Composite pane comprising a wedge-shaped intermediate layer and a plurality of reflective regions

Abstract

The invention relates to a composite pane (1) for a projection assembly (100) comprising an HUD region (H), said composite pane comprising: - an outer pane (2), a thermoplastic intermediate layer (4), and an inner pane (3), - a masking layer (5), and - a reflective layer (6), the reflective layer (6) being positioned on an interior surface (IV) of the inner pane (3), said interior surface facing away from the thermoplastic intermediate layer (4), and outside an HUD region (H) of the composite pane (1), the reflective layer (6) being positioned completely within the masking layer (5) as seen from the inner pane (3) when the composite pane (1) is viewed from above, the thermoplastic intermediate layer (4) being wedge-shaped at least in the HUD region (H).

Description

[0001] Composite pane with wedge-shaped intermediate layer and several reflection areas

[0002] The invention relates to a composite pane for a projection arrangement, a method for its production, its use and a projection arrangement with the composite pane.

[0003] Modern automobiles are increasingly being equipped with so-called head-up displays (HUDs). Using a projector, typically located in the dashboard, images are projected onto the HUD area of ​​the windshield, reflected there, and perceived by the driver as a virtual image (as seen from the driver's perspective) behind the windshield. This allows important information to be projected into the driver's field of vision, such as the current speed, navigation information, or warnings, which the driver can perceive without having to take their eyes off the road. Head-up displays can therefore significantly contribute to improving road safety.

[0004] The head-up displays described above have the problem that the virtual image is reflected off both surfaces of the windshield. As a result, the driver not only perceives the desired main image, which is caused by the reflection on the interior surface of the windshield (primary reflection). The driver also perceives a slightly offset, usually less intense secondary image, which is caused by the reflection on the exterior surface of the windshield (secondary reflection). The latter is commonly referred to as a ghost image. This problem is generally solved by arranging the reflective surfaces at a deliberately chosen angle to one another so that the main image and ghost image are superimposed, whereby the ghost image is no longer distracting.

[0005] Windshields consist of two glass panes laminated together using a thermoplastic film. If the surfaces of the glass panes are to be arranged at an angle as described, it is common to use a thermoplastic film with a non-constant thickness. This is also referred to as a wedge-shaped film or wedge film. The angle between the two surfaces of the film is called the wedge angle. The wedge angle can be constant across the entire film (linear change in thickness) or change depending on the position (non-linear change in thickness). Laminated glass with wedge films is known, for example, from W02009 / 071135A1, EP1800855B1, WO2021213884A1 or

[0006] EP1880243A2 known.

[0007] In addition to the transparent see-through area, windshields usually have an opaque masking area with an opaque layer through which no vision is possible. The masking area is typically located around the perimeter of the windshield and surrounds the see-through area. The opaque masking area primarily serves to protect the adhesive used to bond the windshield to the vehicle body from UV radiation. The masking area is typically formed by a black masking print on the surface of the outer pane facing the interlayer.

[0008] It is also possible to create a virtual image in the masking area. The masking area is also illuminated by a projector, and the light is reflected there, creating a display for the driver. For example, information that was previously displayed in the dashboard area, such as the time, driving speed, engine speed, or information from a navigation system, or even the image from a rear-facing camera, which replaces the traditional exterior or rearview mirrors, can be presented in a practical and aesthetically pleasing manner directly on the windshield, for example, in the section of the masking area that borders the lower edge of the windshield. A projection arrangement of this type is known, for example, from DE102009020824A1, WO2022244873A1, and WO2022073894A1.A homogeneous reflection of light in the masking area places different demands on the structure of a composite pane than those for a HUD reflection.

[0009] The object of the present invention is therefore to provide an improved projection arrangement using a composite screen which can be used both as a component of a classic HUD projection arrangement and a projection arrangement with a masking area, whereby a homogeneous reflection is achieved for both types of projection arrangements.

[0010] The object of the present invention is achieved according to the invention by a composite pane according to claim 1. Preferred embodiments emerge from the subclaims. The invention relates to a composite pane for a projection arrangement with a HUD (head-up display) area. The composite pane comprises an outer pane, an inner pane, and a thermoplastic intermediate layer arranged between the inner pane and the outer pane, which is wedge-shaped at least in some regions. The thermoplastic intermediate layer preferably extends over the entire surface of the composite pane, i.e. is arranged flatly between the outer pane and the inner pane. The thermoplastic intermediate layer is wedge-shaped at least in one HUD area of ​​the composite pane.The thermoplastic intermediate layer is therefore wedge-shaped at least in the area in which the thermoplastic intermediate layer and the HUD area overlap when viewed through the composite pane.

[0011] The composite pane according to the invention also comprises a masking layer and a reflective layer. The reflective layer is arranged on an interior-side surface of the inner pane facing away from the thermoplastic intermediate layer. The reflective layer is also arranged outside the HUD region of the composite pane. This means that the reflective layer does not overlap with the HUD region when viewed through the composite pane. In a plan view of the composite pane, as seen from the inner pane, the reflective layer is arranged entirely within the masking layer. In other words, the reflective layer is completely concealed by the masking layer when viewed through the composite pane, as seen from the outer pane. When viewed through the composite pane, “as seen from the outer pane” means looking in the direction from the outer pane to the inner pane.When viewed through the laminated pane, "viewed from the inner pane" means looking from the inner pane to the outer pane. It is understood that when viewed through the laminated pane, from the inner pane, the masking layer is located behind the reflective layer.

[0012] The fact that the reflective layer is completely concealed by the masking layer when viewed through the composite pane from the outer pane means, conversely, in the sense of the invention, that the reflective layer is arranged completely in front of the masking layer when viewed through the composite pane in the direction from the inner pane to the outer pane. The masking layer can be arranged congruently with the reflective layer or it can extend beyond the surface of the reflective layer and beyond the surface of the composite pane. Looking in the direction from the inner pane to the outer pane or from the outer pane to the inner pane means a viewing direction arranged perpendicular to the main surface of the composite pane. In the sense of the invention, the “complete concealment of an element A with an element B” means that the orthonormal projection of element A to the plane of element B is arranged completely within element B.

[0013] The HUD (head-up display) area of ​​the composite pane refers to an area of ​​the composite pane that is intended to be illuminated by a projector in a projection arrangement so that a head-up display image can be displayed in the HUD area. The HUD area is therefore arranged in an area of ​​the composite pane that is at least partially transparent with a light transmittance (according to ISO 9050:2003) of preferably at least 50%, particularly preferably at least 70%. If the composite pane is, for example, a windshield in a car, the HUD area is an area through which a viewer (for example the driver) can see the road. It is understood that, according to the invention, the HUD area does not overlap with the masking layer when viewed through the composite pane.

[0014] The outer pane has an outer surface facing away from the thermoplastic intermediate layer, which is also the outer surface of the composite pane. The outer pane also has an interior surface facing the thermoplastic intermediate layer. The interior surface of the inner pane is also the inner surface of the composite pane. The inner pane also has an outer surface facing the thermoplastic intermediate layer. 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 surface of the inner pane is intended to face the interior.

