagate through the prismatic film before it can couple into the optical waveguide. This avoids multiple interfaces with light refraction.

[0048] In an alternative embodiment B to embodiment A, the light coupling element is arranged on the optical waveguide such that the prismatic surface with the dichroic reflective layer faces away from the optical waveguide. The prismatic surface with the dichroic reflective layer is therefore the outer surface of the light coupling element. A major advantage of this embodiment is that any adhesive used to bond the light coupling element to the optical waveguide does not need to fill the spaces formed by the prisms. This largely prevents unwanted light refraction with air in the spaces. In this case, the inner surface of the light coupling element or the prismatic film is preferably essentially smooth.

[0049] In a particularly preferred further embodiment, in which the glazing element comprises an adhesive as described above, the refractive index of the optical waveguide is lower than the refractive index of the adhesive. In other words: refractive index of the optical waveguide < refractive index of the adhesive. Particularly preferred is a difference in the refractive index between the optical waveguide and the adhesive that is no greater than 0.05, preferably no greater than 0.03, and especially no greater than 0.01. These elements, with their progressively higher refractive indices moving away from the light source, allow for optimization of the light transmission in the optical waveguide. This result was unexpected and surprising to the inventors. SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0050] The optical waveguide is preferably a glass or plastic disc. The optical waveguide has a circumferential surface that connects the first and second surfaces. When the optical waveguide is installed (for example, in or as a vehicle window or building glazing), the first surface is designed to face the external environment. The first surface of the optical waveguide is hereinafter referred to as the outer surface. When the optical waveguide is installed, the second surface is designed to face the interior. The second surface of the optical waveguide is hereinafter referred to as the inner surface. However, the invention is not limited to this.

[0051] In a preferred embodiment of the invention, the light coupling element is arranged in an edge region of the optical waveguide. Preferably, the light coupling element is arranged at a distance of no more than 15 cm, and more preferably no more than 5 cm, from the circumferential side surface of the optical waveguide. This avoids the light coupling element being located in a central region of the optical waveguide (which is generally intended for transparency). This also increases the area of ​​the optical waveguide that can be provided with light-diffusing elements and that overlaps with the transparency area.

[0052] The optical fiber can be, for example, a single pane of glass, but it can also be part of a laminated pane or insulating glass unit (multiple glazing). The optical fiber can be, for instance, the inner or outer pane of a laminated pane or insulating glass unit. It can also be located between two panes of a laminated pane within the thermoplastic interlayer.

[0053] The inclined surfaces of the prismatic surface are sections inclined to the second surface of the optical waveguide. This means that the sections are not parallel to the second surface, but are arranged at an angle greater than 0° to the surface. The light coupling means is preferably designed and applied to the first surface of the optical waveguide such that the said sections have an angle to the second surface of the optical waveguide between 10° and 90°, preferably from 28° to 60° or from 30° to 60°, and most preferably from 30° to 50°, particularly from 40° to 50°, for example, about 45°. The absolute value of the respective angle is meant. The sections can be inclined in different directions. The sections are also preferably inclined to each other.This means that adjacent sections are inclined towards each other, i.e., not parallel, but arranged at an angle between 0° and 160° to each other.

[0054] In a preferred embodiment C, the glazing element can comprise a laminated pane, wherein the laminated pane includes a first pane, a second pane, and an intermediate thermoplastic layer. The optical waveguide is, for example, embedded in the intermediate layer. The optical waveguide is thus arranged planarly between the first and second panes. The optical waveguide is in direct contact with the intermediate layer at both its first and second surfaces. This provides better protection for the light coupling element against external influences. The light source can also be located or attached to a surface of the first or second pane facing away from the thermoplastic intermediate layer. The light from the light source is therefore first transmitted through the first or second pane and a portion of the intermediate layer before reaching the second surface of the optical waveguide.

[0055] In an alternative embodiment D to embodiment C, the glazing element also comprises a laminated pane, wherein the laminated pane consists of a first pane, a second pane, and an intermediate thermoplastic layer. The optical fiber, for example, represents either the first or the second pane. Preferably, the optical fiber is the inner pane of the laminated pane, i.e., the pane that, when installed in a vehicle or building, borders the interior. Preferably, the optical fiber is arranged such that the light coupling element is located between the optical fiber and the other pane. This provides better protection against external damage. The first pane and the second pane are bonded across their entire surface via the thermoplastic layer.

[0056] In a preferred embodiment of the invention, the optical waveguide has at least one light-scattering element. Preferably, the optical waveguide has at least two light-scattering elements, more preferably at least three light-scattering elements, and more preferably at least five light-scattering elements. The light-scattering elements can be applied to or incorporated on the inner surface (first surface) or the outer surface (second surface) of the optical waveguide. Preferably, only on the second surface, SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0057] The first surface has at least one light-diffusing element applied / incorporated; therefore, no light-diffusing elements are applied or incorporated on the first surface. Light effects emitted by the second surface appear brighter in the space adjacent to the second surface.

[0058] In the context of the invention, a "light-scattering element" refers to an element suitable for extracting light from the optical waveguide, i.e., from the light-conducting medium. Coupled light propagates until it either strikes the side surface of the light-conducting medium or a light-scattering element, where it is extracted. The light-scattering elements are preferably arranged such that coupled light is extracted from the optical waveguide primarily on the inner surface. When coupled light strikes a light-scattering element, total internal reflection is interrupted, and the light is instead extracted from the light-conducting medium.

[0059] Light-diffusing elements can be applied, for example, as a print on the optical fiber. The print, especially if the optical fiber is a glass pane, is preferably designed as a light-diffusing enamel. This enamel can be applied, for example, using screen printing or digital printing. It preferably contains glass frits, which are fired into the surface of the optical fiber, creating a roughened and therefore light-diffusing surface.

