CN116075416A - Composite panel for head-up display - Google Patents

Abstract

The invention relates to a composite plate (100) for a head-up display (HUD), said composite plate comprising at least an outer plate (1) having an outer side surface (I), an inner space side surface (II), an upper edge, a lower edge and two side edges; a first thermoplastic intermediate layer (3); -a reflective element (4) adapted to reflect at least 5% of the p-polarized radiation impinging on the reflective element (4); and an inner panel (2) having an outer side surface (III), an inner space side surface (IV), an upper edge, a lower edge, and two side edges. According to the invention, the first thermoplastic intermediate layer (3) is arranged between the outer plate (1) and the inner plate (2), the reflective element (4) is arranged between the outer plate (1) and the first thermoplastic intermediate layer (3) or between the inner plate (2) and the first thermoplastic intermediate layer (3), and the thickness of the inner plate (2) is variable at least section by section in the vertical direction with a maximum wedge angle (alpha) of less than 0.20 mrad.

Description

Composite panels for head-up displays

technical field

The invention relates to a composite panel for a head-up display, a method for producing the composite panel and its use.

Background technique

Composite panels are used today in many places, especially in vehicle manufacturing. The term vehicle here includes in particular road vehicles, aircraft, ships, agricultural machines or also implements.

Composite panels are also used in other fields. For example, building glass or information displays, such as in museums or as advertising displays, fall under this category.

In this case, the composite panel usually has two panels which are laminated to the middle layer.

Especially the wind deflector is often equipped with a so-called head-up display (HUD). Using a projector, typically in the area of the dashboard, an image is projected onto the windshield, where it is reflected and perceived by the driver (from the driver's perspective) behind the windshield as a virtual image. Important information such as the current driving speed, navigation or warning messages can thus be projected into the driver's field of vision, which the driver can perceive without having to take his eyes off the roadway. Head-up displays can thus contribute significantly to improving traffic safety.

DE 10 2014 220 189 A1 discloses a HUD projection device which is operated with p-polarized radiation in order to generate a HUD image. Since the angle of incidence is typically close to the Brewster's angle (Brewsterwinkel) and thus p-polarized radiation is reflected only to a small extent by the glass surface, the windscreen has reflective structures which can reflect in the direction of the driver p-polarized radiation. A separate metal layer, for example made of silver or aluminum, with a thickness of 5 nm to 9 nm is proposed as the reflective structure, which is applied to the outer side of the inner panel facing away from the interior of the passenger vehicle.

US 2004/0135742 A1 likewise discloses a HUD projection device which is operated with p-polarized radiation in order to generate a HUD image and which has reflective structures which can reflect p-polarized radiation in the direction of the driver radiation. Multilayer polymer layers disclosed in US 5,882,774 A are proposed as reflective structures.

CN 113031276 A discloses a HUD projection device operating with p-polarized radiation, said HUD projection device having a p-polarized radiation-reflecting layer on the inner space-side surface of the inner pane of a composite panel.

WO 2019/179783 A1 discloses a projection device for a head-up display, the projection device at least comprising a composite panel, the composite panel comprising an outer panel and an inner panel, the outer panel and the inner panel are connected to each other via a thermoplastic intermediate layer, The composite panel has upper and lower sides and a HUD area; a conductive coating on the surface of the outer or inner panel facing the middle layer or in the middle layer; and a projector aimed at the HUD area, wherein the projector radiates at least A p-polarized component, and wherein the electrically conductive coating has only a single local reflection maximum for p-polarized radiation in the spectral range from 400 nm to 650 nm, said reflection maximum being in the range from 510 nm to 550 nm.

WO 2019/046157 A1 discloses a HUD projection device which is operated with p-polarized radiation in order to generate a HUD image, the HUD projection device having an outer panel, a wedge-shaped intermediate layer and an inner panel, in which p-polarized radiation is reflected A cladding is applied on the outside surface of the inner panel.

CN 113071165 A discloses a HUD projection device, which is operated with p-polarized radiation to generate a HUD image, the HUD projection device has an outer plate, a wedge-shaped middle layer and an inner plate, wherein the cladding that reflects p-polarized radiation A layer is applied on the interior space side surface of the outer panel and a reflection enhancing coating is applied on the interior space side surface of the inner panel.

WO 2021/145387 A1 discloses a composite panel for a head-up display, said composite panel comprising an outer panel and an inner panel connected to each other via an intermediate layer, wherein a film reflecting p-polarized light is glued inside on the outside of the panels, and wherein the inner panel has a wedge-shaped cross-section and additionally the intermediate or outer panels also have a wedge-shaped cross-section.

Since projectors in HUD projection devices operating with p-polarized radiation to produce HUD images typically emit p-polarized radiation not as individual rays but as a beam of countless rays hitting the composite plate at different angles, it is not The entire radiation emitted by the projector impinges on the interior space side surface of the inner panel of the composite panel at the Brewster's angle. This results in a low-intensity second image due to reflection at the interior space-side surface of the inner pane of the composite pane and a high-intensity first image due to reflection at the p-polarized radiation-reflecting layer. To the observer, the two images are visible offset from each other, similar to the occurrence of classic ghosting. However, in the case of classical ghosting, reflections at the interior space-side surfaces of the inner panes of the composite pane possess a higher intensity than reflections within the composite pane.

Contents of the invention

The object underlying the invention is to provide an improved composite panel and an improved projection device for a head-up display. Another object of the invention is to specify a production method.

According to the invention, the object of the invention is solved by a composite panel, a projection device and a method according to the independent claims. Preferred embodiments emerge from the dependent claims.

A composite panel according to the invention comprises an outer panel, a first thermoplastic intermediate layer, a reflective element and an inner panel. A first thermoplastic intermediate layer is disposed between the outer panel and the inner panel. The reflective element is arranged between the outer panel and the first thermoplastic interlayer or between the inner panel and the first thermoplastic interlayer.

