Glazing element which can be illuminated and has controllable optical properties

Abstract

The invention relates to a glazing element (101) which can be illuminated and has controllable optical properties, comprising a laminated pane (100) comprising an outer pane (1), an inner pane (2) and a thermoplastic intermediate layer (3) located therebetween, a functional element (4) located within the thermoplastic intermediate layer (3) and having controllable optical properties, a barrier layer (6) provided for reducing plasticizer diffusion and having at least one opaque region (8), and a light source (5) for coupling visible light (7) into the laminated pane (100), wherein the light source (5) is located in a portion (B) of the inner pane (2) which is at least partially not in overlap with the functional element (4), and wherein the opaque region (8) of the barrier layer (6) extends at least over the portion (B) and is in direct spatial contact with the functional element (4) at least in an edge region (R1) of the functional element (4).

Description

[0001] Illuminatable glazing element with controllable optical properties

[0002] The invention relates to an illuminable glazing element with controllable optical properties.

[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 US2020241189A1, it was proposed to couple light through a main surface of the glass pane. For this purpose, a reflective structure is attached to the surface of the glass pane facing away from the light source. The reflective structure has sections inclined towards the surface of the glass pane. The light source irradiates the reflective structure through the glass pane, with the light being reflected at the inclined sections in such a way that it spreads through the surfaces of the glass pane as a result of total internal reflection. One problem with this solution concerns the radiation of light into the external environment, since a portion of the emitted light is transmitted through the reflective structure. This residual portion of the light can be perceived as disturbing or irritating from the outside.When used in traffic, it can even cause unwanted distraction or irritation to other road users, thus posing a safety risk. This residual light is often still visible from the outside, even if the glass pane is covered with a masking print in the area of ​​the light source.

[0007] Illuminated glazing elements often have additional controllable optical properties. They comprise laminated panes equipped with functional elements whose optical properties can be modified by applying an electrical voltage. The electrical voltage is applied via a control unit connected to two surface electrodes of the functional element, between which the active layer of the functional element is located. One example of such functional elements are SPD functional elements (suspended particle devices), which are known, for example, from EP0876608B1 and WO2011033313A1. The applied voltage can be used to control the transmission of visible light through SPD functional elements. Another example is PDLC functional elements (polymer dispersed liquid crystal), which are known, for example, from DE102008026339A1.The active layer contains liquid crystals embedded in a polymer matrix. If no voltage is applied, the liquid crystals are randomly aligned, resulting in strong scattering of the light passing through the active layer. If a voltage is applied to the surface electrodes, the liquid crystals align in a common direction, increasing the light transmission through the active layer. The PDLC functional element works less by reducing overall transmittance than by increasing scattering, which can prevent clear visibility or provide glare protection.

[0008] Such glazing elements can be used, for example, as vehicle windows, whose light transmission behavior can then be electrically controlled. They can also be used, for example, as roof windows to reduce glare. Such roof windows are known, for example, from DE10043141A1 and EP3456913A1. Functional elements with controllable optical properties often require sealants in the form of barrier layers to protect them from moisture or plasticizers from the interlayer.

[0009] The present invention is based on the object of providing an improved glazing element that is largely free from the possibility of uncoupled residual light from the light source being visually perceived by an external environment. The glazing element should also be inexpensive to manufacture.

[0010] The object of the present invention is achieved by a glazing element according to claim 1. Preferred embodiments emerge from the subclaims.

[0011] The illuminable glazing element with controllable optical properties according to the invention comprises a composite pane and a light source for coupling visible light into the composite pane. The composite pane comprises an outer pane, an inner pane, and a thermoplastic intermediate layer arranged flat between the inner pane and the outer pane. The composite pane also comprises a functional element with controllable optical properties arranged within the thermoplastic intermediate layer and at least one barrier layer for reducing plasticizer diffusion. The barrier layer has at least one opaque region. In other words, the barrier layer is opaque at least in some regions.

[0012] The light source is designed to couple light into the composite pane. The light from the light source can be coupled into the inner pane as an optical fiber, for example; however, it can also be coupled into an additional optical fiber arranged between the functional element and the inner pane. The light source is positioned relative to the composite pane in such a way that, during operation, it couples visible light into the composite pane.

[0013] For the purposes of the invention, a barrier layer “for reducing plasticizer diffusion” means that the barrier layer is designed such that the diffusion of plasticizers through the barrier layer is reduced compared to the plasticizer diffusion through the surrounding thermoplastic intermediate layer. The barrier layer is intended to reduce, in particular to substantially prevent, the diffusion of plasticizers from the thermoplastic intermediate layer to the functional element, in particular to the active layer of the functional element. According to the invention, the light source is arranged in a partial region of the inner pane. The partial region of the inner pane is at least partially non-overlapping with the functional element, i.e., when viewed through the composite pane, it is at least partially not overlapping with the functional element.When referring to "viewing through the composite pane," the viewing direction within the meaning of the invention is perpendicular to the main surface of the composite pane. This does not mean an oblique view of the composite pane or viewing through the composite pane.

[0014] "Within the thermoplastic intermediate layer" means that the functional element is completely enclosed by the intermediate layer, i.e., it is located within the boundaries of the thermoplastic intermediate layer. It goes without saying that additional layers, such as the barrier layer, can be arranged between the intermediate layer and the functional element, i.e., also within the thermoplastic intermediate layer.

[0015] According to the invention, the opaque region of the barrier layer extends at least over the partial region of the inner pane when viewed through the composite pane. In other words, the opaque region of the barrier layer, when viewed through the composite pane, covers the entire partial region of the inner pane. The barrier layer is in direct spatial contact with the functional element at least in one edge region of the functional element. "Direct spatial contact" means that the barrier layer is in direct contact with the functional element, without any additional layers or elements being arranged between the edge region of the functional element and the barrier layer.

[0016] The functional element has an outer surface facing the outer pane and an interior surface facing the inner pane. The barrier layer is preferably in contact with the functional element on the interior surface of the functional element. The functional element also has a circumferential edge surface that connects the interior surface of the functional element to the exterior surface of the functional element. The "edge region" of the functional element can refer to a region of the functional element on the interior surface or the exterior surface. The edge region is directly adjacent to the edge surface of the functional element.An edge area does not necessarily mean the entire peripheral edge area of ​​the functional element, i.e. the area which extends like a frame along the entire edge surface, but it can also mean only a section of the peripheral edge area of ​​the functional element.

[0017] Unless otherwise stated, all elements of the laminated pane mentioned here, which are arranged between the outer pane and the inner pane, are arranged "flat" or "flatly superimposed." In other words, the main surfaces of these elements are arranged essentially parallel to the surfaces of the outer pane and the inner pane. The "thickness" or "layer thickness" of an element refers to the dimension essentially orthogonal to the main surface of the element. The main surface of the element describes the surface of the element with the greatest extent.

[0018] The opaque area of ​​the barrier layer absorbs the visible light emitted by the light source, which is not coupled into the laminated pane. This means that when looking at the outer pane of the laminated pane, no visible light is visually perceptible in the area of ​​the light source (the partial area of ​​the inner pane), since light losses, i.e. light that is unintentionally not coupled into the laminated pane, cannot reach the outer pane due to the at least partially opaque barrier layer. At the same time, the barrier layer prevents the diffusion of plasticizers to the functional element. The use of the barrier layer according to the invention to prevent light emission in the area of ​​the light source reduces costs, as it achieves two different functions with just one component of the laminated pane.

[0019] "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 less than 0%.

[0020] In a particularly preferred embodiment of the invention, the barrier layer has an optical density of at least 3.0, more preferably 3.2, in particular 3.5 in the opaque region. In particular, the barrier layer has an optical density of at least 3.0, more preferably 3.2, in particular 3.5 across all regions (i.e. the entire barrier layer). The optical density is a measure of the absorption of visible light by a material. It indicates how much visible light is absorbed by light propagating through the material. The higher the optical density, the more visible light is absorbed and the less visible light transmits completely through the material, i.e. passes through it. The value 0 can be used as a reference. At an optical density of 0, the material absorbs no light at all.

