Laminated pane with light source

Description

[0001] The invention relates to a composite pane with a light source, a method for its production and its use.

[0002] Composite panes with electrically controllable optical properties are known as such. They comprise composite panes equipped with functional elements whose optical properties can be modified by an applied electrical voltage. The functional elements are planar structures with electrically controllable optical properties of an active layer. This means that the optical properties of the active layer, and in particular its transparency, scattering behavior, or luminosity, can be controlled by an electrical voltage. Examples of electro-optical functional elements are SPD functional elements (SPD = Suspended Particle Device), known, for example, from EP0876608B1 and WO2011033313A1, and PDLC functional elements (PDLC = Polymer Dispersed Liquid Crystal), known, for example, from DE102008026339A1.Apart from that, there are also electrochromic functional elements, which are known, for example, from EP3702572A1 or EP2917159A1.

[0003] Optically controllable functional elements, such as SPD, PDLC or electrochromic functional elements, are commercially available as multilayer films, with the active layer arranged between two surface electrodes that are used to apply a voltage to control the active layer. As a rule, the two surface electrodes are arranged between two carrier films, typically made of PET. Commercially available multilayer films are also covered on both sides with a protective film made of polypropylene or polyethylene, which serves to protect the carrier films from contamination or scratches. In particular, in the production of a laminated pane, the electro-optical functional element is cut out of the multilayer film in the desired size and shape and inserted between the films of an intermediate layer, by means of which two glass panes are laminated together to form a laminated pane.A typical application is windshields with electrically adjustable sun visors, which are known, for example, from DE102013001334A1, DE102005049081B3, DE102005007427A1, DE202020005499U1 and DE102007027296A1.

[0004] Apart from optically controllable functional elements, a composite pane can also comprise other elements that have optically controllable properties. For example, lighting effects can be created in a composite pane that is part of the composite pane using a light source, a light guide and an outcoupling element. The light from the light source is coupled into the light guide, where it remains in the light guide by utilising the effect of total internal reflection until it hits the outcoupling element. At the outcoupling element, the light is emitted from the light guide, whereby a locally limited glow can be generated. The light guide and the outcoupling element can be laminated within the composite pane. However, it can also be the case that the light guide represents the inner pane of the composite pane, for example, and the outcoupling element is created, for example, by locally limited roughening a surface of the inner pane.The light source is usually an LED module positioned at the edge or in a hole of the light guide to optimally couple the light into the light guide. Such designs have already been disclosed in several publications (e.g., WO200777099A1, WO2010049638A1, US20120104789A1, and WO2018149568A1).

[0005] US10139080B2 discloses a roof pane with an inner pane, an outer pane, a thermoplastic intermediate layer, and an SPD element. Laminated between the outer pane and the inner pane, as well as within the thermoplastic intermediate layer, are LEDs that can be switched on and off via an electrical connection. The SPD element is positioned closer to the exterior than the LEDs in the roof pane. As a result, when dimmed, the SPD element blocks the emission of light from the diodes into the exterior. No light coupling is shown; the LEDs radiate light through the inner pane into the vehicle interior.

[0006] US2019255812A1 discloses a laminated pane with a laminated PDLC element. It does not disclose a light source for coupling in light or an output element for coupling out light.

[0007] Both technologies can be combined. This is particularly useful for roof windows in vehicles. For example, by switching the functional element, vehicle occupants can alternate between a view through the roof window and a view blocked, e.g., by light scattering (if it is a PDLC functional element). On the other hand, light coupling and decoupling can be used to create lighting effects on the roof window. These can provide aesthetic added value to improve the well-being of the occupants or provide light in the dark. Documents that teach the combination of functional elements with light coupling and targeted, regionally limited light decoupling include CN102785555A, CN105291788A, US2019106055A1, and CN109606251A.

[0008] However, it has been recognized that arranging the light source in close proximity to the functional element can result in unsightly lighting effects in the area of ​​the functional element. Since the light from the light source cannot be fully coupled into the light guide, light can strike the functional element and be reflected. This reflection is perceived by the observer as a kind of halo of light on the pane and varies in intensity depending on the functional element used.

[0009] In contrast, the object of the present invention is to provide an improved composite pane with a light source and a functional element with electrically controllable optical properties, wherein preferably disturbing and undesired light effects, which arise from the functional element in interaction with coupled-in visible light, are to be reduced or completely avoided.

[0010] The object of the present invention is achieved by a composite pane according to claim 1. Advantageous embodiments of the invention emerge from the subclaims.

[0011] The composite pane according to the invention with a light source comprises at least one outer pane and one inner pane, a first thermoplastic film, a functional element, a darkened layer, and a decoupling element. The first thermoplastic film is arranged between the outer pane and the inner pane. The functional element and the darkened layer are preferably arranged between the outer pane and the inner pane. The functional element has electrically controllable optical properties. The functional element is preferably arranged in a see-through region of the composite pane. The decoupling element is provided for decoupling light from the inner pane. The light source is arranged on a side edge of the inner pane or in a recess in the inner pane. The light source is provided for coupling light into the inner pane.The decoupling element is designed to decouple the light coupled into the inner pane by the light source from the inner pane. The darkened layer has at least one opaque area with a light transmittance of less than or equal to 50%. The opaque area of ​​the darkened layer is present at least in the area between the light source and the functional element. This means that the opaque area of ​​the darkened layer extends at least over the entire area between the light source and the functional element.