The composite panel according to the invention has an upper side and a lower side as well as two side sides. The upper side designates that side of the composite panel which is intended to point upwards in the installed position. The lower side denotes the side which is provided for pointing downwards in the installation position. If the composite panel is a windshield of a motor vehicle, the upper side is often also referred to as the roof side and the lower side as the engine side.

The outer panel, the inner panel, the first thermoplastic intermediate layer and the reflective element respectively have an outer side surface and an inner space side surface, an upper side, a lower side and two side sides. The upper side denotes the side which is provided for pointing upwards in the installation position. The lower side denotes the side which is provided for pointing downwards in the installation position. In the sense of the invention, by the outer surface is meant that main surface which is provided to face the external environment in the installed position. In the sense of the present invention, the interior space side surface designates that main surface which is provided to face the interior space in the installed position. The interior space side surface of the outer panel and the outer side surface of the inner panel face each other and are connected to each other by the first thermoplastic intermediate layer.

The outside surface of the outer plate is called side I. The inner space side surface of the outer panel is referred to as side II. The outside surface of the inner panel is called side III. The interior space side surface of the inner panel is referred to as side IV.

According to the invention, the reflective element is suitable for reflecting at least 5%, preferably 10% to 70%, particularly preferably 15% to 60%, in particular 20% to 50%, of the p-polarized radiation impinging on the reflective element.

The reflective element is especially suitable for reflecting at least 5%, preferably 10%, of the p-polarized radiation impinging on the reflective element at an angle of incidence of 55° to 80°, preferably 55° to 75°, particularly preferably 60° to 70° to 70%, particularly preferably 15% to 60%, especially 20% to 50%.

The composite panel according to the invention is a composite panel for head-up displays. It therefore goes without saying that the p-polarized radiation that the reflective element is suitable for reflecting is p-polarized radiation in the visible spectral range, ie in the range from 400 nm to 780 nm.

According to the invention, the thickness of the inner panel is variable at least in sections in the vertical direction. According to the invention, the maximum wedge angle α (alpha) of the inner plate is less than 0.20 mrad. However, the wedge angle has a limited wedge angle, ie a wedge angle greater than 0°, at least in sections. "Segmentally" means here that the vertical course between the lower side and the upper side has at least one section in which the thickness of the inner panel changes position-dependently. However, the thickness can also vary in several sections or over the entire vertical course. By vertical course is meant a course between the lower side and the upper side which has a direction of course which is substantially perpendicular to the said side.

The angle between the two surfaces of the inner panel, ie the outer side surface of the inner panel and the side surface of the interior, is denoted by the wedge angle. If the wedge angle is not constant, the tangent to the surface at one point can be used for measuring the wedge angle.

The outer plate has a substantially constant thickness. Accordingly, the outer plate has a substantially rectangular cross-section. The outer panels are therefore not wedge-shaped glass panels.

The first thermoplastic intermediate layer has a substantially constant thickness. Thus, said first thermoplastic intermediate layer has a substantially rectangular cross-section. Thus, the first thermoplastic interlayer is not a wedge film.

Since the inner panel has the largest wedge angle and the outer panel and the first thermoplastic intermediate layer have a substantially constant thickness, the composite panel according to the invention also has the largest wedge angle. It goes without saying that the maximum wedge angle of the composite panel according to the invention corresponds to the maximum wedge angle of the inner panel.

In this application, a substantially constant thickness of a sheet or layer is understood to mean that the thickness of the sheet or layer is constant in length and width within normal manufacturing tolerances. This preferably means that the thickness does not vary by more than 5%, preferably not more than 3%.

In a preferred embodiment, the inner plate has a maximum wedge angle α between 0.01 mrad and 0.19 mrad, particularly preferably between 0.12 mrad and 0.15 mrad, for example 0.12 mrad, 0.14 mrad or 0.15 mrad. The largest wedge angle that occurs in the inner plate is indicated by the maximum wedge angle.

The maximum wedge angle of less than 0.20 mrad according to the invention is significantly smaller than that used for conventional composite panels in the range of 0.5 mrad.

The wedge angle of the inner plate may be constant vertically, which results in a linear thickness variation of the inner plate, wherein the thickness typically increases from bottom to top. In this embodiment, the inner plate thus has a wedge-shaped cross-section. Direction Explanation "From bottom to top" means the direction from bottom to top, ie vertically. However, more complex thickness profiles are also possible in which the wedge angle is variable from bottom to top (that is to say position-dependent in the vertical direction), linearly or non-linearly.

The thickness of the inner plate preferably increases in the vertical direction from bottom to top at least in sections.

The variable thickness of the inner panel can be limited to vertically running sections. This section preferably corresponds at least to the so-called HUD region of the composite panel, ie the region in which the HUD projector generates the image in the case of a projection device. However, this section can also be larger. The thickness of the inner panel may be variable throughout the vertical direction, for example increasing substantially continuously from the lower edge to the upper edge.

In a preferred embodiment, the reflective element is designed as a reflective coating of the interior-side surface of the outer pane.

In an alternative preferred embodiment, the reflective element is designed as a reflective coating of the outer surface of the inner pane.

According to the invention, the reflective element configured as a reflective coating of the interior-side surface of the outer pane or the outer surface of the inner pane is suitable for reflecting at least 5% of the p-polarized radiation impinging on the reflective element.

Suitable reflective coatings are known to those skilled in the art. The reflective coating includes, in particular, a metal-containing layer, for example made of silver, aluminum, copper or gold. Reflective coatings can also be constructed, for example, as in WO 2019/179683 A1 or WO 2020/094423 A1.

In a preferred embodiment, the reflective coating is a layer stack or layer sequence comprising one or more electrically conductive layers, in particular metal-containing layers, wherein each electrically conductive layer is arranged on two sides respectively. between dielectric layers or layer sequences. The reflective coating is therefore preferably a thin layer stack with n electrically conductive layers and (n+1) dielectric layers or layer sequences, where n is a natural number and in which each alternately conductive layer follows the lower dielectric layer or layer sequence Layers and dielectric layers or layer sequences.