[0021] The composite pane is intended to separate an interior space from the exterior environment in a window opening of a vehicle or building. In this context, the term “inner pane” within the meaning of the invention refers to the pane facing the interior (vehicle interior). The term “outer pane” refers to the pane facing the exterior environment. However, the invention is not limited to this. The inner pane has an interior-side surface facing away from the intermediate layer and an exterior surface facing the thermoplastic intermediate layer. If the inner pane of the composite pane is also the optical fiber intended to guide the visible light from the light source, the exterior surface of the optical fiber is the exterior surface of the inner pane, and the interior surface of the optical fiber is correspondingly the interior surface of the inner pane.The interior surface of the inner pane is also the interior surface of the laminated pane. The outer pane has an exterior surface facing away from the thermoplastic interlayer and an interior surface facing the thermoplastic interlayer. The exterior surface of the outer pane is also the exterior surface of the laminated pane. The laminated pane can be flat or curved in one or more directions of the room.

[0022] For the purposes of the invention, "optical waveguide" refers to a light-conducting medium, preferably a glass pane or a plastic pane, which 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 light. The principle of light guidance using 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 thus designed such that the light from a light source can be coupled into the optical waveguide and propagate therein.

[0023] In a preferred embodiment of the invention, the entire barrier layer is opaque. In other words, the barrier layer is completely opaque and has no transparent or semi-transparent regions. This leads to even more cost-effective production of the glazing element according to the invention, since partially tinting the barrier layer to achieve opacity in certain regions would involve additional process steps or be more expensive to purchase.

[0024] In a further preferred embodiment of the glazing element, the thermoplastic intermediate layer comprises at least a first thermoplastic intermediate film and a second thermoplastic intermediate film. The functional element is arranged between the first thermoplastic intermediate film and the second thermoplastic intermediate film. The second thermoplastic intermediate film is preferably arranged between the functional element and the inner pane, and the first thermoplastic intermediate film is arranged between the outer pane and the functional element. In the laminated composite pane, the functional element is thus arranged within the thermoplastic intermediate layer, and the outer pane and the inner pane are firmly connected to one another via the thermoplastic intermediate layer.

[0025] Particularly preferably, the second thermoplastic intermediate film is arranged between the functional element and the inner pane, and the barrier layer is arranged between the functional element and the second thermoplastic intermediate film. The barrier layer thus prevents, at least in sections, plasticizers from the second thermoplastic intermediate film from penetrating the functional element.

[0026] Alternatively or in addition to the first thermoplastic intermediate film and the second thermoplastic intermediate film, a frame-shaped, circumferential thermoplastic intermediate film can be arranged around the functional element. The functional element preferably extends only over a central region of the composite pane. The composite pane therefore has an area free of the functional element, which extends circumferentially around the functional element. This arrangement prevents moisture from penetrating the functional element via the edge surface of the composite pane. However, such an arrangement also results in differences in thickness, which can be compensated for by the frame-shaped, circumferential thermoplastic intermediate film. The functional element and the frame-shaped, circumferential thermoplastic intermediate film together extend essentially over the entire surface of the composite pane.The frame-shaped thermoplastic intermediate film is part of the thermoplastic intermediate layer.

[0027] In a particularly preferred embodiment of the invention, the partial area of ​​the inner pane is arranged completely without overlap with the functional element. This means that, when viewed through the composite pane from the inner pane, the partial area of ​​the inner pane does not cover the functional element, and the light source therefore does not cover the functional element when viewed through the composite pane. This is particularly useful when the functional element is a PDLC functional element, which exhibits particularly high light scattering in certain optical states. Light that is misdirected from the light source onto the PDLC functional element would thus create irritating lighting effects for users.

[0028] The description that, for example, an element A completely overlaps or covers an element B means, within the meaning of the invention, that the orthonormal projection from element A to the surface plane of element B is arranged completely within element B. The description that, for example, an element A partially overlaps or covers an element B means, within the meaning of the invention, that the orthonormal projection from element A to the surface plane of element B is arranged partially but not completely within element B. In this context, elements can also mean regions of elements.

[0029] In a first preferred embodiment of the invention, the light source is arranged relative to the composite pane such that the visible light emitted by the light source can be coupled into the inner pane. In this embodiment, the inner pane is therefore the optical waveguide, which is intended to guide the visible light from the light source.

[0030] The light source can, for example, be mounted in a recess in the inner pane. This recess is preferably a hole, i.e., a feedthrough, extending between the outer and inner surfaces of the inner pane. Alternatively, however, the recess can also be a recess similar to a blind hole (a pocket-like recess) extending from the outer surface or the inner surface into the inner pane, but without reaching the opposite main surface, thus creating a feedthrough.

[0031] The recess can be created in the inner pane, for example, by mechanical drilling or laser processing. The recess is preferably round, but can basically have any desired shape, for example a polygonal shape. This refers to the base area of ​​the recess on the surface of the inner pane, via which the recess is introduced into the inner pane. The recess has the overall shape of a cylinder, preferably a vertical cylinder (extending from the interior surface of the inner pane to the exterior surface of the inner pane). The cylinder is preferably a circular cylinder (circular base area), but can also have any other base area, for example an elliptical base area (elliptical cylinder) or a polygonal base area (prism).

[0032] The recess, whether a feedthrough or a recess, is defined by a circumferential edge surface extending between the main surfaces of the inner pane. In the case of a feedthrough, this is the only boundary surface of the recess. In the case of a pocket-like recess, there is an additional boundary surface facing the main surface of the optical fiber to which the recess does not extend, and which, as it were, forms the bottom of the pocket hole.

[0033] The light source is arranged on the edge surface of the recess in the inner pane, preferably attached, in particular glued, or arranged in a mount attached to the recess. The visible light is then coupled into the inner pane via the inner edge surface and propagates through the inner pane under the effect of total internal reflection.

[0034] Alternatively, the light source can also be arranged on the interior surface of the inner pane and a coupling means can be arranged between the inner pane and the light source or on the exterior surface of the inner pane, which means refracts or reflects the incident light emitted by the light source in such a way that it can be coupled into the inner pane.

[0035] In a second embodiment of the invention, an optical waveguide is arranged between the outer pane and the inner pane, and the light source is arranged relative to the composite pane such that the visible light emitted by the light source can be coupled into the optical waveguide. The light source is preferably arranged on the interior-side surface of the inner pane. A coupling means is preferably arranged between the optical waveguide and the light source, preferably between the inner pane and the light source, or on the surface of the optical waveguide facing the outer pane. The coupling means refracts or reflects the light emitted by the light source and incident on the coupling means, so that it can be coupled into the optical waveguide. For the purposes of the invention, “visible light” means light with a wavelength of 400 nm to 800 nm.

[0036] The thickness of the outer pane is preferably from 0.5 mm to 10 mm, particularly preferably from 1 mm to 5 mm. The outer pane is preferably made of soda-lime glass. The thermoplastic intermediate layer 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 based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA) or polyurethane (PU). This means that all thermoplastic films are preferably based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA) or polyurethane (PU). In addition, the films or the entire intermediate layer can contain further components, for example plasticizers, stabilizers, UV or IR blockers.

[0037] The inner pane is preferably made of soda-lime glass, as is common for window panes. Alternatively, the inner pane can also be made of other types of glass, for example borosilicate glass, aluminosilicate glass or quartz glass. The inner pane can also be a plastic pane. If the inner pane is a plastic pane, it is preferably made of a clear, rigid plastic, particularly preferably polycarbonate (PC) or polymethyl methacrylate (PMMA). The thickness of the inner pane is preferably from 0.5 mm to 10 mm, particularly preferably from 1 mm to 5 mm. If the inner pane is the optical waveguide, it preferably has an iron oxide content of a maximum of 1%, particularly preferably a maximum of 0.1%. This low iron oxide content means that the inner pane is particularly suitable as an optical waveguide for visible light.If the inner pane of the fiber optic cable is clear, it is preferably clear and has no significant tints or colorings to ensure efficient light propagation. The outer pane can also be clear, tinted, or colored.