[0012] The inner pane has an outer surface facing the first thermoplastic film and an interior surface facing away from the first thermoplastic film. The outcoupling element preferably couples out the light coupled in by the light source predominantly via the interior surface of the inner pane.

[0013] The light from the light source cannot be 100% coupled into the inner pane via total internal reflection. Part of the light transmits through the interior surface of the inner pane and the exterior surface of the inner pane. This part of the light is reflected by the outer pane and at least partially hits the functional element. If light emitted by the light source hits the functional element, this results in an optically visible glow, which increases in intensity the closer the affected area of ​​the functional element is to the light source. The opaque area largely prevents the light emitted by the light source from hitting the functional element. The opaque area absorbs the light that escapes through the exterior surface of the inner pane, thereby largely preventing the creation of an optically visible glow.

[0014] The outer pane has an outer surface facing away from the first thermoplastic film, which is also the outer surface of the composite pane. The outer pane also has an interior-side surface facing the first thermoplastic film. The interior-side surface of the inner pane is also the inner surface of the composite pane. The composite pane is intended to separate an outer environment from an interior, preferably a vehicle interior. The outer surface of the outer pane is intended to face the outer environment, and the interior-side surface of the inner pane is intended to face the interior.

[0015] The composite pane has a circumferential side edge, which preferably comprises an upper edge and a lower edge, as well as two edges running between them, a left edge and a right edge. The upper edge refers to the edge intended to face upwards in the installed position. The lower edge refers to the edge intended to face downwards in the installed position. The upper edge is often referred to as the roof edge, and the lower edge is referred to as the engine edge.

[0016] In a preferred embodiment of the invention, the darkened layer is arranged between the functional element and the inner pane, and the first thermoplastic film is arranged between the functional element and the outer pane. When viewed through the composite pane, the opaque region of the darkened layer coincides with at least one edge region of the functional element closest to the light source. The opaque region therefore extends over the entire region between the light source and the functional element and one edge region of the functional element. By arranging the darkened layer between the functional element and the inner pane, light is effectively prevented from striking the surface of the functional element facing the inner pane. In the edge region of the functional element closest to the light source, the light is particularly intense.By extending the opaque region to the edge region of the functional element closest to the light source, the intensity of the light is reduced. This is a major advantage of the invention. The edge region of the functional element closest to the light source, which overlaps with the opaque region when viewed through the composite pane, is preferably strip-shaped. The width of this edge region is preferably at least 1 cm, particularly preferably at least 3 cm, and especially at least 5 cm. "Width" in the context of the invention refers to the extent perpendicular to the direction of extension.

[0017] The composite pane preferably comprises a second transparent thermoplastic film, which particularly preferably has the same thickness as the functional element or a thickness that differs by up to 10% from the thickness of the functional element. The second thermoplastic film is arranged at least partially in a frame-like manner around the functional element. Particularly preferably, the second thermoplastic film is designed in a frame-like manner with a recess into which the functional element is inserted. "Partially arranged in a frame-like manner around the functional element" can mean, for example, that the functional element is flush with a section of the circumferential side edge of the composite pane, so that the second thermoplastic film only surrounds the functional element outside this section.Due to the second thermoplastic film, which is at least partially arranged around the functional element, differences in the thickness of the composite pane can be avoided, which in turn increases the stability of the composite pane.

[0018] In a further preferred embodiment of the invention, at least the opaque region of the darkened layer has a light transmittance of less than 10% and preferably less than 1%. In this embodiment, the darkened layer is particularly preferably formed as a thermoplastic film with the opaque region and a transparent region. The transparent region of the darkened layer has a light transmittance of 50% or higher. The darkened layer preferably extends over the entire surface of the composite pane and, together with the first thermoplastic film and optionally with the second thermoplastic film in the laminated composite pane, forms a thermoplastic intermediate layer.The functional element is embedded within the thermoplastic intermediate layer, with the first thermoplastic film preferably being arranged between the outer pane and the functional element, and the darkened layer preferably being arranged between the functional element and the inner pane. In this embodiment, the darkened layer preferably consists of the same material as the first thermoplastic film, with the opaque region of the darkened layer being achieved by coloring or tinting certain areas. This embodiment is particularly advantageous because, in addition to solving the technical problem, the darkened layer is also used to bond the outer pane, the functional element, and the inner pane, thereby reducing material costs and process steps.

[0019] Alternatively, the entire darkened layer has a light transmittance of less than 10% and preferably less than 1%. In this case, the darkened layer preferably extends over no more than 40%, preferably no more than 30% and particularly preferably no more than 20% of the surface area of ​​the composite pane. A transparent third thermoplastic film is arranged offset from the darkened layer in the surface plane of the composite pane, so that the transparent thermoplastic film and the darkened layer, viewed together, extend over the entire surface of the composite pane. The darkened layer therefore extends over an area of ​​the composite pane which makes up no more than 40% of the surface area of ​​the composite pane; the third thermoplastic film extends over the remaining surface of the composite pane.The first thermoplastic film, the optionally second thermoplastic film, the third thermoplastic film, and the darkened layer form a thermoplastic intermediate layer in a laminated state of the composite pane. The functional element is embedded within the thermoplastic intermediate layer, with the first thermoplastic film preferably being arranged between the outer pane and the functional element, and the darkened layer and the third thermoplastic film preferably being arranged between the functional element and the inner pane. In this embodiment, the darkened layer preferably consists of the same material as the first thermoplastic film and the third thermoplastic film, with the low light transmittance of the darkened layer being achieved by coloring or tinting.This embodiment is particularly advantageous because, in addition to solving the technical problem, the darkened layer is also used to bond the outer pane, the functional element and the inner pane, thereby reducing material costs and process steps.

