Illuminable glass window element with controllable optical properties

Abstract

The present invention relates to an illuminated glass window element (101) having controllable optical properties, comprising: a laminated window pane (100) including an outer window pane (1), an inner window pane (2) and a thermoplastic interlayer (3) disposed therebetween; a functional element (4) having controllable optical properties disposed within the thermoplastic interlayer (3); 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 laminated window pane (100), wherein the light source (5) is disposed in a sub-region (B) of the inner window pane (2) that is at least partially not overlapping with the functional element (4), and wherein the opaque region (8) of the barrier layer (6) extends at least over the sub-region (B) and is in direct spatial contact with the functional element (4) at least in the edge region (R1) of the functional element (4).

Description

Technical Field

[0001] This invention relates to an illuminated glass window element with controllable optical properties. Background Technology

[0002] Illuminable window elements are known in themselves. An illuminateable window element is equipped with a light source whose light is coupled into an optical waveguide (typically a glass pane) and propagates due to total internal reflection. The light is typically coupled back from the optical waveguide through a coupling element, thereby achieving illumination. The shape of the coupling element can be freely chosen, allowing the creation of illuminated surfaces of any shape, such as patterns. This type of illuminated window element is known, for example, from WO2014 / 060409A1 or WO2014 / 167291A1.

[0003] In the automotive industry, such illuminated window elements are of particular interest as top panes. These window elements are typically designed as laminated panes, in which light is coupled into their inner panes. However, such illuminated window elements can also be used for panes in other vehicles or in buildings and construction or home furnishings. The coupled elements create an illuminated surface that can be used to display aesthetically pleasing shapes and patterns or to display information such as directional arrows, status indicators, warning notices, price lists, or similar information.

[0004] Various options for coupling light from a light source into an optical waveguide designed as a glass pane are known. The light source (typically a light-emitting diode) can be positioned on the side edges so that light radiates through the side edges into the glass pane and is thus coupled in. However, such coupling is generally not possible, especially since the side edges of the glass pane are typically ground to improve the pane's mechanical stability, which causes the side edges to become cloudy.

[0005] US2020241189A1 proposes a method for coupling light through the main surface of a 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 a portion that slopes towards the surface of the glass pane. The reflective structure is illuminated by the light source through the glass pane, where light is reflected at the sloped portion, causing the light to propagate within the glass pane due to total internal reflection on the surface. One problem with this solution involves the radiating of light into the external environment, as a portion of the emitted light is transmitted through the reflective structure. This residual light can be perceived as a disturbance or irritant from the outside. When used in road traffic, this residual light can even undesirably distract or irritate other road users, thus posing a safety risk. Even when the glass pane is covered with a covering imprint in the area of ​​the light source, this residual portion of the light is often still visible from the external environment.

[0006] Illuminated window elements typically possess additional controllable optical properties. These elements comprise laminated panes equipped with functional elements whose optical properties can be altered by an applied voltage. The voltage is applied via a control unit connected to two planar electrodes of the functional element, with the active layer of the functional element located between these two planar electrodes. An example of such a functional element is, for instance, the SPD (Suspended Particle Device) functional element known from EP0876608B1 and WO2011033313A1. The transmission of visible light can be controlled by the SPD functional element by applying a voltage. Another example is, for instance, the PDLC (Polymer Dispersed Liquid Crystal) functional element known from DE102008026339A1. The active layer contains liquid crystals embedded in a polymer matrix. Without an applied voltage, the liquid crystals align in a disordered manner, resulting in strong scattering of light through the active layer. When a voltage is applied to the planar electrodes, the liquid crystals align in a common direction, and the transmittance of light through the active layer increases. PDLC functional elements operate primarily by increasing scattering rather than reducing total transmission, thus preventing clear viewing or ensuring anti-glare protection.

[0007] Such window elements can be used, for example, as vehicle windows, and their light transmission behavior can then be electrically controlled. For example, these window elements can be used as top panes to reduce solar glare. Such top panes are known, for example, from DE10043141A1 and EP3456913A1. Functional elements with controllable optical properties typically require a sealant in the form of a barrier layer to protect the functional element from moisture or plasticizers from the intermediate layer. Summary of the Invention

[0008] This invention is based on the objective of providing an improved window element that largely eliminates uncoupled residual light from a light source that is visually perceptible from the external environment. The window element should also be inexpensive to manufacture.

[0009] The objective of this invention is achieved by the glass window element according to claim 1. Preferred embodiments are derived from the dependent claims.

[0010] The illuminateable glass window element with controllable optical properties according to the present invention includes a laminated window pane and a light source for coupling visible light into the laminated window pane. The laminated window pane includes an outer window pane, an inner window pane, and a thermoplastic interlayer disposed flat between the inner and outer window panes. The laminated window pane also includes a functional element with controllable optical properties disposed within the thermoplastic interlayer and at least one barrier layer for reducing plasticizer diffusion. The barrier layer has at least one opaque area. In other words, the barrier layer is opaque in at least some areas.

[0011] The light source is configured to couple light into the laminated panes. Light from the light source may, for example, be coupled into an inner pane that serves as an optical waveguide; alternatively, the light may also be coupled into an additional optical waveguide disposed between the functional element and the inner pane. The light source is arranged relative to the laminated panes such that the light source couples visible light into the laminated panes during operation.

[0012] In the context of this invention, the term "barrier layer for reducing plasticizer diffusion" means that the barrier layer is designed such that the diffusion of plasticizer through the barrier layer is reduced compared to the diffusion of plasticizer through the surrounding thermoplastic interlayer. The barrier layer is intended to reduce, and in particular substantially prevent, the diffusion of plasticizer from the thermoplastic interlayer to the functional element, and in particular to the active layer of the functional element.

[0013] According to the invention, the light source is arranged in a sub-region of the inner window pane. This sub-region of the inner window pane does not overlap with the functional elements at least partially; that is, when viewed through the laminated window pane, this sub-region does not overlap with the functional elements at least partially. In the case of "viewing through the laminated window pane," the viewing direction, as understood in this invention, is perpendicular to the main surface of the laminated window pane. Therefore, this does not imply oblique viewing onto the laminated window pane or viewing through the laminated window pane.

[0014] "Within the thermoplastic interlayer" means that the functional element is completely encapsulated by the interlayer, that is, the functional element is arranged within the boundary of the thermoplastic interlayer. It goes without saying that additional layers (such as barrier layers) can certainly be arranged between the interlayer and the functional element, that is, similarly arranged within the thermoplastic interlayer.

[0015] According to the present invention, when viewed through a laminated window pane, the opaque area of ​​the barrier layer extends at least over a sub-region of the inner window pane. In other words, when viewed through a laminated window pane, the opaque area of ​​the barrier layer covers the entire sub-region of the inner window pane. The barrier layer is in direct spatial contact with the functional element at least in the edge region of the functional element. "Direct spatial contact" means that the barrier layer directly touches 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 inner surface facing the inner pane. The barrier layer preferably contacts the functional element on the inner surface. The functional element also has a circumferential edge surface connecting the inner surface to the outer surface. The term "edge region" of the functional element can refer to an area of ​​the functional element on either the inner or outer surface. The edge region is adjacent to the edge surface of the functional element. The edge region does not necessarily mean the entire peripheral edge region of the functional element, i.e., the area extending along the entire edge surface like a frame, but may also mean only a portion of the peripheral edge region of the functional element.

[0017] Unless otherwise stated, all elements of the laminated panes arranged between the outer and inner panes mentioned herein are arranged "flat" or "top-to-bottom flat." In other words, the main surfaces of these elements are substantially parallel to the surfaces of the outer and inner panes. The "thickness" or "layer thickness" of an element refers to the extension that is substantially orthogonal to the main surface of the element. The main surface of an element describes the area of ​​the element with the greatest extension.

[0018] The opaque area of ​​the barrier layer absorbs 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, visible light cannot be visually perceived in the area of ​​the light source (a sub-area of ​​the inner pane) because light loss (i.e., light unintentionally not coupled into the laminated pane) cannot reach the outer pane due to the at least partially opaque barrier layer. Simultaneously, the barrier layer prevents plasticizer diffusion into the functional elements. Using the barrier layer according to the invention to prevent light emission in the area of ​​the light source reduces costs because two different functions are achieved using only one component of the laminated pane.

