Pane for a glazing which can be illuminated three-dimensionally

Abstract

The invention relates to a pane (100), at least comprising - a first substrate (1) with a first surface (III) and a second surface (IV), - a layer stack (2) which is provided on the second surface (IV) of the first substrate (1) and which comprises, in the following order starting from the second surface (IV), - a first light-guiding layer (3.1) comprising at least one output coupling element (5) for coupling out light (11), - a first low-refractive layer (4.1) which extends over the entire surface of the first light-guiding layer (3.1) with the exception of a first sub-region (A), and - a second light-guiding layer (3.2) comprising at least one output coupling element (5) for coupling out light (11), said layer extending over the entire surface of the first low-refractive layer (4.1), wherein the first low-refractive layer (4.1) has a lower refractive index than the first light-guiding layer (3.1) and a lower refractive index than the second light-guiding layer (3.2).

Description

[0001] Pane for three-dimensionally illuminated glazing

[0002] The invention relates to a pane for an illuminable glazing and to a glazing with such a pane.

[0003] Illuminated glazing elements are well known. They are equipped with a light source whose light is coupled into an optical fiber, usually a glass pane, and spreads through total internal reflection. Often, the light is extracted from the optical fiber by extraction elements, thus creating the illumination. The shape of the extraction elements is freely selectable, allowing illuminated surfaces of any shape, for example, a pattern, to be created. Illuminated glazing elements of this type are known, for example, from WO2014 / 060409A1 or WO2014 / 167291A1.

[0004] In the automotive sector, such illuminated glazing elements are particularly interesting for roof windows. The glazing element is typically designed as a composite 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 and architecture, or in furnishings. The coupling elements create illuminated surfaces that can be used to display aesthetically pleasing shapes and patterns or to display information, for example, directional arrows, status indicators, warning notices, price lists, or similar.

[0005] There are various known ways to couple the light from the light source into the optical waveguide formed as a glass pane. The light source (typically an LED) can be positioned at the side edge, so that the light is radiated into the glass pane via the side edge and thus coupled into it. However, such coupling is often impossible, particularly because the side edge of the glass pane is usually ground to increase the mechanical stability of the pane, which causes the side edge to become cloudy.

[0006] In many cases, however, illuminated glazing elements feature a large number of light extraction elements or large light extraction areas. If the light is coupled in at the edge of the optical fiber, as is usually the case, this leads to a gradual attenuation of the light extraction intensity towards the center of the extraction element. This attenuation is due to the fact that the amount of light coupled in towards the extraction center decreases as the light extraction progresses. This, in turn, leads to the edge areas of the extraction element closest to the light source being very brightly illuminated, whereas the central areas are less illuminated. For a user, this can give the impression that the glazing is not functioning properly. It also reduces the aesthetics of the glazing when illuminated.

[0007] The present invention is based on the object of providing an improved pane for illuminable glazing, which can be illuminated more effectively across the entire surface of the pane and can also be illuminated with higher optical quality. The present invention is also based on the object of providing glazing with such a pane.

[0008] The object of the present invention is achieved by a pane according to claim 1 and an illuminable glazing according to claim 13. Preferred embodiments emerge from the subclaims.

[0009] The pane according to the invention comprises at least a first substrate with a first surface and a second surface, as well as a layer stack which is arranged on the second surface of the first substrate. Starting from the second surface, the layer stack comprises in the following order: a first light-conducting layer with at least one outcoupling element for coupling out light, a first low-refractive-index layer which extends over the entire surface of the first light-conducting layer with the exception of a first partial region, and a second light-conducting layer with at least one outcoupling element for coupling out light, which extends over the entire surface of the first low-refractive-index layer. The layer stack is arranged on the second surface, which means that further layers, in particular exactly one further layer, can be arranged between the layer stack and the substrate.Particularly preferably, the layer stack is applied to the second surface of the substrate, i.e., directly adjacent to the first substrate, such that no further layers are arranged between the layer stack and the first substrate. For the purposes of the invention, "starting from the second surface" means that the layer closest to the second surface of the first substrate among the above-mentioned layers is the first light-conducting layer. The layer furthest away from the second surface of the first substrate is accordingly the second light-conducting layer, with further layers optionally being able to be applied to the second light-conducting layer, which are then arranged even further from the second surface of the first substrate.

[0010] According to the invention, the low-refractive-index layer has a lower refractive index than the first light-conducting layer and a lower refractive index than the second light-conducting layer. As already described, the layer stack is preferably applied directly to the second surface of the substrate, i.e., it is in direct contact with the first substrate. However, alternatively, other layers, such as an emissivity-reducing layer (also called a low-E layer), can also be arranged between the layer stack and the first substrate.

[0011] The light-guiding layers are intended to guide light that is coupled into them. The light-guiding layers therefore serve as optical waveguides. In the context of the invention, “optical waveguide” means a light-guiding medium that is designed such that light can be coupled into the optical waveguide using the effect of total internal reflection, and is also suitable for guiding coupled-in light. The principle of light guidance by means of total internal reflection is generally known to those skilled in the art and is described in more detail, for example, in WO2008 / 047442A1, JP2011086547A or JP2015043321A. The optical waveguide is therefore designed such that the light from a light source can be coupled into the optical waveguide and can propagate therein. The outcoupling elements serve to specifically couple the coupled-in light out of the light-guiding layer and the pane.

[0012] The invention is based on the fact that visible light can be coupled into different layers of the layer stack. By separating the light-guiding layers with a low-refractive-index layer, the light is largely prevented from propagating from one light-guiding layer to the other, thus avoiding unwanted light loss in the light-guiding layers. Due to the lower refractive index of the low-refractive-index layer, the resulting critical angle is smaller, thereby increasing the angular range at which light propagates under total internal reflection. A further advantage achieved by the invention is that the outcoupling element of the first light-guiding layer is located at a different height or on a different plane of the pane than the outcoupling element of the second light-guiding layer. The outcoupling elements are therefore arranged at different locations, measured perpendicular to the main surface of the pane.This creates a three-dimensional illumination of the panel when light is coupled into the light-guiding layers, increasing the quality of the illumination depending on the intended use. A further advantage is that the output coupling elements in the different light-guiding layers can be illuminated with light of different colors. This allows for output coupling areas with different colors to be created.

[0013] Each light-conducting layer has a first surface facing the first substrate and a second surface facing away from the first substrate. Each low-refractive-index layer has a first surface facing the first substrate and a second surface facing away from the first substrate.

[0014] The first surface and the second surface of a light-conducting layer represent interfaces to the adjacent medium. The first surface of a light-conducting layer is, for example, the interface to a low-refractive-index layer or to the first substrate. The second surface of a light-conducting layer is, for example, the interface to the surrounding atmosphere or to another low-refractive-index layer. Typically, the media adjacent to the surfaces of the light-conducting layers (for example, the interior atmosphere or the low-refractive-index layer) have a different refractive index than the light-conducting layers. In the case that the adjacent medium has a different refractive index than the light-conducting layer, this results in a critical angle of total reflection, which is determined as a T= arcsinf— ), where ni is the refractive index of the optically denser medium and n2 is the refractive index of the optically rarefying medium. In the case of the interface between a light-conducting layer and air, the refractive index of the light-conducting layer is m and the refractive index of the air is n2. If light hits the interface at an angle of incidence that is greater than the critical angle, the light is completely reflected (total internal reflection). As is usual in ray optics, the angle of incidence is the angle that the light ray incident on the surface makes to the surface normal at the point of impact. The angle of reflection is determined analogously to the surface normal, as is the critical angle of total internal reflection.

[0015] The pane is intended to separate an interior space from the exterior environment in a window opening of a vehicle or building. If the pane comprises only a substrate, i.e. is not a laminated pane or insulating glazing, then the first surface of the first substrate is preferably the exterior surface and the second surface of the first substrate is accordingly the interior surface. By “exterior surface” is meant that in the installed position the surface faces the exterior environment, and by “interior surface” is meant that in the installed position the surface faces the interior. However, the invention is not restricted to this. The pane can be flat or curved in one or more directions of the space.

[0016] In a preferred embodiment of the invention, the pane further comprises a second substrate, which is connected to the first substrate via a thermoplastic intermediate layer. The pane is therefore a composite pane, preferably a vehicle pane composite pane, in particular a vehicle roof pane. Preferably, the first surface of the first substrate faces the thermoplastic intermediate layer. The second pane comprises a first surface and a second surface. Preferably, the second surface of the second substrate faces the first substrate. The thermoplastic intermediate layer is therefore arranged on the first surface of the first substrate and on the second surface of the second substrate.