[0060] In the event that the glazing element according to the invention comprises a laminated pane, as described for embodiments C and D, preferably at least one light-diffusing element is applied as a print on the thermoplastic intermediate layer, such that the print is in direct contact with the first surface or the second surface of the optical waveguide. The light-diffusing element as a print on the intermediate layer can be realized by printing one of the surfaces of the laminated films with a light-diffusing printing paste. The laminated film or films form the intermediate layer after lamination. The print (printing paste) preferably contains no pigment and is therefore transparent. Alternatively, the transparent print can also contain pigments such as TiO2 pigments. In a further embodiment of the invention, the printing paste is opaque, semi-transparent, or colored by dyes and / or color pigments.The at least one light-diffusing element can alternatively be provided as a film. The film is, for example, located between the SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT.

[0061] The optical fibers and the intermediate layer are arranged. However, it is equally possible for light-diffusing elements to be provided as either a printed element or a film.

[0062] In a further preferred embodiment of the disk according to the invention, the optical waveguide is designed as a mineral glass disk or a plastic disk, wherein at least one light-scattering element is formed by roughening the first surface and / or the second surface of the optical waveguide. This roughening can be carried out mechanically (for example, by grinding techniques) or by laser processing. Laser processing has the particular advantage in the case of a laminated disk that the light-scattering structure can also be incorporated into the finished laminated disk, even if it is to be located inside the laminated disk, since the laser radiation can also be focused onto a plane inside the laminated disk. Furthermore, laser processing makes it possible to form the light-scattering structure not on an external surface, but inside the optical waveguide.

[0063] In a particularly advantageous configuration, each light-diffusing element is transparent, so that it does not significantly restrict the view through the glazing element. However, opaque or semi-transparent light-diffusing elements with pigments are also conceivable, for example, white structures. The light-diffusing element can also create a colored tint, meaning that it does not completely block the view through the glazing element, but makes it appear in one or more color tones.

[0064] The optical waveguide can also have several light-scattering elements. Preferably, all light-scattering elements are configured according to exactly one of the variants mentioned above. However, it is also possible for the light-scattering elements to differ from one another. For example, one or more light-scattering elements can be applied as imprints on the intermediate layer, while one or more other light-scattering elements can be configured as a roughening of the first surface and / or the second surface of the optical waveguide.

[0065] The light-diffusing element appears as a luminous surface on the disc. This can be used, for example, to illuminate an interior space and, in particular, to display symbols or patterns that serve to convey information or are intended for purely aesthetic reasons. Any shape or pattern can be realized using the light-diffusing elements. SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0066] The glazing element is designed to separate an interior space from the outside environment within a window opening of a vehicle or building. In this context, if the glazing element comprises a laminated pane or multiple glazing, the pane facing the interior (vehicle interior) is referred to as the "inner pane" within the meaning of the invention. The pane facing the outside environment is referred to as the "outer pane".

[0067] The thermoplastic interlayer comprises at least one thermoplastic composite film, but may also include several thermoplastic composite films. The thermoplastic composite films preferably contain polyvinyl butyral (PVB), ethylene-vinyl acetate copolymers (EVA), and / or thermoplastic polyurethanes (TPU). The composite films of the interlayer are preferably made of the same material, but can, in principle, also be made of different materials. The thickness of each individual thermoplastic composite film is preferably from 0.1 mm to 2 mm, and particularly preferably from 0.3 mm to 1 mm. Particularly preferably, the total thickness of the interlayer, i.e., the sum of the thicknesses of all thermoplastic layers of the interlayer, is from 0.2 mm to 5 mm (based on the average thickness). Most preferably, the thermoplastic interlayer has an average thickness of 0.38 mm or 0.76 mm.The layers of the thermoplastic intermediate layer can be tinted or untinted. Preferably, the intermediate layer is based on thermoplastic materials, i.e., it consists predominantly (> 50 vol.%) of them.

[0068] If something, for example a film or a layer, is based on a polymeric material, this means that it contains the said material predominantly (proportion of greater than 50 wt.%), preferably at least 60%, particularly preferably at least 70%, in particular at least 90%, and may optionally contain other components, for example plasticizers, stabilizers, UV or IR absorbers.

[0069] Embodiments A and B are described as alternatives to each other. The same applies to embodiments C and D. However, embodiment A or B can be combined with any other embodiments described herein, for example, C or D. Likewise, embodiment C or D can be combined with any other embodiments described herein, for example, A or B. SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0070] The optical waveguide preferably has a light transmission of at least 70%, more preferably at least 80%, and most preferably at least 90%. "Transparent" within the meaning of the invention means a light transmission of at least 70%, more preferably at least 80%, and more preferably at least 90%. "Semi-transparent" within the meaning of the invention means a light transmission of at most 70%, more preferably at most 50%, and more preferably at most 30%. "Opaque" within the meaning of the invention means a light transmission of less than 30%, more preferably less than 20%, more preferably less than 5%, and more preferably less than 0.1%.

[0071] The determination of luminous transmittance is carried out according to ISO 9050:2003 (see section 3.3 of the standard). The relative spectral distribution of illuminant D65 (see, for example, ISO 11664-2:2007) and / or the relative spectral distribution of illuminant A (see, for example, ISO 11664-2:2007) can be used for the determination. In other words, the described luminous transmittance range applies to determination using illuminant A and / or illuminant D65.

[0072] The glazing element preferably has an opaque masking area through which no visibility is possible. This masking area is preferably arranged around the perimeter of the optical fiber. It can be part of the laminated glass. The masking area surrounds a central transparent viewing area in a frame-like manner. This is particularly common for vehicle windows. The masking area is preferably formed by an opaque element, for example, by an opaque printed overlay. If the glazing element comprises a laminated glass, the opaque element can also be formed by an opaque section of the interlayer. The masking area is particularly preferably formed by an opaque printed overlay.Such a cover print is typically formed by an enamel containing glass frits and a black pigment, which is applied using screen printing or digital printing and then fired into the surface of the disc and / or optical fiber. When applied using digital printing, the enamel is preferably applied to the disc as ink from an inkjet printer.