[0019] Within the meaning of this invention, "transparent" means at least 70%, preferably at least 80%, and particularly preferably at least 90% light transmittance (according to ISO 9050:2003). Within the meaning of this invention, "semi-transparent" (according to ISO 9050:2003) means less than 70%, preferably at most 50%, and particularly preferably at most 5% light transmittance. Within the meaning of this invention, "opaque" means less than 5%, preferably less than 0.1%, and particularly less than 0% light transmittance (according to ISO 9050:2003).

[0020] In a particularly preferred embodiment of the invention, the barrier layer in the opaque region has an optical density of at least 3.0, particularly preferably 3.2, and particularly particularly 3.5. Specifically, the barrier layer has an optical density of at least 3.0, particularly preferably 3.2, and particularly particularly 3.5 over all regions (i.e., the entire barrier layer). Optical density is a measure of a material's absorption of visible light. Optical density 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 is transmitted completely through the material, i.e., passes through the material. A value of 0 can be used as a reference. At an optical density of 0, the material does not absorb light at all.

[0021] Laminated panes are configured to separate the interior from the external environment within the window openings of a vehicle or building. In this context, "inner pane" refers to the pane facing inwards (the interior of the vehicle), and "outer pane" refers to the pane facing outwards. However, the invention is not limited thereto. The inner pane has an inner surface facing away from the interlayer and an outer surface facing the thermoplastic interlayer. If the inner pane of the laminated pane is also an optical waveguide designed to guide visible light from a light source, then the outer surface of the optical waveguide is the outer surface of the inner pane, and the inner surface of the optical waveguide is the inner surface of the inner pane. The inner surface of the inner pane is also the inner surface of the laminated pane. The outer pane has an outer surface facing away from the thermoplastic interlayer and an inner surface facing the thermoplastic interlayer. The outer surface of the outer pane is also the outer surface of the laminated pane. The laminated pane may be flat or curved in one or more spatial directions.

[0022] Within the meaning of this invention, "optical waveguide" refers to an optical medium, preferably a glass pane or a pane made of plastic, designed such that light can be coupled into the optical waveguide by utilizing total internal reflection, and is also suitable for conducting the coupled light. The principle of light conduction by means of total internal reflection is generally known to those skilled in the art and is described in more detail, for example, in WO2008 / 047442A1, JP2011086547A, or JP2015043321A. Thus, the optical waveguide is designed such that light from a light source can be coupled into and propagate within it.

[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 translucent areas. This results in a more cost-effective and even more efficient production of the glass window element according to the invention, since partially coloring the barrier layer to achieve opacity in certain areas would involve additional process steps or be more expensive to purchase.

[0024] In another preferred embodiment of the window element, the thermoplastic interlayer includes at least a first thermoplastic interlayer film and a second thermoplastic interlayer film. Functional elements are disposed between the first and second thermoplastic interlayer films. The second thermoplastic interlayer film is preferably disposed between the functional element and the inner window pane, and the first thermoplastic interlayer film is disposed between the outer window pane and the functional element. In the laminated window pane, the functional elements are thus disposed within the thermoplastic interlayer. Furthermore, the outer and inner window panes are securely connected to each other via the thermoplastic interlayer.

[0025] Particularly preferably, a second thermoplastic interlayer is disposed between the functional element and the inner window pane, and a barrier layer is disposed between the functional element and the second thermoplastic interlayer. Thus, the barrier layer prevents plasticizer from the second thermoplastic interlayer from permeating into the functional element, at least in some sections.

[0026] Alternatively, or in addition to the first and second thermoplastic interlayers, a frame-like circumferential thermoplastic interlayer may be arranged around the functional element. The functional element preferably extends only over the central region of the laminated pane. Thus, the laminated pane has an area without functional elements and extends circumferentially around them. This arrangement prevents moisture from penetrating the functional element via the edge surfaces of the laminated pane. However, such an arrangement also results in a difference in thickness, which can be compensated for by the frame-like thermoplastic interlayer. The functional element and the frame-like thermoplastic interlayer together extend substantially over the entire surface of the laminated pane. The frame-like thermoplastic interlayer is part of the thermoplastic interlayer.

[0027] In a particularly preferred embodiment of the invention, the sub-regions of the inner pane are arranged so as not to overlap with the functional elements at all. This means that when viewed from the inner pane through the laminated pane, the sub-regions of the inner pane do not cover the functional elements, and therefore, when viewed through the laminated pane, the light source does not cover the functional elements. This is particularly useful when the functional elements are PDLC functional elements that have particularly high light scattering in some optical states. Thus, light misdirected from the light source onto the PDLC functional elements will produce a stimulating illumination effect on the user.

[0028] In the context of this invention, for example, a description that element A completely overlaps with or completely covers element B means that the orthogonal projection from element A to the plane from element B is completely arranged within element B. In the context of this invention, a description that element A partially overlaps with element B means that the orthogonal projection from element A to the plane from element B is partially arranged within element B, rather than completely arranged within element B. In this context, "element" may also refer to a region of an element.

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

[0030] The light source can be installed, for example, in a recess in the inner window pane. This recess is preferably an aperture, i.e., a through-passage extending between the outer and inner surfaces of the inner window pane. Alternatively, however, the recess can also be a blind hole (a sac-like recess) extending from either the outer or inner surface into the inner window pane, but not reaching the opposing main surface, which would result in a through-passage.

[0031] The recess can be created in the inner window pane, for example, by mechanical drilling or laser machining. The recess is preferably circular, but in principle it can have any shape, including polygonal shapes. This refers to the base of the recess on the surface of the inner window pane, through which the recess is created in the inner window pane. The recess has an overall cylindrical shape, preferably a vertical cylinder (extending from the inner surface of the inner window pane to the outer surface of the inner window pane). This cylinder is preferably a circular cylinder (circular base), but it can also have any other base, such as an elliptical base (elliptical cylinder) or a polygonal base (prism).

[0032] Whether the recess is in the form of a through passage or a depression, it is limited by a circumferential edge surface extending between the main surfaces of the inner panes. If it is formed as a through passage, this is the only boundary surface of the recess. In the case of a capsule-shaped depression, there is an additional boundary surface facing the main surface of the optical waveguide, the depression does not extend to this main surface, and this boundary surface acts as the bottom of the blind aperture.

[0033] A light source is arranged (preferably attached, particularly glued, or arranged in a socket attached to the recess) on the edge surface of the recess of the inner window pane. Visible light is then coupled into the inner window pane via the inner edge surface and dispersed through the inner window pane under total internal reflection.

[0034] Alternatively, the light source may be arranged on the inner surface of the inner window pane, and a coupling member may be arranged between the inner window pane and the light source or on the outer surface of the inner window pane, the coupling member causing the incident light emitted by the light source to refract or reflect, so that the incident light can be coupled into the inner window pane.

[0035] In a second embodiment of the invention, an optical waveguide is arranged between the outer and inner panes, and a light source is arranged relative to the laminated panes such that visible light emitted by the light source can be coupled into the optical waveguide. The light source is preferably arranged on the inner surface of the inner pane. In this case, a coupling member 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 member causes light emitted by the light source and incident on the coupling medium to refract or reflect, such light can be coupled into the optical waveguide.

[0036] For the purposes of this invention, "visible light" means light with a wavelength of 400 nm to 800 nm.

[0037] The thickness of the outer window pane is preferably 0.5 mm to 10 mm, particularly preferably 1 mm to 5 mm. The outer window pane is preferably made of soda-lime glass. The thermoplastic interlayer has a thickness of, for example, 0.3 mm to 1.0 mm (the total thickness of all films in the interlayer). The interlayer 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). Additionally, the film or the entire interlayer may contain other components such as plasticizers, stabilizers, and UV or IR blockers.

[0038] The inner window pane is preferably made of soda-lime glass, which is typical for window panes. Alternatively, the inner window pane may also be made of other types of glass (such as borosilicate glass, aluminosilicate glass, or quartz glass). The inner window pane may also be a pane made of plastic. If the inner window pane is made of plastic, it will preferably be made of transparent rigid plastic, particularly preferably polycarbonate (PC) or polymethyl methacrylate (PMMA). The thickness of the inner window pane is preferably 0.5 mm to 10 mm, particularly preferably 1 mm to 5 mm. If the inner window pane is an optical waveguide, it preferably has an iron oxide content of up to 1%, particularly preferably up to 0.1%. This low iron oxide content makes the inner window pane particularly suitable as an optical waveguide for visible light. If the inner window pane of an optical waveguide is similar, then in order to make light propagation efficient, the inner window pane will preferably be transparent and without any significant color or tint. The outer window pane may also be transparent, stained, or colored.