[0015] The composite pane has a circumferential edge, which particularly preferably comprises an upper edge and a lower edge, as well as two side edges running between them, with a left and a right side edge. The upper edge refers to the edge which is intended to point upwards in the installed position. The lower edge refers to the edge which is intended to point downwards in the installed position. The upper edge is often also referred to as the roof edge and the lower edge as the engine edge. The composite pane can have any suitable geometric shape and / or curvature. The designations “left” and “right” refer to the side or direction for a viewer looking at the installed composite pane according to the invention from an interior space.

[0016] The masking layer can be an opaque enamel or an opaque thermoplastic film. The masking layer can also be a partially opaque thermoplastic film and thus be a component of the thermoplastic intermediate layer. The masking layer is in particular a dark, preferably black, enamel, which is applied to the outer pane. The masking layer is preferably applied to the interior-facing surface of the outer pane. However, the masking layer can also be applied to the interior-facing surface of the inner pane. The masking layer is preferably a peripheral (frame-shaped) layer that extends along the circumferential edge of the composite pane and can be widened in the region of the reflective layer. The masking layer primarily serves as UV protection for the assembly adhesive of the composite pane (e.g., for bonding into a vehicle).The masking layer preferably has a transmittance (according to ISO 9050:2003) for visible light of less than 15%, preferably less than 10%, particularly preferably less than 1%. The masking layer can also be semitransparent, at least in sections, for example, as a dot matrix, striped matrix, or checkered matrix. Alternatively, the masking layer can also have a gradient, for example, from an opaque coverage to a semitransparent coverage. "Width" in the context of the invention refers to the extent perpendicular to the direction of extension.

[0017] The composite pane can also have several, preferably two, masking layers, with a first masking layer preferably being applied to the interior surface of the outer pane and a second masking layer being applied to the interior surface of the inner pane. If two or more masking layers are part of the composite pane, the "masking layer" according to the invention preferably refers to only one of the several masking layers.

[0018] In a particularly preferred embodiment of the invention, the masking layer is arranged in a frame-like manner in the peripheral edge region of the composite pane and is widened in a section of the peripheral edge region adjacent to the lower edge of the composite pane. The masking layer preferably has a width of 10 cm or more, particularly preferably 20 cm or more, in particular 30 cm or more, in the widened region. This embodiment is particularly suitable for use in vehicles, in which the projection arrangement can be used as an alternative to displays installed in the dashboard. Alternatively, the masking layer can be applied in a lower edge region of the composite pane adjacent to the lower edge and / or in an upper edge region of the composite pane adjacent to the upper edge.

[0019] In a particularly preferred embodiment of the invention, the reflective layer is applied to the interior-side surface of the inner pane. If the masking layer is applied to the interior-side surface of the inner pane, the reflective layer is preferably applied to the masking layer. In this embodiment, the reflective layer is preferably a coating made of one or more conductive and / or dielectric layers. Alternatively, the reflective layer is an uncoated or coated polymeric film arranged on the interior-side surface of the inner pane. The reflective layer can be applied to the interior-side surface of the inner pane by means of an adhesive layer. Particularly preferably, the reflective layer is applied as a coating to the interior-side surface of the inner pane or, if appropriate, the masking layer.By applying a coating, material can be saved.

[0020] In another particularly preferred embodiment of the invention, the reflective layer is applied to a surface of another pane. The other pane is preferably made of transparent glass, in particular soda-lime glass. However, it can also be made of other glass (e.g., borosilicate glass, quartz glass, aluminosilicate glass) or transparent plastics (e.g., polymethyl methacrylate or polycarbonate). The other pane has two surfaces, one surface facing the interior-side surface of the inner pane and the other surface facing away from the interior-side surface of the inner pane. The other pane also has a circumferential edge.

[0021] Preferably, the additional pane coated with the reflective layer is applied to the interior-side surface of the inner pane by means of an adhesive layer. The reflective layer is preferably arranged between the additional pane and the inner pane. The reflective layer is thus applied to a surface of the additional pane that faces the interior-side surface of the inner pane. This better protects the reflective layer from external influences. For example, the reflective layer cannot be scraped off without first detaching the additional pane from the composite pane. The reflective layer preferably extends over at least 80%, particularly preferably over at least 90%, of the surface of the additional pane.In particular, the reflective layer extends over the entire surface of the additional pane, with the exception of a surrounding, frame-shaped edge area located adjacent to a peripheral edge of the additional pane. This provides better protection for the reflective layer against moisture and corrosion.

[0022] In a further particularly preferred embodiment of the invention, the reflective layer is applied to the interior-side surface of the inner pane. If the masking layer is applied to the interior-side surface of the inner pane, the reflective layer is preferably applied to the masking layer. A further pane is arranged on the reflective layer or a protective layer is applied. The further pane is applied to the reflective layer, for example, via an adhesive layer. The protective layer or the further pane is preferably transparent and applied flatly to the reflective layer. The further pane or the protective layer preferably extends over the entire area of ​​the interior-side surface of the inner pane coated with the reflective layer.The additional pane or the protective layer can also extend beyond the area of ​​the interior-side surface of the inner pane coated with the reflective layer. In particular, the protective layer or the additional pane extends over the entire area of ​​the interior-side surface of the inner pane coated with the reflective layer and additionally over an area of ​​the inner pane surrounding the reflective layer. This provides better protection for the reflective layer against moisture and associated corrosion. The width of the area of ​​the inner pane surrounding the reflective layer is preferably between 1 mm and 5 cm.

[0023] The protective layer is preferably a polymer based on polyacrylates, polyoximes, alkyd resins, polyurethanes, or mixtures thereof. Particularly preferably, the protective layer contains or consists of diamond-like amorphous carbon (DLC). The protective layer preferably has a thickness of 50 nm to 10 pm, and particularly preferably of 100 nm to 5 pm. The protective layer is preferably applied to the reflective layer by spraying or atomizing, for example, using a pressure atomizer. The protective layer protects the metallic coating from mechanical damage such as scratches. It can also serve to increase the durability of the coating. With the protective layer, less material separates from the reflective layer on the inner pane over time, and the reflective layer retains its homogeneous shape for longer.

[0024] In a particularly preferred embodiment of the invention, the protective layer is an easy-to-clean layer and / or an anti-fingerprint layer. For the purposes of the invention, "easy-to-clean layer" means that dirt in the form of, for example, fingerprints, grease stains, and dirt particles on the protective layer can be removed from the protective layer using a cloth, preferably a microfiber cloth. Grease-dissolving or abrasive cleaning agents as well as solvents, for example based on alcohols, are therefore largely avoided for cleaning the protective layer. For the purposes of the invention, an "anti-fingerprint" layer means a layer in which fingerprints adhering to the protective layer are barely or not at all visually perceptible.Fingerprints are specifically the fatty components of a human finger that can remain on a surface when touching it and can have an unsightly effect.