Each electrically conductive layer preferably contains at least one metal or metal alloy, such as silver, aluminum, copper or gold, and is particularly preferably constructed on the basis of a metal or metal alloy, that is to say essentially except for possible dopants or impurities. Composed of metal or metal alloys. Silver or silver-containing alloys are preferably used. In an advantageous configuration, the electrically conductive layer contains at least 90% by weight (Gew.%) silver, preferably at least 99% by weight silver, particularly preferably at least 99.9% by weight silver.

Each electrically conductive layer preferably has a layer thickness of 3 nm to 20 nm, particularly preferably 5 nm to 15 nm. The total layer thickness of all electrically conductive layers is preferably 20 nm to 50 nm, particularly preferably 30 nm to 40 nm.

As mentioned above, the dielectric layer or layer sequence is preferably arranged between the conductive layers as well as below the lowermost conductive layer and above the uppermost conductive layer. Each dielectric layer or layer sequence has at least one antireflection layer. The antireflective layer reduces the reflection of visible light and thus increases the transparency of the coated pane. The antireflection layer contains, for example, silicon nitride (SiN), silicon metal mixed nitrides such as silicon zirconium nitride (SiZrN), aluminum nitride (AlN) or tin oxide (SnO). The antireflection layer can also contain dopants. The layer thickness of the individual antireflection layers is preferably 10 nm to 70 nm.

The antireflection layer can in turn be subdivided into at least two sublayers, in particular into a dielectric layer with a refractive index of less than 2.1 and an optically high-refractive layer with a refractive index of greater than or equal to 2.1. At least one antireflection layer arranged between two electrically conductive layers is preferably subdivided in this way, particularly preferably each antireflection layer arranged between two electrically conductive layers is subdivided. The subdivision of the antireflection layer results in a lower surface resistance of the electrically conductive coating with simultaneously high transmission and high color neutrality. The sequence of the two sublayers can in principle be chosen arbitrarily, wherein the optically high-refractive layer is preferably arranged above the dielectric layer, which is particularly advantageous with regard to surface resistance. The thickness of the optically high refractive layer is preferably 10% to 99%, particularly preferably 25% to 75%, of the total thickness of the antireflection layer.

An optically high refractive layer having a refractive index greater than or equal to 2.1 comprises, for example, MnO, WO ₃ , Nb ₂ O ₅ , Bi ₂ O ₃ , TiO ₂ , Zr ₃ N ₄ and/or AlN, preferably a silicon metal mixed nitride, for example Silicon aluminum mixed nitride, silicon hafnium mixed nitride or silicon titanium mixed nitride, particularly preferably silicon zirconium mixed nitride (SiZrN). This is particularly advantageous with regard to the surface resistance of the electrically conductive coating. The silicon-zirconium mixed nitride preferably has dopants. The layer of optically highly refractive material may, for example, comprise aluminum-doped silicon-zirconium mixed nitride. The proportion of zirconium here is preferably between 15 and 45% by weight, particularly preferably between 15 and 30% by weight.

The dielectric layer with a refractive index of less than 2.1 preferably has a refractive index n between 1.6 and 2.1, particularly preferably between 1.9 and 2.1. The dielectric layer preferably contains at least one oxide, for example tin oxide, and/or a nitride, particularly preferably silicon nitride.

In an alternative preferred embodiment, the reflective element is designed as a reflective film and the composite pane additionally has a second thermoplastic intermediate layer which is arranged between the outer pane and the first thermoplastic intermediate layer or between the Between the inner pane and the first thermoplastic intermediate layer, wherein the reflective element in the form of a reflective film is arranged between the first thermoplastic intermediate layer and the second thermoplastic intermediate layer.

The reflective element configured as a reflective film can be a carrier film with a reflective coating or a metal-free reflective polymer film. In this embodiment, the reflective coating is preferably applied to the interior-side surface of the carrier film, ie the surface facing the vehicle interior, and preferably comprises at least one metal-based layer or a purely dielectric layer with alternating refractive indices. layer sequence. The metal-based layer preferably contains or consists of silver and/or aluminum. The dielectric layer sequence preferably contains silicon nitride, silicon oxide and/or zinc oxide. The reflective polymer film preferably comprises or consists of a dielectric polymer layer. The dielectric polymer layer preferably comprises PET. Reflective films of this composition are suitable for reflecting p-polarized radiation impinging on the layer in the visible spectral range.

The reflective element configured as a reflective film is preferably a polyethylene terephthalate (PET)-based film coated with a PET-based and/or or polyethylene naphthalate (PEN) copolymer layer stack. The coating is preferably applied to the interior-side surface of the PET-based film, ie the surface facing the vehicle interior. Suitable reflective films are described, for example, in US 5,882,774 A.

The reflective film may be between 20 µm (micrometer) and 2 mm, preferably between 20 µm and 120 µm thick. The thickness of the reflective film is substantially constant over the entire length, so that the reflective film has a substantially rectangular cross-section. Therefore the reflective film is not a wedge shaped film.

The first thermoplastic intermediate layer may comprise or consist of at least polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU) or mixtures or copolymers or derivatives thereof, preferably polyvinyl alcohol Butyral (PVB) or consisting thereof.

The first thermoplastic intermediate layer can be formed by a single film or also by more than one film.

The first thermoplastic intermediate layer may be between 20 µm (micrometer) and 2 mm thick. The thickness of the first thermoplastic intermediate layer is substantially constant over the entire length, so that the first thermoplastic intermediate layer has a substantially rectangular cross-section. Thus, the first thermoplastic interlayer is not a wedge film.

In a preferred embodiment, the first thermoplastic intermediate layer has a thickness of 200 μm to 1000 μm, preferably 300 μm to 850 μm or between 10 μm and 120 μm, particularly preferably between 15 μm and 90 μm, very particularly preferably between 20 μm and 75 μm between the thickness.

The second thermoplastic intermediate layer may comprise or consist of at least polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), polyurethane (PU) or mixtures or copolymers or derivatives thereof, preferably polyvinyl alcohol Butyral (PVB) or consisting thereof.

The second thermoplastic intermediate layer can be formed by a single film or also by more than one film.