[0039] If the inner pane is not an optical waveguide, an optical waveguide is arranged between the inner and outer panes, 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 (such as borosilicate glass, aluminosilicate glass, or quartz glass). The optical waveguide can also be a flexible light-guiding film and act as a transparent layer, for example, a PET film with a thickness of 30 µm to 200 µm. Optical waveguides made of mineral glass preferably have a maximum iron oxide content of 1%, particularly preferably a maximum of 0.1%. To ensure efficient light propagation, the optical waveguide will preferably be transparent and without significant color or tinting. The outer pane can also be transparent, stained, or colored.

[0040] Whether the inner window pane is an optical waveguide or the optical waveguide is arranged between the functional element and the inner window pane, the optical waveguide preferably has a light transmittance of at least 70%, particularly preferably at least 80%, and most preferably at least 90% (according to ISO 9050:2003).

[0041] In another preferred embodiment of the invention, a coupling element, preferably a microprism film, is arranged between the light source and the barrier layer. The coupling element is preferably arranged on the optical waveguide of the laminated pane. The optical waveguide may be an inner pane of the laminated pane or may be arranged as an additional element between the functional element and the inner pane. In any case, the optical waveguide has an outer surface facing the functional element and an inner surface facing away from the functional element. Preferably, the optical waveguide is an inner pane of the laminated pane. The coupling element is arranged such that light emitted by the light source irradiates the coupling element and is then coupled into the optical waveguide by means of reflection or refraction at the coupling element. Light from the light source may be transmitted through other elements of the laminated pane before irradiating the coupling element; for example, light from the light source may first be transmitted through the inner pane before irradiating the coupling element. Even after the light has irradiated the coupling element and has been refracted or reflected there, the light may still be transmitted through other elements of the laminated pane before being coupled into the optical waveguide. When viewed through the laminated pane, the coupling element is arranged in accordance with the opaque area of ​​the barrier layer.

[0042] In a first particularly preferred embodiment, the coupling element is a reflective structure. The reflective structure is preferably formed in or applied to the outer surface of the optical waveguide. The reflective structure has a plurality of inclined portions with reflective surfaces and is configured such that light radiating into and transmitted through the optical waveguide is reflected by the reflective surfaces of the inclined portions and at least partially recoupled into the optical waveguide. Light from the light source is at least partially reflected by the reflective surfaces of the inclined portions at a coupling angle into the optical waveguide and coupled into it. The light from the light source preferably enters the optical waveguide via an inner surface and subsequently illuminates the reflective structure, allowing the light to be coupled into the optical waveguide. Before illuminating the inner surface of the optical waveguide, the light may have already passed through (i.e., transmitted through) other elements of the optical waveguide. More precisely, - In the case where the reflective structure is formed in the outer surface: light from the light source illuminates the inner surface of the optical waveguide, then passes through the optical waveguide to illuminate the outer surface of the optical waveguide, and is reflected by the reflective structure there. Therefore, the reflective structure is a sub-region of the outer surface of the optical waveguide, and light is reflected from this sub-region; - Alternatively, in the case where the reflective structure is applied to the outer surface of the optical waveguide: light from the light source enters the inner surface of the optical waveguide, is then transmitted through the optical waveguide, exits the optical waveguide again via the outer surface, and is reflected by the reflective structure. Preferably, light emanating from the optical waveguide passes through the reflective structure and is reflected on its surface facing away from the optical waveguide, which forms a sloping reflective surface. For the purposes of this invention, "sloping portion" means that the reflective structure has one or more regions that are sloping relative to the surface of the optical waveguide facing away from the functional element.

[0043] The reflective structure preferably has a reflective coating responsible for its reflective properties. The reflective coating is preferably disposed on, and preferably applied to, the surface of the reflective structure opposite to the optical waveguide. The reflective coating comprises at least one reflective layer based on a metal or metal alloy. This improves the reflectivity of the reflective coating.

[0044] The reflective structure is particularly preferably a microprism film. The microprism film is attached (e.g., adhesively bonded) to the outer surface of the optical waveguide. The reflective surface of the reflective structure is preferably arranged facing away from the optical waveguide. Except for the reflective surface, the microprism film is transparent. After entering the optical waveguide, light from the light source exits the optical waveguide via the outer surface, passes through the microprism film, and illuminates its reflective surface, where the light is reflected and passes through the microprism film again, re-entering the optical waveguide via the outer surface.

[0045] The microprism film is a flexible (particularly, film-shaped) polymer film having a smooth surface facing and specifically arranged thereon towards the optical waveguide, and a structured surface facing away from the optical waveguide. The structured surface is in the form of a planar arrangement of multiple prisms having dimensions in the micrometer range, wherein the prism surfaces form inclined portions of a reflective structure. Preferably, the structured surface of the microprism film is coated with a reflective coating. The microprism specifically acts as a reflective prism and reflects light incident on the microprism in a direction depending on the tilt angle of the prism surface and the angle of incidence of the light. The microprism film is commercially available and can be purchased or specifically produced during the production of glass window elements according to the invention or laminated window panes according to the invention. The edge length of an individual microprism is preferably from 10 µm to 250 µm, particularly preferably from 20 µm to 100 µm, for example, about 30 µm.

[0046] Microprism films can be formed in multiple layers. For example, microprism films with a substrate layer, such as polyethylene terephthalate (PET), are commonly used, on which microprisms are formed by UV-cured polyacrylate.

[0047] Apart from its reflective surface, the microprism film is transparent and preferably has a light transmittance of at least 70%, particularly preferably at least 80%, and most particularly preferably at least 90% relative to the light source. It is advantageous if the difference between the refractive index of the optical waveguide and the refractive index of the microprism film is as small as possible to minimize reflection loss at the interface between the optical waveguide and the microprism film. Preferably, the refractive index difference is at most 0.02 (based on a wavelength of 550 nm), particularly preferably at most 0.01. If the refractive index of the optical waveguide and the refractive index of the microprism film are different, the microprism film preferably has a higher refractive index than the optical waveguide, which is beneficial for high-efficiency optical coupling.

[0048] In the context of this invention, the refractive index is specified in all cases relative to a wavelength of 550 nm. Methods for determining the refractive index are known to those skilled in the art. The refractive index specified within the scope of this invention can be determined, for example, by ellipsometry, wherein a commercially available ellipsometer can be used. Unless otherwise indicated, layer thickness or thickness specifications refer to the geometric thickness of the layer.

[0049] In principle, rigid microprism plates, i.e. rigid plastic plates with a planar arrangement of microprisms, can also be used instead of flexible microprism films.

[0050] However, reflective structures can also be formed directly on the outer surface of the optical waveguide. For this purpose, a sub-region of the outer surface is formed as a reflective surface. This is relatively easy to achieve, especially when the optical waveguide is a polymer layer (such as a pane or plate made of plastic). Light from the light source is directly reflected on the outer surface and back into the optical waveguide without leaving the optical waveguide.

[0051] The reflective surface of the reflective structure has a portion that is inclined towards the inner surface of the optical waveguide. This means that the portion is arranged not parallel to the inner surface, but at an angle greater than 0° with the inner surface. The portion has an angle with the inner surface between 0° and 90°, preferably 28° to 60° or 30° to 60°, most particularly preferably 30° to 50°, and especially 40° to 50° (e.g., approximately 45°). This refers to the absolute value of a particular angle. The portion may be inclined in different directions. The portion is also preferably inclined toward each other. This means that adjacent portions are inclined toward each other, i.e., adjacent portions are arranged not parallel to each other, but at an angle between 0° and 180° with each other. The portion of the reflective structure is preferably substantially flat. The inclination of the portion of the reflective structure relative to the inner surface of the optical waveguide determines the angle at which the reflected light is reflected back into the optical waveguide.

[0052] In a second, particularly preferred embodiment, the coupling element is arranged (preferably applied) on the inner surface of the optical waveguide (preferably, the inner pane). The beam path of the light source points towards the coupling element. The coupling element preferably couples light arriving from the light source into the optical waveguide by refraction. Therefore, the coupling element is a light-refracting structure. The light source is preferably connected to the inner pane via the coupling element. A collimator may be arranged between the light source and the coupling element, i.e., in the beam path of the light source.