[0025] The adhesive layer preferably has a light transmittance (according to ISO 9050:2003) of at least 50%, particularly preferably at least 70%, and is preferably based on silicon oxide and / or silicon nitride. Alternatively, the adhesive layer, which can also be called an adhesive layer, preferably has a light transmittance (according to ISO 9050:2003) of at least 50%, particularly preferably at least 70%. The adhesive layer is preferably based on polyurethane, polyacrylate compounds (e.g., polyacrylate or polymethylacrylate), PVB, EVA, or silicone, particularly preferably based on polyurethane, polyacrylate compounds (e.g., polyacrylate or polymethylacrylate), or silicone. Alternatively, the adhesive layer is based on mixtures of these materials. These materials allow for a uniform application of the additional pane to the inner pane.In this way, local differences in the thickness of the adhesive layer between the other pane and the inner or outer pane can be largely avoided, which could otherwise impair the aesthetics of the composite pane.

[0026] The additional pane is preferably a thin pane that is thinner than both the inner pane and the outer pane. In an alternative embodiment, the additional pane is a thin pane with a thickness of 50 μm to 1000 μm, preferably 150 μm to 500 μm, and particularly preferably 150 μm to 250 μm. This thickness achieves a good balance between material costs and mechanical stability on the composite pane. Furthermore, the reflective layer and the thin pane are less aesthetically pleasing, thus improving the optical quality of the composite pane compared to a greater thickness.

[0027] The reflective layer preferably reflects at least 10% of visible light, particularly preferably at least 40%, and most preferably at least 70%. The reflective layer preferably reflects at most 90% of visible light. For the purposes of the invention, "reflected" means that the reflective layer reflects visible light that strikes it. For the purposes of the invention, reflection within a certain percentage range means an average reflectance at a defined angle of incidence of 65° to the interior surface normal. The reflective layer is intended to reflect an image projected onto the reflective layer by a projector. The reflective layer can be transparent, but is preferably opaque.

[0028] The reflective layer is designed to reflect visible light in a wavelength range from 380 nm to 780 nm. The reflective layer preferably reflects p-polarized and s-polarized light in equal proportions, but it can also reflect p-polarized and s-polarized light to varying degrees. The reflective layer preferably has a high and uniform reflectance (across different angles of incidence) with respect to p-polarized and / or s-polarized radiation, ensuring a high-intensity and color-neutral image representation. When p-polarized light is reflected, fewer ghost images occur, thus resulting in an improved visual quality of the reflected light (e.g., a virtual image). The reflectance can be increased by adding s-polarized light.

[0029] The reflectance is measured at an angle of incidence of 65° to the interior surface normal (surface normal to the interior surface of the inner pane), which roughly corresponds to the irradiation by conventional HUD projectors. The spectral range from 380 nm to 680 nm was used to characterize the reflection properties because the viewer's visual impression is primarily shaped by this spectral range. It also covers the wavelengths relevant for HUD display (RGB: 473 nm, 550 nm, 630 nm). The reflectance describes the proportion of the total incident radiation that is reflected. It is given as a percentage (relative to 100% incident radiation) or as a unitless number from 0 to 1 (normalized to the incident radiation). Plotted as a function of wavelength, it forms the reflection spectrum.In the context of the present invention, the statements regarding the reflectance (or percentage reflection) with respect to p-polarized, unpolarized, or s-polarized radiation refer to the reflectance measured at an angle of incidence of 65° to the interior surface normal. The information on the reflectance or the reflection spectrum refers to a reflection measurement with a light source that radiates uniformly in the spectral range under consideration with a standardized radiation intensity of 100%.

[0030] The reflective layer preferably extends over a maximum of 50%, particularly preferably a maximum of 40%, in particular a maximum of 20%, of the surface of the composite pane. The reflective layer is particularly preferably arranged in an upper edge region of the composite pane adjacent to the upper edge and / or in a lower edge region of the composite pane adjacent to the lower edge of the composite pane, wherein a coating-free edge region is preferably located between the reflective layer and the upper edge and / or lower edge. Alternatively, the reflective layer can also be arranged additionally or exclusively in a lateral edge region adjacent to one or both side edges of the composite pane, wherein in this case too, a coating-free edge region is preferably located between the reflective layer and the side edge (left and / or right side edge).The coating-free edge region preferably has a width of less than 20 cm, particularly preferably less than 10 cm, in particular less than 1 cm. The reflective layer preferably extends in a strip-like manner from one (left) side edge to the other (right) side edge and is in particular adjacent to the lower edge of the composite pane. The reflective layer preferably has a width of at least 10 cm, particularly preferably at least 20 cm, in particular at least 30 cm. The arrangement of the reflective layer in an edge region adjacent to the lower edge, left side edge, right side edge and / or upper edge is particularly suitable when the composite pane is in the form of a vehicle window, in particular a windshield, since the area of ​​the composite pane intended for viewing remains free of the reflective layer.The reflective layer preferably comprises at least one metal selected from a group consisting of aluminum, magnesium, tin, indium, titanium, tantalum, niobium, nickel, copper, chromium, cobalt, iron, manganese, zirconium, cerium, scandium, yttrium, silver, gold, platinum, palladium, ruthenium, or mixtures thereof. Alternatively or additionally, the reflective layer comprises oxides, carbides, silicon compounds, and / or nitrides selected from a group consisting of boron-doped silicon, silicon-zirconium mixed nitride, silicon nitride, titanium oxide, silicon oxide, titanium carbide, zirconium carbide, silicon-zirconium-aluminum, or mixtures thereof. Aluminum, titanium, nickel-chromium, and / or nickel are preferably applied to the inner pane or the further pane because they can exhibit high reflection for p-polarized or s-polarized light. They are therefore particularly suitable as a component of a projection arrangement.The reflective layer preferably has a thickness of 10 nm (nanometers) to 100 pm (micrometers), particularly preferably from 50 nm to 50 pm, in particular from 100 nm to 5 pm.

[0031] In a particular embodiment of the invention, the reflective layer is a coating comprising a thin-film stack, i.e., a sequence of thin individual layers. This thin-film stack contains one or more electrically conductive layers based on nickel, nickel-chromium, titanium, and / or aluminum. The electrically conductive layer based on nickel, nickel-chromium, titanium, and / or aluminum imparts basic reflective properties to the reflective layer, as well as an IR-reflecting effect and electrical conductivity. The electrically conductive layer is based on nickel, nickel-chromium, titanium, and / or aluminum. The conductive layer preferably contains at least 90% by weight of nickel, titanium, and / or aluminum, more preferably at least 99% by weight of aluminum, and most preferably at least 99.9% by weight of nickel, titanium, and / or aluminum.The layer based on aluminum, nickel-chromium, nickel, and / or titanium can contain dopants, for example palladium, gold, copper, or silver. Materials based on aluminum, nickel, nickel-chromium, and / or titanium are particularly suitable for reflecting light, particularly preferably p-polarized light. The use of nickel, nickel-chromium, titanium, and / or aluminum in reflective layers has proven particularly advantageous for reflecting light. Aluminum, nickel, nickel-chromium, and / or titanium are significantly cheaper than many other metals such as gold or silver. In addition, these metals have high chemical and thermomechanical resistance. The individual layers of the thin-film stack preferably have a thickness of 10 nm to 1 pm. The thin-film stack preferably has 2 to 20 individual layers, and in particular 5 to 10 individual layers.