The second thermoplastic intermediate layer may be between 20 µm (micrometers) and 2 mm thick. The thickness of the second thermoplastic intermediate layer is substantially constant over the entire length, so that the second thermoplastic intermediate layer has a substantially rectangular cross-section. Therefore, the second thermoplastic interlayer is not a wedge film.

In a preferred embodiment, the second thermoplastic intermediate layer has a thickness of 200 μm to 1000 μm, preferably 300 μm to 850 μm, or between 10 μm and 120 μm, particularly preferably between 15 μm and 90 μm, very particularly preferably between 20 μm and 75 μm between thicknesses.

In the embodiment in which the composite panel additionally comprises a second thermoplastic interlayer and the reflective element is configured as a reflective film arranged between the first thermoplastic interlayer and the second thermoplastic interlayer, the second thermoplastic interlayer and the reflective film can also be It is present as a so-called double layer and can be introduced as such into a stacking sequence for the production of the composite panel according to the invention. This means that the second thermoplastic intermediate layer and the reflective film do not necessarily have to be introduced into the stacking sequence one after the other as two separate layers, but can instead be introduced into the stacking sequence as a common double layer.

As mentioned above, the second thermoplastic intermediate layer can also be constructed from more than one film. Here, too, one of the films can be present together with the reflective film as a so-called double layer and introduced as such into the stacking sequence for producing the composite panel according to the invention. In this embodiment, the bilayer and the further film or films of the second thermoplastic intermediate layer are successively introduced into the stacking sequence.

The larger the image distance of the HUD, that is, the greater the distance between the virtual image and the composite plate, the smaller the wedge angle must be in order to avoid double images. Large image distances arise especially in the case of so-called "Augmented Reality" HUDs, where not only information is projected onto a limited area of the windshield, but elements of the external environment are included in the representation. Examples of this are the marking of pedestrians, the display of the distance to vehicles driving ahead or the projection of navigation instructions directly onto the roadway, for example to mark the lane to be selected.

The reflective element preferably extends over the entire surface of the composite pane or substantially over the entire surface of the composite pane. Essentially on the full surface of the composite panel means on the full surface of the composite panel minus a surrounding edge area of eg 20 mm.

The reflective element particularly preferably extends over the entire surface of the composite pane minus the surrounding edge region of, for example, 20 mm. If the composite pane has a sensor window, the reflective element preferably has a recess in the region of the sensor window.

The composite panel according to the invention may additionally comprise a cover print, in particular made of dark, preferably black enamel. The cover print is in particular a peripheral, ie frame-shaped cover print, which is therefore arranged in the surrounding edge region and/or a cover print which is arranged in the region surrounding the camera window. The peripheral masking print was first used as a UV protector for the assembly adhesive of the composite panel. Cover prints can be constructed both opaque and full-surface. The cover print can also be translucent at least in sections, for example as a dot grid, strip grid or grid grid. Alternatively, the cover print can also have a gradient, for example from an opaque cover to a translucent cover. The cover print is usually applied to the interior space side surface of the outer panel or to the interior space side surface of the inner panel.

In a preferred embodiment, the composite pane has a sensor window and the outer and/or inner pane has a cover print in the region of the surrounding edge and in the region surrounding the sensor window.

The first thermoplastic interlayer and, if present, the second thermoplastic interlayer may also independently of each other be an interlayer having acoustic damping properties, an interlayer reflecting infrared radiation, an interlayer absorbing infrared radiation, an interlayer absorbing UV radiation, at least Segmentally colored intermediate layers and/or at least segmentally colored intermediate layers. Thus, the first thermoplastic intermediate layer or, if present, the second thermoplastic intermediate layer can also be, for example, a bandpass filter membrane.

The outer and inner panes are preferably made of glass, especially soda-lime glass, as is usual for window panes. In principle, however, the plates can also be made of other glass types (eg borosilicate glass, quartz glass, aluminosilicate glass) or transparent plastics (eg polymethyl methacrylate or polycarbonate).

The thickness of the outer and inner panels can vary widely and can thus be adapted to the requirements of the individual case. The outer and inner panels preferably have a thickness of 0.5 mm to 5 mm, particularly preferably 1 mm to 3 mm, very particularly preferably 1.6 mm to 2.1 mm. Particularly preferably, the outer sheet has a thickness of 2.1 mm and the inner sheet has a thickness of 1.2 mm or 1.6 mm. However, the outer pane or in particular the inner pane can also be thin glass with a thickness of eg 0.55 mm or 0.7 mm. In the case of inner panels, the thickness specification refers to the thickness at the thinnest point.

The outer and inner sheets can be clear and colorless independently of each other, but can also be colored or dyed. In a preferred configuration, the total transmission through the composite glass is greater than 70%. The term total transmission is referred to by ECE-R 43 Appendix 3 Methods specified for testing the light transmission of motor vehicle panels.

The outer and inner plates can be non-prestressed, partially prestressed or prestressed independently of each other. If at least one of the plates is to have a prestress, this can be thermal or chemical.

The outer pane and/or the inner pane can have an anti-reflection coating, an anti-adhesive coating, an anti-scratch coating, a photocatalytic coating, an electrically heatable coating, a sun protection coating and/or a low-radiation coating.

The height of the outer and inner panels, ie the distance between the roof side of the composite panel and the engine side of the composite panel in the case of a wind deflector, is preferably between 0.8 m and 1.40 m, particularly preferably between 0.9 m and 1.25 m between m. It goes without saying that the height of the first thermoplastic intermediate layer, the reflector element and, if present, the second thermoplastic intermediate layer is thus also preferably between 0.8 m and 1.40 m, particularly preferably between 0.9 m and 1.25 m.

The composite panel according to the invention may be a vehicle panel. The vehicle panel is configured to separate the vehicle interior from the external environment. A vehicle panel is thus a window panel inserted into a window of the vehicle body or provided for this purpose. The composite panel according to the invention is in particular a windshield for a motor vehicle.

In the case of a vehicle panel, by inner panel is meant that panel which is arranged to face the interior of the vehicle in the installed position. By outer panel is meant that panel which is provided for facing the exterior of the vehicle in the installation position.

