Vehicle window panel with composite structure

Abstract

The invention relates to a vehicle pane (11), in particular a pane of a roof (10), comprising a composite structure having a pane outer body (16), a light-shielding component (20), a pane inner body (18) and a light-conducting layer (40), the light-shielding component (20) being arranged between the pane outer body (16) and the pane inner body (18) and comprising a switchable liquid crystal component (26). According to the invention, the light-shielding arrangement (20) comprises a carrier layer (15) which is arranged directly or indirectly on an outer side (41) of the light-guiding layer (40) oriented in the direction of the light-shielding arrangement (20) and which has a coating (17) made of a material having a refractive index n2 which is smaller than the refractive index n1 of the material constituting the light-guiding layer (40).

Description

Field of the Invention

[0001] The present invention relates to a vehicle window pane having the features of the preamble of claim 1. Background Art

[0002] Such vehicle window panes are known in practice and can in particular be used as fixed roof elements in the roof area or as adjustable cover elements of a roof opening system. The vehicle window pane is constructed as a composite member and includes an outer window pane body facing the vehicle surroundings and an inner window pane body facing the vehicle interior space and forming the inner view surface of the vehicle window pane. A light-shielding assembly is usually arranged between the inner window pane body and the outer window pane body, and the light-shielding assembly includes a liquid crystal assembly that can be switched electrically, namely a so-called LC layer (liquid crystal layer) or PDLC layer (polymer dispersed liquid crystal layer). The LC layer or PDLC layer is arranged between two films, and transparent electrodes are respectively arranged on the inner sides of the two films. Through these electrodes, the LC layer or PDLC layer can be switched between a through state and a blocking state.

[0003] In known applications, the liquid crystal assembly and / or the plastic film are constructed to be semi-transparent or translucent. In order to match the vehicle appearance, for example, dyed glass is used for the inner window pane body and / or the outer window pane body, or a dyed or tinted (polymer) adhesive film is used. Due to the increased haze, accommodating a dyed film or the like in the composite structure may cause the vehicle window pane to be blurred. In addition, especially dyed or tinted adhesive films result in increased costs compared to traditional transparent adhesive films because the dyeing and / or tinting costs are high. The multiple layers of the composite structure that may also include a dyed intermediate layer also make the manufacturing complex and result in high manufacturing costs.

[0004] Similarly, it is known from the prior art to couple the light of a light source directly or with the use of a prism or other coupling elements into a light conductor layer. The use of a prism or coupling elements enables a more free choice when placing the light source because the light source no longer has to be directly arranged in the edge region of the light conductor layer. The advantage of this design freedom is that, unlike in the case of being directly arranged in the edge region of the light conductor layer, the light source is no longer arranged in a humid area but can also be arranged in a moisture-proof dry area. Thereby, seals and / or moisture-proof protection elements can be omitted. For example, by using a prism (which is applied, for example, on the inner side of the light conductor layer used), the light source can be arranged laterally below the edge region of the light conductor layer, especially offset from the edge region. Light coupling can also be directly achieved on the inner side of the inner window pane body. In addition, some vehicle window panes are known in which light is coupled into the inner window pane body by a light source arranged in the edge region of the vehicle window pane.

[0005] In the case of known optical coupling of light from a light source into a photoconductive layer, light losses inevitably occur. On the one hand, these light losses negatively affect the light quality or light intensity of the light subsequently coupled out from the photoconductive layer. On the other hand, these light losses may have to be compensated for by using a stronger or brighter light source and / or by increasing the number of light sources, resulting in additional cost expenses. For example, in known optical coupling, the light beam not only couples into the photoconductive layer via the optical coupling surface of the photoconductive layer from the light source, and especially remains in the photoconductive layer until it is coupled out due to multiple total internal reflections within the photoconductive layer. However, at least a part of the coupled-in light beam is transmitted in the direction towards the outer body of the window pane through the inner body of the window pane configured as the photoconductive layer, and for example enters the upper polymer adhesive layer and / or the light-shielding component arranged above the polymer adhesive layer, especially at least into at least one of the plastic films and / or the liquid crystal component, and / or even until it enters the tinted outer body of the window pane. Especially in the case of a polymer adhesive layer that is tinted, dyed or black-dyed, this undesired light emitted from the photoconductive layer is absorbed. This part of the light is no longer available for the optical coupling out from the photoconductive layer, which is manifested as a lower luminous density. The undesired optical coupling out from the photoconductive layer especially leads to the fact that, due to the differences in the refractive indices of different layers, the coupled-in light tends to leave the photoconductive layer and enter the adjacent interface layer, such as the adjacent air layer or polymer adhesive layer. This results in light losses. Here, the closer the refractive index of the surrounding medium and / or material is to the refractive index of the photoconductive layer or the inner body of the window pane, the stronger the light losses caused by the undesired optical coupling out into the surrounding layer.

[0006] As a solution, it is known from the prior art that the outer side of the inner body of the window pane, which serves as the photoconductive layer and is oriented towards the outside of the vehicle, is provided with a coating having a low refractive index, so as to increase the difference between the refractive index of the inner body of the window pane and the refractive index of the coating in this way, such that the share of the undesired optical coupling out from the photoconductive layer is reduced, and the light losses can be significantly reduced in this way. It is also known that a film is laminated on the outer side of the inner body of the window pane, and the film is made of a material having a refractive index lower than that of the inner body of the window pane. The light losses can also be significantly reduced in this way. However, such a film is costly. In addition, the coating of the inner body of the window pane incurs high manufacturing costs.

[0007] As an exemplary prior art, it may relate to patent documents US2016 / 0349442A1, US2016 / 0325528A1 and DE202120100843U1.

[0008] Although solutions for reducing light losses are already known in the prior art, there is still a need for further alternative solutions, which can especially achieve low-cost and simple manufacturing of composite structures. Summary of the Invention

[0009] Therefore, the object of the present invention is to further develop a vehicle window pane in such a way that the above-mentioned disadvantages are at least partially minimized, and in particular to provide an alternative technical solution which in particular enables a low-cost and simple manufacture of a composite structure, by means of which light losses can be minimized.

[0010] According to the present invention, this object is solved by a vehicle window pane having the features of claim 1.