[0020] For the purposes of the present invention, something is "transparent" if its light transmittance is more than 70%, especially more than 75%. "Opaque" for the purposes of the invention means a light transmittance of less than 50%, particularly preferably less than 10%, and especially less than 1%. The light transmittance can be determined according to ISO 9050 (2003-08) for building glazing.

[0021] In a further embodiment of the invention, the darkened layer is applied to the outer surface of the inner pane. In this embodiment, the darkened layer is preferably formed as a screen print, particularly preferably a black one. The darkened layer is formed, for example, from an enamel containing glass frits and a pigment, in particular a black pigment. The enamel is typically applied using a screen printing process and fired. This has the advantage that no additional film or layer is required to reduce the halo effect. This can save material costs.

[0022] The composite pane can be provided with an opaque black print, particularly in a peripheral edge area, as is common in the automotive sector, particularly for windshields, rear windows, and roof windows. The black print is typically formed from an enamel containing glass frits and a pigment, particularly black pigment. The printing ink is typically applied using a screen printing process and baked in. Such a black print is applied to at least one of the pane surfaces, preferably the interior-facing surface of the outer pane and / or the inner pane. The cover print preferably surrounds a central see-through area in a frame-like manner and serves, in particular, to protect the adhesive, with which the composite pane can be bonded, for example, to a vehicle body, from UV radiation. The opaque black print preferably has a thickness of at least 10 µm and a maximum of 25 µm.At such thicknesses, the black print is opaque without compromising the stability of the disc.

[0023] In a particularly preferred embodiment, the darkened layer is a tinted or colored thermoplastic film and has a light transmittance of at least 15% and at most 50%. The darkened layer preferably extends over the entire surface of the laminated pane. In this embodiment, the darkened layer is preferably arranged between the functional element and the inner pane. The extension of the darkened layer over the entire laminated pane effectively reduces the halo effect. It therefore does not matter where exactly the light transmits beyond the outer surface of the inner pane. The darkened layer has a high light absorption across the entire surface of the laminated pane.

[0024] The first thermoplastic film, the optionally present second thermoplastic film, and the optionally present third thermoplastic film are preferably formed as thermoplastic composite films. They are preferably based on ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), or polyurethane (PU), or mixtures or copolymers or derivatives thereof, particularly preferably based on polyvinyl butyral (PVB), and additionally contain additives known to those skilled in the art, such as plasticizers. The thermoplastic composite films preferably contain at least one plasticizer.

[0025] The thermoplastic intermediate layer can be formed by just the first thermoplastic film or by more than one film. The thermoplastic intermediate layer can be formed by one or more thermoplastic films arranged one above the other, wherein the thickness of the thermoplastic intermediate layer after lamination of the layer stack is preferably from 0.25 mm to 1 mm, typically 0.38 mm or 0.76 mm. The thermoplastic intermediate layer can also be formed from a film that is colored or tinted in certain regions. The first thermoplastic film or multiple thermoplastic films can also be functional thermoplastic films, in particular films with acoustically dampening properties, an infrared radiation-reflecting film, an infrared radiation-absorbing film, and / or a UV radiation-absorbing film.For example, the first, possibly second, and / or possibly third thermoplastic films can also be band filter films. The darkened layer, if formed as a thermoplastic film, can also be part of the thermoplastic intermediate layer.

[0026] In a preferred embodiment, the darkened layer is formed as a polymeric film, preferably a thermoplastic film. The darkened layer is preferably based on ethylene vinyl acetate (EVA), polyethylene terephthalate (PET), polyvinyl butyral (PVB), or polyurethane (PU), or mixtures or copolymers or derivatives thereof, particularly preferably based on polyvinyl butyral (PVB), and additionally contains additives known to those skilled in the art, such as plasticizers.

[0027] If something is "based" on a polymeric material, it consists predominantly of this material, i.e., at least 50%, preferably at least 60%, and especially at least 70%. It may therefore also contain other materials such as stabilizers or plasticizers.

[0028] In a particularly preferred embodiment, the functional element is a PDLC functional element ( polymer dispersed liquid crystal ) .The PDLC functional element contains liquid crystals embedded in a polymer matrix. If no voltage is applied to the PDLC functional element, the liquid crystals are randomly aligned, which leads to a strong scattering of the light passing through the active layer (translucency). If a voltage is applied to the functional element, the liquid crystals align in a common direction, and the transmission of light through the functional element is increased (transparency). However, it is also possible for the liquid crystals to be ordered in a voltage-free state and correspondingly randomly when a voltage is applied. However, other functional elements can also be used whose variability of optical properties is based on liquid crystals, for example, PNLC functional elements ( polymer networked liquid crystal ) .If the application of a voltage is mentioned in the context of the functional element as a PDLC functional element, then in the sense of the invention an alternating voltage (the effective value of the alternating voltage, not the instantaneous voltage) is meant.