The composite panels according to the invention are preferably curved in one or more directions in space, as is usual for motor vehicle panels, with typical radii of curvature in the range of about 10 cm to about 40 m. However, the composite glass can also be flat, for example when it is provided as a pane for a bus, train or tractor.

The invention also relates to a projection device for a head-up display for representing a virtual image to a viewer, said projection device comprising at least a composite panel according to the invention and a projector aimed at zone B.

As is usual in the case of a HUD, the projector illuminates the area B of the windshield where the radiation is reflected in the direction of the observer (driver), thereby producing a virtual image from which the observer sees the The virtual image is perceived behind the wind panel. The area B of the wind deflector that can be illuminated by the projector is also referred to as the HUD area. The beam direction of the projector can typically be changed by means of mirrors, in particular vertically, in order to adapt the projection to the height of the observer. The region in which the observer's eyes must be located at a given mirror position is called the eye range window. This eye-movement window can be displaced vertically by means of an adjustment mirror, the entire area accessible thereby (that is to say the superposition of all possible eye-movement windows) being referred to as the eyebox. Observers located within the range of eye movement can perceive the virtual image. Of course, this means that the observer's eyes have to be in the eye range, not for example the whole body is in the eye range.

The terminology used herein from the field of HUDs is well known to those skilled in the art. For a detailed description one should refer to the paper "Simulationsbasierte Messtechnik zur Prüfung von Head-Up Displays" by Alexander Neumann of the Institute of Computer Science at the Technical University of Munich (Munich: University Library of the Technical University of Munich, 2012), especially chapter 2 "Das Head -Up Display".

According to the invention, the radiation of the projector has a p-polarized component of at least 70%, and at least 5% of the p-polarized radiation emitted by the projector and impinging on the reflective element of the composite panel is reflected by the reflective element in the direction of the observer for The virtual image is generated at a distance from the composite sheet, wherein the thickness of the inner sheet is variable in the vertical direction at least in this region B with a maximum wedge angle α of less than 0.20 mrad.

The proportion of p-polarized radiation in the total radiation of the projector is preferably 80%, particularly preferably 100%.

The specification of the polarization direction refers to the plane of incidence of the radiation on the composite plate. By p-polarized radiation is meant radiation whose electric field oscillates in the plane of incidence. By s-polarized radiation is meant radiation whose electric field oscillates perpendicular to the plane of incidence. The plane of incidence is spanned by the incidence vector and the surface normal of the composite plate in the geometric center of the irradiated area.

In a preferred embodiment of the projection device according to the invention, the radiation of the projector hits the composite pane at an angle of incidence of 55° to 80°, preferably 55° to 75°, particularly preferably 60° to 70° superior. This angle of incidence is relatively close to the Brewster's angle (57.2° for soda-lime glass) for the air-glass transition.

It goes without saying that the projector's radiation is in the visible range of the electromagnetic spectrum. Typical HUD projectors operate at wavelengths around 470 nm, 550 nm, and 630 nm (RGB).

In a preferred embodiment of the projection device according to the invention, 10% to 70%, preferably 15% to 60%, particularly preferably Between 20% and 50% are reflected by the reflective element in the direction of the observer.

In a preferred embodiment, the image distance of the HUD, ie the distance of the virtual image from the composite panel in the case of the projection device according to the invention, is at least 2500 mm, preferably at least 3500 mm, very particularly preferably at least 4500 mm. The image distance can also be 10000 mm or more. Thus, the image distance can be, for example, 2500 mm, 3000 mm, 4500 mm or 10000 mm.

Due to the wedge-shaped configuration of the inner panel, in the projection device according to the invention the two images produced by reflection of the projector image at the interior side surface of the inner panel and at the reflective element are superimposed on one another. Consequently, disturbing ghost images do not occur or occur only to a small extent.

The above-described preferred configurations of the composite panel according to the invention also apply correspondingly to the projection device according to the invention, and vice versa.

The invention also relates to a method for producing a composite panel according to the invention, wherein at least:

(a) providing an outer sheet, a first thermoplastic intermediate layer, a reflective element adapted to reflect at least 5% of p-polarized radiation impinging on the reflective element, and an inner sheet having a thickness less than The maximum wedge angle α of 0.20 mrad is variable at least section by section in the vertical direction;

(b) forming a stacking sequence wherein said first thermoplastic interlayer is arranged between said outer sheet and said inner sheet, said reflective element is arranged between said outer sheet and said first thermoplastic interlayer or between the inner panel and the first thermoplastic intermediate layer;

(c) Connecting the stacked sequences by lamination.

As mentioned above, in one embodiment of the composite pane according to the invention, the reflective element is designed as a reflective film and the composite pane additionally has a second thermoplastic intermediate layer which is arranged between the outer pane and the first Between the thermoplastic intermediate layers or between the inner pane and the first thermoplastic intermediate layer, the reflective element in the form of a reflective foil is arranged between the first thermoplastic intermediate layer and the second thermoplastic intermediate layer.

Therefore, according to the invention there is also a method for producing a composite panel according to the invention, wherein at least

(a) providing an outer sheet, a first thermoplastic intermediate layer, a reflective element configured as a reflective film and an inner sheet and a second thermoplastic intermediate layer, the reflective element being adapted to reflect at least 5%, the thickness of the inner plate is variable at least section by section in the vertical direction with a maximum wedge angle α less than 0.20 mrad;

(b) forming a stacking sequence in which the first thermoplastic interlayer is arranged between the outer panel and the inner panel and the second thermoplastic interlayer is arranged between the outer panel and the first thermoplastic interlayer or between Between the inner panel and the first thermoplastic intermediate layer, and the reflective element configured as a reflective film is arranged between the first thermoplastic intermediate layer and the second thermoplastic intermediate layer;

(c) Connecting the stacked sequences by lamination.

If the composite panels are to be bent, the outer and inner panels are preferably subjected to a bending process prior to lamination. The outer sheet and the inner sheet are preferably bent together (ie simultaneously and by the same tool) in perfect agreement, since the shapes of the sheets are thus optimally adapted to each other for the later lamination. For example, typical temperatures for glass bending processes are 500°C to 700°C.