[0073] The optical fiber and any additional disk or disks are preferably made of mineral glass, in particular soda-lime glass, as specified in SAINT-GOBAIN SEKURIT FRANCE 2024256- WO-PCT

[0074] Window panes are commonly used. However, they can also be made of other types of glass (e.g., borosilicate glass, quartz glass, aluminosilicate glass) or transparent plastics (e.g., polymethyl methacrylate or polycarbonate). The thickness of the optical fiber and the panes (e.g., inner pane, outer pane) can vary widely. Preferably, optical fibers and any additional pane(s) with a thickness in the range of 0.8 mm to 5 mm, more preferably from 1.4 mm to 2.5 mm, are used, for example, those with standard thicknesses of 1.6 mm or 2.1 mm. They can be independently unstressed, partially stressed, or stressed. If at least the optical fiber and / or an additional pane or panes are to have a stress, this can be a thermal or chemical stress. In an advantageous embodiment of the invention, the outer pane of the laminated glass is tinted.This is particularly suitable when the glazing element is used as a laminated glass panel, such as a vehicle roof panel.

[0075] The optical waveguide is preferably made of low-iron glass (also referred to as "ultra-clear glass"). Low-iron glass is defined as glass with an integrated light transmittance (TL) for visible light (according to ISO 9050:2003) of 90% or more and a low iron content. Preferably, the optical waveguide has the following soda-lime glass composition, based on 100 wt% of the total glass composition:

[0076] SiO₂: 67 to 75 wt.%, Na₂O: 10 to 20 wt.%, CaO: 5 to 15 wt.%, MgO: 0 to 7 wt.%, Al₂O₃: 0 to 5 wt.% and K₂O: 0 to 5 wt.%

[0077] In addition to the aforementioned components and iron, the glass of the optical fiber may contain other components in small amounts. For example, the glass may contain SO3 as a refining agent in a proportion of 0.01 to 1.0 wt%, chloride in a proportion of 0.01 to 0.03 wt%, and Ti2 in a proportion of 0.001 to 0.03 wt%.

[0078] The total proportion of iron in the oxidation state Fe 3+ , which is present in the glass mass or in the resulting glass, is here in accordance with standard practice as SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0079] expressed as Fe2Ü3. However, this does not mean that all iron is actually present in the form of Fe2Ü3. Likewise, the Fe 2+ The proportion is given here as FeO, even if possibly not all iron is in the Fe state. 2+ Iron is present in the glass mass or the resulting glass in the form of FeO. Iron is in the Fe state. 2+(FeO) is a blue-green pigment, while iron in the Fe state 3+ a yellow-green dye. In particular, those produced by Fe 2+ The blue-green tint caused by the glass should be avoided to achieve a neutral or clear glass. Using glass panes with a low iron content for the optical waveguide allows for particularly good light transmission, ensuring that as much light as possible from the light source is carried from the coupling point to the light-diffusing element. Furthermore, the use of glass panes with a low iron content allows the visible light generated by the light source to pass through them without discoloration, thus forming the luminous surface.

[0080] The optical waveguide is preferably a glass pane with a low iron content. The term "glass pane with a low iron content" is known to those skilled in the art. In particular, "glass pane with a low iron content" is understood to mean a glass pane that does not exhibit any coloration perceptible to the human eye due to iron. Preferably, the glass pane with a low iron content has a total iron content, expressed in the form of Fe₂Ü₃, of 0.020 wt.% or less, more preferably 0.015 wt.% or less, and even more preferably 0.012 wt.% or less, based on 100 wt.% of the total glass composition. Alternatively or in combination with the foregoing, the glass pane with a low iron content has an Fe 2+The proportion of iron, expressed in the form of FeO, of 0.0030 wt.% or less, more preferably 0.0025 wt.% or less, and even more preferably 0.0024 wt.% or less, based on 100 wt.% of the total glass composition, is measured. Methods for determining the percentage of iron in the glass composition are generally known to those skilled in the art. The measurement of the proportion of iron in the form of Fe 2+ and / or Fe 3+ This can be done, for example, according to ISO 14719:2011.

[0081] The glazing element, or the optical fiber, and optionally the laminated pane, can have any three-dimensional shape. Preferably, the optical fiber, inner pane (first pane), and / or outer pane (second pane) have no shadowed areas, so that they can be efficiently coated by cathodic sputtering. Preferably, the pane is flat or slightly or strongly curved in one or more directions in space.

[0082] In a further preferred embodiment of the invention, the glazing element comprises a laminated pane, as described above for embodiments C and D, and additionally has a low-refractive-index layer on at least one surface of the optical waveguide, which faces the thermoplastic interlayer; preferably, this is the first surface of the optical waveguide. If the optical waveguide is arranged within the thermoplastic interlayer, i.e., is completely enclosed by it, the low-refractive-index layer can also be applied to the first and second surfaces. The low-refractive-index layer has a refractive index for light that is at least 0.1 lower than the refractive index of the optical waveguide. This reduces the unwanted light leakage from the optical waveguide via the first surface.This increases the amount of light that can be extracted via light-scattering elements. The low-refractive-index layer is in direct contact with the surface of the optical waveguide and is preferably applied to the first surface using conventional coating methods.

[0083] The low-refractive index layer preferably has a refractive index of at most 1.50, particularly preferably at most 1.45, and especially at most 1.40. The low-refractive index layer preferably has a refractive index of at least 1.35, particularly preferably at least 1.40. The lower the refractive index, the smaller the critical angle at which total internal reflection is possible. In other words, the light loss is reduced compared to layers with a higher refractive index.