[0017] If the pane is a composite pane, the first substrate is preferably the inner pane and the second substrate is the outer pane. For the purposes of the invention, “inner pane” refers to the substrate facing the interior (for example, the vehicle interior). “Outer pane” refers to the substrate facing the outside environment. However, the invention is not restricted to this. The inner pane has a surface facing away from the intermediate layer and an outer surface facing the thermoplastic intermediate layer. The interior surface of the inner pane is simultaneously also the interior surface of the composite pane. The outer pane has an outer surface facing away from the thermoplastic intermediate layer and an interior surface facing the thermoplastic intermediate layer.The outer surface of the outer pane is also the outer surface of the laminated pane. The laminated pane can be flat or curved in one or more directions of the room.

[0018] The thickness of the first substrate and of the optionally present second substrate is preferably each from 0.5 mm to 10 mm, particularly preferably from 1 mm to 5 mm. The first substrate and / or the second substrate are preferably made of soda-lime glass. The thermoplastic intermediate layer can comprise one or more thermoplastic composite films. The thermoplastic intermediate layer preferably has a thickness of, for example, 0.3 mm to 1.0 mm (sum of the thicknesses of all films of the intermediate layer). The intermediate layer is particularly preferably made of polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA) or polyurethane (PU). This means that all thermoplastic films are preferably based on these materials. In addition, the films or the entire intermediate layer can contain further components, for example plasticizers, stabilizers, UV or IR blockers.The thermoplastic intermediate layer may be clear or tinted, preferably it is tinted and has a light transmittance (according to ISO 9050:2003) of less than 70%, preferably less than 50%, particularly preferably less than 30%.

[0019] The first substrate and / or the optionally present second substrate are preferably made of soda-lime glass, as is common for window panes. Alternatively, the first substrate and the optionally present second substrate can also be made of other types of glass, for example, borosilicate glass, aluminosilicate glass, or quartz glass. It is also possible for the first substrate or all substrates to be formed as plastic panes. If the first substrate and / or the second substrate is formed as a plastic pane, it is preferably made of a clear, rigid plastic, particularly preferably polycarbonate (PC) or polymethyl methacrylate (PMMA).

[0020] The first substrate and / or, if present, the second substrate may comprise further suitable, conventional layers, for example, anti-reflective coatings, non-stick coatings, anti-scratch coatings, photocatalytic coatings, sunscreen coatings, or low-E coatings. It is understood that further layers on the second main surface of the first substrate must not impair the properties of the layer stack according to the invention, and in particular, the total reflection of light in the light-conducting layers.

[0021] In a preferred embodiment of the invention, the first substrate is tinted and has a light transmittance of less than 70%, preferably less than 50%, particularly preferably less than 30%. Alternatively, the first substrate can also be clear and have a light transmittance of greater than or equal to 70%. The tinting of the substrate improves the light-absorbing properties of the substrate. If light is coupled out of the layer stack according to the invention in the direction of the first substrate, the tint prevents the light from propagating through the substrate into the external environment. This can be necessary, for example, when the pane is used in vehicles. In a further preferred embodiment of the invention, the layer stack comprises an outer low-refractive-index layer. The outer low-refractive-index layer is arranged between the second surface of the first substrate and the first light-conducting layer.Preferably, the outer low-refractive-index layer is applied to the second surface of the first substrate and is thus the layer that delimits the layer stack in the direction of the first substrate. The first light-conducting layer is applied to the outer low-refractive-index layer. The outer low-refractive-index layer is therefore arranged between the first substrate and the first light-conducting layer. The layer stack is thus arranged in direct contact with the first substrate. The outer low-refractive-index layer has a lower refractive index than the first light-conducting layer. The outer low-refractive-index layer effectively prevents or at least greatly reduces the light loss from the first light-conducting layer into the substrate.

[0022] In a further preferred embodiment of the invention, the layer stack, starting from the second light-guiding layer, comprises in the following order a second low-refractive-index layer which extends over the entire area of ​​the second light-guiding layer with the exception of a second partial region, and a third light-guiding layer with at least one outcoupling element which extends over the entire area of ​​the second low-refractive-index layer. In other words, the second low-refractive-index layer is applied to the second light-guiding layer, wherein a second partial region of the second light-guiding layer is free of the second low-refractive-index layer. It is understood that the second low-refractive-index layer is also not arranged on the first partial region of the first light-guiding layer, since it is only applied to the second light-guiding layer.The third light-guiding layer is applied congruently to the second low-refractive-index layer. The second low-refractive-index layer has a lower refractive index than the second light-guiding layer and a lower refractive index than the third light-guiding layer. This arrangement creates an even more pronounced three-dimensional effect and allows for even more homogeneous light extraction, as the extraction elements are distributed across different light-guiding layers.

[0023] In a further supplemented embodiment of the aforementioned embodiment, the layer stack, starting from the third light-conducting layer, comprises, in the following order, a third low-refractive-index layer, which extends over the entire surface of the third light-conducting layer with the exception of a third partial region, and a fourth light-conducting layer with at least one coupling-out element, which extends over the entire surface of the third low-refractive-index layer. In other words, the third low-refractive-index layer is applied to the third light-conducting layer, wherein a third partial region of the third light-conducting layer is free of the third low-refractive-index layer.It is understood that the third low-refractive-index layer is also not arranged on the first partial region of the first light-conducting layer or the second partial region of the second light-conducting layer, as it is only applied to the third light-conducting layer. The fourth light-conducting layer is applied congruently to the third low-refractive-index layer. The third low-refractive-index layer has a lower refractive index than the third light-conducting layer and a lower refractive index than the fourth light-conducting layer. This arrangement creates an even more pronounced three-dimensional effect, and even more homogeneous light extraction can be achieved, as the extraction elements are distributed across different light-conducting layers.This arrangement is particularly preferred because a layer stack of 7 to 8 layers can be stably applied to the substrate while simultaneously achieving highly homogeneous and 3-dimensional light emission. More layers can lead to detachment and damage to the layer stack, and fewer layers reduce the aforementioned advantages.

[0024] Apart from the optionally present outer low-refractive-index layer, the layer stack can also have more than four light-conducting and three low-refractive-index layers. For example, the layer stack can additionally have n light-conducting layers (also called further light-conducting layers) and n low-refractive-index layers (also called further low-refractive-index layers), where n is preferably = 1, 2, 3 or 4. The n low-refractive-index layers are always arranged between two light-conducting layers, and the layer furthest away from the first substrate is a light-conducting layer. The n low-refractive-index layers and n light-conducting layers are thus arranged alternately, with the low-refractive-index layer with n=1 being applied to the fourth light-conducting layer.Each of the n low-refractive-index layers is therefore applied between a light-conducting layer that is arranged closer to the first substrate than itself, and a light-conducting layer that is arranged further away from the first substrate than itself. Each of the n low-refractive-index layers is applied to the light-conducting layer that is arranged closer to the first substrate than itself. The n low-refractive-index layers extend, with the exception of one partial region, over the entire light-conducting layer on which they are applied. The light-conducting layer that is further away from the first substrate and is arranged immediately adjacent to the low-refractive-index layer, in contrast, is applied congruently to this low-refractive-index layer. Due to this arrangement, each light-conducting layer has an (exposed) partial region that does not border a layer of the layer stack.

[0025] Each of the (exposed) subregions of the light-conducting layers (the first subregion and - if present - the second subregion, the third subregion and further subregions) is intended to be arranged in relation to a light source such that the light from the light source can be coupled into the respective light-conducting layer via the subregion. Each subregion is preferably arranged in an edge region of the layer stack according to the invention. The first subregion and, if present, the second subregion, the third subregion and / or further subregions each preferably extend by a maximum of 5%, particularly preferably by a maximum of 3%, in particular preferably by a maximum of 1%, over the area of ​​the layer stack according to the invention. The area of ​​the layer stack is essentially defined by the area of ​​the first light-conducting layer.

[0026] In a further preferred embodiment of the invention, the first light-conducting layer and / or the second light-conducting layer has at least two, preferably at least three, outcoupling elements. If present, the third light-conducting layer and / or the fourth light-conducting layer has at least two, preferably at least three, outcoupling elements. In particular, each light-conducting layer has at least two, preferably at least three, outcoupling elements. The outcoupling elements of all light-conducting layers are preferably arranged so as not to overlap one another when viewed through the pane. More outcoupling elements allow for more creative lighting, which improves the aesthetics of the pane.