[0032] In a particularly preferred embodiment of the invention, the reflective layer is a metal-free reflective film. The reflective layer is then preferably a film based on synergistically interacting prisms and reflective polarizers. The reflective layer preferably has a carrier film based on polyvinyl chloride or polyethylene terephthalate. Synergistically interacting prisms and reflective polarizers are applied to this carrier film. Such films for using reflective layers are commercially available, for example from the 3M Company. In this way, complex metal deposition can be avoided. The reflective layer is applied as a reflective film, preferably via an adhesive layer, to the interior-facing surface of the inner pane.

[0033] In a further particularly preferred embodiment of the invention, the reflection layer contains

[0034] • a dielectric layer stack containing TiO2 layers and SiO2 layers,

[0035] • a dielectric layer stack containing SiZrN layers and SiO2 layers,

[0036] • a layer stack containing Si:B layers or SiZrAI layers,

[0037] • a layer stack containing Si layers and SiO2 layers,

[0038] • a layer stack containing Si layers and SiA / N layers or

[0039] • a carbide layer stack containing TiC layers and / or ZrC layers, or consists of one or more of these layer stacks. The described layer stacks have suitable reflection properties to achieve a homogeneous image as part of a projection arrangement. Preferably, the described layer stacks are applied as a coating on the inner pane or the other pane.

[0040] The above-mentioned desired reflection characteristics of the reflection layer are achieved in particular by the choice of materials and thicknesses as well as the structure of the individual layers or layer sequences.

[0041] In a particularly preferred embodiment of the invention, the composite pane further comprises a preferably transparent, heatable functional layer. The heatable functional layer is preferably applied to the outer pane or the inner pane, in particular to the outer surface of the inner pane or the interior surface of the outer pane.

[0042] The heatable functional layer preferably extends over more than 50%, preferably more than 70%, particularly preferably more than 90%, of the surface of the composite pane. The heatable functional layer preferably extends at least over the entire area intended for viewing through the composite pane. This refers to the area through which one can see through the finished composite pane and optionally in the installed state (e.g. installation of the composite pane in a vehicle) and which is transparent. In particular, the heatable functional layer extends over the entire surface of the composite pane minus a circumferential, frame-shaped edge region (adjacent to the circumferential edge of the composite pane). The uncoated circumferential, frame-shaped edge region serves to better separate the heatable functional layer from the external environment.This provides better protection for the heatable functional layer against corrosion or mechanical damage. The coating-free edge area preferably has a width of less than 20 cm, particularly preferably less than 10 cm, and especially less than 1 cm.

[0043] The heatable functional layer preferably has a light transmittance (according to ISO 9050:2003) for light in the visible spectral range of at least 50%, preferably at least 60%, and particularly preferably at least 70%. Furthermore, the heatable functional layer has a light transmittance (according to ISO 9050:2003) for light in the visible spectral range of 90% or less, preferably 80% or less, particularly preferably exactly 70%.

[0044] For the purposes of the invention, "opaque" means a light transmission (according to ISO 9050:2003) of less than 30%, preferably less than 20%, particularly preferably less than 5%, and especially less than 0.1%. "Transparent" for the purposes of the invention means a light transmission (according to ISO 9050:2003) of at least 50%, preferably at least 60%, and particularly preferably at least 70%.

[0045] The heatable functional layer is preferably designed to absorb and / or reflect infrared light. This achieves the technical advantage that the entry of infrared light is reduced, thus improving the heat-insulating effect of the composite pane. The heatable functional layer typically contains one or more, for example two, three or four, functional layers. The functional layers preferably contain at least one metal, for example silver, gold, copper, nickel and / or chromium or a metal alloy. The functional layers particularly preferably contain at least 90 wt.% of the metal, in particular at least 99.9 wt.% of the metal. The functional layers can consist of the metal or the metal alloy.

[0046] In a further advantageous embodiment of the composite pane, the heatable functional layer comprises at least one silver layer and preferably a plurality of silver layers. Such silver layers have particularly advantageous electrical conductivity with simultaneous high transmission in the visible spectral range. The thickness of a silver layer is preferably from 5 nm to 50 nm, particularly preferably from 8 nm to 25 nm. In this range for the thickness of the silver layer, an advantageously high transmission in the visible spectral range and a particularly advantageous electrical conductivity are achieved. Preferably, at least one dielectric layer is arranged between each two adjacent silver layers of the coating. Preferably, a further dielectric layer is arranged below the first and / or above the last silver layer.A dielectric layer contains at least one individual layer of a dielectric material, for example containing a nitride such as silicon nitride or an oxide such as aluminum oxide. However, dielectric layers can also comprise multiple individual layers, for example individual layers of a dielectric material, smoothing layers, adaptation layers, blocking layers, and / or anti-reflection layers. The thickness of a dielectric layer is, for example, from 10 nm to 200 nm. This achieves the technical advantage, for example, that infrared light can be effectively blocked. The blocking of infrared light is particularly well achieved when the heatable functional layer comprises at least two silver layers, particularly preferably three silver layers, and in particular exactly three silver layers.The heatable functional layer can alternatively contain or consist of indium tin oxide (ITO), fluorine-doped tin oxide (SnO2:F) or aluminum-doped zinc oxide (ZnO:Al).

[0047] The geometric layer thickness of the heatable functional layer is preferably at most 200 nm, more preferably at most 100 nm, and most preferably at most 15 nm. This allows advantageous reflectivity in the IR range to be achieved without excessively reducing transmission. The geometric layer thickness of the silver layer is preferably at least 6 nm, more preferably at least 8 nm. Thinner silver layers can lead to dewetting of the layer structure. The geometric layer thickness of the silver layer is particularly preferably between 10 nm and 14 nm, in particular between 11 nm and 13 nm.

[0048] When talking about thin layers, i.e., layers with a thickness of less than 1000 nm, the following applies: if something is "based" on a material, it consists predominantly of this material, in particular, essentially of this material alongside any impurities or dopants. Unless otherwise stated, the specified layer thickness or thicknesses refer to the geometric thickness of a layer.

[0049] In a particularly preferred embodiment of the invention, the heatable functional layer is electrically contacted by means of at least two bus bars, so that when a direct voltage is applied, an electric heating current flows through the heatable functional layer, taking into account the electrical resistance between the bus bars. The bus bars are preferably arranged in opposite edge regions of the heatable functional layer.

[0050] It is also possible for more than two bus bars to be electrically contacted with the heatable functional layer. Particularly preferably, three bus bars are electrically contacted with the heatable functional layer, wherein the bus bars are arranged at a distance from one another on the heatable functional layer. The bus bars are arranged in such a way that a heating region is formed between each two bus bars, wherein the heatable functional layer has a total of two heating regions. One heating region can, for example, extend over the area of ​​the composite pane intended for transparency, wherein the other heating region is arranged in the area of ​​the reflective layer. In this way, the transparency area and the area of ​​the reflective layer can be heated independently of one another. Furthermore, less energy is consumed because the electrical resistance increases with the distance between the bus bars.