[0084] In particular, at least one layer or all layers of the low-refractive index layer comprises or consists of a cross-linked polymer matrix such that the low-refractive index layer has a refractive index of at most 1.42, preferably at most 1.40, and particularly at most 1.3, wherein the matrix is ​​preferably formed from polymers based on polyacrylate, and especially preferably based on polyacrylate functionalized with fluorine. The refractive index of the low-refractive index layer can be reduced by means of fluorine functionalization. The use of polyacrylate as the material for the low-refractive index layer is advantageous because acrylate compounds can be efficiently cross-linked by photopolymerization, thus facilitating the production of the low-refractive index SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0085] The layer is simplified. In particular, the polymer matrix is ​​based on urethane acrylate, fluorourethane acrylate, or fluorosilicone acrylate. Alternatively, the polymer matrix can also be based on silicone, polydimethylsiloxane, epoxy polymer, polyepoxides, polyurethane, polyvinyl acetate, or polyester. Preferably, the low-refractive-index layer does not contain free silicone or silicon compounds (source of surface contamination); any silicone or silicon compounds that may be present are therefore integral components of the polymer matrix and are not removed from the low-refractive-index layer, for example, during a deaeration process during lamination.

[0086] For the purposes of the invention, "polyacrylate" means a polymer containing repeating units of acrylic compounds, whose monomers therefore belong to the acrylic group. The repeating unit can be substituted or unsubstituted within the permissible valence range. The polyacrylate can be a homopolymer or a copolymer, i.e., composed of only one type of monomer or of several different types of monomers. In particular, "polyacrylate" refers to polymers such as polymethyl acrylate, polyethylene acrylate, polypropyl methacrylate, polymethyl methacrylate, polyethylene methacrylate, polyethylene methacrylate, polyethyl methacrylate, or polypropyl methacrylate. "Polyacrylate" can also refer to mixtures of such polymers.

[0087] For the purposes of the invention, "epoxy polymer" means that the polymer contains epoxy compounds. Preferably, the epoxy polymer comprises one or more compounds from the group consisting of bisphenol-A epoxy resins, halogenated phenolic epoxy resins, phenolic epoxy resins, cycloaliphatic epoxy resins, and bisphenol-S epoxy resins.

[0088] For the purposes of the invention, "polymers of butene" means a polymer containing repeating butyl and / or isobutyl units, whose monomers therefore belong to the olefins. The repeating unit can be substituted or unsubstituted within the permissible valence range. The polymer of butene can be a homopolymer or a copolymer, i.e., composed of only one type of monomer or of several different types of monomers. Polymers of butene can contain compounds from the group consisting of 1-butene, (Z)-2-butene, (E)-2-butene, 1,3-butdiene, or isobutene (2-methylprop-1-ene), or mixtures thereof.

[0089] The average thickness of the low-refractive-index layer is preferably at most 1 mm, particularly preferably less than 250 pm, and in particular less than 10 pm, and at least SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0090] 300 nm. If the low-refractive index layer comprises several individual layers, the specified layer thickness refers to the sum of the layer thicknesses of all individual layers of the low-refractive index layer.

[0091] In a preferred embodiment of the disk according to the invention, the low-refractive-index layer extends over at least 80%, and particularly preferably at least 90%, of the first surface of the optical waveguide. In particular, the low-refractive-index layer extends over the entire main surface of the optical waveguide. Preferably, the low-refractive-index layer is not applied to the area of ​​the optical waveguide surface where the layer stack, the light source, and light-scattering elements are located. Preferably, a frame-shaped circumferential edge region of the optical waveguide is also free of the low-refractive-index layer. Thus, in a top view of the optical waveguide, the low-refractive-index layer is framed by an area that is not provided with the low-refractive-index layer. The coating-free edge region protects the low-refractive-index layer from moisture that can enter via the edge surface of the composite disk.

[0092] In a preferred embodiment, the glazing element comprises more than one light coupling element according to the invention; preferably, the glazing element comprises at least two, more preferably at least three, and more preferably at least four light coupling elements according to the invention. The light coupling elements are preferably all applied to the first surface of the optical waveguide. Advantageously, the light coupling elements are arranged in the edge regions of the optical waveguide. For example, a plurality of light coupling elements can be arranged in a frame-like arrangement around the edge region of the optical waveguide. Preferably, the light coupling elements are arranged less than 30 cm, more preferably at most 15 cm, and more preferably at most 5 cm, from the circumferential side surface of the optical waveguide.This avoids placing the light-injecting elements in an area of ​​the glazing element that is typically intended for transparency. Furthermore, the area that can be fitted with light-diffusing elements and that overlaps with the transparency area is thereby increased.

[0093] In a preferred embodiment of the invention, the light source is arranged relative to the optical waveguide and illuminates the light coupling element such that the light it emits strikes the second surface of the optical waveguide at an angle of 0° to 40°, preferably 20° to 25°, for example 22°, to the surface normal. This angle is particularly preferred because it ensures that the light strikes the prismatic surface at an angle suitable for the inclined surfaces, thereby increasing the coupling efficiency.

[0094] Preferably, a collimator is arranged in front of the emission surface of the light source to align the visible light. In other words, a collimator is arranged between the optical waveguide and the light source. The collimator is located in the beam path of the light source.

[0095] Collimators transform the typically divergent light rays from a light source into a single beam with a preferably essentially parallel path, or at least a less divergent, and therefore more concentrated, path. The collimator narrows the beam cone of the light source. This has the advantage that the entire light beam is directed into the optical waveguide at a substantially uniform angle of incidence, and in particular, at an angle of incidence which, in conjunction with the reflective properties of the light coupling element, ensures that a majority of the light is coupled into the optical waveguide in such a way that total internal reflection occurs. This optimizes the light output.

[0096] In its simplest form, the collimator is a type of converging lens, with the light source preferably positioned at its focal point. The collimator can be made of glass or a transparent plastic, particularly polycarbonate (PC) or polymethyl methacrylate (PMMA). The collimator is preferably attached to the second surface of the optical fiber, for example, by gluing. If the light source consists of an array of multiple LEDs, a separate collimator can be provided for each LED. However, a single collimator for the entire LED array is preferred. In the case of a linear LED array, for example, a rod-shaped collimator can be used, the length of which is at least equal to the length of the LED array.