[0053] In a particularly preferred embodiment of the invention, regardless of whether the optical waveguide is an inner pane of a laminated pane or a light guide element disposed between a functional element and an inner pane, the optical waveguide of the laminated pane includes at least one coupling element. For the purposes of this invention, "coupling element" means an element suitable for coupling light out of the optical waveguide. Preferably, at least one first coupling element is disposed on an inner or outer surface of the optical waveguide.

[0054] Optical waveguides may have multiple coupling elements in different regions. Preferably, the optical waveguide has at least one additional coupling element on its inner surface or its outer surface, particularly preferably at least two additional coupling elements, and especially at least three additional coupling elements. Thus, the coupled light is coupled out of the optical waveguide at the coupling element via the inner or outer surface of the optical waveguide.

[0055] It goes without saying that the coupling element extends only on a portion of the optical waveguide, that is, it does not extend across the entire surface, because otherwise optical coupling and light propagation by means of total internal reflection would be impossible.

[0056] At least one coupling element of the optical waveguide on the outer or inner surface of the optical waveguide may be incorporated into the surface of the optical waveguide, for example, by means of roughening. Alternatively, at least one coupling element of the optical waveguide may also be imprinted onto the outer or inner surface. Alternatively, at least one coupling element of the optical waveguide may also be applied (preferably printed) to the surface of the thermoplastic interlayer facing the optical waveguide, wherein at least one coupling element is arranged to be in direct spatial contact with the outer or inner surface of the optical waveguide (if the optical waveguide is arranged between the functional element and the inner pane). If light propagating in the optical waveguide shines on the coupling element, the light will be scattered, thereby preventing total internal reflection, so that the scattered light is coupled out and leaves the laminate pane.

[0057] The coupling element appears as a luminous surface of the laminated windowpane. This can be used, for example, to illuminate the interior, and is particularly useful for displaying symbols or patterns used to convey information, or may be provided for purely aesthetic reasons. The coupling element can be used to achieve any shape or pattern.

[0058] At least one coupling element may be configured, for example, as a film bonded to the optical waveguide. Additional coupling elements may also be configured as films.

[0059] Preferably, at least one coupling element is formed as an imprint on the optical waveguide. If the optical waveguide is a glass pane, such as an inner pane, the imprint thereon is preferably designed as a light-scattering enamel. This enamel can be applied, for example, using a screen printing method. The enamel preferably comprises a glass frit that is fired into the surface of the glass layer, thus creating a roughened and therefore light-scattering surface. If the optical waveguide is primarily made of a polymeric material, this is preferably achieved by printing the optical waveguide using a light-scattering, transparent printing paste. If at least one coupling element is designed as an imprint on the surface of a thermoplastic interlayer facing the optical waveguide (wherein at least one coupling element is additionally arranged to be in direct spatial contact with the outer surface or the inner surface of the optical waveguide), this is preferably achieved by printing the thermoplastic interlayer using a light-scattering, transparent printing paste.

[0060] In an advantageous embodiment, the coupling element is transparent, such that it substantially does not restrict the view through the laminated panes. Therefore, the print (print paste) preferably does not contain pigment. However, opaque or translucent coupling elements (e.g., white structures) with pigment are also conceivable. The print can also produce colored colors, i.e., at least not completely obstructing the view through the laminated panes, but allowing it to appear in one or more colors. If the print paste is opaque, translucent, or dyed, it preferably contains dyes or colored pigments.

[0061] However, coupling elements disposed on an optical waveguide can also be formed by roughening the relevant surfaces of the optical waveguide, with the coupling elements designed as glass panes or panes made of plastic. This roughening can be performed mechanically (e.g., by grinding techniques) or by laser machining. Particularly in the case of laminated panes, laser machining has the advantage that even if the coupling element is to be located inside the laminated pane, the coupling element can be introduced into the finished laminated pane, because the laser radiation can also be focused onto a plane inside the laminated pane. Laser machining also makes it possible to form at least a first coupling element inside the optical waveguide rather than on its surface.

[0062] Light coupled into an optical waveguide propagates within the waveguide until it strikes a side edge surface of the waveguide and couples out there, or strikes at least one coupling element on one of the two surfaces of the waveguide, which interrupts total internal reflection due to light scattering, thereby causing light to couple out of the optical waveguide via the surface in question.

[0063] In a preferred embodiment, the functional elements, in the indicated order, include at least: • First carrier membrane; • First planar electrode; •Active layer; • Second planar electrode; and • Second carrier membrane.

[0064] The planar electrode is preferably applied to a carrier film adjacent to it. In such embodiments of the functional element, the planar electrode and the active layer are arranged between the carrier film. Thus, the carrier film forms the surface of the functional element and provides a liquid or soft active layer with the necessary mechanical stability. Therefore, the functional element can be configured as a laminated film that can be advantageously processed. The functional element is advantageously protected from damage (especially corrosion) by the carrier film. The functional element is particularly preferably a PDLC functional element. The functional element is designed like a film. The active layer has controllable optical properties that can be controlled by a voltage applied to the planar electrode.

[0065] Preferably, the first planar electrode is electrically connected to at least one first busbar, and the second planar electrode is electrically connected to at least one second busbar. The first and second busbars, as well as any other busbars, are intended to be electrically connected to an external voltage source in a manner known per se. Electrical contact is achieved via suitable connecting cables (e.g., foil conductors).

[0066] The planar electrode is preferably designed as a transparent conductive layer. The planar electrode preferably comprises at least one metal, a metal alloy, or a transparent conductive oxide (TCO). The planar electrode may, for example, comprise 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 planar electrode preferably has a thickness of 10 nm to 2 µm, particularly preferably 20 nm to 1 µm, and most particularly preferably 30 nm to 500 nm.

[0067] In addition to the active layer, carrier film, and planar electrode, the functional element may also have other layers known to the user, such as barrier layer, blocking layer, antireflective layer, protective layer, and / or smoothing layer.

[0068] The carrier film preferably comprises at least one thermoplastic polymer, particularly preferably low- or plasticizer-free polyethylene terephthalate (PET). This is particularly advantageous for the stability of the functional components. However, the carrier film may also comprise or consist of other low- or plasticizer-free polymers, such as ethylene vinyl acetate (EVA), polypropylene, polycarbonate, polymethyl methacrylate, polyacrylate, polyvinyl chloride, polyacetal resin, molding resin, acrylate, 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. The carrier film provides particularly effective protection against the diffusion of plasticizers into the active layer.

[0069] In a particularly advantageous embodiment of the invention, the thermoplastic interlayer comprises at least 3% by weight, preferably at least 5% by weight, particularly preferably at least 20% by weight, even more preferably at least 30% by weight, and particularly at least 40% by weight, of a plasticizer. The plasticizer preferably comprises or is composed of triethylene glycol bis(2-ethylhexanoate).

[0070] Plasticizers are chemical compounds that make plastics softer, more flexible, smoother, and / or more elastic. They shift the thermoelastic range of plastics to lower temperatures, giving the plastics the desired more elastic properties over the operating temperature range. Further preferred plasticizers are carboxylic acid esters, particularly low-volatility carboxylic acid esters, fats, oils, soft resins, and camphor. Additional plasticizers are preferably aliphatic diesters of triethylene glycol or tetraethylene glycol. Particularly preferred plasticizers are 3G7, 3G8, or 4G7, where the first number indicates the number of ethylene glycol units, and the last number indicates the number of carbon atoms in the carboxylic acid moiety of the compound. 3G8 thus represents triethylene glycol bis(2-ethylhexanoate), i.e., a compound with the molecular formula C4H9CH(CH2CH3)CO(OCH2CH2)3O2CCH(CH2CH3)C4H9.

[0071] The functional element is preferably a PDLC (polymer-dispersed liquid crystal) functional element. The active layer of the PDLC functional element contains liquid crystal embedded in a polymer matrix. If no voltage is applied to the surface electrode, the liquid crystal will align in a disordered manner, resulting in strong scattering of light through the active layer. If a voltage is applied to the planar electrode, the liquid crystal in the second region of the active layer and any other region of the active layer aligns in a common direction, and the transmission of light through the active layer increases. Alternatively, it is possible to use a functional element, and particularly a PDLC functional element, which is transparent when no voltage is applied (zero volts) and scatters strongly when a voltage is applied.