[0027] For the purposes of the invention, "the light-conducting layers" refers to at least the first light-conducting layer and the second light-conducting layer. However, if the embodiment comprises further light-conducting layers such as the third light-conducting layer, the fourth light-conducting layer, and / or further light-conducting layers, then these also fall under the term "the light-conducting layers." Likewise, for the purposes of the invention, "the low-refractive-index layers" refers to at least the first low-refractive-index layer. However, if the embodiment comprises further low-refractive-index layers such as the outer low-refractive-index layer, the second low-refractive-index layer, the third low-refractive-index layer, and / or further low-refractive-index layers, then these also fall under the term "the low-refractive-index layers."The light-conducting layers preferably contain titanium oxide, aluminum oxide, silicon nitride, in particular SiN4, silicon zirconium nitride, silicon oxynitride and / or silicon dioxide, in particular SiO2. The light-conducting layers particularly preferably consist of titanium oxide, aluminum oxide, silicon nitride, in particular SiN4, silicon zirconium nitride, silicon oxynitride and / or silicon dioxide, in particular SiO2. The light-conducting layers do not all have to be formed from the same material. This means that the light-conducting layers independently contain or consist of one or more of the materials mentioned. Preferably, however, all light-conducting layers consist of the same material or materials. The first and second light-conducting layers particularly preferably contain or consist of titanium oxide, aluminum oxide, silicon nitride, silicon zirconium nitride and / or silicon dioxide.In particular, all light-conducting layers, including any third light-conducting layer, the fourth light-conducting layer and further light-conducting layers, contain or consist of titanium oxide, aluminum oxide, silicon nitride, silicon zirconium nitride and / or silicon dioxide.

[0028] The light-conducting layers preferably have a refractive index greater than 1.5, particularly preferably greater than 1.8, and in particular greater than 2.0. The light-conducting layers can have different refractive indices independently of one another. Preferably, all light-conducting layers have the same refractive index, whereby "same refractive index" means that the refractive indices may differ by a maximum of 0.01. These refractive indices are preferred because the critical angle for total internal reflection decreases as the difference between the refractive indices of two adjacent media increases.

[0029] Refractive indices are generally given in the context of the present invention relative to a wavelength of 550 nm. Methods for determining refractive indices are known to those skilled in the art. The refractive indices given in the context of the invention can be determined, for example, by ellipsometry, whereby commercially available ellipsometers can be used. The specification of layer thicknesses or thicknesses refers, unless otherwise stated, to the geometric thickness of a layer.

[0030] The light-conducting layers preferably have a layer thickness of 1 μm to 20 μm, preferably 5 μm to 15 μm. The light-conducting layers can independently have different layer thicknesses within these ranges. Preferably, all light-conducting layers have the same layer thickness, whereby "same layer thickness" means that the layer thicknesses may differ by a maximum of 0.1 μm. Within this layer thickness range, light can be coupled in effectively; however, significant quality problems of the layer stack due to layer detachment do not occur.

[0031] According to the invention, the first low-refractive index layer and any second low-refractive index layer present, the third low-refractive index layer, the outer low-refractive index layer and / or further low-refractive index layers have a lower refractive index than the light-conducting layers immediately adjacent to them. Each low-refractive index layer preferably has a refractive index that is at least 0.1, particularly preferably at least 0.15, in particular at least 0.2, lower than the light-conducting layers immediately adjacent to it. Such refractive index differences are preferred because they reduce the critical angle for total internal reflection. It is also possible for only one or some of the low-refractive index layers to have a refractive index of at most 1.5, preferably at most 1.45, in particular at most 1.4. However, it is particularly preferred for all low-refractive index layers to each have such a refractive index.Most preferably, all low-refractive-index layers have the same refractive index, whereby “same refractive index” means that the refractive indices may differ by a maximum of 0.01.

[0032] The first low-refractive-index layer and, if present, the outer low-refractive-index layer, the second low-refractive-index layer, the third low-refractive-index layer and / or further low-refractive-index layers may each be an organic, cross-linked or thermoplastic polymer or alternatively a mineral layer.

[0033] In a preferred embodiment of the invention, at least the first low-refractive-index layer, and preferably all low-refractive-index layers, are formed as a lacquer, which can be obtained from a photocrosslinkable resin, optionally mixed with photoinitiators. Alternatively, the resin is thermally crosslinkable. It can, for example, be formed from a two-component mixture.

[0034] In particular, at least the first low-refractive-index layer, preferably all low-refractive-index layers, comprises or consists of a cross-linked polymer matrix with a refractive index of at most 1.42, preferably at most 1.40, in particular at most 1.3, wherein the matrix is ​​preferably formed from polymers based on polyacrylate, particularly preferably based on fluorine-functionalized polyacrylate. The refractive index of the low-refractive-index layer can be reduced by means of fluorine functionalization. The use of polyacrylate as a material for the low-refractive-index layer is advantageous because acrylate compounds can be efficiently cross-linked by photopolymerization, thereby simplifying the production of the low-refractive-index layer. In particular, the polymer matrix is ​​formed from urethane acrylate or fluorourethane acrylate or fluorosilicone acrylate.Alternatively, the polymer matrix can also be based on silicone, polydimethylsiloxane, epoxy polymer, polyvinyl butyral, polyepoxides, polyurethane, polyvinyl acetate, or polyester. Preferably, the low-index layer does not contain free silicone or silicon compounds (sources of surface contamination). Any silicone or silicon compounds present are therefore an integral part of the polymer matrix and are not removed from the low-index layer, for example, in a deaeration process during lamination (if the pane is designed as a composite pane).

[0035] For the purposes of the invention, "polyacrylate" refers to a polymer containing repeating units of acrylic compounds, i.e., whose monomers 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 polymethylacrylate, polyethyleneacrylate, polypropylmethacrylate, polymethylmethacrylate, polyethylenemethacrylate, polyethylmethacrylate, or polypropylmethacrylate. Polyacrylate can also refer to mixtures of such polymers.

[0036] For the purposes of the invention, "epoxy polymer" means that the polymer contains epoxy compounds. The epoxy polymer preferably comprises one or more compounds from the group consisting of bisphenol A epoxy resins, halogenated phenol epoxy resins, phenol epoxy resins, cycloaliphatic epoxy resins, and bisphenol S epoxy resins, particularly preferably in a proportion of at least 1 wt.%, in particular at least 5 wt.%.

[0037] The first low-refractive-index layer and, if present, the outer low-refractive-index layer, the second low-refractive-index layer, the third low-refractive-index layer and / or further low-refractive-index layers can be formed in particular by means of

[0038] • Flow coating,

[0039] • Dip coating,

[0040] • Screen printing,

[0041] • Digital printing or • Inkjet printing. The application can be done in particular by rotation coating, film puller 1 ), curtain or slot die coating (eng.: "curtain or slot die"), Meyer bar printing or gravure printing (eng.: "gravure printing 1The low-index layers are preferably applied as a UV-photocrosslinkable substrate and subsequently polymerized using UV radiation. Alternatively, it is also possible to apply two components that react with each other spontaneously (exergonic reaction) or under the influence of heat (endergonic). This is a two-component formulation that crosslinks to form a polymer through a chemical reaction. Crosslinking using UV radiation is preferred because it is faster and the process is more cost-effective / compact than with a chemical reaction. In particular, components that polymerize under the influence of UVA radiation (wavelength range from 315 nm to 405 nm) are used.

[0042] In a preferred embodiment, the first low-refractive-index layer and, if present, the outer low-refractive-index layer, the second low-refractive-index layer, the third low-refractive-index layer, and / or further low-refractive-index layers contain a polymer that can be produced by photopolymerization, particularly preferably photopolymerization initiated by UV radiation. The low-refractive-index layers are preferably based on a polyacrylate (for example, a urethane acrylate resin) or a silicone compound.