[0038] If the inner pane is not the optical waveguide, the optical waveguide is arranged between the inner pane and the outer pane and preferably has a thickness of 0.03 mm to 1.5 mm, particularly preferably 0.1 mm to 1 mm. Such an optical waveguide is preferably made of soda-lime glass or, alternatively, of other types of glass, for example borosilicate glass, aluminosilicate glass or quartz glass. The optical waveguide can also be a flexible optical waveguide film and function as a transparent layer, for example a PET film with a thickness of 30 μm to 200 μm. The optical waveguide made of mineral glass preferably has an iron oxide content of a maximum of 1%, particularly preferably a maximum of 0.1%. The optical waveguide is preferably clear and has no significant tints or colorations in order to make the light propagation efficient. The outer pane can also be clear or tinted or colored.

[0039] Regardless of whether the inner pane is the optical waveguide or the optical waveguide is arranged between the functional element and the inner pane, the optical waveguide preferably has a light transmittance of at least 70%, particularly preferably at least 80%, most preferably at least 90% (according to ISO 9050:2003).

[0040] In a further preferred embodiment of the invention, a coupling means, preferably a microprism film, is arranged between the light source and the barrier layer. The coupling means is preferably arranged on the optical waveguide of the composite pane. The optical waveguide can be the inner pane of the composite pane or can be arranged as an additional element between the functional element and the inner pane. Irrespective of this, the optical waveguide has an outer surface facing the functional element and an inner surface facing away from the functional element. The optical waveguide is preferably the inner pane of the composite pane. The coupling element is arranged such that light emitted by the light source strikes the coupling element and is then coupled into the optical waveguide by reflection or light refraction at the coupling element.The light from the light source can transmit through other elements of the composite pane before hitting the coupling element. For example, the light from the light source can first transmit through the inner pane before hitting the coupling element. Even after the light has hit the coupling element and been refracted or reflected there, it can transmit through other elements of the composite pane before being coupled into the optical fiber. The coupling element is positioned congruently with the opaque area of ​​the barrier layer when viewed through the composite pane.

[0041] In a first particularly preferred embodiment, the coupling means is a reflective structure. The reflective structure is preferably formed in the outer surface of the optical waveguide or applied to the outer surface of the optical waveguide. The reflective structure has a plurality of inclined sections with a reflective surface and is configured such that the light radiated into the optical waveguide and passed through the optical waveguide is reflected by the reflective surface of the inclined sections and at least partially recoupled into the optical waveguide. The light from the light source is at least partially reflected by the reflective surface of the inclined sections at a coupling angle into the optical waveguide and coupled into it.The light from the light source preferably enters the optical fiber via the interior surface and then encounters the reflective structure, allowing it to be coupled into the optical fiber. Before the light hits the interior surface of the optical fiber, it may have previously passed through other elements of the optical fiber (i.e., transmitted through them). More specifically:

[0042] - In the case where the reflective structure is formed on the outer surface: the light from the light source hits the inner surface of the optical fiber, then transmits through the optical fiber, hits the outer surface of the optical fiber, and is reflected by the reflective structure. The reflective structure is therefore a portion of the outer surface of the optical fiber, and the light is reflected by this portion.

[0043] - Alternatively, in the case where the reflective structure is applied to the outer surface of the optical waveguide: the light from the light source hits the inner surface of the optical waveguide, then transmits through the optical waveguide, exits the optical waveguide again via the outer surface, and is reflected by the reflective structure. Preferably, the light exiting the optical waveguide passes through the reflective structure and is reflected by its surface facing away from the optical waveguide, which forms the reflective surface of the inclined sections. For the purposes of the invention, "inclined sections" means that the reflective structure has one or more regions that are inclined with respect to the surface of the optical waveguide facing away from the functional element.

[0044] The reflective structure is preferably provided with a reflective coating, which is responsible for the reflective properties of the reflective structure. The reflective coating is preferably arranged, preferably applied, on the surface of the reflective structure facing away from the optical waveguide. The reflective coating comprises at least one reflective layer based on a metal or a metal alloy. This increases the reflectivity of the reflective coating.

[0045] 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 optical waveguide. The microprism film is transparent except for the reflective surface. After entering the optical waveguide, the light from the light source exits the optical waveguide 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 optical waveguide via the outer surface.

[0046] A microprism film is a flexible, particularly foil-like, polymeric film that has a smooth surface facing the optical waveguide and, in particular, is arranged on this surface, and a structured surface facing away from the optical waveguide. The structured surface is in the form of a planar arrangement of a plurality of prisms with dimensions in the micrometer range, wherein the prism surfaces form the inclined sections of the reflective structure. The structured surface of the microprism film is preferably coated with a reflective coating. The microprisms act, in particular, as reflective prisms and reflect the light striking them in a direction that depends on the angle of inclination of the prism surfaces and the angle of incidence of the light. Microprism films are commercially available and can be purchased or used in the production of the glazing element according to the invention.The composite pane according to the invention is specifically manufactured. The edge length of the individual microprisms is preferably from 10 pm to 250 pm, particularly preferably from 20 pm to 100 pm, for example approximately 30 pm.

[0047] The microprism film can be multilayered. Commonly used microprism films include a substrate layer, for example, based on polyethylene terephthalate (PET), on which the microprisms are formed from a UV-curing polyacrylate.

[0048] The microprism film is transparent except for its reflective surface and preferably has a light transmittance of at least 70%, more preferably at least 80%, and most preferably at least 90%, relative to the light from the light source. It is advantageous if the difference between the refractive indices of the optical waveguide and the microprism film is as small as possible in order to reduce reflection losses at the interface between the optical waveguide and the microprism film. Preferably, the said difference in refractive indices is at most 0.02 (relative to a wavelength of 550 nm), more preferably at most 0.01. If the optical waveguide and the microprism film differ in their refractive index, the microprism film preferably has a higher refractive index than the optical waveguide, which is advantageous for high-yield light coupling.

[0049] 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.

[0050] Instead of a flexible microprism film, a rigid microprism plate can also be used, i.e. a rigid plastic plate with a flat arrangement of microprisms.

[0051] The reflective structure can also be formed directly into the outer surface of the optical fiber. For this purpose, a portion of the outer surface is designed as a reflective surface. This is particularly easy to implement when the optical fiber is a polymer layer, such as a plastic disc or plate. The light from the light source is reflected directly off the outer surface and returned to the optical fiber without exiting the fiber.

[0052] The reflective surface of the reflective structure has sections that are inclined relative to the interior-side surface of the optical waveguide. This means that the sections are not arranged parallel to the interior-side surface, but at an angle greater than 0° to the interior-side surface. Said sections have an angle to the interior-side surface that lies 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 parallel, but rather arranged at an angle between 0° and 180° to one another.The aforementioned sections of the reflective structure are preferably essentially planar. The inclination of the sections of the reflective structure relative to the interior surface of the optical fiber determines the angle at which the reflected light is reflected back into the optical fiber.

[0053] In a second particularly preferred embodiment, the coupling element is arranged, preferably applied, on the interior-side surface of the optical waveguide, preferably the inner pane. 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 optical waveguide, preferably by refraction. The coupling means is thus a light-refracting structure. The light source is preferably connected to the inner pane 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.

[0054] In a particularly preferred embodiment of the invention, the optical waveguide of the composite pane comprises at least one outcoupling element, regardless of whether the optical waveguide is the inner pane of the composite pane or a light-conducting element arranged between the functional element and the inner pane. For the purposes of the invention, "outcoupling element" refers to an element suitable for coupling the light out of the optical waveguide. Preferably, at least one first outcoupling element is arranged on the interior surface or the exterior surface of the optical waveguide.

[0055] The optical waveguide can have multiple outcoupling elements in different regions. Preferably, the optical waveguide has at least one further outcoupling element, particularly preferably at least two further outcoupling elements, in particular at least three further outcoupling elements, on its interior surface or its exterior surface. Thus, coupled-in light is coupled out of the optical waveguide via the interior surface or the exterior surface of the optical waveguide at the outcoupling element.

[0056] It is understood that the outcoupling element extends only over a portion of the optical waveguide, i.e., not over the entire surface, since otherwise, coupling and propagation of the light by means of total internal reflection would not be possible. The at least one outcoupling element of the optical waveguide on the outer surface or the inner surface of the optical waveguide can be incorporated into the surface of the optical waveguide, for example, by roughening. Alternatively, the at least one outcoupling element of the optical waveguide can also be printed onto the outer surface or the inner surface.Alternatively, the at least one outcoupling element of the optical waveguide can also be applied, preferably printed, to a surface of the thermoplastic intermediate layer facing the optical waveguide, wherein the at least one outcoupling element is arranged in direct spatial contact with the outer surface of the optical waveguide or with the inner surface (if the optical waveguide is arranged between the functional element and the inner pane). When the light propagating in the optical waveguide strikes the outcoupling element, it is scattered, preventing total internal reflection and thus the scattered light is outcoupled and leaves the composite pane.