[0072] In principle, other types of controllable functional elements may also be used, such as electrochromic functional elements or SPD functional elements (suspended particle devices). The aforementioned controllable functional elements and their operating modes are known to those skilled in the art and therefore need not be described in detail here. PDLC functional elements are particularly preferred because, especially with respect to PDLC elements, effective protection against plasticizers must be ensured so as not to impair the optical quality of the functional element.

[0073] Functional elements are commercially available. Typically, functional elements are cut from larger, multilayered films into desired shapes and sizes. This can be achieved mechanically, for example, using a cutting tool. In an advantageous embodiment, the cutting is performed using a laser. It has been found that the side surfaces are more stable in this case than when mechanically cut. With mechanically cut side surfaces, there is a risk of material shrinkage, which is arguably visually perceptible and adversely affects the aesthetics of the window pane.

[0074] Within the meaning of this invention, electro-controllable optical properties are understood to mean properties that can be continuously controlled, but also properties that can be switched between two or more discrete states.

[0075] Electrical control of functional elements or light sources, which are components of the glass window element according to the invention, installed in a vehicle, is achieved, for example, by means of switches, rotary or sliding controllers integrated into the vehicle's dashboard. However, buttons (e.g., capacitive buttons) for controlling the functional elements can also be integrated into the laminated window pane. Alternatively or additionally, the functional elements can be controlled by non-contact methods (e.g., by recognizing gestures) or depending on the state of the pupil or eyelids determined by a camera and suitable evaluation electronics. Alternatively or additionally, the functional elements or light sources can be controlled by sensors that detect light incident on the window pane.

[0076] In a preferred embodiment of the invention, the functional element is divided into multiple segments that can be electrically controlled independently of each other. For example, it is possible to switch one or more segments to be translucent, i.e., light-scattering, while at least one other 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, and especially at least four segments. The segments can be generated, for example, by insulating wires on planar electrodes. Preferably, the first planar electrode is divided into multiple planar electrodes of smaller areas by means of insulating wires. To further improve the optical quality of the functional element, the first planar electrode can be divided into separate layer elements, and the active layer can also be divided into separate layer elements by means of insulating wires. The insulating wires that divide the active layer and / or the planar electrodes can be introduced, for example, by means of laser radiation.

[0077] In an advantageous embodiment of the invention, the first carrier film and the first planar electrode disposed (preferably applied) on the first carrier film have protrusions relative to the active layer of the functional element in at least some portions. Particularly preferably, the second carrier film and the second planar electrode disposed (preferably applied) on the second carrier film also have protrusions relative to the active layer in at least some portions. Specifically, the protrusions of the second planar electrode are disposed on the edge of the functional element opposite to the protrusions of the first electrode. These protrusions of the planar electrodes make it possible to make simplified electrical contacts for the functional element.

[0078] Preferably, at least one first busbar is applied to the protruding area of ​​the first planar electrode by means of welding or gluing, and at least one second busbar is applied to the protruding area of ​​the second planar electrode by means of welding or gluing. The busbars applied in this manner are preferably designed as conductors or strips of conductive foil. In this case, the busbars, for example, comprise at least aluminum, copper, tin-plated copper, gold, silver, zinc, tungsten, and / or tin or alloys thereof. The strips preferably have a thickness of 10µm to 500µm, particularly preferably 30µm to 300µm. Busbars made of conductive films having these thicknesses are technically easy to implement and have advantageous current-carrying capacity. The strips can be conductively attached to the conductive structure, for example, via a welding compound, via a conductive adhesive, or by direct placement.

[0079] Alternatively, the first busbar and / or the second busbar and / or any additional busbar are designed as a printed and burned-in conductive structure. The printed busbar preferably contains at least one metal, metal alloy, metal compound, and / or carbon, particularly a precious metal, and especially silver. The printing paste preferably contains metallic particles, metal particles, and / or carbon, and particularly precious metal particles, such as silver particles. Conductivity is preferably achieved by conductive particles. The particles can be in an organic and / or inorganic matrix (such as paste or ink), and are preferably as a printing paste containing glass frit. This design can be produced quickly and easily, wherein the silver-containing material is characterized by high conductivity and relatively long-term stability.

[0080] The layer thickness of the printed busbar is preferably from 5µm to 40µm, particularly preferably from 8µm to 20µm, and most particularly preferably from 8µm to 12µm. Printed busbars with these thicknesses are technically easy to implement and have advantageous current carrying capacity.

[0081] The first busbar, the second busbar, and / or any other busbar are preferably applied to the surface of the active layer of the particular planar electrode facing the functional element. This arrangement is simpler because the planar electrode is disposed between the active layer and the carrier film, and thus can be poorly connected to the busbar via the surface of the planar electrode facing away from the active layer. In principle, the first busbar, the second busbar, and / or any other busbar can also be applied to the surface of the particular planar electrode facing away from the active layer. For this purpose, the carrier film (if present) may, for example, have slits through which the busbar and the planar electrode can be connected to each other.

[0082] If something is formed "based" on an inorganic material, then the material will consist primarily of that material, and in particular essentially of it, except for any impurities or dopants. Unless otherwise indicated, the layer thickness or thickness specification refers to the geometric thickness of the layer. If something is formed "based" on a polymeric material, then the material consists primarily (that is, at least 50%, preferably at least 60%, and particularly at least 70%) of that material. Therefore, the material may also contain other materials, such as, for example, stabilizers or plasticizers.

[0083] In a particularly preferred embodiment of the invention, the second carrier film has protrusions relative to the active layer in at least some portions, and the barrier layer is arranged such that the barrier layer is in direct spatial contact with the protrusions of the second carrier film. Preferably, the second carrier film is arranged closer to the inner window pane than the first carrier film, and the barrier layer is arranged between the functional element and the inner window pane. The second planar electrode is preferably also arranged on the protrusions of the second carrier film, particularly preferably applied to the protrusions of the second carrier film. Most preferably, the barrier layer is arranged only in the edge region of the functional element, wherein the second carrier film has protrusions relative to the active layer. The arrangement of the barrier layer on the functional element prevents direct spatial contact between the barrier layer and the active layer, which could lead to undesirable chemical reactions, but prevents the plasticizer from diffusing from the intermediate layer, which is also partially arranged between the inner window pane and the functional element. Within the meaning of the invention, the protrusions of the carrier film relative to the active layer also belong to the edge region of the functional element.

[0084] In another preferred embodiment, in addition to the barrier layer, the laminated window pane also includes an additional barrier layer. Here, this barrier layer and other barrier layers are arranged together to form a functional element, such 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 with the barrier layer and / or additional barrier layers.

[0085] In the context of this invention, "sealed" means that the corresponding portion of the surface is completely covered by a barrier layer that acts as a protective layer, thereby making the portion more durable and resistant to the diffusion of harmful substances (such as moisture), but also particularly resistant to plasticizers from the environment, which could otherwise penetrate into the interior of the active layer.

[0086] In another preferred embodiment, the barrier layer and the active layer are in direct and immediate contact. For example, there is no separate adhesive or other intermediate layer between the barrier layer and the active layer of the functional element.

[0087] The barrier layer and any other barrier layers present are preferably designed such that they prevent the plasticizer from diffusing through the respective barrier layer to the same or greater extent as the plasticizer diffusing through the planar electrode.

[0088] In an advantageous embodiment of the invention, the barrier layer is designed to prevent the plasticizer from diffusing from the thermoplastic interlayer through the barrier layer.

[0089] The barrier layer is preferably a single layer or a multi-layer layer, such as a two-layer, three-layer, four-layer, or five-layer layer. Each layer of the barrier layer is also referred to below as a single layer and may be composed of the same or different materials.

[0090] The barrier layer can be completely opaque, partially opaque, partially transparent, or translucent. The opaque areas of the barrier layer can be achieved, for example, by coloring or staining the desired areas.

[0091] The barrier layer and any additional barrier layers present preferably comprise polyethylene terephthalate (PET) or polyvinyl fluoride (PVC) or composed thereof. Alternatively, the barrier layer and any 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 laminated panes.

[0092] In an advantageous embodiment, one or more adhesion-enhancing layers may be disposed between the functional element and the barrier layer, as well as any additional barrier layers that may be present. In particular, the peripheral edge surfaces of the active layer of the functional element must undergo an adhesion-promoting surface treatment.

[0093] In an advantageous embodiment, an additional barrier layer comprising one or more single layers has a thickness of 10 nm to 50 μm (nanometers), preferably 15 nm to 25 μm, and particularly preferably 15 nm to 5 μm (also referred to as material thickness).