[0097] In an advantageous embodiment, the light source is arranged in a masking area of ​​the glazing element, and the light coupling occurs within this masking area. This means that the light source is not visible from the outside environment, at least to an observer (SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT). It is understood that in this case, there is no masking in the beam path between the light source and the reflecting structure. However, if the glazing element comprises a laminated pane or multiple glazing, the intermediate layer and / or at least one pane other than the optical fiber can be provided with a masking, for example, a printed cover. Preferably, the glazing element comprises a laminated pane, as described above for embodiment D, and the optical fiber is the inner pane of the laminated pane.Preferably, in this case, the outer pane is provided with such a masking area.

[0098] The glazing element is equipped with a light source capable of coupling light into the pane. During operation, the light source emits visible light, i.e., electromagnetic radiation in the range of 380 nm to 780 nm. The light source can have one or more emission bands located in the visible spectral range, covering a portion of it. Alternatively, the light source can have a broad emission band covering the entire visible spectral range. The emission band(s) – and thus the color of the emitted light – can be freely selected according to the requirements of the specific application.

[0099] The glazing element can have a single light source or several separate light sources, the light from which is coupled into the pane at different locations. These light sources, with different emission wavelengths, preferably include a red emission source (in particular with a (mean) emission wavelength of about 630 nm), a green emission source (in particular with a (mean) emission wavelength of about 550 nm), and a blue emission source (in particular with a (mean) emission wavelength of about 473 nm). The light from these (RGB) light sources superimposes to form white light, thus coupling white light into the pane.

[0100] The light source preferably comprises at least one light-emitting diode (LED). The light source can be a single LED, but preferably it is an array of several LEDs. This array is preferably housed in a common package, for example, as a linear arrangement in which the LEDs are arranged along a line. The electroluminescent material of the LED can be, for example, an inorganic semiconductor or an organic semiconductor. In the latter case, it is also referred to as an organic light-emitting diode (OLED).

[0101] The dichroic reflective layer is preferably a thin film. It preferably has a thickness of at least 20 nm, particularly preferably from 50 nm to 500 nm, and most preferably from 100 nm to 200 nm. Dichroic reflective layers consist of a material or materials that have the ability to reflect or absorb light differently depending on its wavelength and polarization direction. This phenomenon is called dichroism. The dichroic reflective layer can change the polarization direction of the light by reflecting or absorbing one component of the electric field more strongly than the other. This can lead to the following situations:

[0102] • In one embodiment, the dichroic reflective layer is designed such that of light containing both s-polarized and p-polarized components striking the dichroic reflective layer, only the p-polarized light is reflected, while the s-polarized light is absorbed by the reflective layer. The term "is reflected" here is not absolute. The p-polarized light is reflected predominantly, while the s-polarized light is absorbed predominantly. Therefore, 100% reflection and / or absorption is not necessarily implied.

[0103] • In one embodiment, the dichroic reflective layer is designed such that of light containing both s-polarized and p-polarized components striking the dichroic reflective layer, only the s-polarized light is reflected, while the p-polarized light is absorbed by the reflective layer. The term "is reflected" here is not absolute. The p-polarized light is reflected predominantly, while the s-polarized light is absorbed predominantly. Therefore, 100% reflection and / or absorption is not necessarily implied.

[0104] The term p-polarized light refers to light from the visible spectral range that consists entirely of light exhibiting p-polarization. The term s-polarized light refers to light from the visible spectral range that consists entirely of light exhibiting s-polarization.

[0105] The polarization direction is specified in relation to the plane of incidence of the radiation on the composite disk. P-polarized radiation is radiation whose electric field oscillates in the plane of incidence. S-polarized radiation is radiation whose electric field oscillates perpendicular to the plane of incidence. The plane of incidence is defined by the incidence vector and the surface normal of the disk at the geometric center of the irradiated area.

[0106] In a particularly preferred embodiment of the invention, the dichroic reflective layer is configured such that it at least partially, preferably predominantly, absorbs certain components of visible light in a wavelength range of 380 nm to 780 nm and reflects other components at least partially, preferably predominantly. The dichroic reflective layer particularly preferably absorbs light with a wavelength of 380 nm to 600 nm, and most preferably with a wavelength of 380 nm to 680 nm, at least partially. This means that any light with a wavelength in this range is at least partially, preferably predominantly, absorbed by the dichroic reflective layer. The dichroic reflective layer also preferably reflects at least partially, and most preferably predominantly, light with a wavelength of 600 nm to 780 nm, and most preferably with a wavelength of 680 nm to 780 nm.This can be achieved by having the dichroic reflective layer have a layered structure consisting of several thin layers with different refractive indices, which influence the incident and reflected light through interference. The layered structure can be selected to produce the desired polarization and wavelength selectivity. By absorbing the shorter wavelengths of visible light, a more pleasing color impression can be created, especially if the glazing element is equipped with IR- or UV-reflecting layers or emissivity-reducing layers (so-called low-E layers), which can also lead to unwanted absorption of light in the higher wavelength range.

[0107] With regard to the reflection or absorption of light, "at least partially reflected" or "at least partially absorbed" means that at least 30%, preferably at least 40%, of the light incident on the dichroic reflective layer is absorbed or reflected. With regard to the reflection or absorption of light, "predominantly reflected" or "predominantly absorbed" means that at least 50%, preferably at least 70%, and in particular at least 90%, of the light incident on the dichroic reflective layer is absorbed or reflected. The reflection or absorption values ​​are limited by technical and physical feasibility. SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0108] Dichroic reflective coatings can be applied, for example, by coating the prismatic film with one or more thin layers of different materials. The thickness and material of each layer determine the colors that are reflected and transmitted.

[0109] There are various methods for applying dichroic coatings, including:

[0110] • Vacuum evaporation: In vacuum evaporation, the material is heated in a vacuum until it evaporates. The vapor then condenses on the prismatic film, forming a thin layer.

[0111] • Sputtering: In sputtering, the material is bombarded with ions to sputter atoms or molecules from the surface. These atoms or molecules then condense onto the prismatic film, forming a thin layer.