The stacked sequence can be laminated by means of customary lamination methods. For example, a so-called autoclaving process can be carried out at an elevated pressure of about 10 to 15 bar and a temperature of 130°C to 145°C within about 2 hours. Alternatively, a pressureless steaming method is also possible. Vacuum bag or vacuum ring methods known per se work, for example, at about 200 mbar and 80° C. to 110° C.

Alternatively, a vacuum laminator can be used. These vacuum laminators consist of one or more heatable and evacuatable chambers in which the first and second plates are subjected to reduced pressure from 0.01 mbar to 800 mbar and from 80°C to Laminated at a temperature of 170° C. within, for example, about 60 minutes.

The above-described preferred configurations of the composite panel according to the invention also apply correspondingly to the method for producing the composite panel according to the invention, and vice versa.

The invention also relates to a composite panel according to the invention as a vehicle panel for head-up displays in means of transport by land, air or water, in particular in motor vehicles and especially in wind deflectors, quite in particular Use of a head-up display in a motor vehicle.

Description of drawings

The invention is explained in more detail below with reference to figures and examples. The figures are schematic and not to scale. The drawings do not limit the invention in any way.

Figure 1 shows a top view of an embodiment of a composite panel according to the invention;

Figure 2 shows a cross-section through the composite panel according to Figure 1 along the cutting line XX';

FIG. 3 shows a cross-section through an embodiment of a projection device according to the invention;

Figure 4 shows a cross-section through another embodiment of a composite panel according to the invention;

Figure 5 shows a cross-section through another embodiment of the projection device according to the invention;

Figure 6 shows a cross-section through another embodiment of a composite panel according to the invention;

Figure 7 shows a cross-sectional view through another embodiment of the projection device according to the invention;

Figure 8 shows a cross-section through another embodiment of a composite panel according to the invention;

Figure 9 shows a cross-section through another embodiment of a projection device according to the invention; and

FIG. 10 shows a flow chart of an embodiment of the method according to the invention.

Detailed ways

FIG. 1 shows a plan view of an embodiment of a composite panel 100 according to the invention, and FIG. 2 shows a cross section through the composite panel 100 according to FIG. 1 along the cutting line XX′. The composite panel 100 is constructed from an outer panel 1 , a first thermoplastic intermediate layer 3 , reflective elements 4 and an inner panel 2 . A first thermoplastic intermediate layer 3 is arranged between the outer panel 1 and the inner panel 2 . The outer panel 1 and the inner panel 2 are connected to each other via a first thermoplastic intermediate layer 3 .

The composite panel 100 shown in FIGS. 1 and 2 is, for example, a windshield of a passenger car. In the installed position, the outer panel 1 faces the external environment and the inner panel 5 faces the vehicle interior. The lower side U of the composite panel 100 is arranged downward in the direction of the engine of the passenger vehicle, the upper side O of the composite panel 100 is arranged upward in the direction of the roof, and the two sides S are arranged laterally.

In the embodiment shown in FIGS. 1 and 2 , the reflective element 4 is designed as a reflective coating of the outer surface III of the inner panel 2 .

The outer pane 1 and the inner pane 2 consist, for example, of soda lime glass. The outer panel 1 has, for example, a thickness of 2.1 mm, the inner panel 2 has, for example, a thickness of 1.6 mm or 1.2 mm at the thinnest point, and the thickness of the inner panel 2 increases continuously from the bottom U to the top O in the vertical direction. For simplicity, the thickness increase is shown in a linear fashion in Figure 2, but more complex profiles are also possible. The wedge angle α is approximately 0.1 mrad, for example 0.14 mrad or 0.12 mrad.

The first thermoplastic intermediate layer 3 is, for example, an intermediate layer composed of PVB and has a thickness of 0.76 mm.

Also indicated in FIG. 1 is region B, which corresponds to the HUD region of composite panel 100 . In this area, an image should be produced by the HUD projector. Due to the wedge-shaped configuration of the inner panel 2 , the two images produced by reflection of the projector image at the interior-side surface IV of the inner panel 2 and at the reflective element 4 are superimposed on one another. Consequently, disturbing ghost images do not occur or occur only to a small extent.

The reflective element 4 configured as a reflective coating of the outer surface III of the inner pane 2 is suitable, for example, for reflecting 20% to 50% of the fraction of p-polarized radiation impinging on the coating.

The outer panel 1, the inner panel 2 and the first thermoplastic interlayer 3 have the same outer dimensions such that the sides, top and bottom of the outer panel 1, the inner panel 2 and the first thermoplastic interlayer 3 are aligned when viewed through the composite panel 100 Stacked flat.

In the embodiment shown in FIGS. 1 and 2 , the reflective element 4 in the form of a reflective coating extends over the entire surface of the composite pane 100 . However, the reflective element 4 preferably extends over the entire surface of the composite pane 100 minus a 20 mm circumferential edge region, so that the reflective element 4 in the composite pane 100 is protected from external influences.

FIG. 3 shows a cross-section of a projection device 101 according to the invention comprising the composite panel 100 from FIGS. 1 and 2 . In addition to the laminated glass 100 , the device also includes a projector 7 aimed at the area B . In area B (HUD area) an image can be generated by a projector, which is perceived by the observer 8 (vehicle driver) as a virtual image on the side of the composite panel 100 facing away from the observer. The wedge angle in region B leads to mutually inclined surfaces of inner pane 2 and reflector element 4 , whereby ghost images can be avoided.

The beam paths of the two p-polarized light beams emitted by the projector 7 are also drawn in FIG. 3 . The light beam C impinges on the interior space side surface IV of the inner panel 2 at the Brewster's angle. Thus, the projection angle corresponds to Brewster's angle. There, the light beam enters the composite panel 100 and is refracted, and is then reflected by the reflective element 4 and emerges from the composite panel 100 again at the interior space-side surface IV of the inner panel 2, where it is refracted again and finally Shoots on Observer 8.