[0011] Preferred embodiments of the present invention are the subject matter of the dependent claims. Within the scope of the present invention, all combinations of at least two features disclosed in the description, the claims and / or the drawings are included. It goes without saying that the statements made with respect to the vehicle window pane apply mutatis mutandis to the vehicle and / or roof according to the present invention, without repeating them here for that purpose. In particular, it should be understood here that within the scope of the usual language practice, common linguistic transformations and / or reasonable substitutions of the corresponding terms, in particular the use of synonyms supported by generally recognized linguistic literature, are within the scope of this disclosure, even if not explicitly mentioned in their respective formulations.

[0012] Therefore, according to the present invention, there is provided a vehicle window pane, in particular a window pane of a roof, the vehicle window pane comprising a composite structure having an outer window pane body, a light-shielding assembly, an inner window pane body and a light conductor layer, wherein the light-shielding assembly is arranged between the outer window pane body and the inner window pane body. The light-shielding assembly comprises a liquid crystal assembly, which is preferably arranged between two plastic films. According to the present invention, the light-shielding assembly comprises a carrier layer, which is arranged directly (i.e., in particular without interposing other layers) or indirectly (in particular via at least one additional layer, such as a polymer adhesive layer or another adhesive layer) on the outer side of the inner window pane body. For the present invention, it is preferred that the color adjustment part or the color adjustment function is realized within the light-shielding assembly, rather than between the low-reflection layer and the light conductor layer. Accordingly, if the color adjustment part is realized by means of a colored polyvinyl butyral (PVB) arranged towards the light conductor layer, the present invention does not apply. The carrier layer has a layer, in particular a coating, made of a material whose refractive index n2 is less than the refractive index n1 of the material constituting the light conductor layer.

[0013] Particularly preferably, the inner window pane body is configured as a light conductor layer. However, alternatively, the composite structure may also comprise an additional layer configured as a light conductor layer, which is made of plastic, for example. The light conductor layer is preferably configured to conduct light coupled into the vehicle window pane.

[0014] If the liquid crystal module includes at least one plastic film, preferably, at least one of the plastic films and / or the liquid crystal module itself includes a black dyeing portion and / or a color adjusting portion and / or a dyeing portion. By adjusting the color and / or blackening and / or dyeing the liquid crystal module and / or the plastic film, the brightness of the light incident through the vehicle window pane can be preferably reduced. The liquid crystal module can be a liquid crystal layer (LC layer) or a polymer dispersed liquid crystal layer (PDLC layer). Herein, the "black dyeing portion" should be understood in the broadest sense and includes deep black, dark gray, and other dyeing states.

[0015] By providing a carrier layer with a coating having a low refractive index according to the present invention, it is possible to dispense with coating the outer side of the inner body of the window pane, which is usually configured as a light conductor layer, as practiced in the prior art. In addition, it is also possible to dispense with manufacturing an entire film made of a material having a low refractive index. Compared with the solutions in the prior art, cost can be saved thereby. Moreover, the solution of the present invention has advantages in terms of manufacturing technology, because for example, the carrier layer can be configured as a simple plastic film including the coating of the present invention and can preferably be purchased by the meter. In contrast, in the solutions of the prior art, each inner body of the window pane has to be coated individually, which means increased manufacturing costs. The coating according to the present invention enables effective and efficient reduction of light loss due to light refraction. Thereby, the light density achievable by the light conductor layer is increased, so that the size of at least one light source can be designed smaller if necessary, thereby saving installation space.

[0016] In a preferred embodiment, the refractive index of the coating can be further reduced by configuring the coating or the layer to be porous. Such porosity can be formed, for example, by applying a method or process such as off-axis sputtering or sputtering at a grazing incidence angle with respect to the coating.

[0017] In a preferred embodiment, the carrier layer is made of polycarbonate (PC), polyethylene (PE), and / or polyethylene terephthalate (PET). Other plastic types are also possible. Polycarbonate and polyethylene terephthalate are widely used low-cost materials.

[0018] In a preferred embodiment, the coating is applied to the side of the carrier layer facing the outer side of the light conductor layer. The coating can be applied by printing and / or evaporation and / or in other ways.

[0019] In a preferred embodiment, the coating comprises a fluoropolymer and / or an oxide, in particular silica gel, silicon dioxide (SiO2), and / or comprises magnesium fluoride (MgF2). Silica gel or silicagel is a colorless, amorphous form of silicon dioxide, the consistency of which ranges from gel-like, rubbery to solid. Crystalline silicon dioxide can be formed in the case of high temperatures. The coating based on silicon oxide (SiOx) can form a combination of stoichiometric oxides (in particular SiO2) and non-stoichiometric lower oxides (such as SiOx, x < 2, based on SiO2 as the stoichiometric base oxide) depending on the oxygen content present. As a powder, it has strong hygroscopicity and is suitable for use as a gelling agent, filter material, adsorbent material and desiccant. As a thin layer, it is suitable for use as an insulating and passivating material in semiconductor and optical technologies. Magnesium fluoride (MgF2) is a material that is transparent in the wavelength range between 0.12 µm and 7.5 µm. In addition, it is birefringent. The combination of these two properties enables the manufacture of polarization optical elements.

[0020] In a preferred embodiment, the difference between the refractive index n1 of the inner body of the window pane and the refractive index n2 of the coating is greater than or equal to (≥) 0.06. Alternatively or additionally, the refractive index n2 of the coating is less than or equal to (≤) 1.46. Preferably, the refractive index n1 of the inner body of the window pane is 1.52. Preferably, the refractive index of the first and / or second polymer adhesive layer is 1.48. In other embodiments, the refractive index n2 of the optical isolation layer can be between 1.3 and 1.52, wherein the refractive index can particularly preferably also be less than 1.45. By increasing the pore fraction in the material, the refractive index of the solid can be further reduced.