[0057] The decoupling elements appear as a luminous surface of the composite 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] The at least one coupling element can be provided, for example, as a foil that is glued to the optical fiber. The other coupling elements can also be provided as foils.

[0059] Preferably, the at least one output coupling element is formed as an imprint on the optical waveguide. If the optical waveguide is a glass pane, for example, the inner pane, then the imprint on this is preferably formed as a light-scattering enamel. This enamel can be applied, for example, using a screen printing process. It preferably contains glass frits, which are fired into the surface of the glass layer, creating a roughened and therefore light-scattering surface. If the optical waveguide is predominantly made of a polymeric material, this is preferably achieved by printing the optical waveguide with a light-scattering, transparent printing paste.If the at least one coupling-out element is designed as a print on a surface of the thermoplastic intermediate layer facing the optical waveguide - wherein the at least one coupling-out element is additionally arranged in direct spatial contact with the outer surface of the optical waveguide or with the inner surface of the optical waveguide - then this is preferably realized by printing the thermoplastic intermediate layer with a light-scattering, transparent printing paste.

[0060] In an advantageous embodiment, the coupling-out element is transparent, so that it does not significantly restrict the view through the laminated 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 blocking the view through the laminated pane, but allowing it to appear in one or more color shades. The printing paste, if it is opaque, semi-transparent, or color-tinting, preferably contains dyes or color pigments.

[0061] Outcoupling elements arranged on the optical waveguide, which is designed as a glass or plastic disc, can also be formed by roughening the relevant surface of the optical waveguide. This roughening can be done mechanically (e.g., by grinding techniques) or by laser processing. Laser processing, particularly in the case of a composite disc, has the advantage that the outcoupling element can also be incorporated into the finished laminated composite disc, even if it is to be located inside the composite disc, since the laser radiation can also be focused onto a plane inside the composite disc. Laser processing also makes it possible to form the at least first outcoupling element not on a surface, but inside the optical waveguide.

[0062] The light coupled into the optical waveguide propagates in the optical waveguide until it either hits the side edge surface of the optical waveguide and is coupled out there or hits the at least one coupling-out element on one of the two surfaces of the optical waveguide, which interrupts the total reflection by light scattering, whereby the light is coupled out of the optical waveguide via the surface in question.

[0063] In a preferred embodiment, the functional element comprises in the specified order at least

[0064] • a first carrier film,

[0065] • the first surface electrode,

[0066] • the active layer, the second surface electrode and a second carrier foil.

[0067] The surface electrodes are preferably applied to the respective adjacent carrier foil. With such a design of the functional element, the surface electrodes and the active layer are arranged between the carrier foils. The carrier foils thus form the surfaces of the functional element and provide a liquid or soft active layer with the necessary mechanical stability. The functional element can thus be provided as a laminated foil that can be advantageously processed. The functional element is advantageously protected from damage, in particular corrosion, by the carrier foils. The functional element is particularly preferably a PDLC functional element. The functional element is designed in a foil-like manner. The active layer has controllable optical properties, which can be controlled via the voltage applied to the surface electrodes.

[0068] Preferably, the first surface electrode is electrically connected to at least one first bus bar, and the second surface electrode is electrically connected to at least one second bus bar. The first bus bar and the second bus bar, as well as any additional bus bars that may be present, are intended to be electrically connected to an external voltage source in a manner known per se. The electrical contact is implemented using suitable connecting cables, for example, foil conductors.

[0069] The surface electrodes are preferably configured as transparent, electrically conductive layers. The surface electrodes preferably contain at least one metal, a metal alloy, or a transparent conducting oxide (TCO). The surface electrodes can contain, for example, silver, gold, copper, nickel, chromium, tungsten, indium tin oxide (ITO), gallium-doped or aluminum-doped zinc oxide, and / or fluorine-doped or antimony-doped tin oxide. The surface electrodes preferably have a thickness of 10 nm to 2 pm, more preferably of 20 nm to 1 pm, and most preferably of 30 nm to 500 nm.

[0070] In addition to the active layer, the carrier films, and the surface electrodes, the functional element can have other known layers, for example barrier layers, blocking layers, anti-reflective layers, protective layers, and / or smoothing layers. The carrier films preferably contain at least one thermoplastic polymer, particularly preferably low-plasticizer or plasticizer-free polyethylene terephthalate (PET). This is particularly advantageous with regard to the stability of the functional element. However, the carrier films can also contain or consist of other low-plasticizer or plasticizer-free polymers, for example, ethylene-vinyl acetate (EVA), polypropylene, polycarbonate, polymethyl methacrylate, polyacrylate, polyvinyl chloride, polyacetate resin, casting resins, acrylates, fluorinated ethylene-propylene, polyvinyl fluoride, and / or ethylene-tetrafluoroethylene. The thickness of each carrier film is preferably from 0.02 mm to 1 mm, particularly preferably from 0.04 mm to 0.2 mm.Carrier films provide particularly effective protection against the diffusion of plasticizers into the active layer.

[0071] In a particularly advantageous embodiment of the invention, the thermoplastic intermediate layer contains at least 3 wt.%, preferably at least 5 wt.%, particularly preferably at least 20 wt.%, even more preferably at least 30 wt.%, and especially at least 40 wt.% of a plasticizer. The plasticizer preferably contains or consists of triethylene glycol bis(2-ethylhexanoate).

[0072] Plasticizers are chemicals that make plastics softer, more flexible, more supple and / or more elastic. They shift the thermoelastic range of plastics towards lower temperatures so that the plastics have the desired more elastic properties near the application temperature. Other preferred plasticizers are carboxylic acid esters, particularly low-volatility carboxylic acid esters, fats, oils, plastic resins and camphor. Other plasticizers are preferably aliphatic diesters of tri- or tetraethylene glycol. Particular preference is given to using plasticizers 3G7, 3G8 or 4G7, where the first digit indicates the number of ethylene glycol units and the last digit indicates the number of carbon atoms in the carboxylic acid moiety of the compound. For example, 3G8 stands for triethylene glycol bis(2-ethylhexanoate), i.e. a compound of the formula C4H9CH(CH2CH3)CO(OCH2CH2)3O2CCH(CH2CH3)C4H9.

[0073] The functional element is preferably a PDLC (polymer dispersed liquid crystal) functional element. The active layer of a PDLC functional element contains liquid crystals embedded in a polymer matrix. If no voltage is applied to the surface electrodes, the liquid crystals are aligned in a disordered manner, which leads to strong scattering of the light passing through the active layer. If a voltage is applied to the surface electrodes, the liquid crystals in the second region of the active layer and optionally further regions of the active layer align in a common direction, and the transmission of light through the active layer is increased. Alternatively, functional elements, and in particular PDLC functional elements, can be used that are transparent when no voltage is applied (zero volts) and strongly scatter when a voltage is applied.

[0074] In principle, however, it is also possible to use other types of controllable functional elements, for example, electrochromic functional elements or SPD (suspended particle device) functional elements. The controllable functional elements mentioned and their mode of operation are known per se to those skilled in the art, so a detailed description is unnecessary here. A PDLC functional element is particularly preferred, since, especially with PDLC elements, effective protection against plasticizers must be ensured to avoid impairing the optical quality of the functional element.

[0075] Functional elements are commercially available. The functional element is typically cut from a larger, multilayer film in the desired shape and size. This can be done mechanically, for example, with a knife. In an advantageous embodiment, the cutting is done using a laser. It has been shown that the side surface is more stable in this case than with mechanical cutting. With mechanically cut side surfaces, there is a risk of the material shrinking, which is visually noticeable and adversely affects the aesthetics of the pane.

[0076] For the purposes of the invention, electrically controllable optical properties are understood to mean properties that are continuously controllable, but equally also those that can be switched between two or more discrete states.