The light beam D does not impinge on the interior side surface IV of the inner panel 2 at the Brewster's angle, but is reflected there in the direction of the observer 8 .

C1 indicates the optical path of the light beam C between the projector 7 and the interior space side surface IV of the inner panel 2 . C2 denotes the optical path of the light beam C between the interior space side surface IV of the inner panel 2 and the reflective element 4 . C3 denotes the optical path of the light beam C between the reflective element 4 and the interior space-side surface IV of the inner panel 2 . C4 denotes the optical path of the light beam C between the interior space side surface IV of the inner panel 2 and the observer 8 .

D1 represents the optical path of the light beam D between the projector 7 and the interior space side surface IV of the inner panel 2 . D2 represents the optical path of the light beam D between the interior space side surface IV of the inner panel 2 and the observer 8 .

The observer 8 perceives only the virtual image 6 due to the overlapping of the virtual images formed from the light beams C and D.

FIG. 4 shows a cross section through another embodiment of a composite panel 100 according to the invention. The embodiment shown in cross section in FIG. 4 differs from the embodiment shown in cross section in FIG. 2 only in that the reflective element 4 is not formed as a reflective coating of the outer surface III of the inner panel 2 , but is configured as a reflective coating of the interior-side surface II of the outer panel 1 .

FIG. 5 shows a cross-section of a projection device 101 according to the invention comprising the composite panel 100 from FIG. 4 . In addition to the laminated glass 100 , the device also includes a projector 7 aimed at the area B . In area B (HUD area) an image can be generated by a projector, which is perceived as a virtual image by an observer 8 (vehicle driver) on the side of the composite panel 100 facing away from the observer. The wedge angle in region B leads to mutually inclined surfaces of inner pane 2 and reflector element 4 , whereby ghost images can be avoided.

Also depicted in FIG. 5 are the beam paths of the two p-polarized light beams emitted by the projector 7 . The light beam C impinges on the interior space side surface IV of the inner panel 2 at the Brewster's angle. Thus, the projection angle corresponds to Brewster's angle. There, the light beam enters the composite panel 100 and is refracted, and is then reflected by the reflective element 4 and emerges from the composite panel 100 again at the interior space-side surface IV of the inner panel 2, where it is refracted again and finally Shoots on Observer 8.

The light beam D does not impinge on the interior side surface IV of the inner panel 2 at the Brewster's angle, but is reflected there in the direction of the observer 8 .

C1 indicates the optical path of the light beam C between the projector 7 and the interior space side surface IV of the inner panel 2 . C2 denotes the optical path of the light beam C between the interior space side surface IV of the inner panel 2 and the reflective element 4 . C3 denotes the optical path of the light beam C between the reflective element 4 and the interior space-side surface IV of the inner panel 2 . C4 denotes the optical path of the light beam C between the interior space side surface IV of the inner panel 2 and the observer 8 .

D1 represents the optical path of the light beam D between the projector 7 and the interior space side surface IV of the inner panel 2 . D2 represents the optical path of the light beam D between the interior space side surface IV of the inner panel 2 and the observer 8 .

The observer 8 perceives only the virtual image 6 due to the overlapping of the virtual images formed from the light beams C and D.

FIG. 6 shows a cross section through another embodiment of a composite panel 100 according to the invention. The embodiment shown in cross section in FIG. 6 differs from the embodiment shown in cross section in FIG. 4 only in that the reflective element 4 is not configured as a reflection of the interior side surface II of the outer panel 1 . Instead, the cladding is designed as a reflective film, and the composite pane 100 additionally has a second thermoplastic intermediate layer 5 , which is arranged between the outer pane 1 and the reflective element 4 designed as a reflective film.

In the embodiment of the composite panel 100 shown in FIG. 6 , the reflective element 4 is, for example, a reflective film based on polyethylene terephthalate (PET), which is coated in the direction of the inner panel. Copolymer layer stacks based on PET and polyethylene naphthalate (PEN) are coated and are suitable for reflecting from 20% to 50% of the fraction of p-polarized radiation impinging on the reflective element 4 . The reflective element 4 configured as a reflective foil has, for example, a thickness of between 20 μm and 120 μm.

The first thermoplastic intermediate layer 3 and the second thermoplastic intermediate layer 5 are, for example, respectively intermediate layers made of PVB with a thickness of 0.38 mm.

FIG. 7 shows a cross-section of a projection device 101 according to the invention comprising the composite panel 100 from FIG. 6 . In addition to the laminated glass 100 , the device also includes a projector 7 aimed at the area B . In area B (HUD area) an image can be generated by a projector, which is perceived as a virtual image by an observer 8 (vehicle driver) on the side of the composite panel 100 facing away from the observer. The wedge angle in region B leads to mutually inclined surfaces of inner pane 2 and reflector element 4 , whereby ghost images can be avoided.

Also depicted in FIG. 7 are the beam paths of the two p-polarized light beams emitted by the projector 7 . The light beam C impinges on the interior space side surface IV of the inner panel 2 at the Brewster's angle. Thus, the projection angle corresponds to Brewster's angle. There, the light beam enters the composite panel 100 and is refracted, and is then reflected by the reflective element 4 and emerges from the composite panel 100 again at the interior space-side surface IV of the inner panel 2, where it is refracted again and finally Shoots on Observer 8.

The light beam D does not impinge on the interior side surface IV of the inner panel 2 at the Brewster's angle, but is reflected there in the direction of the observer 8 .

C1 indicates the optical path of the light beam C between the projector 7 and the interior space side surface IV of the inner panel 2 . C2 denotes the optical path of the light beam C between the interior space side surface IV of the inner panel 2 and the reflective element 4 . C3 denotes the optical path of the light beam C between the reflective element 4 and the interior space-side surface IV of the inner panel 2 . C4 denotes the optical path of the light beam C between the interior space side surface IV of the inner panel 2 and the observer 8 .

D1 represents the optical path of the light beam D between the projector 7 and the interior space side surface IV of the inner panel 2 . D2 represents the optical path of the light beam D between the interior space side surface IV of the inner panel 2 and the observer 8 .