[0094] The barrier layer, consisting of one or more individual layers, preferably has a thickness of 0.02 mm to 0.2 mm, more preferably 0.04 mm to 0.15 mm. The specified thickness refers to the total thickness of all possible individual layers. With such a layer thickness, visible light is completely blocked in the opaque regions of the barrier layer, preventing visible light from transmitting through these regions.

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

[0096] In a preferred embodiment of the invention, the barrier layer is at least partially disposed, preferably applied, to the 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 located between the main surface of the active layer facing the outward pane and the main surface of the active layer facing the inward pane. The circumferential edge surface connects the two main surfaces of the active layer. The active layer preferably has no other surfaces besides the two main surfaces and the circumferential edge surface.

[0097] The glass window element is equipped with a light source suitable for coupling light into the laminated window pane. During operation, the light source emits visible light, i.e., electromagnetic radiation in the visible spectrum, particularly from 400 nm to 800 nm. The light source may have one or more emission bands arranged within and covering a portion of the visible spectrum. However, the light source may also have a wide emission band covering the entire visible spectrum. The emission band(s) can be freely selected according to the requirements of the specific application, and thus the color of the radiated light can be freely selected.

[0098] The glass window element may have a single light source or multiple separate light sources whose light is coupled to the laminated window pane at different points, or more specifically to an optical waveguide.

[0099] The light source preferably includes at least one light-emitting diode (LED). The light source may be a single LED, but is preferably an arrangement of multiple LEDs. This arrangement is preferably mounted in a common housing, for example, as a linear arrangement in which the LEDs are arranged along a line. The electroluminescent material of the LED may 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).

[0100] Optionally, a collimator may be arranged between the light source and the laminated 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 inner surface of the optical waveguide, particularly between the light source and the inner surface of the inner pane, such that light radiates into the laminated pane or into the optical waveguide via the collimator. The collimator generates a beam from the typically divergent beam of the light source, which preferably has a substantially parallel beam path, but at least a less divergent (i.e., more concentrated) beam path. Thus, the beam cone of the light source is narrowed by the collimator. This has the advantage that the entire beam radiates into the laminated pane at the same angle of incidence. In particular, if the optical waveguide is provided with a reflective structure having such a substantially converging angle of incidence, a large proportion of the light can be coupled into the optical waveguide via the reflective structure, resulting in total internal reflection. Therefore, the light output is optimized.

[0101] In its simplest case, the collimator is a type of converging lens in which the light source is preferably positioned at its focal point. The collimator can be formed, for example, of glass or a transparent plastic material, particularly polycarbonate (PC) or polymethyl methacrylate (PMMA). The collimator is preferably attached (e.g., adhesively bonded) to the inner surface of the inner pane. If the light source is formed as an arrangement of multiple light-emitting diodes (LEDs), a separate collimator can be provided for each LED. Preferably, however, a common collimator is used for the entire LED arrangement. In the case of a linear LED arrangement, a rod-shaped collimator can be used, for example, whose length at least corresponds to the length of the LED arrangement.

[0102] 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 particularly 280 lm / m. Most preferably, the light source comprises at least one light-emitting diode having a luminous intensity of at least 200 lm / m, preferably 240 lm / m, and particularly 280 lm / m. At such high light intensities, a larger proportion of the light is coupled into the laminated window panes. "lm / m" means "lumens per meter," that is, the luminous intensity per meter.

[0103] Laminated panes preferably have a masking area independent of the barrier layer, and it is impossible to see through the masking area. This masking area is referred to as the masking area of ​​the laminated pane, and is preferably arranged circumferentially in the edge area of ​​the laminated pane and surrounds the central area of ​​the laminated pane intended for visibility in a frame-like manner. This is particularly common for vehicle panes. The masking area is particularly formed by elements (e.g., by a covering imprint). The masking area is particularly preferably formed by a covering imprint on the inner surface of the outer pane. Preferably, the masking area completely covers a sub-area of ​​the inner pane. Such a covering imprint is typically made of enamel, which contains glass frit and black pigment, and is applied using a screen printing method and subsequently baked into the surface. Despite the substantially covering effect, such a covering imprint does not completely block light emitted by a light source, so that even when the outer surface of the outer pane is viewed from above, light not coupled into the laminated pane will be visually perceptible, depending on the arrangement of the light source relative to the masking area. In other words, in this type of glass window element, light from the light source is at least partially perceptible visually from the external environment because the covering imprint does not completely block the light. The covering imprint preferably has an optical density of up to 3.5, preferably up to 3.0.

[0104] In a preferred embodiment of the invention, an IR reflective coating is provided on the inner surface of the outer window pane. The IR reflective coating comprises, for example, a conductive metal, preferably silver. Specifically, the IR reflective coating comprises at least two, preferably at least three silver layers, wherein the silver layers are arranged in a stacked order, and at least one dielectric layer is disposed between the silver layers. Particularly preferably, the IR reflective coating extends over the entire inner surface of the outer window pane, except for the frame-like edge region. The uncoated edge region of the outer window pane is protected from corrosion by moisture penetrating the IR reflective coating.

[0105] Specifically, the frame-like edge region of the outer window pane is peeled off using a decomposition layer. If the decomposition layer comes into contact with the IR-reflective coating, a chemical reaction occurs, thus decomposing the IR-reflective layer; that is, the area is thereby stripped of the coating, and the reaction products of the two layers form a covering imprint in the stripped area. However, it is particularly important to note that this type of covering imprint does not completely block light from the light source. Particularly preferably, the covering imprint formed by the decomposition layer and the IR-reflective coating is arranged to overlap with a sub-region of the inner window pane. The covering imprint formed in this manner preferably has an optical density of at most 3.5, preferably at most 3.0.

[0106] The decomposition layer preferably comprises zirconium oxide-based particles. The zirconium oxide-based particles comprise at least 80% by weight, particularly at least 85% by weight, zirconium oxide (ZrO2). The zirconium oxide is preferably stabilized, particularly by means of yttrium. It may also contain additives, particularly selected from Al2O3, TiO2, ZnO, SiO2, and mixtures thereof. Particularly preferably, the zirconium oxide-based particles have a chemical composition particularly comprising the following components within the following weight range: - ZrO2: 83-97% - Y2O3: 2-8% - Al2O3: 0-3% - Black pigment: 0-6%, especially 1-6%.

[0107] Various embodiments of the present invention may be implemented individually or in any combination.

[0108] The glass window element according to the present invention can be manufactured by the following method: (A) Provides an outer window pane, an inner window pane, a thermoplastic intermediate layer, a functional element with controllable optical properties, and a barrier layer having at least one opaque area for reducing plasticizer diffusion; (B) A thermoplastic interlayer is arranged between the outer window pane and the inner window pane, wherein the functional elements are arranged within the interlayer; (C) The barrier layer is arranged such that the opaque area of ​​the barrier layer extends at least over the sub-area of ​​the inner window pane, and the barrier layer is in direct spatial contact with the functional element at least in the edge area of ​​the functional element. (D) Laminating the outer pane, inner pane, functional elements, barrier layer, and intermediate layer to form a laminated pane; and (E) Arrange laminated panes and light sources designed to couple visible light into the laminated panes to form glass window elements, wherein the light sources are arranged in sub-regions of the inner panes that do not at least partially overlap with the functional elements.

[0109] Laminated window panes can be produced using methods known per se for lamination, such as autoclave processes, vacuum bag processes, vacuum ring processes, calendering processes, vacuum laminators, or combinations thereof. Outer and inner window panes are typically joined under the influence of heat, vacuum, and / or pressure.

[0110] The laminated window panes of the glass window element according to the invention can be used as window panes of vehicles. A particularly preferred application is as top window panes of vehicles that can be three-dimensionally illuminated. In principle, the vehicle can be any land vehicle, water vehicle, or aircraft, and is preferably a passenger car, a heavy cargo vehicle, or a rail vehicle. The glass window element can also be used in buildings; for example, the laminated window panes can be used as window panes, glass curtain walls, or glass doors in exterior or interior areas, particularly as window panes in buildings or interiors. The glass window element can also be used as components of furniture, appliances, decorative components, or decorative items.