[0077] The electrical control of the functional element or the light source, which are installed in a vehicle as part of the glazing element according to the invention, is carried out, for example, by means of switches, rotary or slide controls integrated into the vehicle's instruments. However, a button for controlling the functional element can also be integrated into the laminated pane, for example a capacitive button. Alternatively or additionally, the functional element can be controlled by contactless methods, for example by recognizing gestures, or depending on the condition of the pupil or eyelid determined by a camera and suitable evaluation electronics. Alternatively or additionally, the functional element or the light source can be controlled by sensors that detect light incidence on the pane.

[0078] In a preferred embodiment of the invention, the functional element is divided into several segments that can be electrically controlled independently of one another. For example, it is possible to switch one or more segments to be translucent, i.e., light-scattering, while at least one further segment is switched to be transparent, i.e., non-light-scattering. The functional element preferably has at least two segments, particularly preferably at least three, in particular at least four segments. The segments can be produced, for example, by insulation lines on the surface electrodes. Preferably, the first surface electrode is divided by insulation lines into several smaller surface electrodes. In order to further improve the optical quality of the functional element, in addition to the first surface electrode, the active layer can also be divided by insulation lines into individual layer elements.The insulation lines with which the active layer and / or the surface electrodes are divided can be introduced, for example, using laser radiation.

[0079] In an advantageous embodiment of the invention, the first carrier film and the first surface electrode arranged on the first carrier film, preferably applied, have at least some sections of an overhang relative to the active layer of the functional element. Particularly preferably, the second carrier film and the second surface electrode arranged on the second carrier film, preferably applied, also have at least some sections of an overhang relative to the active layer. In particular, the overhang of the second surface electrode is arranged on an edge of the functional element opposite the overhang of the first electrode. These overhangs of the surface electrodes enable simplified electrical contacting of the functional element.

[0080] Preferably, at least one first bus bar is applied by soldering or gluing to the protruding region of the first surface electrode, and at least one second bus bar is applied by soldering or gluing to the protruding region of the second surface electrode. The bus bars applied in this way are preferably in the form of a wire or strip of an electrically conductive foil. The bus bars then contain, for example, at least aluminum, copper, tin-plated copper, gold, silver, zinc, tungsten, and / or tin, or alloys thereof. The strip preferably has a thickness of 10 μm to 500 μm, particularly preferably of 30 μm to 300 μm. Bus bars made of electrically conductive foils with these thicknesses are technically simple to produce and have advantageous current-carrying capacity.The strip can be electrically connected to the electrically conductive structure, for example, via a solder compound, via an electrically conductive adhesive or by direct application.

[0081] Alternatively, the first bus bar and / or the second bus bar and / or the further bus bars that may be present are designed as a printed and fired-in conductive structure. The printed bus bars preferably contain at least one metal, a metal alloy, a metal compound and / or carbon, particularly preferably a noble metal and in particular silver. The printing paste preferably contains metallic particles, metal particles and / or carbon and in particular noble metal particles such as silver particles. The electrical conductivity is preferably achieved by the electrically conductive particles. The particles can be located in an organic and / or inorganic matrix such as pastes or inks, preferably as a printing paste with glass frits. This design can be manufactured quickly and easily, with silver-containing materials being characterized by high electrical conductivity and relatively long-term stability.

[0082] The layer thickness of the printed bus bars is preferably from 5 pm to 40 pm, particularly preferably from 8 pm to 20 pm, and most particularly preferably from 8 pm to 12 pm. Printed bus bars with these thicknesses are technically simple to implement and exhibit advantageous current-carrying capacity.

[0083] The first bus bar, the second bus bar and / or any additional bus bars that may be present are preferably applied to a surface of the respective surface electrode that faces the active layer of the functional element. This arrangement is simpler because the surface electrodes are arranged between the active layer and a carrier film and are therefore difficult to connect to a bus bar via the surface of the surface electrode that faces away from the active layer. In principle, however, the first bus bar, the second bus bar and / or any additional bus bars that may be present can also be applied to the surface of the respective surface electrode that faces away from the active layer. For this purpose, a carrier film that may be present can, for example, have a recess via which the bus bar and surface electrode can be connected to one another.

[0084] 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.

[0085] In a particularly preferred embodiment of the invention, the second carrier film has at least some sections of an overhang relative to the active layer, and the barrier layer is arranged such that it is in direct spatial contact with the overhang of the second carrier film. The second carrier film is preferably arranged closer to the inner pane than the first carrier film, and the barrier layer is arranged between the functional element and the inner pane. The second surface electrode is preferably also arranged, particularly preferably applied, on the overhang of the second carrier film. Most preferably, the barrier layer is arranged only in the edge region of the functional element in which the second carrier film has an overhang relative to the active layer.The arrangement of the barrier layer on the functional element prevents the barrier layer from coming into direct spatial contact with the active layer, which could lead to an undesirable chemical reaction, but also prevents the diffusion of plasticizers from the intermediate layer, which is also partially arranged between the inner pane and the functional element. According to the invention, the overhang of the carrier film to the active layer also belongs to the edge region of the functional element.

[0086] In a further preferred embodiment, the composite pane comprises additional barrier layers in addition to the barrier layer. The barrier layer and the additional barrier layers are arranged together to form the functional element in such a way that the active layer is largely protected from plasticizers from the intermediate layer. In particular, the entire peripheral edge surface of the active layer is sealed by the barrier layer and / or the additional barrier layers.

[0087] "Sealed" in the context of this invention means that the corresponding section of a surface is completely covered with the barrier layer as a protective layer, making it more resistant and durable, particularly against the diffusion of harmful substances such as moisture, but also particularly against plasticizers from the environment that could otherwise penetrate the interior of the active layer. In another preferred embodiment, the barrier layer is in direct and immediate contact with the active layer. For example, there is no separate adhesive or other intermediate layer between the barrier layer and the active layer of the functional element.

[0088] The barrier layer and any additional barrier layers present are preferably designed such that they prevent the diffusion of plasticizer through the respective barrier layer to the same or greater extent as the diffusion of plasticizer through the surface electrodes.

[0089] In an advantageous embodiment of the invention, the barrier layer is designed in such a way that it prevents the diffusion of plasticizers from the thermoplastic intermediate layer through the barrier layer.

[0090] The barrier layer is preferably single-layered or multi-layered, for example, two-layered, three-layered, four-layered, or five-layered. The individual layers of the barrier layer are also referred to below as individual layers and can be made of the same or different materials.

[0091] The barrier layer can be completely opaque or partially opaque and partially transparent or semi-transparent. The opaque portion of the barrier layer can be achieved, for example, by coloring or tinting the desired area.

[0092] The barrier layer and any additional barrier layers present preferably contain or consist of polyethylene terephthalate (PET) or polyvinyl fluoride. Alternatively, the barrier layer and any additional barrier layers present are based on polyethylene terephthalate (PET) or polyvinyl fluoride. These materials are particularly well suited for reducing plasticizer diffusion and can also be easily embedded into the composite pane.

[0093] In an advantageous embodiment, one or more adhesion-enhancing layers can be arranged between the functional element and the barrier layer, as well as any additional barrier layers that may be present. In particular, the peripheral edge surface of the active layer of the functional element is subjected to an adhesion-enhancing surface treatment. In an advantageous embodiment, the additional barrier layer, consisting of one or more individual layers, has a thickness (also called material thickness) of 10 nm to 50 pm (nanometers), preferably of 15 nm to 25 pm, and particularly preferably of 15 nm to 5 pm.

[0094] The barrier layer, consisting of one or more individual layers, preferably has a thickness of 0.02 mm to 0.2 mm, preferably 0.04 mm to 0.15 mm. The specified thickness refers to the total layer thickness of all individual layers present, if any. At such a layer thickness, visible light is completely blocked in the opaque region of the barrier layer, so that it cannot transmit through the opaque region of the barrier layer.

[0095] Other types of barrier layers, also called barrier films, are generally known to those skilled in the art. These can be designed, for example, as disclosed in WO2018188844A1 or WO2019077014A1.