[0112] • Sol-gel process: In the sol-gel process, a solution of chemicals is used to form a gel-like coating on the prismatic film. The gel is then heated to convert the chemicals into solids, forming a thin layer.

[0113] The choice of method depends on the materials used, the desired thickness of the layers, and the desired properties of the coating.

[0114] The invention also extends to a method for manufacturing the glazing element, wherein

[0115] (A) the light coupling element is placed on the first surface of the optical waveguide and

[0116] (B) the light source is placed on the second surface of the optical waveguide.

[0117] The glazing element according to the invention can be used as vehicle glazing, building glazing, or furniture glazing, in particular as a roof window, windshield, rear window, or side window of a vehicle. A particularly preferred use is as a vehicle roof window, which is used to display information in the vehicle interior. The vehicle can, in principle, be any land vehicle, watercraft, or aircraft, but is preferably a passenger car, truck, or rail vehicle. The glazing element can also be used in buildings, for example, as a window pane, glass facade, or glass door in exterior or interior areas, in particular as a window pane of a building or an interior space. The glazing element can also be used as a component of furniture, electrical appliances, furnishings, or as a furnishing element.

[0118] The various embodiments of the invention can be implemented individually or in any combination. In particular, the aforementioned features can be used not only in the specified combinations, but also in other combinations or on their own, unless they are explicitly described as possible only as alternatives to one another without departing from the scope of the present invention.

[0119] The invention is explained in more detail with reference to drawings and embodiments. The drawings are schematic representations and not to scale. The drawings do not limit the invention in any way. They show:

[0120] Fig. 1 shows a cross-sectional view of an embodiment of a light coupling element as it is used in a glazing element according to the invention.

[0121] Fig. 2 shows an enlarged section of the light coupling element from Fig. 1 ,

[0122] Figs. 3-4 show different embodiments of an illuminated glazing element according to the invention in cross-sectional view.

[0123] Fig. 5 shows an alternative embodiment of a light coupling element as it is used in a glazing element according to the invention with the light coupling element from Figs. 1 and 2 in a cross-sectional view.

[0124] Fig. 6 shows an enlarged section of the light coupling element from Fig. 5,

[0125] Fig. 7 shows an alternative embodiment of an illuminated glazing element according to the invention with the light coupling element from Figs. 5 and 6 in cross-sectional view and

[0126] Fig. 8 shows a top view of the glazing element from Fig. 7.

[0127] Figures 1 and 2 show different aspects of an embodiment of the light coupling element 100 as it is used on an optical waveguide 1. Figure 1 shows the light coupling element 100 in a cross-sectional view. Figure 2 shows an enlarged section Z1 of the light coupling element 100. The section Z1 is indicated by a dashed circle in Figure 1. The light coupling element 100 comprises a prismatic film 2 with a prismatic surface 2.2, which is the outer surface of the film 2, and an inner surface 2.1, wherein the outer surface 2.2 of the SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT prismatic film 2 is formed by a plurality of inclined surfaces F. A dichroic reflective layer 3 is applied to the inclined surfaces F. The prismatic film is bonded to an adhesive 4 via its inner surface 2.1, so that the dichroic reflective layer 3 is on the side 2 facing away from the adhesive 4.2 of the prismatic film 2 is applied.

[0128] The adhesive 4 has an inner surface 4.2, which faces the light coupling element 100 or the prismatic film 2 and is in direct contact with the inner surface 2.1 of the prismatic film 2. The adhesive 4 also has an outer surface 4.1, which faces away from the prismatic film 2 and is intended to be used as an adhesive surface on an optical waveguide 1. The prismatic film 2, in turn, has, in addition to its inner surface 2.1 facing the adhesive layer 1, an outer surface 2.2 facing away from the adhesive layer 1, which is simultaneously the prismatic surface. The inclined surfaces F of the prismatic film 2, for example, have an average angle α of 45° to a straight line that is drawn along the principal direction of extension of the prismatic film 2. The straight line is indicated by a dashed line in Figure 2.

[0129] Adhesive 4, for example, is an optically clear adhesive layer based on polyacrylate and has a thickness of 50 pm. Adhesive 4 can also be an immersion oil layer. The dichroic reflective layer 3, for example, consists of a gold layer and reflects green light while transmitting red and blue light. The dichroic reflective layer was applied to the prismatic film 2, for example, by cathode sputtering. The dichroic reflective layer 3 has a thickness of 50 nm. The prismatic film 2 is based on polymethyl methacrylate and has an average thickness of 50 pm. The refractive index of the adhesive 1 is, for example, 1.53, and the refractive index of the prismatic film 2 is, for example, 1.54.

[0130] Figure 3 shows an illuminated glazing element 101 with an optical fiber 1. The optical fiber 1 is, for example, a vehicle window, in particular a vehicle roof window. The optical fiber 1 has a first surface III (also called the outer surface) and a second surface IV (also called the inner surface). The second surface IV is intended to face the interior of the vehicle. The first surface III is intended to face the external environment. The optical fiber 1 is, for example, a glass pane made of soda-lime glass with a thickness of 1.5 mm. The optical fiber 1 has, for example, a refractive index between 1.51 and 1.52.