[0021] In a preferred embodiment, the carrier layer forms the electrode of the liquid crystal assembly on its side facing the light-shielding assembly, and / or comprises a color-tuning part and / or a dyeing part and / or a black dyeing part. In some embodiments, the carrier layer can be a multi-functional film which, in addition to having a low-refractive-index coating, also provides other functions for the vehicle window pane and / or the light-shielding assembly. It can be preferred to color-tune the carrier layer because absorption of light by the color-tuned regions of the carrier layer can be prevented by means of the low-refractive-index coating. Particularly preferably, in the case of color-tuning and / or dyeing, the coating is arranged on the side of the carrier layer facing the inner body of the window pane. Since the coating faces the outside of the light conductor layer and is connected thereto, if necessary, by means of a polymer adhesive layer (such as a so-called second polymer adhesive layer), wherein the polymer adhesive layer is preferably constructed to be transparent, light that is undesirably coupled out of the light conductor layer is coupled back into the light conductor layer again by means of the coating. In other embodiments, the carrier layer itself can also be constructed as an adhesive layer and comprise a coating. A direct attachment to the outside of the light conductor layer can thus be achieved.

[0022] In a preferred embodiment, the light-shielding assembly includes other colored and / or dyed and / or transparent plastic layers and / or additional adhesive layers, in particular transparent adhesive layers and / or layers for reflecting infrared radiation. Thus, the light-shielding assembly can have a multi-layer structure. In addition, each layer can in turn be divided into multiple layers. For example, the plastic film of the light-shielding assembly itself can comprise multiple layers, thus forming a film laminate.

[0023] Particularly preferably, the carrier layer is composed of at least one plastic layer of the light-shielding assembly and / or of at least one polymer adhesive layer and / or of an additional adhesive layer, and the at least one plastic abuts the liquid crystal assembly.

[0024] Particularly preferably, the carrier layer is herein configured as one of the colored plastic layers of the light-shielding assembly. In this way, it is also possible to dispense with the provision of an additional carrier layer, and the existing plastic layers of the light-shielding assembly can be utilized in a synergistic manner. Compared with the prior art, the function of the colored plastic layer of the light-shielding assembly (which preferably bounds the liquid crystal assembly at least on one side) is thus extended by the provision of the coating. The plastic film of the light-shielding assembly preferably comprises polycarbonate, polyethylene or polyethylene terephthalate.

[0025] As described above, preferably at least one of the plastic films and / or the liquid crystal assembly includes a black dyeing portion and / or a tinting portion and / or a dyeing portion. With such a liquid crystal assembly, it is possible to dispense with other colored intermediate layers or dyed windowpane inner bodies for adapting the vehicle windowpane to the light transmittance. It is also possible to dispense with a large number of optionally dyed intermediate films and / or dyed polymer adhesive layers, etc., which can in turn result in a lower haze (preferably also a lower fogginess) compared with known vehicle windowpanes, and thus can result in a better visual appearance. Even so, the vehicle windowpane still meets high safety requirements, specifically even when used as a cover element for a roof opening system or a fixed roof element of the roof.

[0026] In the case of the color-tuning section of at least one plastic layer of the light-shielding component, the existing polymer adhesive layer of the vehicle window pane can preferably be configured to be transparent and / or at least partially transparent, especially non-color-tuned. Thereby, compared with the prior art, the light absorption by the polymer adhesive layer is significantly reduced. Therefore, the amount of light available for optical coupling out is increased. For this purpose, alternatively or additionally, due to the lower light loss, the amount of scattering particles in the color of the optical coupling-out structure or the light extraction element can be reduced while maintaining the same brightness. Thereby, for example, in daylight, the optical coupling-out structure is less visible within the vehicle window pane, which results in an improved visual perception for the customer. By omitting the color-tuning section and / or the black dyeing section and / or the dyeing section in the first and / or second polymer adhesive layer, the haze of the entire composite structure is also reduced, so that the vehicle window pane is more transparent as a whole for the customer. In addition, the contrast is also reduced thereby. Furthermore, in a preferred embodiment, costs can be saved by using a cheaper, non-color-tuned polymer adhesive layer. By the coating of the carrier layer according to the invention, especially in combination with such an embodiment, the light loss can be further minimized.

[0027] The transmittance of the composite structure for visible light is preferably low not only in the passing state but also in the blocking state of the liquid crystal component, which preferably results in less light input through the vehicle window pane into the vehicle interior space.

[0028] The preferably color-tuned and / or dyed and / or black-dyed light-shielding component is preferably characterized by strong absorption of electromagnetic radiation in the wavelength range between 350 nm and 2500 nm. For visible light, the transmittance is preferably below 30%. For infrared radiation in the range of 700 nm to 2500 nm, the transmittance can also preferably be below 40%.

[0029] The preferably black-dyed section of the liquid crystal component can especially be defined by the color coordinates L, a, and b in a laboratory color space, where L < 30, -15 < a < 15, and -15 < b < 15.

[0030] The preferably black-dyed section of at least one plastic film of the light-shielding component (if present) and / or of the liquid crystal layer, i.e., especially of the polymer of the liquid crystal layer, can be adjusted by using suitable dyes and / or by a suitable selection of the materials used and their chemical properties.

[0031] According to a preferred embodiment, the liquid crystal component includes a polymer-dispersed liquid crystal layer having a plurality of liquid crystals arranged in a matrix, wherein the plurality of liquid crystals and / or the matrix are dyed and / or color-tuned and / or dyed black. Alternatively, the liquid crystal component may also not include a carrier matrix, as is the case in this liquid crystal layer.

[0032] In the passage state of the liquid crystal component, the preferred haze of the light-shielding component is preferably at most 5%.

[0033] The preferably present plastic films of the light-shielding component preferably each have a transparent electrode on their inner sides, so that the adjacent liquid crystal components can be adjusted between the blocking state and the passage state by changing the electric field. Alternatively, the carrier layer can also include such a transparent electrode.

[0034] The plastic film and / or the carrier layer according to the invention can in particular be configured as a PET (polyethylene terephthalate) film, a COP (cyclic olefin polymer) film or a PC (polycarbonate) film, and can be coated with ITO (indium tin oxide) or PEDOT:PSS in order to form an electrode for the liquid crystal component.

[0035] The liquid crystal component can be a PNLC (polymer network liquid crystal) layer, in which case the passage state is generated by applying a voltage, while the blocking state exists without applying a voltage. Alternatively, the liquid crystal component can also be a layer in which a voltage is applied in each switching state. Then, this is a so-called reversible, bistable PDLC layer. PDLC is a polymer liquid crystal component (polymer dispersed liquid crystal). Irrespective of the selected PDLC layer variant, the PDLC layer can be provided in segments or with a pattern. Alternatively, the liquid crystal component can also be a liquid crystal layer. PDLC in particular has the advantage that there is no change in brightness, but only a change in the haze (blurriness) of the pane, and thus a change in transparency. In a liquid crystal component based on PDLC, preferably only the haze is changed.