[0096] In a preferred embodiment of the invention, the barrier layer is arranged, preferably applied, at least partially on a circumferential edge surface of the functional element. If the functional element has an active layer, the “edge surface of the functional element” essentially refers to the edge surface of the active layer. The circumferential edge surface of the active layer is the surface arranged between the main surface of the active layer facing the outer pane and the main surface of the active layer facing the inner pane. The circumferential edge surface thus connects the two main surfaces of the active layer to one another. The active layer preferably has no further surfaces apart from the two main surfaces and the circumferential edge surface.

[0097] The glazing element is provided with a light source which is suitable for coupling light into the laminated pane. During operation, the light source emits visible light, i.e. electromagnetic radiation in the visible spectral range, in particular in the range from 400 nm to 800 nm. The light source can have one or more emission bands which are arranged in the visible spectral range and cover or cover part of it. However, the light source can also have a broad emission band which 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. The glazing element can have a single light source or several separate light sources whose light is emitted into the laminated pane or panes at different points.more specifically the optical fiber.

[0098] The light source preferably comprises at least one light-emitting diode (LED). The light source can be a single light-emitting diode, but is preferably an array of multiple light-emitting diodes. Said array is preferably installed in a common housing, for example, as a linear array in which the light-emitting diodes are arranged along a 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).

[0099] Optionally, a collimator can be arranged between the light source and the composite pane, wherein the collimator is located in the beam path of the light source. The collimator is preferably arranged between the light source and the interior-side surface of the optical waveguide, in particular between the light source and the interior-side surface of the inner pane, so that the light is radiated into the composite pane or into the optical waveguide 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, or at least a less divergent, i.e. more concentrated beam path. The beam cone of the light source is thus narrowed by the collimator. This has the advantage that the entire light beam is radiated into the composite pane at the same angle of incidence.Especially when the optical fiber is equipped with a reflective structure, such a substantially convergent angle of incidence allows a large proportion of the light to be coupled into the optical fiber via the reflective structure, resulting in total internal reflection. This optimizes the light yield.

[0100] 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 interior surface of the inner pane. If the light source is designed as an arrangement of several 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 arrangement. In the case of a linear LED arrangement, for example, a rod-like collimator can be used whose length corresponds at least to the length of the LED arrangement.

[0101] In a particularly preferred embodiment of the invention, the light source has a luminous intensity of at least 200 lm / m, preferably 240 lm / m, and in particular 280 lm / m. Most preferably, the light source comprises at least one light-emitting diode with a luminous intensity of at least 200 lm / m, preferably 240 lm / m, and in particular 280 lm / m. At such high luminous intensities, a larger proportion of the light is coupled into the composite pane. "Im / m" refers to "lumens per meter," i.e., the luminous intensity per meter.

[0102] The composite pane preferably has a masking region independent of the barrier layer, through which no vision is possible. This masking region is called the masking region of the composite pane and is preferably arranged circumferentially in an edge region of the composite pane and surrounds a central region of the composite pane intended for vision in a frame-like manner. This is particularly common for vehicle windows. The masking region is formed in particular by an element, for example by a masking print. The masking region is particularly preferably formed by a masking print on the interior-side surface of the outer pane. The masking region preferably completely covers the partial region of the inner pane.Such a masking print is typically formed by an enamel containing glass frits and a black pigment, which is screen-printed and then fired into the surface. Despite their essentially masking effect, such masking prints do not completely block the light emitted by the light source, so that light not coupled into the laminated pane is, depending on the arrangement of the light source in relation to the masking area, visually perceptible even when viewed from above on the outside surface of the outer pane. In other words, the light from the light source is at least partially visually perceptible from the outside environment in glazing elements of this type because the masking print does not completely block the light. The masking print preferably has an optical density of at most 3.5, preferably at most 3.0.

[0103] In a preferred embodiment of the invention, the interior-facing surface of the outer pane is provided with an IR-reflecting coating. The IR-reflecting coating contains, for example, an electrically conductive metal, preferably silver. In particular, the IR-reflecting coating comprises at least two, preferably at least three, silver layers, wherein the silver layers are arranged in a stacked sequence and at least one dielectric layer is arranged between the silver layers. Particularly preferably, the IR-reflecting coating extends over the entire interior-facing surface of the outer pane with the exception of a frame-shaped edge region of the outer pane. The coating-free edge region of the outer pane prevents the IR-reflecting coating from being corroded by moisture penetrating via the edge region.

[0104] In particular, the frame-shaped edge region of the outer pane is stripped of its coating by means of a decomposing layer. If the decomposing layer comes into contact with the IR-reflecting coating, a chemical reaction occurs as a result of which the IR-reflecting layer is decomposed, i.e. the region is stripped of its coating, and the reaction product of the two layers forms a masking print in the stripped region. However, it is particularly important here that this type of masking print cannot completely block the light from the light source. The masking print formed by the decomposing layer and the IR-reflecting coating is particularly preferably arranged in overlap with the partial region of the inner pane. A masking print formed in this way preferably has an optical density of at most 3.5, preferably at most 3.0.

[0105] The decomposing layer preferably contains zirconium oxide-based particles. Zirconium oxide-based particles contain at least 80 wt.%, in particular at least 85 wt.% zirconium oxide (ZrO2). The zirconium oxide is preferably stabilized, in particular by means of yttrium. It may also contain additives, in particular selected from AlO3, TiO2, ZnO, SiO2, and mixtures thereof. Particularly preferably, the zirconium oxide-based particles have a chemical composition that includes, in particular, the following components in the following weight ranges:

[0106] - ZrO2: 83-97%

[0107] - Y2O3: 2-8%

[0108] - Al2O3: 0-3%

[0109] - black pigments: 0-6%, especially 1-6%.

[0110] The various embodiments of the invention can be implemented individually or in any combination.

[0111] The glazing element according to the invention can be produced by means of the following process: (A) providing an outer pane, an inner pane, a thermoplastic intermediate layer, a functional element with controllable optical properties and a barrier layer for reducing plasticizer diffusion with at least one opaque region,

[0112] (B) Arranging the thermoplastic intermediate layer between the outer pane and the inner pane, wherein the functional element is arranged within the intermediate layer,

[0113] (C) arranging the barrier layer such that the opaque region of the barrier layer extends at least over a partial region of the inner pane and the barrier layer is in direct spatial contact with the functional element at least in an edge region of the functional element,

[0114] (D) Lamination of the outer pane, the inner pane, the functional element, the barrier layer and the intermediate layer to form a composite pane and

[0115] (E) arranging the composite pane and a light source intended to couple visible light into the composite pane to form a glazing element, wherein the light source is arranged in the partial region of the inner pane which is at least partially free of overlap with the functional element.

[0116] The composite pane 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.

[0117] The composite pane of the glazing element according to the invention can be used as a window pane of a vehicle. A particularly preferred use is a vehicle roof pane, which can be illuminated three-dimensionally. The vehicle can in principle be any land vehicle, watercraft, or aircraft, and is preferably a passenger car, truck, or rail vehicle. The glazing element can also be used in buildings; for example, the composite pane can be used as a window pane, glass facade, or glass door in an exterior or interior area, 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 devices, as a component of furnishings, or as a furnishing. The invention is explained in more detail below with reference to drawn 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.

[0118] They show:

[0119] Fig. 1 is a plan view of a composite pane of the glazing element according to the invention,

[0120] Fig. 2 is a cross-sectional view of the glazing element from Fig.,

[0121] Fig. 3 an enlarged section of an edge area of ​​the glazing element in the cross-sectional view from Fig. 2 and

[0122] Fig. 4-5 further embodiments of the glazing element according to the invention in cross-sectional view.

[0123] Figures 1 to 3 each show different aspects of a first embodiment of the glazing element 101 according to the invention. Figure 2 shows a cross-sectional view of the glazing element 101 shown in plan view from Figure 1. The section line for the cross section is indicated in Figure 1 by a dashed line XX'. Figure 3 shows an enlarged section Z of an edge region of the glazing element 101. The section Z is indicated in Figure 2 by a circular dashed line.

[0124] The composite pane 100 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 composite pane 100 is structurally formed from an outer pane 1, an inner pane 2, which also serves as an optical fiber, and a thermoplastic intermediate layer 3, via which the outer pane 1 and the inner pane 2 are connected to one another. The outer pane 1 and the inner pane 2 are made, for example, of soda-lime glass and each have a thickness of, for example, 2.1 mm. A functional element 4, for example a PDLC functional element, is arranged within the thermoplastic intermediate layer 3. The functional element 4 is divided into a total of four segments 4'.