[0029] In a further preferred embodiment, the functional element is an SPD functional element ( suspended particle device ). The SPD functional element contains suspended particles. The suspended particles change the optical state of the functional element through the absorption of light by applying a voltage. SPD functional elements therefore exhibit switching states with transparent and opaque optical properties, as well as intermediate states between transparency and opacity. When the application of a voltage is mentioned in the context of the functional element as an SPD functional element, this refers to an alternating voltage (the effective value of the alternating voltage, not the instantaneous voltage) within the meaning of the invention.

[0030] In a further preferred embodiment, the functional element is an electrochromic functional element. In this case, the transmission of visible light through the functional element depends on the degree of ion storage. The ions are released, for example, through an ion storage layer and stored in an electrochromic layer. The transmission can be influenced by the voltage applied to the functional element, which causes the ions to migrate. Suitable electrochromic layers preferably contain at least tungsten oxide or vanadium oxide. If the functional element is an electrochromic functional element, the control unit is preferably not equipped with an inverter, and a direct voltage is applied to the functional element. A direct voltage converter for achieving voltages in the range of 1 V to 50 V and preferably 10 V to 42 V can, however, be a component of the control unit as required.

[0031] In a particularly advantageous embodiment of the invention, the composite pane comprises an emissivity-reducing coating. The emissivity-reducing coating is preferably applied to the interior-facing surface of the inner pane.

[0032] The emissivity-reducing coating is a coating that reflects heat radiation. Such a coating is often also referred to as a low-E coating or low-emissivity coating. Its function is to prevent heat radiation into the interior (thermal radiation from the pane itself) and also to prevent heat radiation from the interior. For the purposes of the invention, emissivity is understood to mean the normal emissivity at 283 K according to the EN 12898 standard. Emissivity-reducing coatings, which the composite pane according to the invention can have, are known to those skilled in the art. These can be designed, for example, as disclosed in WO2018206236A1.

[0033] In another particularly preferred embodiment of the invention, the composite pane comprises an infrared protective layer, which is preferably arranged or applied on the interior surface of the outer pane, the exterior surface of the inner pane, or between the outer pane and the inner pane. The infrared protective layer blocks infrared radiation and allows visible light to pass through. For the purposes of the invention, "blocking infrared radiation" means that the infrared protective layer at least partially reflects and / or absorbs infrared radiation. The infrared protective layer particularly preferably reflects infrared radiation. The reflection of infrared radiation has the advantage that the composite pane does not heat up as much. Infrared protective layers that the composite pane can have are known to those skilled in the art. These can, for example, be designed as disclosed in WO2019120850A1.

[0034] The outer pane and the inner pane are preferably made of transparent glass, in particular soda-lime glass, which is common for window panes. However, the panes can also be made of other types of glass (e.g., borosilicate glass, quartz glass, aluminosilicate glass) or transparent plastics (e.g., polymethyl methacrylate or polycarbonate). The thickness of the outer pane and the inner pane can vary widely. Preferably, panes with a thickness in the range of 0.8 mm to 5 mm, preferably 1.4 mm to 2.5 mm, are used, for example, those with the standard thicknesses of 1.6 mm or 2.1 mm. The outer pane and the inner panes can be untempered, partially tempered, or tempered independently of one another. If at least one of the panes is to be tempered, this can be thermal or chemical. The inner pane can have a recess in which the light source can be arranged.The inner pane is preferably made of soda-lime glass with a maximum iron oxide content of 1%. This low iron oxide content of the inner pane makes it particularly clear and uncolored. This makes the inner pane particularly well-suited as an optical fiber, i.e., for coupling in light.

[0035] The light from the light source is coupled into the inner pane, wherein the light source is arranged in a suitable manner relative to the pane for this purpose. The light source is preferably arranged laterally to the inner pane, i.e. on its side edge, which enables good coupling of light into the pane. Equally preferred is the arrangement of the light source in a recess or opening in the inner pane, which likewise enables good coupling of light into the inner pane. The light source is preferably firmly connected to the inner pane by means of a housing. The light coupled into the inner pane is totally reflected in the pane until it is coupled out of the pane at the coupling-out element. The light emitted by the light source is preferably visible light, i.e. light in a wavelength range from 380 nm to 780 nm.Alternatively, the light source can emit infrared or ultraviolet light, which is preferably converted into visible light by fluorescent or luminescent particles, preferably as a component of the coupling element.

[0036] The light source preferably contains or consists of a light-emitting diode (LED), preferably at least one organic light-emitting diode (OLED), at least one laser diode, at least one incandescent lamp and / or at least one gas discharge lamp.

[0037] The coupling-out element is intended to at least partially couple the light coupled into the inner pane by the light source into the interior and / or the external environment. Preferably, the coupling-out element couples the light into an interior, for example, a vehicle interior, via the interior-side surface of the inner pane. The coupling-out element can be arranged within the see-through area of ​​the composite pane or outside the see-through area. For the purposes of the invention, "see-through area" refers to an area intended for viewing through the composite pane. The see-through area does not have any opaque layers, such as black prints, which prevent viewing. Preferably, the coupling-out element is suitable for coupling out at least part of the light guided in the inner pane through scattering, reflection, refraction, or diffraction.