[0051] In principle, the reflective layer and, if present, the heatable functional layer can be applied by physical or chemical vapor deposition, i.e., a PVD or CVD coating (PVD: physical vapor deposition, CVD: chemical vapor deposition), or, for example, using the sol-gel process. Such coatings can be produced with particularly high optical quality and a particularly low thickness. If the reflective layer and the heatable functional layer, if present, form a layer stack, the individual layers of the layer stack are applied consecutively, i.e., one after the other. The application of layers using the sol-gel process is known to those skilled in the art and can be found, for example, in WO2021209201 A1.

[0052] A PVD coating can be a coating applied by cathode sputtering ("sputtered"), in particular a coating applied by magnetic field-assisted cathode sputtering (magnetron sputtering). Preferably, the reflective layer and any heatable functional layer are applied by magnetron sputtering. Magnetron sputtering can efficiently produce a homogeneous layer just a few nanometers thick.

[0053] If the reflective layer and any heatable functional layer are applied using chemical vapor deposition, this is preferably done using plasma-enhanced chemical vapor deposition (PECVD), particularly at atmospheric pressure (APCVD). The advantage of plasma-enhanced chemical vapor deposition is the speed of application combined with high layer homogeneity compared to many other processes. Silicon oxide, in particular, can be applied homogeneously and efficiently to a substrate using this process.

[0054] The reflective layer is preferably applied by physical vapor deposition (PVD) onto a film or onto the interior surface of the inner pane, particularly preferably by cathode sputtering, and most preferably by magnetic field-assisted cathode sputtering. The reflective layer is preferably applied prior to lamination.

[0055] The outer pane and the inner pane are preferably made of transparent glass, in particular soda-lime glass, which is common for window panes. In principle, 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, more preferably 1.4 mm to 2.5 mm, for example those with the standard thicknesses of 1.6 mm or 2.1 mm, are used. The outer pane, the other pane and the inner panes can independently of one another be untempered, partially tempered or toughened. If at least one of the panes is to be tempered, this can be thermal or chemical tempering.

[0056] The outer pane, the inner pane, and the composite pane can have any three-dimensional shape. The inner pane and the outer pane preferably have no shadow zones, allowing them to be efficiently coated by cathode sputtering. The inner pane and outer pane, and thus also the composite pane, are preferably flat or slightly or strongly curved in one or more directions of space. Any additional pane present is preferably curved in the same shape as the inner pane in the region of the reflective layer.

[0057] The thermoplastic intermediate layer, which is wedge-shaped at least in some regions, is preferably formed as at least one thermoplastic composite film and is 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 contains additives known to those skilled in the art, such as plasticizers. The thermoplastic film preferably contains at least one plasticizer.

[0058] The at least partially thermoplastic intermediate layer can be formed by a single film that is at least partially wedge-shaped or by more than one film, wherein at least one of the films is at least partially wedge-shaped. 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 in some areas and is therefore opaque. The masking layer can also be a component of the thermoplastic intermediate layer. The intermediate layer can also be formed from more than one film, and the at least two films extend over different regions of the surface of the composite pane.With a wedge-shaped interlayer, the thickness is determined at the thinnest point, typically at the bottom edge of the laminated pane. The thermoplastic interlayer can also be a functional thermoplastic film, in particular a film with acoustic damping properties, an infrared-reflecting film, an infrared-absorbing film, and / or a UV-absorbing film. For example, the thermoplastic interlayer can also be a bandpass filter film.

[0059] 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.

[0060] Due to the wedge-shaped thermoplastic intermediate layer, which is at least partially wedge-shaped, the composite pane is designed in such a way that ghost images can be largely avoided when projecting an image onto the HUD area. The wedge film allows the HUD images created by reflections on the outer surface of the inner pane and the outer pane to be superimposed or approximated, thereby avoiding or at least reducing layer ghost images. Preferably, the composite pane has an anti-reflection coating applied to the interior surface of the inner pane. The anti-reflection coating suppresses reflections on the interior surface, so that the projection of an image is only significantly reflected on the outer surface.The anti-reflection coating preferably extends at least over the HUD area of ​​the composite pane, particularly preferably over at least 50% of the area of ​​the composite pane and in particular over the entire area of ​​the composite pane.

[0061] For the purposes of the invention, a “wedge-shaped or partially wedge-shaped thermoplastic intermediate layer” means that the thermoplastic layer, in a cross-sectional view, has the shape of a wedge in one area or entirely. The thermoplastic layer does not have a constant thickness there, but rather a variable thickness with a thicker first end and a thinner second end. The angle between the two surfaces in the wedge-shaped area of ​​the intermediate layer is called the wedge angle. If the wedge angle is not constant, the tangents to the surfaces must be used to measure it at a point. The intermediate layer is wedge-shaped or wedge-like, at least in the HUD area. The wedge angle can be constant in the vertical direction, which leads to a linear change in the thickness of the intermediate layer, with the thickness typically increasing from bottom to top.The direction "from bottom to top" refers to the direction from the bottom edge to the top edge of the laminated pane, i.e., the vertical profile. However, more complex thickness profiles can also exist, in which the wedge angle varies from bottom to top (i.e., the vertical profile is location-dependent), either linearly or non-linearly.

[0062] In addition to a wedge film in the intermediate layer, a wedge-shaped outer pane can also be used to angle the reflective surfaces towards each other.

[0063] The wedge angle is suitably selected to superimpose the projection images caused by reflections on the outer surface of the inner pane on the one hand and on the outer surface of the outer pane on the other, or at least to reduce their distance from one another. In the case of parallel reflection surfaces, the image (created by reflection on the outer surface of the outer pane) and the ghost image (created by reflection of the outer surface of the inner pane) would appear offset from one another, which is disturbing for the viewer. The wedge angle essentially spatially superimposes the ghost image on the image, so that the viewer only perceives a single image or the distance between the image and the ghost image is at least reduced. Typical wedge angles are in the range of 0.3 mrad to 0.7 mrad, in particular from 0.4 mrad to 0.5 mrad.Wedge films with smaller wedge angles are easier and more cost-effective to produce. If the wedge angle is not constant (i.e., variable) across the wedge-shaped region of the thermoplastic intermediate layer, it can exhibit different wedge angles depending on the location, but all of them are within the specified range. The specified upper and lower values ​​are therefore to be understood as limit values. In other words, the variable wedge angle varies depending on the location, but nowhere lies above or below the specified range.

[0064] The thermoplastic intermediate layer is wedge-shaped, at least in the HUD area, so that visible light from a projector can be reflected without, or largely without, ghosting.

[0065] The composite pane can be part of a projection arrangement, wherein the HUD region of the composite pane can be irradiated with one projector and the reflective layer can be irradiated with another projector. The projector and the another projector preferably project a virtual image onto the reflective layer or the HUD region. Due to the different reflective properties, a homogeneous image can be achieved both in the HUD region on the outer surface of the outer pane and outside the HUD region on the reflective layer. This is a major advantage of the invention. If the HUD region is irradiated by means of a projector, preferably up to 30%, particularly preferably up to 20%, in particular up to 15% of the visible light (radiation) from the projector incident on the HUD region is reflected.