[0131] In a peripheral region of the optical waveguide 1, a light coupling element 100 is applied to the first surface III. The light coupling element 100 is configured, for example, as shown and described in Figures 1 and 2. However, it can also be configured as shown and described in Figures 5 and 6. In the same peripheral region of the optical waveguide 1, a light source 6 is attached to the second surface IV. The light source 6 is arranged in transmission through the optical waveguide 1 in overlap with the light coupling element 100. The light source 6 is, for example, an array of LEDs (light-emitting diodes) mounted in a housing.The light source 6 emits visible light 5, which enters the optical waveguide 1 predominantly via the second surface IV, i.e., the inner surface. It then transmits through the optical waveguide 1, exits the optical waveguide 1 at the first surface III, i.e., the outer surface, and immediately enters the adhesive 4. It is transmitted through the adhesive and the prismatic film 2 until it reaches the dichroic reflective layer 3 on the inclined surfaces F and is reflected there. The visible light 5 is reflected in such a way that it propagates back through the prismatic film 2 and the adhesive 1 and then enters the optical waveguide 1 at an angle suitable for coupling. The light 5 then propagates within the optical waveguide 1 by means of total internal reflection until it encounters a light-scattering element 7 or the circumferential side surface of the optical waveguide 1.The optical waveguide 1, for example, has three light-scattering elements 7, with one light-scattering element 7 applied to the first surface III and two further light-scattering elements 7 applied to the second surface IV of the optical waveguide 1. The light-scattering elements 7 are, for example, transparent prints, applied, for example, by digital printing. By using the optically clear adhesive for the bonding agent 4, the light transmission in the optical waveguide 1 can be significantly increased. This is due to the refractive indices typical of optically clear adhesives (OCAs), which are very similar to the refractive indices of conventional optical waveguides made of glass and plastic. The light 5, which passes from the optical waveguide 1 into the bonding agent 4, is only slightly refracted, or hardly refracted at all, when changing the medium.The subsequent light transition from the adhesive to the prismatic film 2 also exhibits very low light refraction, SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT, which allows the light 5 to strike the dichroic reflective layer 3 more uniformly and at a more adjustable angle, where it is reflected.

[0132] Reference is now made to Figure 4. The variant of the glazing element 101 shown in Figure 4 essentially corresponds to the variant in Figure 3, so only the differences will be discussed here, and otherwise reference is made to the description of Figure 3.

[0133] In Figure 4, the glazing element 101 comprises a laminated pane, for example, a vehicle roof window. In addition to the optical fiber 1, the glazing element 101 also comprises a first pane 9, which represents the outer pane, and a second pane 10, which represents the inner pane. The optical fiber 1 is arranged planarly between the first pane 9 and the second pane 10. The optical fiber 1 is embedded in a thermoplastic interlayer 8. The thermoplastic interlayer 8 consists of a first thermoplastic composite film, which is arranged between the optical fiber 1 and the first pane 9, and a second thermoplastic composite film, which is arranged between the optical fiber 1 and the second pane 10. The composite films of the thermoplastic interlayer 8 are, for example, made of PVB.The thermoplastic intermediate layer 8 and the optical waveguide 1 together have a thickness of, for example, 0.86 mm. The optical waveguide 1 is, for example, made of ultra-clear soda-lime glass with an iron content of less than 0.1%.

[0134] The first pane 9 has a first surface I (outer surface) facing away from the second pane 10 and a second surface II (inner surface) facing the second pane 10. The second pane 10, in turn, has a first surface V (outer surface) facing the first pane 9 and a second surface VI (inner surface) facing away from the first pane 9. The first pane 9 has a black print 11 on its second surface II, which runs in a frame-like pattern around the perimeter of the laminated pane. The black print 11 obscures the view through the laminated pane. The black print 11 is, for example, an enamel applied by screen printing or digital printing and then fired. The first pane 9 and the second pane 10 are, for example, made of soda-lime glass with a thickness of 1.5 mm. The first pane 9 is, for example, tinted.The light source 6 and the light coupling device 100 are constructed as described for Figure 3, for example. However, the light source is SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT.

[0135] In this embodiment, the 6 is applied to the second surface VI of the second disk 10. A collimator 12 is also arranged between the light source 6 and the second disk 10 to align the light 5. Since light sources 6 generally emit at least partially divergent light cones, the collimator 12 serves to align the light rays 5 so that a larger amount of the light 5 can be coupled into the optical waveguide 1.

[0136] Figures 5 and 6 show a further embodiment of the light coupling element 100 as it is used on an optical waveguide 1. Figure 5 shows the light coupling element 100 in a cross-sectional view. Figure 6 shows an enlarged section Z2 of the light coupling element 100. Section Z2 is indicated by a dashed circle in Figure 5. The variant of the light coupling element 100 shown in Figures 5 and 6 essentially corresponds to the variant shown in Figures 1 and 2, so only the differences will be discussed here, and otherwise, the reader is referred to the description of Figures 1 and 2.

[0137] In contrast to the configurations shown in Figures 1 and 2, the prismatic film 2 here has its prismatic surface not on the outer surface 2.2 facing away from the adhesive 4, but on the inner surface 2.1 facing the adhesive 4. The dichroic reflective layer 3 is applied to the inclined surfaces F; that is, it is positioned between the adhesive 4 and the prismatic film 2. The adhesive 4, as an optically clear adhesive, essentially fills the spaces formed by the inclined surfaces F completely, for example, to at least 90%. However, the adhesive 4 can also be designed as an immersion oil layer. This has the advantage that the light 5 does not first have to propagate through the prismatic film 2 before it reaches the dichroic reflective layer 3, thus improving the light coupling efficiency.The prismatic film 2 can therefore also be opaque in this variant and thus better prevent light from escaping through the second disk 10.

[0138] Reference is now made to Figures 7 and 8. The variant of the glazing element 101 shown in Figures 7 and 8 essentially corresponds to the variant in Figure 3, so only the differences will be discussed here, and otherwise, reference is made to the description of Figure 3. Figure 7 shows a cross-sectional view of the glazing element 101, whereas Figure 8 shows a top view of the second surface IV of the optical fiber 1. The cross-section XX' is indicated in Figure 8 by a dashed line SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT. In contrast to the embodiment in Figure 3, the glazing element 101 here comprises a laminated pane, including the optical fiber 1, which represents the inner pane, and another pane 9, which represents the outer pane. The light coupling element 100 is designed, for example, as shown and described in Figures 5 and 6.However, it can also be formed as shown and described for figures 1 and 2.