[0038] In a preferred embodiment, the outcoupling element is applied to the outer surface or the inner surface of the inner pane. For this purpose, the outcoupling element is preferably introduced into the inner surface and / or the outer surface of the inner pane by laser structuring, mechanical structuring such as sandblasting, and / or by etching. Alternatively or in combination, the outcoupling element can be materially bonded to the inner surface and / or the outer surface of the inner pane, preferably by printing or gluing on an ink, a paste, or particles, particularly preferably light-scattering, light-refracting, or light-reflecting particles. This form of outcoupling element is preferred because it can be implemented simply and easily even after the inner pane has been manufactured.

[0039] Alternatively or in combination, the coupling-out element can contain or consist of at least one transparent body which is materially connected to the interior and / or exterior surface of the inner pane, for example by gluing, wherein the transparent body is preferably a) a structured plastic film or plastic plate or b) a transmission holographic film contains or consists of. Advantageously, the structured plastic film or plastic plate has a planar arrangement of microprisms like a step prism.

[0040] In a further preferred embodiment of the invention, the decoupling element is arranged between the thermoplastic intermediate layer and the inner pane. In this case, the decoupling element is preferably a plastic film or plastic plate. This protects the decoupling element from external, harmful influences. The decoupling element can also be printed on the thermoplastic intermediate layer.

[0041] It is also possible for the outcoupling element to be arranged within the inner pane. The outcoupling element is preferably introduced during the manufacture of the inner pane, particularly preferably by artificially creating optical defects.

[0042] A further aspect of the invention comprises a method for producing a composite pane according to the invention with a light source. The method comprises the following method steps: (a) A layer stack is created comprising the outer pane, the first thermoplastic film, the functional element, the darkened layer, the decoupling element, and the inner pane. Preferably, the functional element, the darkened layer, and the first thermoplastic film are arranged between the outer pane and the inner pane. (b) The layer stack is laminated to form the composite pane. (c) The light source is arranged on a side edge of the inner pane or in a recess in the inner pane. Preferably, the light source is arranged such that the opaque region of the darkened layer extends at least over the region located between the light source and the functional element.

[0043] The lamination of the layer stack takes place under the influence of heat, vacuum and / or pressure, whereby the individual layers are bonded (laminated) to one another by at least one thermoplastic film. Known processes for producing a composite pane can be used. For example, so-called autoclave processes can be carried out at an elevated pressure of approximately 10 bar to 15 bar and temperatures of 130°C to 145°C for approximately 2 hours. Known vacuum bag or vacuum ring processes operate, for example, at approximately 200 mbar and 130°C to 145°C. The layer stack can also be pressed into a composite pane in a calender between at least one pair of rollers. Systems of this type are known for producing composite panes and usually have at least one heating tunnel upstream of a pressing unit. The temperature during the pressing process is, for example, between 40°C and 150°C.Combinations of calendering and autoclaving processes have proven particularly effective in practice. Alternatively, vacuum laminators can be used. These consist of one or more heated and evacuatable chambers in which the outer and inner panes can be laminated within approximately 60 minutes at reduced pressures of 0.01 mbar to 800 mbar and temperatures of 80°C to 170°C.

[0044] The laminated pane according to the invention can be, for example, the roof pane, windshield, side window, or rear window of a vehicle or other vehicle glazing, for example, a partition in a vehicle, preferably in a rail vehicle or a bus. Alternatively, the laminated pane can be architectural glazing, for example, in an exterior facade of a building or a partition inside a building, or a built-in component in furniture or appliances.

[0045] A further aspect of the invention encompasses the use of the composite pane according to the invention in means of transport for land, air, or water traffic, preferably in motor vehicles, for example as a windshield, rear window, side windows, and / or glass roof, particularly preferably as a roof pane. Alternatively, the composite pane can be used as a functional and / or decorative individual piece and as a built-in component in furniture, appliances, and buildings.

[0046] The invention is explained in more detail below using exemplary embodiments, with reference to the accompanying figures. They show, in simplified form and not to scale: Figure 1a plan view of an embodiment of the composite pane according to the invention, Figure 1a a schematic cross-sectional view of the embodiment of the composite pane according to the invention from Figure 1, Figure 1b shows an enlarged section of an edge area of ​​the composite pane made of Figure 1a , Figure 2 shows a plan view of further embodiments of the composite pane according to the invention and Figures 3-6 show the further embodiments of the composite pane according to the invention from Figure 2 in a schematic cross-sectional view.

[0047] Figure 1 and Figure 1a show different aspects of an embodiment of a composite pane 100 according to the invention. Figure 1 a shows a plan view of the composite pane 100 according to the invention and Figure 1a shows a cross-sectional view of the composite pane 100 according to the invention. The cross-sectional view of Figure 1a corresponds to the section line AA' of the composite pane 100, as shown in Figure 1 is indicated.