[0066] A further aspect of the invention relates to a projection arrangement, comprising a composite pane according to the invention, a projector which projects an image in the form of visible radiation (visible light), preferably via the inner pane, onto the HUD region of the composite pane, and a further projector which projects an image in the form of visible radiation (visible light) onto the reflective layer. In other words: the respective projector irradiates the HUD region or the reflective layer with visible light, wherein the reflective layer and the outer pane and inner pane at least partially reflect the visible light. The projector and the further projector preferably face the interior-side surface of the inner pane. If the composite pane is in an installed state (for example as a windshield in a vehicle), the projector and the further projector irradiate the reflective layer orthe HUD area from an interior (vehicle interior).

[0067] The radiation from the projector and the additional projector, independently of one another, preferably has a p-polarized component > 0%. In principle, the p-polarized component can also be 100%, meaning the projectors emit purely p-polarized radiation. However, for the overall intensity of the HUD image, it is advantageous if the radiation from the projector has both s-polarized and p-polarized components. In this case, the p-polarized radiation components are efficiently reflected by the reflective layer, and the s-polarized radiation components are reflected by the window surfaces. The ratio of p-polarized radiation components to s-polarized radiation components can be freely selected according to the requirements of the individual case. The proportion of p-polarized radiation in the total radiation from the projector and / or the additional projector is, for example, from 10% to 100%, preferably from 10% to 90%.In a particularly advantageous embodiment, the proportion of p-polarized radiation from the projector and / or the additional projector is at least 50%, i.e., from 50% to 90%, preferably from 60% to 80%, which ensures, in particular, that a driver wearing polarization-selective sunglasses can perceive a high-intensity image. In a particularly advantageous embodiment, the radiation from the additional projector is essentially purely p-polarized—the p-polarized radiation proportion is thus 100% or deviates only slightly therefrom. This largely prevents double images.

[0068] The polarization direction refers to the plane of incidence of the radiation on the composite pane. P-polarized radiation refers to radiation whose electric field oscillates in the plane of incidence. S-polarized radiation refers to radiation whose electric field oscillates perpendicular to the plane of incidence. The plane of incidence is defined by the incidence vector and the surface normal of the composite pane at the geometric center of the irradiated area.

[0069] If the projection arrangement is part of a vehicle, the projector and the additional projector are preferably arranged in the vehicle's dashboard. The image projected by the additional projector onto the reflective layer and the image projected by the projector onto the HUD area of ​​the composite window are reflected into the vehicle interior, for example, into the field of vision of an occupant. Due to the reflective layer, which is arranged in front of the masking layer, the image projected onto the reflective layer can be visually perceived with high contrast. This allows the use of projectors with lower energy consumption. Compared to projectors for conventional head-up displays, the energy consumption of the projector can be reduced by up to 80%.

[0070] The projector and / or the further projector are preferably a liquid crystal (LCD) display, thin film transistor (TFT) display, light emitting diode (LED) display, organic light emitting diode (OLED) display, electroluminescent (EL) display or microLED display.

[0071] As is common with HUDs and projection systems based on similar technology, the projector and the additional projector irradiate the reflective layer or the HUD area of ​​the composite pane, particularly with p-polarized radiation in the wavelength range from 380 nm to 780 nm. This means that a projection surface of the reflective layer or the composite pane is irradiated with the additional projector or the projector. The p-polarized and / or s-polarized radiation is reflected in the area of ​​the projection surface towards a viewer, creating a virtual image that the viewer perceives from behind the composite pane (in the case of a HUD). The beam direction of the projector and / or the additional projector can typically be varied using mirrors, particularly vertically, in order to adapt the projection to the viewer's height.The area in which the viewer's eyes must be located for a given mirror position is called the eyebox window. This eyebox window can be moved vertically by adjusting the mirrors, with the entire accessible area (i.e., the overlap of all possible eyebox windows) being called the eyebox. A viewer located within the eyebox can perceive the virtual image. This, of course, means that the viewer's eyes must be located within the eyebox, not their entire body.

[0072] The technical terms used here from the field of HLIDs are generally known to those skilled in the art. For a detailed description, please refer to the dissertation "Simulation-based Measurement Technology for Testing Head-Up Displays" by Alexander Neumann at the Institute of Computer Science at the Technical University of Munich (Munich: University Library of the TU Munich, 2012), particularly Chapter 2, "The Head-Up Display."

[0073] The above statements and preferred embodiments in connection with the composite pane or the projection arrangement apply equally to the method. The following statements and preferred embodiments in connection with the method according to the invention apply equally to the composite pane and projection arrangement.

[0074] A further aspect of the invention relates to a method for producing the composite pane according to the invention. The method steps comprise, preferably in the order given, the following method steps:

[0075] (A) a layer stack comprising the outer pane, the thermoplastic intermediate layer, the masking layer and the inner pane is provided,

[0076] (B) the reflection layer is arranged, preferably by means of magnetron sputtering, on the interior-side surface of the inner pane and

[0077] (C) the layer stack is laminated to form the composite pane. Alternatively, the reflective layer can be applied to the interior surface of the inner pane after lamination.

[0078] 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.

[0079] The composite 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, a car, or a bus. Alternatively, the composite 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. The invention is explained in more detail below using exemplary embodiments, with reference to the attached figures. The figures are schematic representations and not to scale. The figures do not limit the invention in any way. They show:

[0080] Figure 1 shows an embodiment of the composite pane according to the invention in a plan view,

[0081] Figure 2 is a cross-sectional view of a projection arrangement with the composite pane of Figure 1,

[0082] Figure 3 shows an enlarged lower edge area of ​​the projection arrangement from Figure 2 in a cross-sectional view and

[0083] Figure 4 shows an enlarged HUD area of ​​the projection arrangement from Figure 2 in a cross-sectional view and

[0084] Figures 5-8 show further embodiments of the composite pane according to the invention in a projection arrangement in a cross-sectional view.

[0085] Figures 1 to 4 show different aspects of an embodiment of the composite pane 1 according to the invention. Figure 1 shows the composite pane 1 according to the invention in the form of a windshield for a vehicle. The composite pane 1 is shown in a plan view, looking onto an interior-side surface IV of the composite pane 1. Figure 2 shows the composite pane 1 as a component of a projection arrangement 100 according to the invention in a cross-sectional view, wherein the projection arrangement 100 is installed in a vehicle. The cross-sectional view of Figure 2 corresponds to the section line AA' of the composite pane 1, as indicated in Figure 1. Figure 3 shows an enlarged section of the projection arrangement 100 from Figure 2, wherein the enlarged section shows a lower edge region 7.2 adjacent to the lower edge of the composite pane 1.Figure 4 shows an enlarged section of the projection arrangement 100 from Figure 2, wherein a view-through area of ​​the composite pane 1 with a HUD area H is shown.

[0086] The composite pane 1 has an upper edge and a lower edge, as well as two side edges connecting the upper and lower edges (all together forming a circumferential edge of the composite pane 1). The lower edge (also called the engine edge) of the composite pane 1 refers to the edge that faces the ground in the installed position. The upper edge (also called the roof edge) of the composite pane 1 refers to the edge that faces the vehicle roof when installed in a vehicle.