[0036] By means of the preferably black dyeing and / or toning of the light-shielding component, it is possible that, in the blocking state of the liquid crystal layer, the transmittance of visible light directly incident on the liquid crystal component is preferably reduced to a value below 2%, in particular even below 1%. In the passage state of the liquid crystal layer, the transmittance of visible light is preferably in the range between 2% and 30%. This is particularly preferred in the case of an LC liquid crystal component.

[0037] In order to ensure the functional ability of the light-shielding component even at high external temperatures, the composite structure of a preferred embodiment of the vehicle pane according to the invention can include at least one layer for reflecting infrared radiation on the side of the liquid crystal component facing the outer body of the pane. Thereby, undesirable defects that may arise due to the absorption of heat by the liquid crystal component can be avoided.

[0038] The reflectivity of the layer for reflecting infrared radiation is preferably greater than 60%. In particular, when the reflectivity of the layer for reflecting infrared radiation is less than 60%, for example, in the range from 2% to less than 60%, an additional layer for reflecting infrared radiation can be provided between the outer body of the window pane and the light-shielding assembly. This additional layer can be additionally arranged on the light-shielding assembly and / or on at least one plastic film of the light-shielding assembly and / or between such a plastic film and the liquid crystal assembly, for example, arranged on an additionally applied film, which can be an infrared-coated PET film, or can also be arranged on the lower side of the outer body of the window pane, or can be arranged in other ways between the outer body of the window pane and the light-shielding assembly. Through this additional layer, the total reflectivity of the composite structure for infrared radiation can reach at least 60%.

[0039] In a special embodiment of the vehicle window pane according to the invention, the layer for reflecting infrared radiation is arranged on the film of the light-shielding assembly facing the outer body of the window pane, specifically in the form of a direct coating or in the form of an additional coated film, which is provided with the layer and is included by the light-shielding assembly. Therefore, the layer for reflecting infrared radiation forms a coating of this film. In a special embodiment of the vehicle window pane according to the invention, at least one preferably existing plastic layer of the light-shielding assembly is provided with a layer for reflecting infrared radiation.

[0040] It is also conceivable that the layer for reflecting infrared radiation is arranged on the inner side of the outer body of the window pane.

[0041] In order to maintain a particularly high reflection effect on infrared radiation and a high transmission ability for visible light, in a special embodiment of the vehicle window pane according to the invention, the layer for reflecting infrared radiation has a multilayer structure, which is a so-called heat layer or heat coating or low-emissivity coating (Low-E = low emissivity). Constructing the layer for reflecting infrared radiation as a multilayer structure results in a high reflectivity especially in the wavelength range between 650 nanometers and 2500 nanometers.

[0042] In particular, a high reflectivity is achieved by the following means: each layer of the layer or multilayer structure for reflecting infrared radiation is composed of at least one material from the following material group, which includes metals such as gold, silver, and copper, and includes oxides such as tin oxide, titanium dioxide, zinc oxide, indium tin oxide, tin fluoride oxide, zinc tin oxide, and aluminum oxide.

[0043] The light-shielding assembly preferably provided with a black staining part is combined with a black ceramic frit in particular to provide a positive visual appearance. The corresponding reflective coating of the light-shielding assembly ensures protection against infrared radiation. The reflective coating not only protects the interior space of the vehicle from excessive heat input but also protects the liquid crystal layer, thus ensuring its function even in the case of high external temperatures.

[0044] The composite structure of the vehicle window panel can preferably have an additional thermal layer (low emissivity layer), which is preferably arranged on the inner side of the window panel inner body. This low emissivity layer is preferably connected to the inner side of the window panel inner body via an additional carrier layer with a low refractive index. All explanations made for the carrier layer according to the invention apply to this additional carrier layer. It is preferred that the window panel inner body forms a light conductor layer. By arranging an additional low emissivity layer on the inner side, the heat output from the vehicle can be minimized. The low emissivity layer at least partially absorbs and / or reflects light of a certain spectrum from the light guide, which leads to a color shift of the light from the coupling point to the center of the light guide (color coordinate inhomogeneity caused by the color coordinate displacement between the input color of the light source and the light absorbed / reflected by the low emissivity layer) or a color shift as the distance from the light source in the light guide increases. In particular, light in the red spectrum is absorbed by the low emissivity layer. The additional carrier layer with a low refractive index leads to a lower outcoupling of light from the light guide into the low-emissivity layer, resulting in a reduced inhomogeneity of the color coordinates of the light in the light guide. In addition, the luminous density in the light guide is almost maintained, thus resulting in a higher luminous density in the light guide over the planar extension of the light guide compared to an embodiment without an additional carrier layer. It is also possible to design the liquid crystal component such that it can be switched in sections and / or can be adjusted continuously between a pass state and a blocking state.

[0045] In a special embodiment of the vehicle window panel according to the invention, the window panel inner body and the window panel outer body are each curved, in particular in the longitudinal direction of the window panel and / or in the transverse direction of the window panel. The radius of curvature defining the curvature can vary in the relevant direction and, for example, have values ​​between 1000 mm and 10000 mm, in particular between 2000 mm and 5000 mm. The sunshade assembly can follow these curvatures.

[0046] Particularly preferably, the vehicle window panel comprises at least one polymer adhesive layer, which is also referred to below by way of example as first and second polymer adhesive layers. Preferably, the shading component is connected to the outer body of the window panel (by means of one of its layers) via the first polymer adhesive layer, in particular directly or indirectly (i.e., if necessary, with at least one further layer arranged in between), and is connected to the inner body of the window panel via the second polymer adhesive layer, in particular directly or indirectly (i.e., if necessary, with at least one further layer arranged in between). Alternatively, for example, only one polymer adhesive layer can also be provided, by which, for example, attachment to the inner body of the window panel can be achieved directly. The shading component comprises a liquid crystal component, which is particularly preferably arranged between two layers of plastic film.