[0043] The first low-refractive-index layer and, if present, the outer low-refractive-index layer, the second low-refractive-index layer, the third low-refractive-index layer and / or further low-refractive-index layers preferably comprise (nano-)porosities and / or (nano-)particles with a refractive index of less than or equal to 1.3. The porosities and / or particles are preferably hollow and have a diameter of at most 300 nm or in particular at most 100 nm. More preferably, the low-refractive-index layers comprise hollow silicon dioxide nanoparticles. The low-refractive-index layers preferably do not contain any free silicone or volatile silicon compounds (a source of surface contamination). The low-refractive-index layers preferably have a refractive index of at most 60 vol.%, more preferably at most 50 vol.%, most preferably at most 40 vol.%, in particular at most 30 vol.-% (nano-)porosities and / or (nano-)particles with a refractive index of less than or equal to 1.3. In a particularly preferred embodiment of the invention, the low-refractive-index layers comprise a polymer matrix of polyacrylate, with silicon dioxide-based particles embedded in the polymer matrix. In particular, each of the low-refractive-index layers consists of a polymer matrix of polyacrylate, with silicon dioxide-based particles embedded in the polymer matrix. In this way, a refractive index of less than 1.4 can be efficiently achieved.

[0044] In a further embodiment of the invention, the first low-refractive-index layer and, if present, the outer low-refractive-index layer, the second low-refractive-index layer, the third low-refractive-index layer, and / or further low-refractive-index layers are formed based on a mineral layer. The low-refractive-index layers preferably consist of a mineral layer. In particular, each low-refractive-index layer is a sol-gel layer based on porous silicon dioxide or an oxide-based layer, preferably based on silicon dioxide, which was deposited by physical vapor deposition (PVD) such as magnetron sputtering. The low-refractive-index layers, especially if they consist predominantly of silicon dioxide, can contain dopants, for example, aluminum dopants.If the low-refractive-index layers are based on porous silicon dioxide, the pores of the silicon dioxide preferably have an average pore diameter of 10 nm to 200 nm, particularly preferably 30 nm to 200 nm. In addition to or independently of the preferred pore diameter, the porous silicon dioxide preferably has a porosity of 40% to 85%, very particularly preferably 50% to 74%. The porosity indicates the pore volume relative to the total volume of the porous silicon dioxide. In these ranges, a particularly suitable and homogeneously distributed refractive index is achieved.

[0045] It is understood that, according to the invention, a low-refractive-index layer cannot be made of the same material as the immediately adjacent light-conducting layers, since otherwise they would have the same refractive index. In other words, if, for example, the first low-refractive-index layer is made of SiO2, the first light-conducting layer and the second light-conducting layer are made of a different material with a higher refractive index (for example, SiO2).

[0046] If a low-refractive-index layer is formed based on a mineral layer, it consists predominantly of the mineral layer, in particular essentially of this material, along with any impurities or dopants. The layer thickness of the first low-refractive-index layer and, if present, the outer low-refractive-index layer, the second low-refractive-index layer, the third low-refractive-index layer, and / or further low-refractive-index layers is preferably each at most 10 μm, particularly preferably less than 5 μm, in particular less than 400 nm.

[0047] The light-conducting layers and / or the low-refractive-index layers, if formed as a mineral layer (e.g. based on SiC>2), can be applied by physical or chemical vapor deposition, i.e. a PVD or CVD coating (PVD: physical vapor deposition, CVD: chemical vapor deposition), or, for example, using the sol-gel process. Such coatings can be produced with particularly high optical quality and with particularly low thickness. The application of layers using the sol-gel process is known to those skilled in the art and can be found, for example, in WQ2021209201A1. The volume fraction of the pores of porous silicon dioxide can be limited and controlled by production using a sol-gel process.

[0048] A PVD coating can be a coating applied by cathode sputtering, particularly a coating applied by magnetic field-assisted cathode sputtering (magnetron sputtering). Preferably, the light-conducting layers and / or the low-refractive-index layers, if a mineral layer (e.g., SiO2), are applied by magnetron sputtering. Magnetron sputtering can efficiently produce a homogeneous layer just a few micrometers thick.

[0049] If the light-conducting layers and / or the low-refractive-index layers, if formed as a mineral layer, are applied by chemical vapor deposition, this is preferably done using plasma-enhanced chemical vapor deposition (PECVD), particularly at atmospheric pressure (APCVD). The advantage of plasma-enhanced chemical vapor deposition is the speed of application combined with high layer homogeneity compared to other processes. Silicon oxide, in particular, can be applied homogeneously and efficiently to a substrate using this process.

[0050] However, the light-conducting layers and / or the low-refractive-index layers can also be applied by other methods known to the person skilled in the art, for example by wet-chemical methods, for example sol-gel processes, such as spray coating, dip coating, spin coating

[0051] (spin coating) or casting.

[0052] Sol-gel processes generally refer to the condensation of colloidally dissolved particles into three-dimensional networks, with the colloids varying in size from 1 nm to several thousand nm. In spray coating, a sol is atomized by supplying a specific amount of air, and the sol is then transported to the substrate in very small particles. In dip coating, the substrate is immersed in a solution and then withdrawn at a constant speed. In the casting process, a synthesis solution is dripped onto the substrate and the solvent is waited for to evaporate. The production of coatings by casting is also based on the evaporation-induced self-assembly (EISA) mechanism. The films produced in this way can be significantly thicker than those produced by dip or spin coating.

[0053] The layer stack according to the invention preferably extends over at least 80%, particularly preferably at least 90% of the main surface of the first substrate. In particular, the layer stack extends over the entire main surface of the first substrate. In a very advantageous embodiment of the invention, the layer stack extends over the entire main surface of the first substrate less a frame-shaped peripheral edge region of the first substrate. In a plan view of the pane, the layer stack is therefore framed by a region which is not provided with the layer stack according to the invention. The areal extent of the layer stack is defined by the areal extent of the first light-conducting layer, since all other layers, including the outer low-refractive-index layer, do not extend flat beyond the first light-conducting layer.

[0054] The outcoupling elements are suitable for coupling out a portion of the light guided into the pane according to the invention by scattering, reflection, refraction, or diffraction. The outcoupling elements can be incorporated within the respective light-conducting layer or incorporated or arranged on the first surface and / or on the second surface. The outcoupling elements are preferably formed by laser structuring, mechanical structuring such as sandblasting, and / or by etching. Alternatively or in combination, the outcoupling elements can be applied as prints on the first surface and / or the second surface of the respective light-conducting layer to which they belong. The print can contain an ink, a paste, and / or particles, particularly preferably light-scattering, light-refracting, or light-reflecting particles. The print can be transparent or opaque.In an advantageous embodiment, the coupling-out elements are transparent, so that they do not significantly restrict visibility through the pane. The print (printing paste) therefore preferably contains no pigment. However, opaque or semi-transparent coupling-out elements with pigments are also conceivable, for example, white elements. The print can also produce a colored tint, i.e., at least not completely block visibility through the pane, but lead to a tint in one or more areas of the pane. The printing paste, if opaque, semi-transparent, or tinted, preferably contains dyes or color pigments.

[0055] Alternatively or in combination, the coupling-out elements can comprise or consist of particles, particularly preferably light-scattering, light-refracting, light-diffracting, or light-reflecting particles, scattering centers, or cavities arranged within the respective light-conducting layer. Such scattering centers or cavities can be introduced into the layers, for example, by laser structuring.

[0056] "Transparent" in the sense of the invention means a light transmission (according to ISO 9050:2003) of at least 70%, preferably at least 80%, and particularly preferably at least 90%. "Semi-transparent" (according to ISO 9050:2003) in the sense of the invention means a light transmission of less than 70%, preferably at most 50%, and particularly preferably at most 5%. "Opaque" in the sense of the invention means a light transmission (according to ISO 9050:2003) of less than 5%, preferably less than 0.1%, in particular 0%.

[0057] In a preferred embodiment of the invention, the first substrate has at least one outcoupling element, preferably a plurality of outcoupling elements. The outcoupling element or the outcoupling elements can be designed as described for the light-conducting layers. In addition, the outcoupling element or the outcoupling elements of the first substrate can also be applied as a film or coated film to the first surface and / or the second surface of the first substrate. If one or more outcoupling elements are applied to the second surface of the first substrate, then they are arranged between the layer stack and the first substrate. When the pane is used in glazing with coupled-in light, the outcoupling elements appear as a luminous surface of the pane.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 may be intended for purely aesthetic reasons. The decoupling elements allow any shape or pattern to be realized.

[0058] If something is "based" on an inorganic material, it consists predominantly of this material, in particular essentially of this material, along with any impurities or dopants. Unless otherwise stated, the specified layer thickness or thicknesses refer to the geometric thickness of a layer. If something is "based" on a polymeric material, it consists predominantly of this material, i.e., at least 50%, preferably at least 60%, and in particular at least 70%. It may therefore also contain other materials such as stabilizers or plasticizers.

[0059] The invention also extends to a glazing comprising the pane according to the invention and at least one light source for coupling light into the pane.