[0087] The composite pane 1 comprises an outer pane 2, an inner pane 3 and a wedge-shaped thermoplastic intermediate layer 4 arranged between the outer pane 2 and the inner pane 3. The outer pane 2 has an outer surface I facing away from the thermoplastic intermediate layer 4 and an interior-side surface II facing the thermoplastic intermediate layer 4. The inner pane 3 has an outer surface III facing the thermoplastic intermediate layer 4 and an interior-side surface IV facing away from the thermoplastic intermediate layer 4. The outer surface I of the outer pane 2 is also simultaneously the surface of the composite pane 1 that faces the external environment 16, and the interior-side surface IV of the inner pane 3 is also simultaneously the surface of the composite pane 1 that faces the interior 15 of the vehicle.The laminated pane 1, for example, has a shape and curvature typical for windshields.

[0088] The outer pane 2 and the inner pane 3 are each made of glass, preferably thermally toughened soda-lime glass, and are transparent to visible light. The outer pane 2 has a thickness of 2.1 mm, for example, and the inner pane 3 has a thickness of 1.5 mm, for example. The thermoplastic intermediate layer 4 comprises a thermoplastic, preferably polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), and / or polyethylene terephthalate (PET). The thermoplastic intermediate layer 4 is wedge-shaped, with the thickest region of the intermediate layer 4 being located at the upper edge of the composite pane 1 and the thinnest end being located at the lower edge of the composite pane 1. The wedge angle ß of the thermoplastic intermediate layer 4 is, for example, 0.2 mrad.In the sense of the invention, an embodiment would also be possible in which the thermoplastic intermediate layer 4 is wedge-shaped only in the HUD area H and otherwise has a constant thickness (not shown here).

[0089] An opaque masking layer 5 is applied to the interior-side surface II of the outer pane 2. A further opaque masking layer 5' is applied to the interior-side surface IV of the inner pane 3. The masking layer 5 and the further masking layer 5' extend in a frame-like manner along the circumferential edge of the composite pane 1. The masking layer 5 is applied in a widened manner in the lower edge region 7.2 directly adjacent to the lower edge of the composite pane 1, in contrast to the upper edge region 7.1 directly adjacent to the upper edge of the composite pane 1. The masking layer 5 and the further masking layer 5' are opaque and prevent the view of structures arranged on the inside or outside of the composite pane 1, for example an adhesive bead for bonding the composite pane 1 into a vehicle body.The masking layer 5 and the further masking layer 5' consist of an electrically non-conductive material conventionally used for black prints, for example a black-colored screen printing ink that is baked.

[0090] The composite pane 1 has a HUD area H, which is designed to display a head-up display image for a driver or passenger of the vehicle. The HUD area H is arranged in the view-through area of ​​the composite pane 1, so that an image projected onto the HUD area H can be perceived by a viewer as if it were appearing behind the composite pane 1 (i.e., in the external environment 16) (HUD technology).

[0091] An opaque reflective layer 6 is applied in certain areas to the interior-side surface IV of the inner pane 3. This opaque reflective layer 6 overlaps the masking layer 5 in the lower edge region 7.2 of the composite pane 1, and is therefore arranged closer to the lower edge than to the upper edge of the composite pane 1. When installed in a vehicle, the reflective layer 6 is arranged in the vicinity of the dashboard 17. The opaque reflective layer 6 therefore extends from the left side edge to the right side edge of the composite pane 1. The reflective layer e has a width of 30 cm, for example. The reflective layer e is also arranged such that, when viewed through the composite pane 1 from the interior 15, it is completely covered by the widened section of the masking layer 5. The reflective layer 6 is therefore arranged in front of the masking layer 5 on the vehicle interior side.Conversely, it is understood that the masking layer 5 completely conceals the reflective layer e when viewed through the composite pane 1 from the external environment 16. The opaque reflective layer 6 is arranged outside a view-through area intended for viewing and the HUD area H of the composite pane 1. The reflective layer 6 is, for example, a dielectric layer stack containing TiCh layers and SiCh layers. The reflective layer 6 is applied, for example, by magnetron sputtering, to the interior-side surface IV of the inner pane 3. The opaque reflective layer 6 is, for example, designed to reflect at least 30% of visible light.

[0092] A projector 12 and a further projector 13 are arranged on a dashboard 17 of the vehicle, each projecting a virtual image in the form of visible radiation (light) 14.1, 14.2 onto the opaque reflective layer 6 or the HUD region H of the composite pane 1. The angle of incidence α at which the visible radiation 14.1, 14.2 of the projector 12 or the further projector 13 strikes the interior-side surface IV of the inner pane 3 is, for example, 65°. The projector 12 projects a virtual image in the form of visible radiation 14.1 onto the HUD region H of the composite pane 1. The HUD region H irradiated by the projector 12 is indicated by a dashed trapezoidal region on the composite pane 1 in Figure 1. The further projector 13 projects a virtual image in the form of visible radiation 14.2 onto the opaque reflection layer 6.The area of ​​the opaque reflective layer 6 irradiated by the additional projector 13 is indicated by a dashed, striped area on the composite pane 1 in Figure 1. The visible radiation 14.1, 14.2 of the projector 12 and the additional projector 13 is reflected by the reflective layer 6 or the outer surface I of the outer pane 2 and the outer surface III of the inner pane 3, and the reflected radiation 14.1, 14.2 is visually perceived by an observer (for example, the driver of the vehicle). The wedge-shaped design of the thermoplastic intermediate layer 4 reduces double images caused by the double reflection on the outer pane 2 and the inner pane 3.Due to the wedge shape of the thermoplastic intermediate layer 4, the reflections on the outer surface I of the outer pane 2 and the outer surface III of the inner pane 3 are aligned, whereby only one image is visible to the observer.

[0093] The projector 12 illuminates a HUD area H of the composite pane 1, creating a HUD (head-up display) image for the viewer. The additional projector 13 illuminates the opaque reflection layer 6 outside the HUD area H, which is additionally arranged in front of the masking layer 5. Because the reflection layer 6 is opaque and arranged in front of the opaque masking layer 5, the virtual image is visually perceptible with a higher contrast (compared to the HUD image). This makes it possible to use projectors 13 with low light intensity, thus lower energy consumption. The projector 12 and the additional projector 13 are, for example, light-emitting diode displays (LED displays). Reference is now made to Figures 5 to 8, which show enlarged cross-sectional views of various embodiments of the composite pane 1. The cross-sectional views of Figures 5 to 8 correspond to the section line AA' in the lower edge region 7.2 adjacent to the lower edge of the composite pane 1, as indicated in Figure 1 and Figure 2. The variants shown in Figures 5 to 8 essentially correspond to the variant from Figures 1 to 4, so that only the differences are discussed here and otherwise reference is made to the description of Figures 1 to 4.

[0094] Unlike the variant from Figures 1 to 4, the reflective layer 6 in Figure 5 is designed as a reflective film, which is applied to the interior-side surface IV of the inner pane 3 by means of an adhesive layer 8. The reflective layer 6 is, for example, a PET film, on which synergistically interacting prisms and reflective polarizers are applied.