[0048] A light source 7 is arranged in a recess of the composite pane 100. The composite pane 100 is, for example, a roof pane of a vehicle and the composite pane 100 is installed in a roof of a vehicle. The composite pane 100 comprises an outer pane 1 and an inner pane 2, which are connected to one another by a flat intermediate layer 10. The outer pane 1 has an outer surface I facing away from the intermediate layer 10 and an interior-side surface II facing the intermediate layer 10. The inner pane 2 has an interior-side surface IV facing away from the intermediate layer 10 and an outer surface III facing the intermediate layer 10.The interior-side surface IV of the inner pane 2 is simultaneously the surface of the laminated pane 100 that faces the vehicle interior, and the exterior surface I of the outer pane 1 is simultaneously the surface of the laminated pane 100 that faces the outside environment. The outer pane 1 consists, for example, of slightly tinted soda-lime glass with a thickness of 2.1 mm. The inner pane 2 consists, for example, of soda-lime glass with an iron oxide content of a maximum of 1%. The inner pane 2 has, for example, a thickness of 1.6 mm. Due to its low iron oxide content, the inner pane 2 has a very slight color tint and is significantly less colorant than soda-lime glass typically produced for the vehicle sector. Due to its colorlessness, the inner pane 2 has good properties as a light guide.

[0049] The intermediate layer comprises a first thermoplastic film 10.1, a second thermoplastic film 10.2 and a darkened layer 6. The first thermoplastic film 10.1 is arranged flat on the interior-side surface II of the outer pane 1, wherein the darkened layer 6 is arranged flat on the exterior-side surface III of the inner pane 2. The darkened layer 6 extends, among other things, over the entire area 8 of the composite pane 100 located between the light source 7 and the functional element 4 and over an edge area 12 of the functional element 4 closest to the light source 7 (the edge area 12 of the functional element 4 is Figure 4 and the Figure 5shown). The second thermoplastic film 10.2 is arranged in a frame-like manner, similar to a passepartout, around a functional element 4, wherein the second thermoplastic film 10.2 and the functional element 4 are arranged between the first thermoplastic film 10.1 and the darkened layer 6. The second thermoplastic film 10.2 and the functional element 4, viewed together, extend over the entire surface of the composite pane 100. The first and second thermoplastic films 10.1, 10.2 as well as the darkened layer 6 are made of the same thermoplastic material, for example PVB, so that after lamination to form the composite pane 100, they fuse together to form the intermediate layer 10. The intermediate layer 10 has, for example, a thickness of 0.76 mm.

[0050] On the interior-side surface IV of the inner pane 2, an opaque black print 13 is applied in a frame-like manner in the edge region of the inner pane 2. The black print 13 runs along the peripheral edge of the inner pane 2 and prevents visibility through the composite pane 100 in the area where it is applied. For example, the black print 13 does not have the same width in all areas; however, it is also possible for the black print 13 to have the same width everywhere. "Width" in the sense of the invention refers to the extent perpendicular to the direction of extension. When viewed through the composite pane 100, the black print 13 overlaps with a peripheral edge region of the functional element 4. The overlapped peripheral edge region of the functional element 4 has a width of 2 cm, for example.The partial overlap of the functional element 4 with the black print 13 serves to conceal the unsightly edge of the functional element for vehicle occupants. Optionally, another black print 13 can also be applied in a peripheral edge area on the outside surface I or the inside surface II of the outer pane 1 (not shown here).

[0051] The functional element 4 is, for example, a PDLC functional element, which is connected by a conduction element, for example a flat conductor, to a control unit located outside the composite pane 100 (not shown here). The functional element 4 can change its optical state via an applied alternating voltage (effective value of the alternating voltage), which can be output by the control unit. The functional element 4 can, for example, switch between two states, a translucent state (i.e., a state with high light scattering) and a transparent state, using the applied voltage. The translucent state is preferably achieved when the functional element 4 is voltage-free, i.e., no electrical voltage is applied. The transparent state is preferably achieved when an electrical voltage is applied to the functional element 4 by the control unit.States between a maximum transparency of the functional element 4 and the maximum translucency of the functional element 4 are also possible.

[0052] A light source 7 is arranged in a recess 9 of the inner pane 2. The recess 7 is arranged in an edge region of the composite pane 100 and, when viewed from above onto the interior-side surface IV of the inner pane, is located within the area to which the black print 13 is applied. The light source 7 is, for example, an LED (light-emitting diode) arrangement. The recess 9 of the inner pane 2 has, for example, a cylindrical shape and is only open on the interior-side surface IV of the inner pane 2. The opening of the recess 9 can optionally be concealed (for example, by a black-colored and opaque film). When the light source 7 is activated, visible light 3 is coupled into the inner pane 2 via the inner surface of the recess 9. Total internal reflection of the coupled light 3 takes place within the inner pane 2.The light source 7 radiates the visible light 3 toward an outcoupling element 5, which is centrally mounted on the interior-side surface IV of the inner pane 2. Total reflection of the visible light 3 in the inner pane 2 occurs until the visible light 3 strikes the outcoupling element 5. In this case, the visible light 3 is coupled out of the inner pane 2 at this point and scattered outward, in particular toward the vehicle interior.