[0060] The glazing comprises a light source suitable for coupling light into the pane. During operation, the light source emits visible light, i.e., electromagnetic radiation in the visible spectral range, particularly in the range from 400 nm to 800 nm. The light source can have one or more emission bands located in the visible spectral range and covering part of it. However, the light source can also have a broad emission band that covers 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.

[0061] The glazing may have a single light source or several separate light sources, the light of which is coupled into the pane, or more specifically the light-conducting layers and / or the substrate, at different locations.

[0062] The light source is preferably arranged relative to the pane in such a way that the light emitted by it can be coupled into all of the light-guiding layers. The light from the light source can be coupled into the first light-guiding layer via the first partial region, since this partial region is not covered by the first low-refractive-index layer and the second light-guiding layer. If the layer stack has further light-guiding layers and low-refractive-index layers, the light from the light source can be coupled into the second light-guiding layer via the second partial region, into the third light-guiding layer via the third partial region, and so on. This means that the light source is arranged in such a way that it can couple light into the individual light-guiding layers via the partial regions of the layer stack.With respect to the uppermost light-conducting layer, the light source is preferably arranged such that it couples light into this layer via an edge region of the uppermost light-conducting layer.

[0063] For the purposes of the invention, “uppermost light-conducting layer” means that light-conducting layer which, of all light-conducting layers of the layer stack, is arranged furthest away from the first substrate and whose surface facing away from the first substrate (second surface) is therefore not in contact with other light-conducting layers or low-refractive-index layers.

[0064] Each light source preferably comprises at least one light-emitting diode (LED). Each light source can be a single light-emitting diode, but preferably it comprises an array of multiple light-emitting diodes. Said array is preferably installed in a common housing, for example as a linear array or a circular array in which the light-emitting diodes are arranged along a substantially straight line or a circular line. The electroluminescent material of the light-emitting diode 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).

[0065] In a preferred embodiment of the invention, a first light source is assigned to the first light-guiding layer and a second light source is assigned to the second light-guiding layer. The pane preferably also comprises a third light-guiding layer, with a third light source assigned to this layer. In particular, in addition to the third light-guiding layer, the pane also comprises a fourth light-guiding layer, with a fourth light source assigned to this layer. In particular, at least one light source is assigned to each light-guiding layer. For the purposes of this embodiment, each light source is arranged relative to the light-guiding layer assigned to it in such a way that the light from the light source can essentially only be coupled into the light-guiding layer assigned to it. Each light-guiding layer can thus be illuminated separately.For example, the different light sources can emit light of different wavelengths, which allows the output elements of the light-conducting layers to be illuminated in different colors.

[0066] In a further developed embodiment, the light source assigned to the first light-conducting layer is arranged in the first subregion. If the layer stack also has a second low-refractive-index layer and a third light-conducting layer, which are applied to the second light-conducting layer with the exception of a second subregion, then the light source assigned to the second light-conducting layer is arranged in the second subregion. If the layer stack additionally also has a third low-refractive-index layer and a fourth light-conducting layer, which are applied to the third light-conducting layer with the exception of a third subregion, then the light source assigned to the third light-conducting layer is arranged in the third subregion.The arrangement of any additional light sources present preferably applies analogously if additional light-conducting layers and low-refractive-index layers are applied alternately and consecutively to the fourth light-conducting layer, and a partial area of ​​each light-conducting layer always remains free of subsequent low-refractive-index layers and light-conducting layers. The light source assigned to the uppermost light-conducting layer can be arranged arbitrarily on the surface facing away from the substrate, preferably in an edge area of ​​the uppermost light-conducting layer.

[0067] The light-conducting layers can be provided with a coupling means. The coupling means can be arranged between the light-conducting layer and the light source associated with it. Alternatively, the coupling means can also be arranged on the surface of the light-conducting layer facing the first substrate (first surface of the light-conducting layer). The coupling element is arranged such that light emitted by the light source impinges on the coupling element and is then coupled into the respective light-conducting layer by means of reflection or light refraction at the coupling element. If the coupling means is arranged on the first surface of the light-conducting layer, the light from the associated light source propagates at least through the respective light-conducting layer before impinging on the coupling element.The majority of the light is reflected or diffracted at the coupling means such that it is reradiated to the light-conducting layer at an angle of incidence that is advantageous for coupling. In this context, the "relevant light-conducting layer" refers to the light-conducting layer that has the described coupling means. If the coupling means is arranged on the first surface of the light-conducting layer, the coupling means is preferably a reflective structure. The reflective structure has a plurality of inclined sections with a reflective surface and is configured such that the light radiated into the relevant light-conducting layer and passing through the relevant light-conducting layer is reflected at the reflective surface of the inclined sections and at least partially radiated back into the relevant light-conducting layer.The reflective structure is preferably provided with a reflective coating, which is responsible for the reflective properties of the reflective structure. The reflective coating comprises at least one reflective layer based on a metal or metal alloy. This increases the reflectivity of the reflective coating.

[0068] The reflective structure is particularly preferably a microprism film. The microprism film is applied, for example, glued, to the outer surface of the optical waveguide. The reflective surface of the reflective structure is preferably arranged facing away from the respective light-conducting layer. The microprism film is transparent except for the reflective surface. After entering the respective light-conducting layer, the light from the light source exits the respective light-conducting layer via the outer surface, passes through the microprism film, and strikes its reflective surface, where it is reflected and passes through the microprism film again, re-entering the respective light-conducting layer via the outer surface.

[0069] The reflective surface of the reflective structure has sections that are inclined relative to the respective light-conducting layer. This means that the sections are not arranged parallel to the first surface of the light-conducting layer, but at an angle greater than 0° to the surface. Said sections have an angle to the first surface that is between 0° and 90°, preferably from 28° to 60° or from 30° to 60°, very particularly preferably from 30° to 50°, in particular from 40° to 50°, for example approximately 45°. This refers to the absolute value of the respective angle. The sections can be inclined in different directions. The sections are preferably also inclined relative to one another. This means that adjacent sections are inclined relative to one another, i.e., are not arranged parallel, but at an angle between 0° and 180° to one another.Said sections of the reflective structure are preferably substantially planar. The inclination of the sections of the reflective structure relative to the first surface of the respective light-conducting layer determines the angle at which the reflected light is reflected back into the respective light-conducting layer.

[0070] In a second particularly preferred embodiment, the coupling element is applied to the second surface of the light-conducting layer. The beam path of the light source is directed toward the coupling means. The coupling means couples the light arriving from the light source into the respective light-conducting layer, preferably by refraction. The coupling means is thus a light-refracting structure. The light source is preferably connected to the respective light-conducting layer via the coupling means. A collimator can be arranged between the light source and the coupling means, i.e., in the beam path of the light source.

[0071] Regardless of whether the coupling means is arranged between the respective light-conducting layer and the light source assigned to it or is arranged on the first surface of the respective light-conducting layer, the coupling means of each light-conducting layer is preferably arranged in one of the exposed partial regions of the light-conducting layer. This means that the coupling means of the first light-conducting layer is preferably arranged in the first partial region of the first light-conducting layer, the coupling means of the second light-conducting layer is preferably arranged in the second partial region of the second light-conducting layer, and the coupling means of the third light-conducting layer is preferably arranged in the third partial region of the third light-conducting layer, and so on. In the uppermost light-conducting layer, the coupling element is preferably arranged in the edge region of the layer.

[0072] In a preferred embodiment of the invention, the glazing comprises at least one first light source assigned to the first light-guiding layer and a second light source assigned to the second light-guiding layer. Preferably, at least one light source is assigned to each light-guiding layer. These light sources assigned to the light-guiding layers are each arranged on or in a light-guiding element. Preferably, each light source is arranged in or on a light-guiding element separate from the other light-guiding elements. Each light-guiding element is arranged on the second surface of the light-guiding layer to which the respective light source is assigned and has a light output surface facing this light-guiding layer. The light-guiding element preferably comprises a body made of an optically transparent, cured adhesive.The light generated by the light source is intended to be coupled into the light-guiding layer assigned to it via the light output surface. The refractive index of the optically transparent, cured adhesive differs by a maximum of 0.05, preferably a maximum of 0.01, from the refractive index of the light-guiding layer on which it is arranged. This allows the light to be coupled into the light-guiding layer with little or no loss of light intensity. The light is almost completely transmitted at the transition from the light-guiding element to the light-guiding layer and is largely not refracted or reflected. The light source assigned to the light-guiding layer is arranged in particular in or on the light-guiding element in such a way that the light emitted by it strikes the light-guiding layer at a suitable angle of incidence, so that the light is coupled in and propagates in the light-guiding layer.In other words, the light emitting surface of each light source is arranged at an angle to its associated light-guiding layer which is greater than the critical angle of the light-guiding layer at its first surface.