[0095] Figure 6 shows an embodiment of the composite pane 1 according to the invention, in which the reflective layer 6 is applied to a surface of a further pane 9, for example by means of magnetron sputtering. The reflective layer 6 extends over the entire surface of the further pane 9. The further pane 9 is applied by means of an adhesive layer 8 to the interior-side surface IV of the inner pane 3, wherein the reflective layer 6 is applied to that surface of the further pane 9 which faces the inner pane 3. The reflective layer 6 is therefore arranged between the adhesive layer 8 and the further pane 9. The further pane 9 has, for example, a thickness of 200 pm and extends over a region of the composite pane 1 as described for the reflective layer 6 for Figures 1 to 4.

[0096] In Figure 7, a further pane 9 with a thickness of 200 μm is applied to the reflective layer 6 by means of an adhesive layer 8. The further pane 9 extends flatly over the entire reflective layer 6. The reflective layer 6 is applied to the interior-side surface IV of the inner pane 3. In addition, a heatable functional layer 10 is applied to the exterior surface III of the inner pane 3. The heatable functional layer 10 extends over the entire exterior surface III of the inner pane 3 with the exception of a circumferential edge region and optionally local areas which, as communication, sensor or camera windows, are intended to ensure the transmission of electromagnetic radiation through the composite pane 1 (not shown) and are therefore not provided with the heatable functional layer 10. The circumferential uncoated edge region has a width of 2 cm, for example.It prevents direct contact of the heatable functional layer 10 with the surrounding atmosphere, so that the heatable functional layer 10 inside the composite pane 1 is protected from corrosion and damage, and the vehicle body is electrically insulated from the heatable functional layer 10. The heatable functional layer 10 is, for example, a thin-film stack containing a silver layer with a layer thickness of 15 nm.

[0097] As described in Figure 7, in Figure 8, a heatable functional layer 10 is also applied to the outer surface III of the inner pane 3. Instead of an additional pane 9, which is arranged on the reflective layer 6 by means of an adhesive layer 8, the reflective layer 6 in this embodiment of the composite pane 1 is covered by a transparent protective layer 11. The protective layer 11 is applied to the reflective layer 6, for example, by means of a spraying process. The protective layer 11 extends not only over the entire reflective layer 6, but also beyond it, so that the reflective layer 6 and the edge regions of the inner pane 3 adjacent to the reflective layer 6 are completely covered by the protective layer 11. The protective layer 11 is formed, for example, based on amorphous carbon (DLC) and protects the reflective layer 6 from moisture and other external influences (e.g., scratches).

[0098] Reference symbol

[0099] 1 composite pane

[0100] 2 outer pane

[0101] 3 inner pane

[0102] 4 thermoplastic intermediate layer

[0103] 5 Masking layer

[0104] 5' additional masking layer

[0105] 6 reflective layer

[0106] 7.1 upper edge area of ​​the composite pane 1

[0107] 7.2 lower edge area of ​​the composite pane 1

[0108] 8 Adhesive layer

[0109] 9 more discs

[0110] 10 heatable functional layers

[0111] 11 Protective layer

[0112] 12 projectors

[0113] 13 additional projectors

[0114] 14.1 Visible radiation of the projector 12

[0115] 14.2 Visible radiation of the additional projector 13

[0116] 15 Interior

[0117] 16 external environment

[0118] 17 Dashboard

[0119] 100 projection arrangement

[0120] H HUD area a Angle of incidence ß Wedge angle of the thermoplastic intermediate layer 4

[0121] I outside surface of the outer pane 2

[0122] II Interior surface of the outer pane 2

[0123] III outer surface of the inner pane 3

[0124] IV Interior surface of the inner pane 3

[0125] AA' section line

Claims

Patent claims 1. A composite pane (1) for a projection arrangement (100) with a HUD region (H), comprising: an outer pane (2), a thermoplastic intermediate layer (4) and an inner pane (3), a masking layer (5) and a reflective layer (6), wherein the reflective layer (6) is arranged on an interior-side surface (IV) of the inner pane (3) facing away from the thermoplastic intermediate layer (4) and outside a HUD region (H) of the composite pane (1), wherein the reflective layer (6) is arranged completely within the masking layer (5) in a plan view of the composite pane (1), viewed from the inner pane (3), wherein the thermoplastic intermediate layer (4) is wedge-shaped at least in the HUD region (H).

2. Composite pane (1) according to claim 1, wherein the masking layer (5) is arranged in an upper or lower edge region (7.1, 7.2) of the composite pane (1).

3. Composite pane (1) according to claim 1 or 2, wherein the reflective layer (6) has a reflectance for visible radiation (14.2) of at least 10%, preferably at least 40%.

4. Composite pane (1) according to one of claims 1 to 3, wherein the reflective layer (6) contains silicon, aluminum, zirconium, nickel, chromium, boron-doped silicon, silicon-zirconium mixed nitride, silicon nitride, titanium oxide, silicon oxide, titanium carbide, zirconium carbide, silicon-zirconium-aluminum and / or mixtures thereof.

5. Composite pane (1) according to one of claims 1 to 4, wherein a heatable functional layer (10) is arranged between the outer pane (2) and the inner pane (3).

6. Composite pane (1) according to claim 5, wherein the heatable functional layer (10) comprises at least one silver layer, preferably two silver layers, particularly preferably three silver layers.

7. Composite pane (1) according to one of claims 1 to 6, wherein the thermoplastic intermediate layer (4) is wedge-shaped over the entire surface of the composite pane (1).

8. Composite pane (1) according to one of claims 1 to 7, wherein the wedge angle (ß) of the thermoplastic intermediate layer (4) is from 0.3 mrad to 0.7 mrad, preferably from 0.4 mrad to 0.5 mrad.

9. Composite pane (1) according to one of claims 1 to 8, wherein the reflective layer (6) is applied to the interior-side surface (IV) of the inner pane (3).

10. Composite pane (1) according to claim 9, wherein a further pane (9) or a protective layer (11) is arranged on the reflective layer (6).

11. Composite pane (1) according to one of claims 1 to 8, wherein the reflective layer (6) is applied to a surface of another pane (9).

12. Composite pane (1) according to claim 11, wherein the surface of the further pane (9) coated with the reflective layer (6) is connected to the interior-side surface (IV) of the inner pane (3) by means of an adhesive layer (8).

13. Projection arrangement (100), comprising a composite pane (1) according to one of claims 1 to 12, a projector (12) which projects visible radiation (14.1) onto the HUD area (H) of the composite pane (1) and a further projector (13) which projects visible radiation (14.2) onto the reflection layer (6).

14. A method for producing a composite pane (1) according to one of claims 1 to 12, wherein (A) a layer stack comprising the outer pane (2), the masking layer (5), the thermoplastic intermediate layer (4) and the inner pane (3) is provided, (B) the reflection layer (6), preferably by means of magnetron sputtering, is arranged on the interior-side surface (IV) of the inner pane (3) and (C) the layer stack is laminated to form the composite pane (1). Use of a composite pane (1) according to one of claims 1 to 12 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 or as a functional and / or decorative individual piece and as a built-in component in furniture, appliances, and buildings.

Images