[0047] The attachment of the light-shielding component to the outer body and the inner body of the window pane can be carried out directly by means of (first and / or second) polymer adhesive films, or in the case where additional layers are provided in between, and these additional layers can in turn be connected by adhesive layers.

[0048] Preferred polymer adhesive films are composed of, for example, thermoplastic polyurethane (TPU), ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), epoxy resin, silicone, polyethylene terephthalate or other transparent plastic films. The refractive index of the polymer adhesive film used accordingly is preferably within the range of the refractive index of the inner body or the outer body of the window pane, and has a value of about 1.5, for example.

[0049] In some preferred embodiments, the vehicle window pane further includes at least one light source configured to couple light into the light conductor layer, in particular directly through the inner side of the inner body of the window pane and / or through a coupling-in element. Preferably, a light-coupling-out structure is provided on the outer side of the light conductor layer for light-coupling-out, and the light-coupling-out structure is configured to couple the light coupled into the light conductor layer out of the inner body of the window pane in the direction of the vehicle interior space, in particular directionally and / or in a predetermined manner, preferably in a manner defined by the light-coupling-out structure. The light source is preferably an LED light source and / or includes a plurality of light-emitting diodes. When observing the composite structure, the outer side of the light conductor layer preferably faces the inner side of the inner body of the window pane.

[0050] In order to be able to use the vehicle window pane according to the invention as a so-called ambient light element (which forms a planar or structured light emitter in the vehicle interior space), at least one light source is provided according to the invention, wherein the inner body of the window pane forms a light conductor layer into which the light of the light source can be coupled, such that the inner body of the window pane emits light as a whole or in defined sections. According to the invention, the functions of switchable glass, optional thermal protection function and ambient light illumination function are integrated in the vehicle window pane according to the invention. The light-shielding component according to the invention facilitates the achievement of an ambient light effect. Particularly preferably, at least one light source is arranged directly or indirectly on the inner side of the inner body of the window pane, so that light can be directly coupled in through the inner side of the inner body of the window pane. Alternatively or additionally, a coupling-in element is arranged on the inner side of the inner body of the window pane, and the light source is arranged on the side of the coupling-in element, such that the light emitted by the light source can be deflected and coupled into the light conductor layer through the coupling-in element. The coupling-in element is preferably a body of material transparent to the light of the light source, which is configured in strips and / or has a wedge-shaped or trapezoidal cross-section. The coupling-in element is preferably configured as a prism, which is adhered to the inner side. Particularly preferably, the coupling-in element is a prism. Alternatively or additionally, white and / or translucent scattering structures and / or structured films can be used for vertical light-coupling-in.

[0051] In a preferred embodiment, the coupling-in element is a body of material that is optically transparent to the light of the light source, which is configured strip-shaped and / or has a wedge-shaped or trapezoidal cross-section. The coupling-in element is preferably arranged close to the edge on the inner side of the window pane body assembly. Then, light can be coupled into the light conductor layer of the window pane body assembly through the extension of the strip-shaped coupling-in element. The coupling-in element can be configured, for example, as an optical prism. The coupling-in element is preferably made of a material comprising polymethyl methacrylate (PMMA), polycarbonate (PC), polyamide (PA), cycloolefin copolymer (COC) or cycloolefin polymer (COP). The refractive index of the coupling-in element is particularly adapted to the refractive index of the adjacent light conductor layer and preferably has a value between 1.40 and 1.65, in particular between 1.48 and 1.59. The coupling-in element is preferably manufactured according to an extrusion process or an injection molding process. Alternatively or additionally, the coupling-in element can be made of glass or resin and / or consist of transparent polyurethane and is preferably arranged on the window pane body assembly. To improve internal reflection, the coupling-in element can be provided with a reflective coating, which can comprise a metal such as aluminum or silver and can be applied according to an evaporation process or a sputtering process. To further improve the coupling performance of light into the light conductor layer, in an advantageous embodiment of the vehicle window pane according to the invention, an additional steering structure is arranged between the coupling-in element and the window pane body assembly. By means of this additional steering structure, the angle of incidence of light on the light conductor layer can be changed by corresponding refraction to increase internal reflection in the light conductor layer. The additional steering structure can comprise a row of asymmetric prisms, which have dimensions in the millimeter range or in the micrometer range and which are arranged in a three-dimensional array or linearly, as is the case, for example, in a Fresnel lens array. The additional steering structure can be integrally constructed with the coupling-in element and can be directly constructed during the manufacture of the coupling-in element, for example during an extrusion process or an injection molding process. It is also conceivable that the additional steering structure is a coating of the coupling-in element, for example in the form of a separate structured film.

[0052] In a preferred embodiment, the coupling-in element is adhesively bonded to the window pane body, in particular to the inner side, by means of an adhesive layer. The adhesive layer preferably has a refractive index between 1.40 and 1.65, in particular between 1.48 and 1.56, and the adhesive layer can be composed of any optically suitable adhesive. For example, the adhesive layer is composed of a pressure-sensitive adhesive, an optically clear liquid adhesive (LOCA = liquid optical clear adhesive), ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), thermoplastic polyurethane (TPU), an epoxy resin adhesive or an acrylic adhesive. The materials selected preferably each have a refractive index that minimizes the refraction of the light beam at the interface and optimizes the coupling efficiency under ideal angular conditions.

[0053] In one embodiment, the light source is arranged such that its main emission direction is oriented perpendicular to the main surface of the inner body of the window pane and points towards the inner body of the window pane. A light scattering component is arranged on the side of the inner body of the window pane opposite to the light source. The light scattering component is arranged such that the light coupled into the inner body of the window pane by the light source is scattered in such a way that the coupled-in light that is conducted towards the light scattering component is mostly reflected back in all possible spatial directions, and this light is conducted by total internal reflection within the window pane body. The light scattering component can for example be a printed part, a surface-structured part, and / or a coating, for example having a white color. On the surface of the inner body of the window pane assigned to the light source, additional light scattering components and / or reflectors can be arranged in the region of the light source, preferably having a notch at the light source for directly and preferably almost perpendicularly (e.g., ±30°) coupling into the inner body of the window pane.

[0054] Furthermore, the light source can have a background reflector and / or a background light scattering component such that the light of the light source that is not coupled into the inner body of the window pane is reflected back or scattered back onto the inner body of the window pane again.