[0125] The intermediate layer 3 has a first thermoplastic intermediate film 3.1, which is arranged between the outer pane 1 and the functional element 4. The intermediate layer 3 also has a second thermoplastic intermediate film 3.2, which is arranged between the inner pane 2 and the functional element 4. The functional element 4 extends over the entire surface of the composite pane 100 with the exception of an edge region of the composite pane 100 that surrounds the functional element 4 in a frame-like manner. In this region of the composite pane 100 that surrounds the functional element 4 in a frame-like manner, a third thermoplastic intermediate film 3.3 is arranged, which represents a type of "picture frame" for the functional element 4. The third thermoplastic intermediate film 3.3 has approximately the same thickness as the functional element 4, so that there are largely no local thickness differences within the composite pane 100. The third thermoplastic intermediate film 3.3 is arranged between the first thermoplastic intermediate film 3.1 and the second thermoplastic intermediate film 3.2. The total thickness of the thermoplastic intermediate layer 3 is, for example, 0.76 mm. In this case, the total thickness refers to the combined visible thickness of all layer thicknesses of the thermoplastic intermediate films 3.1, 3.2, 3.3. The inner pane 2 and the intermediate layer 3 are clear and transparent; the outer pane 1 is, for example, tinted to reduce the light transmission of the composite pane 100 (for example, to less than 15%), as is common with vehicle roof windows.

[0126] The outer pane 1 faces the outside environment of the vehicle in the installed position. It has an outside surface I that faces the outside environment and an inside surface II that faces the vehicle interior. The inner pane 2, which also represents the optical fiber, faces the vehicle interior in the installed position. It has an outside surface III that faces the outside environment and an inside surface IV that faces the vehicle interior. The inside surface II of the outer pane 1 and the outside surface III of the inner pane 2 are connected to one another via the thermoplastic intermediate layer 3. The functional element 4 has an outside surface V that faces the outer pane 1 and an inside surface VI that faces the inner pane 2.

[0127] The composite pane 100 has a frame-shaped, surrounding masking area in which a black masking print 15 is applied to the interior-facing surface II of the outer pane 1, preventing visibility through the composite pane 1. The masking print 15 is produced, for example, by the chemical conversion of a decomposing layer and an IR-reflecting layer on the interior-facing surface II of the outer pane 1. The IR-reflecting layer (not shown here) is applied, for example, to the entire interior-facing surface II of the outer pane 1 and subsequently treated with a decomposing layer in a frame-shaped, surrounding edge area of ​​the composite pane 100, which is intended to be the masking area. In this process, the masking print 15 is created in the edge area, and the IR-reflecting properties are lost.The IR-reflecting layer, for example, comprises three silver layers and the decomposing layer comprises, for example, zirconium oxide-based particles.

[0128] The glazing element 101 comprises a light source 5, which is arranged in a partial area B of the inner pane 2 on the interior-side surface IV of the inner pane 2. A coupling means 13 is arranged on the exterior surface III of the inner pane 2 in partial area B. This coupling means 13 is thus arranged in overlap with the light source 5 when viewed through the composite pane 100, so that visible light 7 emitted by the light source 5 orthogonally to the interior-side surface IV of the inner pane 2 impinges on the coupling means 13. The coupling means 13 is, for example, a reflective structure in the form of a silver-coated microprism film, which is applied to the inner pane 2 using an optically clear adhesive (not shown here). The partial area B of the inner pane 2 is located in the circumferential edge area of ​​the composite pane 100 and, when viewed through the composite pane 100, does not overlap with the functional element 4.

[0129] The inner pane 2 is designed as a light-conducting medium such that light can be coupled into the inner pane 2 and propagate within the inner pane 2 utilizing the effect of total internal reflection (see dashed arrows in Figure 2). The light 7 from the light source 5 first enters the inner pane 2 through the interior-side surface IV and then transmits through the inner pane 2. The light 7 then exits the inner pane 2 via the exterior surface III and transmits through the optically clear adhesive arranged between the coupling means 13 and the inner pane 2. The light 7 then strikes the coupling means 13 and is reflected back toward the inner pane 2 by the reflective silver coating at a coupling angle.The reflection at a suitable coupling angle, i.e. an angle at which visible light 7 is coupled into the inner pane 2, can be generated by the surfaces of the microprism film inclined to the outer surface III of the inner pane 2. The light 7, after being transmitted through the optically clear adhesive, strikes the inner pane 2 and is coupled into the inner pane 2. The light 7 spreads out in the inner pane 2 until it reaches a side edge of the inner pane 2 or an outcoupling element 14. At the side edge or the outcoupling element 14, the light 7 is coupled out of the inner pane 2. The composite pane 100 comprises an outcoupling element 14 on the surface of the second thermoplastic intermediate film 3.2 facing the inner pane 2. The outcoupling element 14 is, for example, a print on the second thermoplastic intermediate film 3.2.The coupling element 14 is in direct spatial contact with the outer surface III of the inner pane 2.

[0130] The functional element 4 comprises, in this order, a first carrier film 10.1, a first surface electrode 11.1, an active layer 12, a second surface electrode 11.2 and a second carrier film 10.2. The surface of the first carrier film 10.1 facing the outer pane 1 is also the exposed outer surface V of the functional element 4. The surface of the second carrier film 10.2 facing the inner pane 2 is also the exposed interior surface VI of the functional element 4. The “exposed surface” means that surface of the functional element 4 which is in direct contact with the thermoplastic intermediate layer 3. The carrier films 10.1, 10.2 are, for example, transparent films based on PET. The surface electrodes 11.1, 11.2 are formed, for example, on the basis of a transparent conductive oxide, preferably indium tin oxide (ITO), and are applied by means of magnetron sputtering to the carrier foil 10.1, 10.2. The active layer 12 is, for example, the liquid crystal layer of a generic PDLC functional element.

[0131] The surface electrodes 11.1, 11.2 each extend over the entire surface of the carrier foil 10.1, 10.2 to which they are applied. The carrier foils 10.1, 10.2 extend over the entire surface of the active layer 12 and additionally by a projection C beyond it. The projection C of the carrier foils 10.1, 10.2 is only present in a section of the circumferential edge surface K of the functional element 4. The projection C of the first carrier foil 10.1 is arranged on an opposite section, the circumferential edge surface K, to the projection of the second carrier foil 10.2 (not shown here). Collecting conductors (not shown here) can be applied to these projections C, which supply the surface electrodes 11.1, 11.2 with voltage, whereby the optical states of the active layer 12 can be adjusted.For this purpose, the bus bars are connected to a voltage source, for example via flat conductors leading out of the composite disc 100 (not shown here).

[0132] Barrier layers 6, 6' are arranged around the edge surface K of the functional element 4, which in particular prevent moisture or plasticizer from the thermoplastic intermediate layer 3 from penetrating the active layer 12. A partially opaque barrier layer 6 is arranged on a section of the peripheral edge region R of the functional element 4. The barrier layer 6 is arranged in the edge region R on the second carrier film 10.2. The barrier layer 6 is also arranged in sections on the projection C of the second carrier film 10.2, which is also encompassed by the peripheral edge region R of the functional element 4. Apart from the section of the edge region R of the functional element 4, the barrier layer 6 also extends over the entire partial region B of the inner pane 2. The barrier layer 6 is preferably completely opaque. In this case, opaque means a light transmittance of less than 5%.The opaque region 8 of the barrier layer 6 extends over the entire partial region B of the inner pane 2. The barrier layer 6 has, for example, a constant layer thickness of 0.15 mm and is formed from PET. The barrier layer 6 is arranged at the interface between the functional element 4, or the third thermoplastic intermediate film 3.3, and the second thermoplastic intermediate film 3.2 and largely prevents plasticizers from the second thermoplastic intermediate film 3.2 from penetrating the functional element 4, or the active layer 12, in the portion of the edge region R of the functional element 4.