[0053] The coupling-out element 5 can be used to generate visible light patterns on the composite pane 100. The coupling-out element is, for example, a light-diffusing coating, e.g., in the form of a screen-printed and baked paste, which was applied to the interior-side surface IV of the inner pane 2. The coupling-out element forms, for example, the lettering "Saint-Gobain" as in Figure 1 is indicated.

[0054] The light 3 coupled into the inner pane 2 by the light source 7 does not transmit 100% under total internal reflection to the outcoupling element 5. A small proportion of the visible light 3 is already coupled out before hitting the outcoupling element 5 and thus strikes, for example, the functional element 4. The impact of the visible light 3 on the functional element 4 leads to a milky glow on the interior-side surface IV of the inner pane 2, which can be perceived by vehicle occupants as unpleasant or unaesthetic. This glow effect decreases with the distance from the light source 7 and varies in intensity depending on the optical state of the functional element 4. When the functional element 4 is translucent, the glow effect is more pronounced than when it is transparent.It can be seen in particular in a section Z of the functional element 4 that is visible from the vehicle interior and is located in spatial proximity to the light source 7. In the present embodiment according to the invention shown in FIG. Figure 1, Figure 1a and Figure 1b The problem is solved by arranging a darkened layer 6 between the functional element 4 and the inner pane 2. The darkened layer 6 is, for example, tinted black and has a visible light transmittance of 40%. Due to the tint of the darkened layer 6 and the reduced light transmission through the darkened layer 6, a large proportion of the diverted visible light 3 is absorbed by the darkened layer 6. The halo effect in section Z of the functional element 4 can thus be greatly reduced or even completely avoided. This is a major advantage of the invention and was surprising to the inventors.

[0055] The Figure 1bshows an enlarged section of an edge area Y of the composite pane 100. The enlarged edge area Y of the composite pane is in Figure 1a indicated.

[0056] The Figures 2 to 6 The variant shown essentially corresponds to the variant from the Figure 1, Figure 1a and Figure 1b , so that only the differences are discussed here and otherwise the description Figure 1, Figure 1a and Figure 1b is referred to.

[0057] The Figure 2 shows a plan view of the composite pane 100, wherein the light source 7 is not arranged in a recess 9, but by means of a housing 14 on a side edge 11 of the composite pane 100. The Figures 3 to 6 show various embodiments of the invention in cross-sectional view. The cross-sectional views of the Figures 3 to 6 correspond to the section line BB' of the composite pane 100, as shown in Figure 2 This means that the different embodiments of the Figures 3 to 6are (schematically) optically identical in plan view of the composite pane 100.

[0058] In contrast to Figure 1, Figure 1a and Figure 1b the composite pane has 100 Figure 3 no recess 9 in the inner pane 2, and the light source 7 is attached to a side edge 11 of the inner pane 2 via a housing 14. The light source 7 thus couples the visible light 3 emitted by it into the inner pane 2 via a side edge of the inner pane 2.

[0059] In contrast to Figure 1, Figure 1a and Figure 1b the composite pane has 100 Figure 4no recess 9 in the inner pane 2, and the light source 7 is attached to a side edge 11 of the inner pane 2 via a housing 14. The light source 7 thus couples the visible light 3 emitted by it into the inner pane 2 via a lateral edge of the inner pane 2. Furthermore, the darkened layer 6 extends only partially, for example, 20%, over the surface of the composite pane 100. A third transparent thermoplastic film 10.3 is arranged next to the darkened layer 6, which is located in the same plane as the darkened layer 6, i.e., does not overlap with the composite pane 100 when viewed through the composite pane 100. The darkened layer 6 and the transparent third thermoplastic film 10.3, viewed together, extend over the entire surface of the composite pane 100.The thermoplastic intermediate layer 10 is thus composed of the first, the second, the third thermoplastic film and the darkened layer 6.

[0060] The coupling element 5 is different from Figure 1 and 1a not applied to the interior-side surface IV of the inner pane 2, but to the surface of the third thermoplastic film 10.3 facing the inner pane 2.

[0061] The darkened layer 6 extends over the entire area 8 of the composite pane 100 located between the light source 7 and the functional element 4 and over an edge area 12 of the functional element 4 closest to the light source 7. When viewed from above onto the interior-side surface IV of the inner pane 2, the darkened layer 6 is completely concealed by the black print. The darkened layer 6 has a light transmittance for visible light of less than 1% and is colored black. Due to the low transmittance of the darkened layer, a large portion of the coupled-in light 3 that is not transmitted under total reflection in the inner pane 2 to the outcoupling element 5 is absorbed by the darkened layer 6, so that the halo effect in the section Z of the functional element 4 facing the vehicle interior can be reduced or avoided.

[0062] The coupling element 5 is in Figure 5 unlike in Figure 1 and 1a not applied to the interior surface IV of the inner pane 2, but to the exterior surface III of the inner pane 2. The light source 7 is identical to Figure 3 attached to a side edge 11 of the inner pane 2 by means of a housing 14. The darkened layer 6 is applied in the form of an opaque black print on the outer surface III of the inner pane 2 and extends over the entire region 8 of the composite pane 100 located between the light source 7 and the functional element 4 and over the edge region 12 of the functional element 4 closest to the light source 7. The intermediate layer 10 comprises, in addition to the first and second thermoplastic films 10.1, 10.2, a third transparent thermoplastic film 10.3, which is arranged between the functional element 4 and the inner pane 2 and extends over the entire surface of the composite pane 100.