[0055] In one embodiment, the light source is arranged such that the light of the light source is mainly coupled in through the side edges of the inner body of the window pane, i.e., through the sides that extend substantially perpendicular to the planar orientation of the inner body of the window pane or at an angle to the planar orientation of the inner body of the window pane. The light source is preferably arranged laterally offset from the inner body of the window pane in the planar orientation of the inner body of the window pane.

[0056] To optimize the light coupling into the inner body of the window pane and the light coupling out of the inner body of the window pane, in a special embodiment of the vehicle window pane according to the invention, a reflective layer for reflecting visible light is arranged on the plastic film of the light-shielding component facing the inner body of the window pane. The reflection ability of the reflective layer is preferably at least 2%, and / or the reflective layer can form a layer for reflecting infrared radiation. Additionally, the ambient light effect is enhanced by internal reflection within the inner body of the window pane.

[0057] The reflective layer for reflecting visible light can also be constructed as a multilayer structure or as a single layer. The individual layers of the single-layer or multilayer structure can each be composed of at least one substance from the following group of substances, which group of substances for example includes silver, gold, copper, tin oxide, titanium dioxide, zinc oxide, indium tin oxide, tin fluoride oxide, zinc tin oxide, and aluminum oxide.

[0058] In a special embodiment, for example, at least 2% of the share of the light input by the light source can be coupled out in the direction of the vehicle interior space by a preferably color-tuned and / or dyed and / or black-dyed liquid crystal component and / or two plastic films particularly preferably provided with a reflective layer.

[0059] As described above, in a preferred embodiment, the vehicle window pane includes a light extraction structure. Such a light extraction structure can be printed and / or applied on a carrier layer, wherein the carrier layer is laminated onto the outer side of the light conductor layer, in particular by means of a (as described above) polymer adhesive layer or another adhesive layer. Alternatively, the preferred light extraction structure can be directly printed and / or applied onto this outer side. Other configurations of the light extraction structure are also conceivable, as will be explained below.

[0060] To improve the extraction of light from the light conductor layer in the direction of the vehicle interior space, it is advantageous to provide scattering centers on the reflective layer for reflecting visible light and / or on the light extraction structure. Alternatively or additionally, the scattering centers can also be integrated into the light extraction structure and / or directly integrated into the outer side opposite to the inner side of the window pane body, or applied onto at least one surface of the surface of the window pane body. Preferably, a scattering center or a scattering medium is arranged between the light-shielding component and the window pane body.

[0061] The light scattering centers can be composed of any suitable material or medium, for example, composed of particles of an opaque organic material, an inorganic material (especially a ceramic material), composed of a transparent, translucent or opaque printed part, composed of a pattern or structure etched, engraved or made by laser ablation on the window pane body. The translucent material can be directly printed onto the glass and / or configured as a printed film between two glass layers.

[0062] The outer window pane body and the inner window pane body of the vehicle window pane according to the invention can be made of translucent glass or other suitable glass, or can also be made of a plastic material, such as polycarbonate. In a special embodiment, the inner window pane body can also be composed of a hard, impact-resistant and wear-resistant coating, which is configured on the side of the light-shielding component facing away from the outer window pane body.

[0063] The invention also relates to a vehicle and / or a roof, which includes at least one vehicle window pane, wherein the vehicle window pane can be a cover element of a roof opening system and / or a fixed roof element.

[0064] The vehicle window pane can be, for example, a windshield and / or a front window pane and / or a rear window pane and / or a side window pane and / or a side window glass and / or an inner partition wall of the vehicle.

[0065] It goes without saying that the above-described and the following embodiments and examples that will be explained can not only be implemented individually, but also can be implemented with each other in any combination without exceeding the scope of the invention. It is also self-evident that the above-described and the following embodiments and examples apply to all embodiments of the invention in an equivalent or at least similar manner without the need to be mentioned separately. Description of the Drawings

[0066] The basic and specific embodiments of the present invention are schematically shown in the drawings and will be explained exemplarily hereinafter. The drawings show:

[0067] Figure 1 A schematic top view of a roof having a vehicle window pane according to the present invention;

[0068] Figure 2 A schematic cross-sectional view of an exemplary vehicle window pane;

[0069] Figure 3 A schematic cross-sectional view of an exemplary vehicle window pane;

[0070] Figure 4 A schematic cross-sectional view of an exemplary vehicle window pane; and

[0071] Figure 5 A schematic cross-sectional view of an exemplary vehicle window pane. Detailed Description of the Invention

[0072] In Figure 1 a roof 10 of a motor vehicle 100 (not further shown) is illustrated. The roof 10 is a panoramic sunroof and has an adjustable cover element 12 and a fixed roof element 14, which is fixedly, i.e., immovably, connected to the vehicle body. The cover element 12 and the fixed roof element 14 are each configured as a glass element and are thus configured as vehicle window panes 11. The cover element 12 and the fixed roof element 14 have the same or different composite structures, which are schematically shown in different implementation variants in Figures 2 to 5 . Alternatively, instead of the cover element 12, the roof 10 may have a second fixed roof element 14, or instead of the fixed roof element 14 and the cover element 12, the roof has only one fixed roof element 14. The roof elements 12 and 14, each configured as a vehicle window pane 11, are each composite members, which include an outer window pane body 16 and an inner window pane body 18. The outer window pane body 16 and the inner window pane body 18 are each made of soda-lime clear glass, but may also be made of other materials, such as plastics.

[0073] The outer window pane body 16 faces the vehicle surroundings, while the inner window pane body 18 faces the vehicle interior space 102 with its inner side 19 and forms the inner viewing surface of the vehicle window pane 10.

[0074] A light-shielding assembly 20 is provided between the outer window pane body 16 and the inner window pane body 18, and the light-shielding assembly is attached to the outer window pane body 16 by a first polymer adhesive layer 22 or by an adhesive layer. According to the present invention, the light-shielding assembly 20 includes a carrier layer 15, which includes a coating 17, which will be explained in more detail hereinafter. The carrier layer 15 is only exemplarily attached to the inner window pane body 18 by a second polymer adhesive layer 24 and / or another adhesive layer.