[0139] A thermoplastic intermediate layer 8, for example a PVB composite film with a thickness of 0.38 mm, is arranged between the optical waveguide 1 and the further disk 9. The further disk 9 has a first surface I (outer surface) facing away from the optical waveguide 1 and a second surface II (inner surface) facing the optical waveguide 1. The first surface III of the optical waveguide 1 faces the further disk 9. The further disk 9 has a black print 11 on its second surface II, which runs in a frame-like pattern around the perimeter of the composite disk. The black print 11 obscures the view through the composite disk. The further disk 9 is, for example, untinted. In contrast to the embodiment shown in Figure 3, a collimator 12 is arranged here between the light source 6 and the optical waveguide 1 to align the light 5.A low-refractive-index layer 14, for example made of a cross-linked polymer matrix based on polyacrylate, is applied to the first surface III of the optical waveguide 1. The low-refractive-index layer 14 has, for example, a refractive index of less than 1.4, which reduces unwanted light leakage 5. The low-refractive-index layer 14 is not applied in the region of the light coupling element 100, but otherwise covers the entire surface of the first surface III.

[0140] SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT

[0141] Reference sign

[0142] 1 optical fiber

[0143] 2 prismatic film

[0144] 2.1 Inside of the prismatic film 2

[0145] 2.2 Outside of the prismatic film 2

[0146] 3 dichroic reflective layer

[0147] 4 Adhesives

[0148] 4.1 Inside of the adhesive 4

[0149] 4.2 Outer surface of the adhesive 4

[0150] 5 visible light

[0151] 6 light sources

[0152] 7 light-scattering element

[0153] 8 thermoplastic intermediate layer

[0154] 9 more panes, first pane (outer pane)

[0155] 10 second disc, (inner disc)

[0156] 11 Black print

[0157] 12 Collimator

[0158] 13 low refractive index layer

[0159] 100 light coupling elements

[0160] 101 Illuminated glazing element

[0161] I first surface (outer surface) of the first or subsequent disk 9

[0162] II second surface (inner surface) of the first or the next disk 9

[0163] III first surface (outer surface) of the optical waveguide 1

[0164] IV second surface (inner surface) of the optical waveguide 1

[0165] V first surface (outer surface) of the second disk 10

[0166] VI second surface (inner surface) of the second disk 10

[0167] F inclined surface

[0168] Z Section of the light coupling element 100

[0169] XX' line of intersection a angle of the inclined surface F

Claims

36 SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT Patent claims 1. Illuminatable glazing element (101) comprising: an optical waveguide (1) with a first and a second surface (I, II), a light coupling element (100) arranged on the first surface (I) of the optical waveguide (1), comprising a prismatic film (2) with at least one prismatic surface (2.1, 2.2) having a plurality of inclined surfaces (F), and a dichroic reflective layer (3) applied to the prismatic surface (2.1, 2.2), and a light source (6) for visible light (5) arranged facing the second surface (II) of the optical waveguide (1), wherein the light source (6) is oriented such that, in operation, it illuminates the light coupling element (100) with light (5) and the emitted light (5) is at least partially reflected into the optical waveguide (1) via reflection at the dichroic reflective layer (3). is coupled in.

2. Glazing element (101) according to claim 1, wherein the light coupling element (100) is attached to the optical waveguide (1) by means of an adhesive (4) consisting of an immersion oil layer or an optically clear adhesive layer.

3. Glazing element (101) according to claim 1 or 2, wherein the light coupling element (100) is arranged on the optical waveguide (1) such that the prismatic surface provided with the dichroic reflective layer (3) (2.1) is facing the optical waveguide (1).

4. Glazing element (101) according to claim 1 or 2, wherein the light coupling element (100) is arranged on the optical waveguide (1) such that the prismatic surface provided with the dichroic reflective layer (3) (2.2) is turned away from the optical fiber (1).

5. Glazing element (101) according to one of claims 1 to 4, wherein the prismatic film (2) is a microprism film. 37 SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT 6. Glazing element (101) according to one of claims 1 to 5, wherein the optical waveguide (1) is a mineral glass pane, which preferably consists of soda-lime glass with a low iron content.

7. Glazing element (101) according to any one of claims 1 to 6, wherein the dichroic reflective layer (3) either reflects s-polarized light (5) and absorbs p-polarized light or reflects p-polarized light (5) and absorbs s-polarized light.

8. Glazing element (101) according to one of claims 1 to 7, wherein the dichroic reflective layer (3) absorbs visible light (5) at least partially depending on the wavelength.

9. Glazing element (101) according to one of claims 1 to 8, further comprising a pane (9) and a thermoplastic intermediate layer (8), wherein the pane (9) is connected to the optical waveguide (1) over a planar area via the thermoplastic intermediate layer (8).

10. Glazing element (101) according to one of claims 1 to 8, further comprising a first pane (9), a second pane (10) and a thermoplastic intermediate layer (8) arranged between them, wherein the optical waveguide (1) with the light coupling element (100) is arranged within the thermoplastic intermediate layer (8) and between the first and the second pane (9, 10).

11. Glazing element (101) according to claim 9 or 10, wherein a low refractive index layer (13) is applied to one of the surfaces (I, II) of the optical waveguide (1) which faces the thermoplastic intermediate layer (8), wherein the low refractive index layer (13) has a refractive index for visible light (5) which is at least 0.1 lower than the refractive index of the optical waveguide (1).

12. Glazing element (101) according to one of claims 1 to 11, wherein a collimator (12) for parallelizing the light (5) of the light source (6) is arranged between the light source (6) and the optical waveguide (1). SAINT-GOBAIN SEKURIT FRANCE 2024256-WO-PCT 13. Glazing element (101) according to any one of claims 1 to 12, wherein the dichroic reflective layer (3) contains or consists of gold, silver, aluminum, or mixtures thereof.

14. Method for producing a glazing element (101) according to any one of claims 1 to 13, where (A) the light coupling element (100) is placed on the first surface (I) of the optical waveguide (1) and (B) the light source (6) is placed on the second surface (II) of the optical waveguide (1).

15. Use of the glazing element (101) according to any one of claims 1 to 13 as vehicle glazing, building glazing or furniture glazing, in particular as a roof window, windshield, rear window or side window of a vehicle.

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