[0111] The invention will now be explained in more detail with reference to the accompanying drawings and exemplary embodiments. The drawings are schematic and not to scale. The drawings do not limit the invention in any way. Attached Figure Description

[0112] In the attached diagram: Figure 1 This is a plan view of the laminated window pane of the glass window element according to the present invention; Figure 2 It comes from Figure 1 A cross-sectional view of the glass window element; Figure 3 It comes from Figure 2 Enlarged details of the edge region of the glass window element in a cross-sectional view; and Figure 4-5 A further embodiment of the glass window element according to the invention is shown in cross-sectional view. Detailed Implementation

[0113] Figures 1 to 3 Different aspects of a first embodiment of the glass window element 101 according to the present invention are shown. Figure 2 Shown in Figure 1 The cross-sectional view of the glass window element 101 shown in the plan view is shown in the figure. The cutting line of the cross-section is... Figure 1 The middle is indicated by the dashed line X–X'. Figure 3 A magnified detail Z of the edge region of the glass window element 101 is shown. Detail Z is... Figure 2 The center is indicated by a circular dashed line.

[0114] The laminated window pane 100 is constructed, for example, as a roof pane of a vehicle, particularly a passenger car. For simplicity, it is shown as flat, but such a roof pane of a vehicle is typically curved. The laminated window pane 100 is structurally formed by the following: an outer window pane 1; an inner window pane 2, which also serves as an inner window pane; and a thermoplastic interlayer 3, through which the outer window pane 1 and the optical waveguide 2 are connected to each other. The outer window pane 1 and the inner window pane 2 are, for example, made of soda-lime glass, and in each case have a thickness of, for example, 2.1 mm. Functional elements 4 (e.g., PDLC functional elements) are arranged within the thermoplastic interlayer 3. The functional elements 4 are divided into a total of four segments 4'.

[0115] Intermediate layer 3 has a first thermoplastic interlayer 3.1 disposed between outer window pane 1 and functional element 4. Intermediate layer 3 also has a second thermoplastic interlayer 3.2 disposed between inner window pane 2 and functional element 4. Functional element 4 extends over the entire surface of laminated window pane 100, except for the edge region surrounding the functional element 4 in a frame-like manner. Disposed in this region of laminated window pane 100 surrounding functional element 4 in a frame-like manner is a third thermoplastic interlayer 3.3, which represents a "picture frame" for functional element 4. The third thermoplastic interlayer 3.3 has approximately the same thickness as functional element 4, such that there are almost no local differences in thickness within laminated window pane 100. The third thermoplastic interlayer 3.3 is disposed between the first thermoplastic interlayer 3.1 and the second thermoplastic interlayer 3.2. The overall thickness of thermoplastic interlayer 3 is, for example, 0.76 mm. In this context, total thickness refers to the total visible thickness of all layers of the thermoplastic interlayer 3.1, 3.2, and 3.3. The inner pane 2 and the interlayer 3 are clear and transparent, while the outer pane 1 is stained, for example, to reduce light transmission through the laminated pane 100 (e.g., to less than 15%), as is common in top panes of vehicles.

[0116] In the installation position, the outer pane 1 faces the external environment of the vehicle. The outer pane 1 has an outer surface I facing the external environment and an inner surface II facing the interior of the vehicle. The inner pane 2, which also acts as an optical waveguide, faces the interior of the vehicle during installation. The inner pane 2 has an outer surface III facing the external environment and an inner surface IV facing the interior of the vehicle. The inner surface II of the outer pane 1 and the outer surface III of the inner pane 2 are connected to each other via a thermoplastic interlayer 3. The functional element 4 has an outer surface V facing the outer pane 1 and an inner surface VI facing the inner pane 2.

[0117] The laminated window pane 100 has a frame-shaped peripheral masking region in which a black covering imprint 15 is applied to the inner surface II of the outer window pane 1, blocking the view through the laminated window pane 1. The covering imprint 15 is produced, for example, by a chemical conversion between a decomposition layer and an IR reflective layer on the inner surface II of the outer window pane 1. The IR reflective layer (not shown here) is applied, for example, to the entire inner surface II of the outer window pane 1, and then disposed of by means of a decomposition layer in the frame-shaped peripheral edge region of the laminated window pane 100, which is intended to serve as a masking region. This produces the covering imprint 15 in the edge region and results in the loss of IR reflective properties. The IR reflective layer comprises, for example, three silver layers, and the decomposition layer comprises, for example, zirconium oxide-based particles.

[0118] The glass window element 101 includes a light source 5, which is arranged in a sub-region B of the inner window pane 2 on the inner surface IV of the inner window pane 2. On the outer surface III of the inner window pane 2, in the sub-region B, a coupling member 13 is arranged; that is, when viewed through the laminated window pane 100, the coupling member 13 is arranged to overlap with the light source 5, such that visible light 7 emitted orthogonally from the light source 5 and the inner surface IV of the inner window pane 2 illuminates the coupling member 13. The coupling member 13 is, for example, a reflective structure in the form of a silver-coated microprism film, which is applied to the inner window pane 2 by means of an optically transparent adhesive (not shown here). The sub-region B of the inner window pane 2 is located in the peripheral edge region of the laminated window pane 100 and does not overlap with the functional element 4 when viewed through the laminated window pane 100.

[0119] The inner window pane 2 is designed as a light-guiding medium, allowing light to be coupled into it and to be transmitted through total internal reflection (see [reference]). Figure 2The light 7 from the light source 5 first enters the inner pane 2 through the inner surface IV and is then transmitted through the inner pane 2. The light 7 then exits the inner pane 2 via the outer surface III and is transmitted through an optically transparent adhesive disposed between the coupling member 13 and the inner pane 2. The light 7 then illuminates the coupling member 13 and is reflected back towards the inner pane 2 by the reflective silver coating at a coupling angle. Reflection at a suitable coupling angle (i.e., the angle at which visible light 7 is coupled into the inner pane 2) can be generated by the surface of the microprism film tilted towards the outer surface III of the inner pane 2. After being transmitted through the optically transparent adhesive, the light 7 illuminates the inner pane 2 and is coupled into the inner pane 2. The light 7 propagates in the inner pane 2 until it illuminates the inner pane 2 or the side edge of the coupling element 14. At the side edge or the coupling element 14, the light 7 is coupled out of the inner pane 2. The laminated pane 100 includes a coupling element 14 on the surface of the second thermoplastic interlayer 3.2 facing the inner pane 2. The coupling element 14 is, for example, an imprint on the second thermoplastic interlayer 3.2. The coupling element 14 is in direct spatial contact with the outer surface III of the inner window pane 2.

[0120] The functional element 4 includes, in sequence, a first carrier film 10.1, a first planar electrode 11.1, an active layer 12, a second planar 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 inner surface VI of the functional element 4. The term "exposed surface" refers to the surface of the functional element 4 that is in direct contact with the thermoplastic interlayer 3. The carrier films 10.1 and 10.2 are, for example, transparent films based on PET. The planar electrodes 11.1 and 11.2 are formed, for example, based on a transparent conductive oxide, preferably indium tin oxide (ITO), and are applied to the carrier films 10.1 and 10.2 adjacent to the planar electrodes 11.1 and 11.2 by means of magnetron sputtering. The active layer 12 is, for example, the liquid crystal layer of a typical PDLC functional element.

[0121] Planar electrodes 11.1 and 11.2 each extend over the entire surface of their applied carrier films 10.1 and 10.2. The carrier films 10.1 and 10.2 extend over the entire region of the active layer 12 and additionally extend around a protrusion C extending beyond the entire region of the active layer 12. The protrusion C of the carrier films 10.1 and 10.2 exists only in a portion of the circumferential edge surface K of the functional element 4. The protrusion C of the first carrier film 10.1 is arranged on the portion (circumferential edge surface K) opposite to the protrusion (not shown) of the second carrier film 10.2. Busbars (not shown) can be applied to these protrusions C and supply voltage to the planar electrodes 11.1 and 11.2, thereby adjusting the optical state of the active layer 12. For this purpose, the busbars are connected to a voltage source, for example, via a flat conductor (not shown) extending from the lamination pane 100.