[0073] In a further embodiment, the light-guiding element has a light-reflecting coating on an outer surface, which is suitable for reflecting the light emitted by the light source toward the light output surface. This prevents the light from escaping from the light-guiding element and enhances the light transmission.

[0074] The light-guiding element preferably comprises a housing having an opening at the light exit surface. The housing can be a hollow body filled with the optically transparent, cured adhesive, wherein the hollow body is formed from a thermally dimensionally stable material, in particular plastic, metal, or aluminum. Furthermore, the housing can have two sides arranged opposite the light exit surface, wherein the two sides define the hollow body with the opening.

[0075] Curable, optically transparent adhesives can be irreversibly cured. Typically, they are plastics that undergo polymer-crosslinking through curing. This distinguishes them significantly from thermoplastics, which are also optically transparent but can be reversibly softened by the application of heat. In contrast, curable adhesives cannot be returned to a flowable state once they have cured. Therefore, optically transparent, curable adhesives are not non-curable thermoplastics. Curable, optically transparent adhesives can be cured by heat, exposure to electromagnetic radiation, preferably UV radiation, and / or chemically. Curing is preferably achieved by applying heat or increasing the temperature and / or UV radiation.

[0076] The transparent adhesive, for example, is based on silicone. Optically transparent adhesives are known, in particular, by the acronym LOCA (liquid optically clear adhesive). These are often used in touch-sensitive displays, for example, to firmly bond them to an LCD or to firmly bond plastic covers to the touch-sensitive displays. After application, the LOCA is often cured using UV radiation.

[0077] The curable, optically transparent adhesive can, for example, contain or consist of polyurethane (PU), polyacrylate, polyacetate resin, casting resin, epoxy resin, Acralyt, or a copolymer or mixture thereof. The optically transparent adhesive is advantageously made of a casting resin, particularly polyurethane- or silicone-based. The housing of the light module can serve as a mold for the curable, optically transparent adhesive.

[0078] In a further embodiment of the glazing arrangement according to the invention, each light-guiding element is firmly bonded to the light-guiding layer, to which the light source arranged in or on the light-guiding element is assigned, by means of the optically transparent, cured adhesive. In other words, each light-guiding element is bonded to the light-guiding layer, to which the light source arranged in or on the light-guiding element is assigned. Alternatively, the light-guiding element can be firmly bonded to the light-guiding layer, to which the light source arranged in or on the light-guiding element is assigned, by means of an adhesive tape. For this purpose, the adhesive tape has the optically transparent adhesive on two sides.

[0079] Optionally, each light source can independently have a collimator arranged between the disk and the light source, wherein the collimator is located in the beam path of the respective light source. Preferably, at least the first light source and the second light source have such a collimator. In particular, all light sources have such a collimator. The collimator is preferably arranged between the light source and the layer stack of the disk, such that the light is coupled into the light-guiding layers via the collimator. The collimator generates from the typically divergent light beam of the light source a light beam with a preferably essentially parallel beam path, but at least a less divergent, i.e. more concentrated beam path. The beam cone of the light source is therefore narrowed by the collimator.This has the advantage that the entire light beam is irradiated into the pane at the same angle of incidence. Especially when the light-conducting layers are provided with a reflective structure, such a substantially convergent angle of incidence allows a large portion of the light to be coupled into the light-conducting layer via the reflective structure, resulting in total internal reflection. This optimizes the light yield.

[0080] In the simplest case, the collimator is a type of converging lens, with the light source preferably positioned at its focal point. The collimator can be made, for example, from glass or a transparent plastic, in particular polycarbonate (PC) or polymethyl methacrylate (PMMA). The collimator is preferably attached, for example glued, to the exposed surface of the layer stack facing away from the substrate. If the light source is embodied as an array of multiple light-emitting diodes, a separate collimator can be provided for each light-emitting diode. However, a common collimator is preferably used for the entire LED array. In the case of a linear LED array, a rod-like collimator whose length corresponds at least to the length of the LED array can be used, for example.

[0081] The various embodiments of the invention can be implemented individually or in any combination.

[0082] The disc can be manufactured using the following process:

[0083] (A) providing a first substrate having a first surface and a second surface,

[0084] (B) Arranging, preferably applying, a layer stack comprising a first light-conducting layer, a first low-refractive-index layer and a second light-conducting layer in this order on the second surface of the first substrate, wherein the low-refractive-index layer is applied to the first light-conducting layer such that it extends over the entire area of ​​the first light-conducting layer with the exception of a first partial region and the second light-conducting layer is applied to the first low-refractive-index layer such that it extends over the entire area of ​​the first low-refractive-index layer, wherein the first low-refractive-index layer has a smaller refractive index than the first light-conducting layer and a smaller refractive index than the second light-conducting layer.If the pane is a composite pane, it can be manufactured using conventional lamination processes, such as autoclave processes, vacuum bag processes, vacuum ring processes, calender processes, vacuum laminators, or combinations thereof. The bonding of the outer and inner panes is typically achieved using heat, vacuum, and / or pressure.

[0085] The pane is intended to be a component of glazing. The pane or glazing can be used as a window pane of a vehicle. A particularly preferred use is a vehicle roof window that can be illuminated in 3 dimensions. The vehicle can in principle be any land vehicle, watercraft or aircraft, and is preferably a passenger car, truck or rail vehicle. The pane or glazing can also be used in buildings. For example, the pane can be used as a window pane, glass facade or glass door indoors or outdoors, in particular as a window pane of a building or an interior space. The pane or glazing can also be used as a component of furniture, electrical devices, as a component of furnishings or as a furnishing.

[0086] The invention is explained in more detail below with reference to figures and exemplary embodiments. The figures shown are schematic representations and not to scale. The figures shown do not limit the invention in any way.

[0087] They show:

[0088] Fig. 1a is a plan view of an embodiment of a glazing according to the invention, Fig. 1b is a cross-sectional view of the glazing shown in Figure 1a,

[0089] Fig. 1c an enlarged edge area in the cross-sectional view from Fig. 1b,

[0090] Fig. 1d is an enlarged central region of the disc according to the invention in the cross-sectional view from Fig. 1b,

[0091] Fig. 2a is a cross-sectional view of an alternative embodiment of a glazing according to the invention,

[0092] Fig. 2b an enlarged edge area in the cross-sectional view from Fig. 2a,

[0093] Fig. 2c an enlarged view of the pane in the cross-sectional view from Fig. 2a,

[0094] Fig. 3a is a plan view of a further embodiment of a glazing according to the invention and

[0095] Fig. 3b is an enlarged plan view of an edge region of the glazing from Fig. 3a. Figures 1a to 1d each show different aspects of a first embodiment of the glazing 101 according to the invention. Figure 1a shows a plan view of a glazing 101. Fig. 1b shows a cross-sectional view of the glazing 101 shown in plan view from Figure 1a. The section line for the cross section is indicated in Figure 1a by a dashed line XX'. Figure 1c shows an enlarged section Z1 of an edge region of the glazing 101. The section Z1 is indicated in Figure 1b by a circular dashed line. Figure 1d shows an enlarged section Z2 of a central region of the pane 100 of the glazing 101. The section Z2 is indicated in Figure 1b by a circular dashed line.

[0096] The pane 100 of the glazing 101 is designed, for example, as a roof pane of a vehicle, in particular a passenger car. For the sake of simplicity, it is shown flat, although such vehicle roof panes are typically curved. The pane 100 is structurally formed from a first substrate 1 with a layer stack 2. The first substrate 1 has a first surface III, which faces the external environment, and a second surface IV, which faces the vehicle interior. The pane 100 is shown here as a monolithic pane; however, it is preferably a composite pane, also comprising a second substrate and an intermediate layer (not shown here) arranged between the first substrate 1 and the second substrate. The first substrate 1 consists, for example, of soda-lime glass and has a thickness of, for example, 2.1 mm in each case.The layer stack 2 is applied to the second surface IV of the first substrate 1, for example, by magnetron sputtering. A frame-shaped masking region 9 is arranged in the edge region of the wafer 100. The masking region 9 is formed, for example, by a black enamel on the first surface III of the first substrate 1.