[0075] Of course, in other embodiments, other layers, especially functional layers, such as layers for reducing infrared radiation, may be provided and / or interposed between the outer window panel body 16 and the first polymer adhesive layer 22. Of course, in other embodiments, other layers, especially functional layers, may be provided and / or interposed between the first polymer adhesive layer 22 and the light-shielding component 20. Of course, in other embodiments, other layers, especially functional layers, may be provided and / or interposed between the light-shielding component 20 and the second polymer adhesive layer 24. Of course, in other embodiments, other layers, especially functional layers, may be provided and / or interposed between the second polymer adhesive layer 24 and the inner window panel body 18. Such functional layers can, for example, supplement and / or extend and / or improve the functions of the vehicle window panel.

[0076] The light-shielding component 20 includes a liquid crystal component (LC layer or PDLC layer) 26. The liquid crystal component 26 includes a large number of crystals that are present in a matrix arrangement within the liquid crystal layer. Both sides of the liquid crystal component 26 are respectively bounded by plastic films 28, 30 belonging to the light-shielding component 20. The plastic films 28, 30 can be made of polyethylene terephthalate (PET), for example. Although the carrier layer 15 and the plastic film 30 are shown separately, this is only for a clearer illustration of the structure. However, preferably, the carrier layer 15 can be constituted by the plastic film 30 itself.

[0077] Transparent electrodes 32 and 34 are respectively arranged on the inner sides of the plastic films 28 and 30. By means of the electrodes 32 and 34, a voltage can be applied to the liquid crystal component 26, enabling the liquid crystal component 26 to switch between a blocking state and a passing state by changing the orientation of a large number of crystals.

[0078] In the illustrated embodiment, the plastic films 28 and 30 and / or the liquid crystal component 26 have a colored and / or blackened portion, which is produced by means of dyes dispersed into the corresponding materials. The coloring and / or blackening and / or dyeing of the crystals and / or the matrix of the polymer-dispersed liquid crystal layer 26 is known in the prior art as dye-dope technology.

[0079] The liquid crystal component 26 can be switched such that the transmittance of visible light in the blocking state without voltage applied to the electrodes 32 and 34 is less than 3%. In the passing state with voltage applied to the electrodes 32 and 34, due to the blackened portions of the plastic films 28 and 30 and / or the liquid crystal component 26, the light-shielding component 20 is transmissive to visible light such that approximately 10% of the share can pass through.

[0080] The vehicle window panel 11 includes at least one light source 36 for providing an ambient light function in the form of a surface light-emitting device. According to Figure 2, the light source 36 is arranged directly on the inner side 19 of the window panel inner body 18, in particular, bonded to the inner side. The light source 36 can also be arranged spaced apart from the inner side 19 of the window panel inner body 18 (not shown). A light scattering component 52 is arranged on the side of the window panel inner body opposite to the light source 36. Alternatively, in order to couple light into the window panel inner body 18, a coupling element 38 can be arranged on the inner side 19, in particular, bonded to the inner side 19, see Figure 3 By means of the coupling element 38, the light source 36 can be arranged on the side of the window panel inner body 18, such as Figure 3 As shown. This increases the design freedom when arranging the light source 36. The coupling element 38 is designed to deflect the light emitted by the light source 36 and thus couple the light into the window inner body 18 via the inner side 19. The window inner body 18 forms a light conductor layer 40 for the light coupled therein.

[0081] In an alternative embodiment, according to Figure 4 1 shows lateral light coupling, wherein the light source 36 is schematically arranged in a lateral region of the optical waveguide layer 40 or of the inner body 18 of the window pane. Apart from this, the structure of the vehicle window pane 11 corresponds to that of the vehicle window pane 11. Figure 2 Known structure.

[0082] A light outcoupling structure 42 is provided on an outer side 41 of the window panel inner body 18, which is opposite to the inner side 19 of the window panel inner body 18, and is designed to couple the light coupled into the optical waveguide layer 40 out again from the window panel inner body 18 in the direction of the vehicle interior 102 in a predefined manner, in particular in a manner predetermined by the light outcoupling structure 42. The light outcoupling structure 42 is preferably printed and / or vapor deposited and / or coated and / or laminated onto the outer side 41 of the window panel inner body 18.

[0083] In the edge region of the vehicle window 11 for light coupling in and on which the light source 36 is arranged, a light shielding element 44 can also be arranged in sections, in particular between the window outer body 16 and the first polymer adhesive layer 22. The light shielding element 44 can be printed onto the window outer body 16 and / or the first polymer adhesive layer 22, for example, or applied as a laminated layer.

[0084] The carrier layer 15 includes a coating 17 on a side oriented in the direction towards the outer side 41 of the inner body 18 of the window pane. The coating 17 is composed of a material having a refractive index n2, which is less than the refractive index n1 of the material constituting the inner body 18 of the window pane. The carrier layer 15 is preferably composed of polycarbonate or polyethylene terephthalate. The coating 17 includes silicon dioxide (SiO2) and / or magnesium fluoride (MgF2). Preferably, the difference between the refractive index n1 of the inner body 18 of the window pane and the refractive index n2 of the coating 17 is ≥ 0.06. Particularly preferably, the refractive index n2 of the coating 17 ≤ 1.46. In other embodiments, the refractive index n2 of the coating 17 can be between 1.3 and 1.52, where the refractive index can particularly preferably also be ≤ 1.45.

[0085] As in Figure 5 the embodiment shown in

[0086] Starting from the outside of the vehicle towards the interior space 102 of the vehicle, Figure 5 the vehicle window pane 11 shown in

[0087] includes the following exemplary multilayer structure. The outer body 16 of the window pane is connected via a first polymer adhesive layer 22 or a hot melt adhesive layer to an optional layer 46 for reflecting infrared radiation. A colored plastic film 28 is attached to the layer 46, and the plastic film 28 is connected via a transparent adhesive layer 48, such as an optically transparent adhesive layer (OCA layer) or a silicone gel, to another transparent plastic film 50. An electrode 32 is attached to the plastic film 50, and the electrode is adjacent to a liquid crystal component 26 (LC layer or PDLC layer). Opposite to the electrode 32, an electrode 34 is provided on the side of the liquid crystal component 26 facing towards the interior space 102 of the vehicle. Then, another transparent plastic film 50 is adjacent again. The plastic film 50 can serve as a carrier for the electrodes 32 and 34, respectively. The transparent plastic film 50 is connected via another transparent adhesive layer 48, such as an optically transparent adhesive layer (OCA layer), to a colored plastic film 30, and the carrier layer 15 with the coating 17 according to the present invention is attached to the plastic film, wherein the carrier layer 15 is connected to the inner body of the window pane via a second polymer adhesive layer 24.