[0122] Barrier layers 6 and 6' are arranged around the edge surface K of the functional element 4 and specifically prevent moisture or plasticizer from the thermoplastic intermediate layer 3 from penetrating into the active layer 12. A partially opaque barrier layer 6 is arranged on a portion of the peripheral edge region R of the functional element 4. Barrier layer 6 is also arranged in the edge region R of the second carrier film 10.2. Barrier layer 6 is also arranged in some areas on the protrusions C of the second carrier film 10.2, which are also surrounded by the peripheral edge region R of the functional element 4. Excluding the portion of the edge region R of the functional element 4, barrier layer 6 also extends over the entire sub-region B of the inner window pane 2. Barrier layer 6 is preferably completely opaque. In this case, opacity means a light transmittance of less than 5%. The opaque region 8 of barrier layer 6 extends over the entire sub-region B of the inner window pane 2. Barrier layer 6 has, for example, a constant layer thickness of 0.15 mm and is formed based on PET. The barrier layer 6 is disposed at the interface between the functional element 4 or the third thermoplastic interlayer 3.3 and the second thermoplastic interlayer 3.2, and to the greatest extent possible prevents plasticizer from the second thermoplastic interlayer 3.2 from penetrating into the functional element 4 or into the active layer 12 in the edge region R of the functional element 4.

[0123] An additional barrier layer 6' is disposed in other portions of the circumferential edge region R of the functional element 4. This additional barrier layer 6' is disposed not only on the first carrier film 10.1 but also on the second carrier film 10.2. Specifically, the additional barrier layer 6' is also disposed on the entire circumferential edge surface K of the functional element 4. "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 films 10.1, 10.2 and the planar electrodes 11.1, 11.2. Thus, the additional barrier layer 6' can either cover only the active layer 12 or cover the active layer 12 and partially cover the edge surfaces of the carrier films 10.1, 10.2 and the planar electrodes 11.1, 11.2.

[0124] The opaque region 8 of the barrier layer 6 in sub-region B of the inner window pane 2 effectively prevents light loss 7 from the light source 5 from radiating into the external environment through the outer window pane 1. Alternatively, the light loss 7 is absorbed by the opaque region 8 of the barrier layer 6. The barrier layer 6 also largely prevents plasticizers or moisture from diffusing through it, thus improving the long-term stability of the functional element 4. Since the barrier layer 6 can address two technical issues simultaneously, material is saved, and therefore costs are reduced. The light 7 of the light source 5 cannot be completely blocked by the overlay imprint 15 alone. That is, for the overlay imprint 15, an atypical layer thickness would be required, which would lead to an undesirable reduction in the quality of the laminated window pane 100.

[0125] The light source 5 is formed, for example, as a strip LED or formed by multiple strip LEDs. For example, the light source 5 has a luminous intensity of 280 lm / m. A collimator may optionally be arranged between the light source 5 and the inner pane 2 (not shown here). The collimator acts as a type of converging lens and reduces the beam cone of the light source 5; ideally, the collimator results in a parallel beam path for the light 7 emitted by the light source 5.

[0126] Figures 4 to 5 The variant shown basically corresponds to the one from Figures 1 to 3 The variations therein mean that only the differences will be discussed here, and references will be made to other aspects. Figures 1 to 3 Related descriptions.

[0127] exist Figure 4 In this design, light source 5 is arranged in a recess of the inner window pane 2. The light source 5 is arranged in the recess such that light 7 is directly coupled into the inner window pane 2 via a circumferential edge surface arranged in the recess. The recess is, for example, a hole in the inner window pane 2. Within the meaning of this invention, the recess of the inner window pane 2 is a component of the inner window pane 2, such that, within the meaning of this invention, the light source 5 is arranged in a sub-region B of the inner window pane 2. Here, the laminated window pane 100 does not include a coupling member 13 because light 7 is directly coupled into the recess via the edge surface. Here, light loss radiated towards the outer window pane 1 may also occur. However, due to absorption in the opaque region 8 of the barrier layer 6, this light will not penetrate the outer window pane 1 and enter the external environment.

[0128] exist Figure 5 In this embodiment, the inner window pane 2 is not an optical waveguide; instead, the laminated window pane 100 includes an optical waveguide 9, for example, in the form of a transparent PET film, disposed between the functional element 4 and the inner window pane 2 and within a second thermoplastic interlayer 3.2. The coupling element 13 is introduced into the optical waveguide 9, for example, by roughening the area of ​​the surface of the optical waveguide 9 facing the outer window pane 1. The coupling element 14 is applied, for example, as an imprint, to the surface of the optical waveguide 9 facing the inner window pane 2.

[0129] Reference number list 1. Exterior window pane 2. Inner window panes 3. Thermoplastic interlayer 3.1 First thermoplastic interlayer 3.2 Second thermoplastic interlayer 3.3 Third thermoplastic interlayer 4 Functional Components 4' Segment of functional element 4 5. Light source 6 Barrier Layer 6' Additional barrier layer 7 Visible light 8. Opaque areas of barrier layer 6 9 Optical waveguide 10.1 First carrier membrane 10.2 Second carrier membrane 11.1 First planar electrode 11.2 Second planar electrode 12 Active Layer 13 Coupling components 14 Coupling elements 15 Covering Imprint 100 laminated window panes 101 Glass Window Components Z-cut I. Outer surface of outer window pane 1 II. Inner surface of outer window pane 1 III. Outer surface of inner window pane 2 IV. Inner surface of inner window pane 2 V outer surface of functional element 4 VI. Inner surface of functional element 4 Sub-region of inner pane 2 (B) C. Protrusions of the second carrier membrane 10.2 K functional element 4 edge surface The peripheral edge region of functional element 4 (R) XX' Intersecting lines.

Claims

1. An illuminated glass window element (101) with controllable optical properties, comprising: - A laminated pane (100), which includes: - Outer window pane (1), inner window pane (2) and thermoplastic interlayer (3) disposed therebetween; - A functional element (4) with controllable optical properties is arranged within the thermoplastic intermediate layer (3); - A barrier layer (6) for reducing plasticizer diffusion, having at least one opaque area (8); and - A light source (5) for coupling visible light (7) into the laminated window pane (100), The light source (5) is arranged in a sub-region (B) of the inner window pane (2) that does not at least partially overlap with the functional element (4), and, The opaque region (8) of the barrier layer (6) extends at least over the sub-region (B), and the barrier layer (6) is in direct spatial contact with the functional element (4) at least in the edge region (R) of the functional element (4).

2. The illuminateable glass window element (101) according to claim 1, wherein, The entire barrier layer (6) is opaque.

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

4. The illuminateable glass window element (101) according to claim 3, wherein, The second thermoplastic interlayer (3.2) is disposed between the functional element (4) and the inner window pane (2), and the barrier layer (6) is disposed between the functional element (4) and the second thermoplastic interlayer (3.2).

5. The illuminateable glass window element (101) according to any one of claims 1 to 4, wherein, The thermoplastic interlayer (3) includes a thermoplastic interlayer film (3.3) surrounding the functional element (4) in a frame-like manner.

6. The illuminateable glass window element (101) according to any one of claims 1 to 5, wherein, The sub-region (B) of the inner pane (2) does not overlap with the functional element (4) at all.

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

8. The illuminateable glass window element (101) according to any one of claims 1 to 7, wherein, The light source (5) is arranged relative to the laminated pane (100) such that visible light (7) emitted by the light source (5) can be coupled into the inner pane (2).

9. The illuminateable glass window element (101) according to any 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 laminated pane (100) such that the visible light (7) emitted by the light source (5) can be coupled into the optical waveguide (9).

10. The illuminateable glass window element (101) according to any one of claims 1 to 9, wherein, The coupling component (13), preferably a microprism film, is arranged between the light source (5) and the barrier layer (6).

11. The illuminateable glass window element (101) according to any one of claims 1 to 10, wherein, The functional element (4) is a PDLC functional element, which includes, in sequence, a first carrier film (10.1), a first planar electrode (11.1), an active layer (12), a second planar electrode (11.2), and a second carrier film (10.2).

12. The illuminateable glass window element (101) according to claim 11, wherein, The second carrier film (10.2) has protrusions (C) in at least some portions relative to the active layer (12), and the barrier layer (6) is in direct spatial contact with the protrusions (C).

13. The illuminateable glass window element (101) according to any one of claims 1 to 12, wherein, The barrier layer (6) comprises polyethylene terephthalate or polyvinyl fluoride or is composed of the same.

14. The illuminateable glass window element (101) according to any one of claims 1 to 13, wherein, The barrier layer (6) has a thickness of 0.02 mm to 0.2 mm, preferably 0.04 mm to 0.15 mm.

15. The illuminateable glass window element (101) according to any 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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