[0097] The layer stack 2 comprises, in the following order, starting from the first substrate 1, a first light-conducting layer 3.1, a first low-refractive-index layer 4.1 and a second light-conducting layer 3.2. In other words, the first light-conducting layer 3.1 is applied to the second surface IV of the first substrate 1, the first low-refractive-index layer 4.1 is applied to the surface of the first light-conducting layer 3.1 facing away from the first substrate 1 and the second light-conducting layer 3.2 is applied to the surface of the first low-refractive-index layer 4.1 facing away from the first substrate 1. The layer stack 2 extends over the entire second surface IV of the first substrate 1. The first light-conducting layer 3.1 and the second light-conducting layer 3.2 are formed, for example, from silicon nitride with a layer thickness of 2 pm. The first low-refractive-index layer 4.1 is, for example, from silicon dioxide with a layer thickness of

[0098] I pm. In a region of the pane 100 intended for viewing, also called the central region, outcoupling elements 5 are arranged in the layer stack 2 (see Fig. 1d). In a plan view of the pane 100, the outcoupling elements 5 form the lettering "Saint-Gobain" when illuminated. The outcoupling elements 5 are arranged partly within the first light-conducting layer 3.1 and partly in the second light-conducting layer 3.2. The outcoupling elements 5 are introduced into the light-conducting layers 3.1, 3.2, for example, by laser structuring.

[0099] The glazing 101 also comprises light sources 6. The first light source 6.1 is arranged relative to the first light-guiding layer 3.1 such that the light 11 emitted by the first light source 6.1 is coupled into the first light-guiding layer 3.1. The second light source 6.2 is arranged relative to the second light-guiding layer 3.2 such that the light 11 emitted by the second light source 6.2 is coupled into the second light-guiding layer 3.2. The first light source 6.1 is arranged in a first partial region A of the first light-guiding layer 3.1. The first partial region A is free of the first low-refractive-index layer 4.1 and free of the second light-guiding layer 3.2. The first low-refractive-index layer 4.1 extends over the entire surface of the first light-guiding layer 3.1 with the exception of the first partial region A of the first light-guiding layer 3.1. The second light-guiding layer 3.2 extends congruently over the entire surface of the first low-refractive-index layer 4.1. This means that the second light-conducting layer 3.2 and the first low-refractive-index layer 4.1 are not arranged between the first light source 6.1 and the first light-conducting layer 3.1. The first partial region A is arranged in an edge region of the first light-conducting layer 3.1 and extends in a strip-like manner along an edge of the pane 100. The first light source 6.1 is arranged in a line on the first partial region A. The second light source 6.2 is arranged parallel to it in a line in an edge region of the second light-conducting layer 3.2 adjacent to the first partial region A. The light sources 6.1, 6.2 are, for example, a linear arrangement of LEDs (light-emitting diodes). The light 11 emitted by the light sources 6.1, 6.2 can be of different colors. For example, the first light source 6.1 emits1 emits light 11 in a wavelength range from 500 nm to 510 nm and the second light source 6.2 emits light.

[0100] II in a wavelength range from 700 nm to 710 nm.

[0101] For coupling the light 11 of the light sources 6.1 , 6.2 , the light-conducting layers 3.1 ,

[0102] 3.2 is provided with a coupling means 10. The coupling means 10 are, for example, reflective microprismatic layers. The coupling means 10 of the first light-conducting layer 3.1 is arranged on the surface of the first light-conducting layer 3.1 facing the first substrate 1. When viewed through the pane 100, the coupling means 10 overlaps with the first light-conducting layer 3.1, so that light 11 of the first light source 6.1 emitted perpendicular to the main surface of the pane 100 first propagates through the first light-conducting layer 3.1 and then impinges on the coupling means 10. The light 11 is reflected at the coupling means 10 such that the reflected light 11 strikes the first light-guiding layer 3.1 at an angle of incidence suitable for coupling into the first light-guiding layer 3.1 and then propagates in the first light-guiding layer 3.1 under the effect of total reflection.Analogously, the coupling means 10, with which the second light-guiding layer 3.2 is provided, is arranged relative to the second light source 6.2. However, the coupling means 10 is arranged between the first low-refractive-index layer 10 and the second light-guiding layer 3.2. The light 11 thus coupled into the light-guiding layers 3.1, 3.2 spreads out until it hits one of the output coupling means 5 of the respective layer 3.1, 3.2 and is thereby largely output to the vehicle interior. The arrangement of the output coupling means 5 in different planes creates a three-dimensional illumination impression for the observer. A further advantage is that the areas of the light-guiding layers provided with output coupling elements 5 can be kept relatively small, since the output coupling elements 5 are distributed across different light-guiding layers 3.1, 3.2. The first low-refractive-index layer 4.1 largely prevents the light 11 from passing from one light-conducting layer 3.1, 3.2 to the other.

[0103] The variants shown in Figures 2a to 2c and in Figures 3a to 3b essentially correspond to the variant from Figures 1a to 1d, so that only the differences are discussed here and otherwise reference is made to the description of Figures 1a to 1d.

[0104] Figures 2a to 2c each show different aspects of a second embodiment of the glazing 101 according to the invention. Figure 2a shows a cross-sectional view of the glazing 101. Figure 2b shows an enlarged section Z3 of an edge region of the glazing 101. The section Z3 is indicated in Figure 2a by a circular dashed line. Figure 2c shows an enlarged section Z4 of a central region of the pane 100 of the glazing 101. The section Z4 is indicated in Figure 2a by a circular dashed line. The pane 100 is designed as a composite pane and comprises a second substrate 7 with a first surface I facing the external environment and a second surface II facing the vehicle interior. The second substrate 7 is connected to the first substrate 1 via a thermoplastic intermediate layer 8.The second substrate 7 consists, for example, of soda-lime glass and has a thickness of, for example, 2.1 mm. The thermoplastic intermediate layer 8 consists, for example, of polyvinyl butyral and is tinted with a light transmittance of less than 10%. The layer thickness of the thermoplastic intermediate layer 8 is, for example, 0.76 mm. The masking region 9 is arranged on the second surface II of the second substrate 7 instead of on the first surface III of the first substrate 1.

[0105] In contrast to the embodiment of Figures 1a to 1d, the layer stack 2 here also has an outer low-refractive-index layer 4', which is arranged between the first light-conducting layer 3.1 and the first substrate 1. The outer low-refractive-index layer 4' extends over the entire second surface IV of the first substrate 1 and is applied to the first substrate 1. The layer stack 2 also has the following: a second low-refractive-index layer 4.2, which is applied to the second light-conducting layer 3.2 with the exception of a second partial region B, a third light-conducting layer 3.3, which is applied congruently to the second low-refractive-index layer 4.2, a third low-refractive-index layer 4.3, which is applied to the third light-conducting layer 3.3 with the exception of a third partial region C, and a fourth light-conducting layer 3.4, which is applied congruently to the second low-refractive-index layer 4.2.

[0106] The light-conducting layers 3.1, 3.2, 3.3, 3.4 are formed, for example, from titanium oxide, each with a layer thickness of 3 pm. The low-refractive-index layers 4.1, 4.2, 4.3, 4' are formed, for example, as a polymer matrix of polyacrylate, with silicon dioxide-based particles embedded in the polymer matrix, and each have a layer thickness of 0.5 pm. In a region of the pane 100 intended for transparency, also called the central region, outcoupling elements 5 are arranged in the layer stack 2 (see Fig. 2c). The outcoupling elements 5 are distributed across the various light-conducting layers 3.1, 3.2, 3.3, 3.4, whereby they do not overlap with one another when viewed through the pane 100. The coupling elements 5 are introduced into the light-conducting layers 3.1, 3.2, 3.3, 3.4, for example, by laser structuring. The glazing 101 comprises, in addition to the first and second light sources 6.1, 6.2 also a third light source 6.3 and a fourth light source 6.4. The third light source 6.3 is arranged relative to the third light-guiding layer 3.3 such that the light 11 emitted by the third light source 6.3 is coupled into the third light-guiding layer 3.3. The fourth light source 6.4 is arranged relative to the fourth light-guiding layer 3.4 such that the light 11 emitted by the fourth light source 6.4 is coupled into the fourth light-guiding layer 3.4. The second light source 6.2 is arranged in the second partial region B, the third light source 6.3 is arranged in the third partial region C, and the fourth light source 6.4 is arranged in an edge region of the fourth light-guiding layer 3.4 adjacent to the third partial region. The light sources 6.1, 6.2, 6.3, 6.4 are each arranged in a light-guiding element 12 and are connected via the light-guiding element 12 to the corresponding light-guiding layer 3.1, 3.2, 3.3, 3.4, into which the light 11 emitted by them is coupled. The light-guiding layers 3.1, 3.2, 3.3, 3.4 are not provided with a light coupling means 10; instead, the light sources 6.1, 6.2, 6.3, 6.4 are arranged within their respective light-guiding element 12 such that the light 11 emitted by them strikes the light-guiding layer 3.1, 3.2, 3.3, 3.4 - on which they are arranged - at an angle of incidence suitable for coupling and then propagates under the effect of total internal reflection in the respective layer 3.1, 3.2, 3.3, 3.4. The light-guiding elements 12 are made, for example, from cured plastic, which has a refractive index similar to titanium oxide. The light 11 emitted by the light sources 6.1, 6.2, 6.3, 6.4 can be of different colors.