[0063] In Figure 6The darkened layer 6 is arranged in a frame around the functional element 4 and has a light transmittance of less than 1%. The intermediate layer 10 comprises the first thermoplastic film 10.1, the darkened layer 6 and a third thermoplastic film 10.3, wherein the third thermoplastic film is arranged between the functional element 4 and the inner pane 2. The light source 7 is identical to Figure 3 attached to a side edge 11 of the inner pane 2 by means of a housing 14.

[0064] The frame-shaped, darkened layer 6 reduces the incidence of visible light 3 on the interior-side surface II of the outer pane 1. In the case of the generic composite pane 100, a portion of the visible light 3 is reflected by the interior-side surface II of the outer pane 1. This reflected light 3 strikes the functional element 4, which in turn can lead to the previously described halo effect in section Z of the functional element 4. The frame-shaped layer 6 can reduce this reflection on the interior-side surface II of the outer pane 1. List of reference symbols

[0065] 1Outer pane 2Inner pane 3Light 4Functional element 5Outcoupling element 6Darkened layer 7Light source 8Area between the light source 7 and the functional element 4 9Recess of the inner pane 2 10Intermediate layer 10.1First thermoplastic film 10.2Second thermoplastic film 10.3Third thermoplastic film 11Side edge of the inner pane 2 12Edge area of ​​the functional element 4 closest to the light source 7 13Black print 14Housing of the light source 7 100 composite panes IOutside surface of outer pane 1 IIInside surface of outer pane 1 IIIOutside surface of inner pane 2 IVInside surface of inner pane 2 ZSection of the light effect YEnlarged section of an edge area of ​​the composite pane 100 A-A'Cross section through the composite pane 100 from Figure 1 B-B'Cross section through the composite pane 100 made of Figure 2

Claims

1. A laminated pane (100) with light source, comprising: - an outer pane (1) and an inner pane (2), - a first thermoplastic film (10.1) arranged between the outer pane (1) and the inner pane (2), - a functional element (4) with electrically controllable optical properties, - a darkened layer (6), - a decoupling element (5) for decoupling light (3) from the inner pane (2), and - a light source (7) for coupling light (3) into the inner pane (2), wherein the darkened layer (6) has at least one opaque region having a light transmittance of less than or equal to 50% and the opaque region is present at least within the region (8) between the light source (7) and the functional element (4), characterised in that the light source (7) is arranged on a side edge (11) of the inner pane (2) or in a recess (9) of the inner pane (2).

2. The laminated pane (100) according to claim 1, wherein at least one edge region (12) of the functional element (4), which is closest to the light source (7), coincides with the opaque region of the darkened layer (6).

3. The laminated pane (100) according to claim 2, wherein a second thermoplastic film (10.2) partially or completely surrounds the functional element (4).

4. The laminated pane (100) according to any of claims 1 to 3, wherein at least the opaque region of the darkened layer (6) has a light transmittance of <10%, preferably of <1%.

5. The laminated pane (100) according to any of claims 1 to 4, wherein the darkened layer (6) is designed as a thermoplastic film having the opaque region and a transparent region, wherein the transparent region of the darkened layer has a light transmittance of ≥50%.

6. The laminated pane (100) according to any of claims 1 to 4, wherein the entire darkened layer (6) has a light transmittance of <10%, preferably of < 1 %.

7. The laminated pane (100) according to claim 6, wherein the darkened layer (6) extends over less than 40%, preferably over less than 30%, particularly preferably over less than 20%, of the area of the laminated pane (100).

8. The laminated pane (100) according to claim 6, wherein the darkened layer (6) is applied to an outer-side surface (III) of the inner pane (2) facing the outer pane (1).

9. The laminated pane (100) according to claim 8, wherein the darkened layer (6) is formed as a, preferably black, screen printing.

10. The laminated pane (100) according to either claim 2 or claim 3, wherein the darkened layer (6) is a tinted or coloured thermoplastic film and has a light transmittance of at least 15% and at most 50%.

11. The laminated pane (100) according to claim 10, wherein the darkened layer (6) extends over the entire surface of the laminated pane (100).

12. The laminated pane (100) according to any of claims 1 to 11, wherein the functional element (4) is a PDLC functional element.

13. The laminated pane (100) according to any of claims 1 to 12, wherein an emissivity-reducing coating is applied to an interior-side surface (IV) of the inner pane (2) facing away from the outer pane (1).

14. A method for producing a laminated pane (100) with light source according to any of claims 1 to 13, wherein (a) a layer stack consisting of the outer pane (1), the first thermoplastic film (10.1), the functional element (4), the darkened layer (6), the decoupling element (5) and the inner pane (2) is provided, (b) the layer stack is laminated to form the laminated pane (100), and (c) the light source (7) is arranged on a side edge (11) of the inner pane (2) or in a recess (9) of the inner pane (2).

15. A use of a laminated pane (100) according to any of claims 1 to 13 in means of transportation for traffic on land, in the air, or in water, preferably in motor vehicles, for example as a windscreen, rear window, side windows, and / or glass roof, particularly preferably as a roof pane or as a functional and / or decorative individual piece and as a built-in part in furniture, devices, and buildings.