[0088] The remaining structure or the remaining description can be learned from the description of Figure 2 and Figure 3 the description of

[0089] List of reference numerals

[0090] 10 Roof

[0091] 11 Vehicle window panel

[0092] 12 Cover element

[0093] 14 Fixed roof element

[0094] 15 Carrier layer

[0095] 16 Outer body of window panel

[0096] 17 Coating

[0097] 18 Inner body of window panel

[0098] 19 Inner side

[0099] 20 Light-shielding component

[0100] 22 Polymer adhesive layer

[0101] 24 Polymer adhesive layer

[0102] 26 Liquid crystal component

[0103] 28 Plastic film

[0104] 30 Plastic film

[0105] 32 Electrode

[0106] 34 Electrode

[0107] 36 Light source

[0108] 38 Coupling-in element

[0109] 40 Light conductor layer

[0110] 41 Outer side

[0111] 42 Light coupling-out structure

[0112] 44 Light shielding element

[0113] 46 Layer for reflecting infrared radiation

[0114] 48 Adhesive layer

[0115] 50 Another plastic film

[0116] 52 Light scattering component

[0117] 100 Vehicle

[0118] 102 Interior space of vehicle

[0119] n1 Refractive index

[0120] Refractive index n2

Claims

1. A vehicle window panel (11), in particular a window panel of a roof (10), said vehicle window panel comprising a composite structure having a window panel outer body (16), a light-shielding assembly (20), a window panel inner body (18) and a light conductor layer (40), wherein, The light-shielding assembly (20) is arranged between the outer body (16) and the inner body (18) of the window pane and includes a switchable liquid crystal assembly (26), characterized in that the light-shielding assembly (20) includes a carrier layer (15), the carrier layer is directly or indirectly arranged on the outer side (41) of the light conductor layer (40) oriented towards the light-shielding assembly (20), and the carrier layer has a coating (17) made of a material having a refractive index n2, which refractive index n2 is less than the refractive index n1 of the material constituting the light conductor layer (40).

2. The vehicle window panel according to claim 1, characterized in that The carrier layer (15) includes polycarbonate, polyethylene (PE) and / or polyethylene terephthalate (PET).

3. The vehicle window pane according to one of the above claims, characterized in that, The coating (17) is applied to the side of the carrier layer (15) facing the outer side (41) of the light conductor layer (40).

4. The vehicle window panel according to one of the above claims, characterized in that, The coating (17) includes fluoropolymer and / or oxide and / or SiO2 and / or MgF2.

5. The vehicle window pane according to one of the above claims, characterized in that, The difference between the refractive index n1 of the light conductor layer (40) and the refractive index n2 of the coating (17) ≥ 0.06, and / or, the refractive index n2 of the coating (17) ≤ 1.

46.

6. The vehicle window panel according to one of the above claims, characterized in that, The carrier layer (15) forms the electrode (34) of the liquid crystal assembly (26) on the side facing the light-shielding assembly (20), and / or includes a color adjustment part and / or a dyeing part and / or a black dyeing part.

7. The vehicle window panel according to one of the above claims, characterized in that, The light-shielding assembly (20) includes at least one plastic layer (28, 30, 50) that is colored and / or dyed and / or transparent and / or another, especially transparent, adhesive layer (48) and / or a layer for reflecting infrared radiation (46).

8. The vehicle window panel according to claim 7, characterized in that The carrier layer (15) is composed of the at least one plastic layer (30, 50) and / or the other adhesive layer (48).

9. The vehicle window panel according to claim 7 or 8, characterized in that, The plastic films (28, 30, 50) of the light-shielding assembly (20) include polycarbonate, polyethylene (PE) and / or polyethylene terephthalate (PET).

10. The vehicle window panel according to one of the above claims, characterized in that, The vehicle window pane (11) includes a light source (42), the light source is configured to couple light into the light conductor layer (40) especially directly through the inner side (19) of the inner body (18) of the window pane and / or through a coupling element (38), wherein, optionally, a light coupling-out structure (42) is provided on the outer side (41) of the inner body (18) of the window pane opposite to the inner side (19) of the inner body (18) of the window pane, and the light coupling-out structure is configured to couple the light coupled into the light conductor layer (40) out of the inner body (18) of the window pane in the direction towards the vehicle interior space (102).

11. The vehicle window panel according to claim 9, characterized in that, The light coupling-out structure (42) is printed and / or applied on the carrier layer (15), the carrier layer is especially laminated onto the outer side (41) of the light conductor layer (40), or wherein, the light coupling-out structure (42) is preferably directly printed and / or applied onto the outer side (41) of the light conductor layer (40), especially printed and / or applied on the inner body (18) of the window pane.

12. The vehicle window panel according to claim 9 or 10, characterized in that, The coupling-in element (38) is arranged on the inner side (19) of the inner body (18) of the window pane, and the light source (36) is arranged on the side of the coupling-in element (38) such that light emitted by the light source (42) can be redirected by the coupling-in element (38) and coupled into the light conductor layer (40).

13. The vehicle window pane according to one of claims 9 to 11, characterized in that, The coupling-in element (38) is a body of a material that is transparent to the light of the light source (36), and the body is configured strip-like and / or has a wedge-shaped or trapezoidal cross-section.

14. The vehicle window pane according to one of the above claims, characterized in that, The light-shielding assembly (20) is connected to the outer body (16) and the inner body (18) of the window pane by at least two polymer adhesive layers (22, 24), wherein the at least two polymer adhesive layers each form a hot-melt adhesive layer, in particular a polyvinyl butyral layer and / or an ethylene-vinyl acetate layer and / or a thermoplastic polyurethane layer.

15. A vehicle (100) and / or a roof (10) comprising a vehicle window pane (11) according to one of the preceding claims, wherein, The vehicle window pane (11) is a cover element (12) of a roof opening system or a fixed roof element (14).

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