[0133] The additional barrier layers 6' are arranged in other sections of the circumferential edge region R of the functional element 4, with additional barrier layers 6' being arranged on both the first carrier foil 10.1 and the second carrier foil 10.2. In particular, additional barrier layers 6' are also arranged on the entire circumferential edge surface K of the functional element 4. The "circumferential edge surface K of the functional element 4" essentially refers to the circumferential edge surface of the active layer 12 and the edge surfaces of the carrier foils 10.1, 10.2 and surface electrodes 11.1, 11.2, whereby only the active layer 12 or the active layer 12 and partially the edge surfaces of the carrier foils 10.1, 10.2 and surface electrodes 11.1, 11.2 can be covered by the additional barrier layers 6'.

[0134] The opaque region 8 of the barrier layer 6 in partial region B of the inner pane 2 effectively prevents light losses 7 of the light source 5 from radiating through the outer pane 1 into the external environment. Instead, they are absorbed by the opaque region 8 of the barrier layer 6. The barrier layer 6 also largely prevents the diffusion of plasticizers or moisture through it, thus increasing the long-term stability of the functional element 4. Because the barrier layer 6 can be used for two technical problems simultaneously, material and thus costs can be saved. The light 7 of the light source 5 cannot be completely blocked with the cover print 15 alone. In other words, atypical layer thicknesses would be required for the cover print 15, which would lead to an undesirable reduction in the quality of the composite pane 100.

[0135] Light source 5 is configured, for example, as a strip-shaped LED or from several strip-shaped LEDs. Light source 5 has, for example, a luminous intensity of 280 lm / m. A collimator (not shown here) can optionally be arranged between light source 5 and inner pane 2. The collimator acts as a type of converging lens and reduces the beam cone of light source 5; ideally, it results in a parallel beam path of the emitted light 7 from light source 5.

[0136] The variants shown in Figures 4 to 5 essentially correspond to the variant in Figures 1 to 3, so that only the differences are discussed here and otherwise reference is made to the description of Figures 1 to 3.

[0137] In Figure 4, the light source 5 is arranged in a recess of the inner pane 2. The light source 5 is arranged in the recess in such a way that the light 7 is coupled directly into the inner pane 2 via a circumferential edge surface arranged in the recess. The recess is, for example, a hole in the inner pane 2. The recess in the inner pane 2 is, within the meaning of the invention, a component of the inner pane 2, so that the light source 5, within the meaning of the invention, is arranged in partial region B of the inner pane 2. The composite pane 100 does not comprise a coupling means 13 here, since the light 7 is coupled directly via the edge surface in the recess. Here, too, light losses can occur, which are emitted in the direction of the outer pane 1. However, due to absorption in the opaque region 8 of the barrier layer 6, these do not reach the external environment via the outer pane 1.

[0138] In Figure 5, the inner pane 2 is not the optical waveguide; instead, the composite pane 100 comprises an optical waveguide 9, for example in the form of a transparent PET film, which is arranged between the functional element 4 and the inner pane 2 and within the second thermoplastic intermediate film 3.2. The coupling means 13 is introduced into the optical waveguide 9, for example, by partially roughening the surface of the optical waveguide 9 facing the outer pane 1. The coupling-out element 14 is applied, for example, as a print on the surface of the optical waveguide 9 facing the inner pane 2. List of Reference Symbols

[0139] 1 outer pane

[0140] 2 inner pane

[0141] 3 thermoplastic intermediate layer

[0142] 3.1 first thermoplastic intermediate film

[0143] 3.2 second thermoplastic intermediate film

[0144] 3.3 third thermoplastic intermediate film

[0145] 4 Functional element

[0146] 4' Segments of the functional element 4

[0147] 5 Light source

[0148] 6 Barrier layer

[0149] 6' additional barrier layer

[0150] 7 visible light

[0151] 8 opaque area of ​​the barrier layer 6

[0152] 9 optical fibers

[0153] 10.1 first carrier film

[0154] 10.2 second carrier film

[0155] 11.1 first surface electrode

[0156] 11.2 second surface electrode

[0157] 12 active layer

[0158] 13 coupling agents

[0159] 14 decoupling elements

[0160] 15 Cover print

[0161] 100 composite panes

[0162] 101 Glazing element

[0163] Z cutout

[0164] I outside surface of the outer pane 1

[0165] II Interior surface of the outer pane 1

[0166] III outer surface of the inner pane 2

[0167] IV Interior surface of the inner pane 2

[0168] V external surface of the functional element 4

[0169] VI interior surface of the functional element 4

[0170] B Partial area of ​​the inner pane 2 C Overhang of the second carrier film 10.2

[0171] K Edge surface of the functional element 4

[0172] R Section of the peripheral edge area of ​​the functional element 4 XX' Cutting line

Claims

Patent claims 1. An illuminable glazing element (101) with controllable optical properties, comprising: a composite pane (100) comprising an outer pane (1), an inner pane (2), and a thermoplastic intermediate layer (3) arranged therebetween; a functional element (4) arranged within the thermoplastic intermediate layer (3) with controllable optical properties; a barrier layer (6) for reducing plasticizer diffusion, having at least one opaque region (8); and a light source (5) for coupling visible light (7) into the composite pane (100), wherein the light source (5) is arranged in a partial region (B) of the inner pane (2) which at least partially does not overlap with the functional element (4), and wherein the opaque region (8) of the barrier layer (6) extends at least over the partial region (B), and the barrier layer (6) is in direct spatial contact with the functional element (4) at least in an edge region (R) of the functional element (4).

2. Illuminable glazing element (101) according to claim 1, wherein the entire barrier layer (6) is opaque.

3. Illuminable glazing element (101) according to claim 1 or 2, wherein the functional element (4) is arranged between a first thermoplastic intermediate film (3.1) and a second thermoplastic intermediate film (3.2) of the thermoplastic intermediate layer (3).

4. Illuminable glazing element (101) according to claim 3, wherein the second thermoplastic intermediate film (3.2) is arranged between the functional element (4) and the inner pane (2) and the barrier layer (6) is arranged between the functional element (4) and the second thermoplastic intermediate film (3.2).

5. Illuminable glazing element (101) according to one of claims 1 to 4, wherein the thermoplastic intermediate layer (3) comprises a thermoplastic intermediate film (3.3) surrounding the functional element (4) in a frame-like manner.

6. Illuminable glazing element (101) according to one of claims 1 to 5, wherein the partial region (B) of the inner pane (2) is completely free of overlap with the functional element (4).

7. Illuminable glazing element (101) according to one of claims 1 to 6, wherein the barrier layer (6) is arranged, preferably applied, at least partially on a circumferential edge surface (K) of the functional element (4).

8. Illuminable glazing element (101) according to one of claims 1 to 7, wherein the light source (5) is arranged relative to the composite pane (100) in such a way that visible light (7) emitted by the light source (5) can be coupled into the inner pane (2).

9. Illuminable glazing element (101) according to one of claims 1 to 7, wherein an optical waveguide (9) is arranged between the outer pane (1) and the inner pane (2) and the light source (5) is arranged relative to the composite pane (100) in such a way that the visible light (7) emitted by the light source (5) can be coupled into the optical waveguide (9).

10. Illuminable glazing element (101) according to one of claims 1 to 9, wherein a coupling means (13), preferably a microprism film, is arranged between the light source (5) and the barrier layer (6).

11. Illuminable glazing element (101) according to one of claims 1 to 10, wherein the functional element (4) is a PDLC functional element which comprises, in this order, a first carrier film (10.1), a first surface electrode (11.1), an active layer (12), a second surface electrode (11.2) and a second carrier film (10.2).

12. Illuminable glazing element (101) according to claim 11, wherein the second carrier film (10.2) has a projection (C) at least in sections relative to the active layer (12) and the barrier layer (6) is in direct spatial contact with this projection (C).

13. Illuminable glazing element (101) according to one of claims 1 to 12, wherein the barrier layer (6) contains or consists of polyethylene terephthalate or polyvinyl fluoride.

14. Illuminable glazing element (101) according to one of claims 1 to 13, wherein the barrier layer (6) has a layer thickness of 0.02 mm to 0.2 mm, preferably 0.04 mm to 0.15 mm.

15. Illuminable glazing element (101) according to one of claims 1 to 14, wherein the light source (5) has a luminous intensity of at least 200 lm / m, preferably 240 lm / m.

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