[0107] Figure 3a shows a plan view of a further embodiment of the glazing 101 according to the invention. Figure 3b shows an enlarged section Z5 of an edge region of the glazing 101 in plan view. Section Z5 is indicated in Figure 3a by a circular dashed line.

[0108] In the variant shown here, the light sources 6.1, 6.2, 6.3, 6.4 are not band-shaped, but point-shaped. The partial regions A, B, C of the light-conducting layer 3.1, 3.2, 3.3 do not extend in strips along an edge of the pane 100, but are arranged quadrangularly next to one another and all border the edge of the pane 100. Apart from this, the layer stack 2 is constructed as described for the variant in Figures 2a to 2c. This arrangement of the light sources 6.1, 6.2, 6.3, 6.4 reduces the space required in the edge region of the pane 100. The low-refractive-index layers 4.1, 4.2, 4.3, 4' are not shown in Fig. 3b for the sake of clarity. List of reference symbols

[0109] 1 first substrate

[0110] 2 layer stacks

[0111] 3.1 first light-conducting layer

[0112] 3.2 second light-conducting layer

[0113] 3.3 third light-conducting layer

[0114] 3.4 fourth light-conducting layer

[0115] 4.1 first low-refractive-index layer

[0116] 4.2 second low-refractive-index layer

[0117] 4.3 third low-refractive-index layer

[0118] 4' outer low-refractive index layer

[0119] 5 Decoupling element

[0120] 6 light sources

[0121] 6.1 first light source

[0122] 6.2 second light source

[0123] 6.3 third light source

[0124] 6.4 fourth light source

[0125] 7 second substrate

[0126] 8 thermoplastic intermediate layer

[0127] 9 Masking area

[0128] 10 coupling agents

[0129] 11 Light

[0130] 12 Light guide element

[0131] 100 slices

[0132] 101 Glazing

[0133] I first surface of the second substrate 7

[0134] II second surface of the second substrate 7

[0135] III first surface of the first substrate 1

[0136] IV second surface of the first substrate 1

[0137] A first part of the first light-conducting layer 3.1

[0138] B second part of the second light-conducting layer 3.2

[0139] C third partial area of ​​the third light-conducting layer 3.3 Z1 enlarged edge area of ​​the glazing 101 from Figure 1b

[0140] Z2 enlarged viewing area of ​​the disc 100 from Figure 1b

[0141] Z3 enlarged edge area of ​​glazing 101 from Figure 2a

[0142] Z4 enlarged view of the pane 100 from Figure 2a Z5 enlarged plan view of the edge area of ​​the glazing 101 from Figure 3a

[0143] XX' cutting line

Claims

Patent claims 1. A pane (100) for an illuminable glazing (101), comprising at least a first substrate (1) with a first surface (III) and a second surface (IV), a layer stack (2) which is arranged on the second surface (IV) of the first substrate (1) and, starting from the second surface (IV), comprises in the following order a first light-conducting layer (3.1) with at least one coupling-out element (5) for coupling out light (11), a first low-refractive-index layer (4.1) which extends over the entire surface of the first light-conducting layer (3.1) with the exception of a first partial region (A), and a second light-conducting layer (3.2) with at least one coupling-out element (5) for coupling out light (11), which extends over the entire surface of the first low-refractive-index layer (4.1), wherein the first low-refractive-index layer (4.1) has a lower refractive index than the first light-conducting layer (3.1) and has a smaller refractive index than the second light-conducting layer (3.2).

2. Disc (100) according to claim 1, further comprising a second substrate (7) which is connected to the first substrate (1) via a thermoplastic intermediate layer (8).

3. A pane (100) according to claim 2, wherein the first surface (III) of the first substrate (1) faces the thermoplastic intermediate layer (8).

4. A pane (100) according to any one of claims 1 to 3, wherein the layer stack (2) comprises an outer low-refractive-index layer (4') which is arranged between the first substrate (1) and the first light-conducting layer (3.1) and which has a smaller refractive index than the first light-conducting layer (3.1), wherein the layer stack (2) is arranged directly to the first substrate (1).

5. A pane (100) according to any one of claims 1 to 4, wherein the layer stack (2) further comprises, starting from the second light-conducting layer (3.2), in the following order: a second low-refractive-index layer (4.2) which extends over the entire surface of the second light-conducting layer (3.2) with the exception of a second partial region (B), and a third light-conducting layer (3.3) with at least one coupling-out element (5) which extends over the entire surface of the second low-refractive-index layer (4.2) wherein the second low-refractive-index layer (4.2) has a smaller refractive index than the second light-conducting layer (3.2) and a smaller refractive index than the third light-conducting layer (3.3).

6. Pane (100) according to claim 5, wherein the layer stack (2) starting from the third light-conducting layer (3.3) also comprises in the following order: a third low-refractive-index layer (4.3), which extends over the entire surface of the third light-conducting layer (3.3) with the exception of a third partial region (C), and a fourth light-conducting layer (3.4) with at least one coupling-out element (5), which extends over the entire surface of the third low-refractive-index layer (4.3) wherein the third low-refractive-index layer (4.3) has a smaller refractive index than the third light-conducting layer (3.3) and a smaller refractive index than the fourth light-conducting layer (3.4).

7. Pane (100) according to one of claims 1 to 6, wherein each light-conducting layer (3.1, 3.2, 3.3, 3.4) has at least two, preferably at least three, coupling-out elements (5).

8. Pane (100) according to one of claims 1 to 7, wherein at least the first light-conducting layer (3.1) and the second light-conducting layer (3.2), preferably all light-conducting layers (3.1, 3.2, 3.3, 3.4), contain or consist of titanium oxide, aluminum oxide, silicon nitride, silicon zirconium nitride and / or silicon dioxide.

9. Disc (100) according to one of claims 1 to 8, wherein the first substrate (1) has at least one coupling-out element (5).

10. Pane (100) according to one of claims 1 to 9, wherein all low-refractive-index layers (4', 4.1, 4.2, 4.3) of the layer stack (2) each have a refractive index of at most 1.5, preferably at most 1.

4.

11. A pane (100) according to any one of claims 1 to 10, wherein all light-conducting layers (3.1, 3.2, 3.3, 3.4) each have a layer thickness of 1 pm to 20 pm, preferably of 5 pm to 15 pm.

12. Disc (100) according to one of claims 1 to 11, wherein the light-conducting layers (3.1, 3.2, 3.3, 3.4) and the low-refractive-index layers (4', 4.1, 4.2, 4.3) are deposited on the first substrate (1) by a thin-film deposition process, preferably by Cathodic sputtering or magnetic field assisted cathodic sputtering, chemical vapor deposition or plasma assisted chemical vapor deposition, wet chemical processes such as sol-gel processes, in particular spray coating, dip coating, spin coating or casting.

13. Illuminable glazing (101), comprising a pane (100) according to one of claims 1 to 12 and at least one light source (6) for coupling light (11) into the pane (100).

14. Glazing (101) according to claim 13, wherein each light-conducting layer (3.1, 3.2, 3.3, 3.4) is assigned at least one light source (6.1, 6.2, 6.3, 6.4) and each light source (6.1, 6.2, 6.3, 6.4) is arranged in relation to the light-conducting layer (3.1, 3.2, 3.3, 3.4) assigned to it in such a way that the light (11) of the light source (6.1, 6.2, 6.3, 6.4) can only be coupled into the light-conducting layer (3.1, 3.2, 3.3, 3.4) assigned to it.

15. Glazing (101) according to claim 14, wherein the light source (6.1) associated with the first light-conducting layer (3.1) is arranged in the first partial region (A).

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