The observer 8 perceives only the virtual image 6 due to the overlapping of the virtual images formed from the light beams C and D.

FIG. 8 shows a cross section through another embodiment of a composite panel 100 according to the invention. The embodiment shown in cross section in FIG. 8 differs from the embodiment shown in cross section in FIG. 2 only in that the reflective element 4 is not formed as a reflective coating of the outer side surface III of the inner panel 2 , but is designed as a reflective film, and the composite pane 100 additionally has a second thermoplastic intermediate layer 5 which is arranged between the inner pane 2 and the reflective element 4 .

In the embodiment of the composite panel 100 shown in FIG. 8 , the reflective element 4 is, for example, a reflective film based on polyethylene terephthalate (PET), which is coated in the direction of the inner panel. Copolymer layer stack based on PET and polyethylene naphthalate (PEN) and adapted to reflect from 20% to 50% of the p-polarized radiation component impinging on the reflective film. The reflective element 4 configured as a reflective foil has, for example, a thickness of between 20 μm and 120 μm.

The first thermoplastic intermediate layer 3 and the second thermoplastic intermediate layer 5 are, for example, respectively intermediate layers made of PVB with a thickness of 0.38 mm.

FIG. 9 shows a cross-section of a projection device 101 according to the invention comprising the composite panel 100 from FIG. 8 . In addition to the laminated glass 100 , the device also includes a projector 7 aimed at the area B . In area B (HUD area) an image can be generated by a projector, which is perceived as a virtual image by an observer 8 (vehicle driver) on the side of the composite panel 100 facing away from the observer. The wedge angle in region B leads to mutually inclined surfaces of inner pane 2 and reflector element 4 , whereby ghost images can be avoided.

Also depicted in FIG. 9 are the beam paths of the two p-polarized light beams emitted by the projector 7 . The light beam C impinges on the interior space side surface IV of the inner panel 2 at the Brewster's angle. Thus, the projection angle corresponds to Brewster's angle. There, the light beam enters the composite panel 100 and is refracted, and is then reflected by the reflective element 4 and emerges from the composite panel 100 again at the interior space-side surface IV of the inner panel 2, where it is refracted again and finally Shoots on Observer 8.

The light beam D does not impinge on the interior side surface IV of the inner panel 2 at the Brewster's angle, but is reflected there in the direction of the observer 8 .

C1 indicates the optical path of the light beam C between the projector 7 and the interior space side surface IV of the inner panel 2 . C2 denotes the optical path of the light beam C between the interior space side surface IV of the inner panel 2 and the reflective element 4 . C3 denotes the optical path of the light beam C between the reflective element 4 and the interior space-side surface IV of the inner panel 2 . C4 denotes the optical path of the light beam C between the interior space side surface IV of the inner panel 2 and the observer 8 .

D1 represents the optical path of the light beam D between the projector 7 and the interior space side surface IV of the inner panel 2 . D2 represents the optical path of the light beam D between the interior space side surface IV of the inner panel 2 and the observer 8 .

The observer 8 perceives only the virtual image 6 due to the overlapping of the virtual images formed from the light beams C and D.

FIG. 10 shows a flow chart of an embodiment of a method according to the invention for producing a composite panel 1 according to the invention.

The method comprises a first step S1 in which an outer sheet 1, a first thermoplastic intermediate layer 3, a reflective element 4 and an inner sheet 2 are provided, said reflective element being adapted to reflect at least 5% of p-polarized radiation impinging on the reflective element, The thickness of the inner plate is variable at least in sections in the vertical direction with a maximum wedge angle α of less than 0.20 mrad.

In a second step S2, a stacking sequence is formed in which the first thermoplastic interlayer 3 is arranged between the outer panel 1 and the inner panel 2 and the reflective element 4 is arranged between the outer panel 1 and the first thermoplastic interlayer 3 or the inner panel 2 and the first thermoplastic intermediate layer 3.

In a third step S3, the stacked sequences are connected by lamination.

List of reference signs

1 outer panel

2 inner panels

3 The first thermoplastic intermediate layer

4 reflective elements

5 Second thermoplastic intermediate layer

6 virtual image

7 projectors

8 observers

100 Composite panels

101 projection device

I Outer surface of outer panel 1

II The side surface of the inner space of the outer panel 1

III Outer surface of inner panel 2

IV Internal space side surface of inner panel 2

O top

U below

S side

B Composite board area/HUD area

C1 optical path

C2 optical path

C3 optical path

C4 optical path

D1 optical path

D2 optical path

α wedge angle

XX' cutting line.

Claims (15)

1. A composite panel (100) for a head-up display (HUD), the composite panel comprising at least

An outer panel (1) having an outer side surface (I), an inner space side surface (II), an upper edge, a lower edge and two side edges,

-a first thermoplastic intermediate layer (3),

-a reflective element (4) adapted to reflect at least 5% of p-polarized radiation impinging on the reflective element (4), and

an inner plate (2) having an outer side surface (III), an inner space side surface (IV), an upper edge, a lower edge and two side edges,

wherein the first thermoplastic intermediate layer (3) is arranged between the outer plate (1) and the inner plate (2),

the reflective element (4) is arranged between the outer plate (1) and the first thermoplastic intermediate layer (3) or between the inner plate (2) and the first thermoplastic intermediate layer (3),

And the thickness of the inner plate (2) is variable at least in sections in the vertical direction with a maximum wedge angle (alpha) of less than 0.20 mrad.

2. The composite plate (100) according to claim 1, wherein the maximum wedge angle (a) is between 0.01 mrad and 0.19 mrad, preferably between 0.12 mrad and 0.15 mrad.

3. The composite plate (100) according to claim 1 or 2, wherein the reflective element (4) is adapted to reflect 10% to 70%, preferably 15% to 60%, particularly preferably 20% to 50% of p-polarized radiation impinging on the reflective element (4).

4. A composite board (100) according to any one of claims 1 to 3, wherein said reflective element (4) is configured as a reflective coating of an inner space side surface (II) of said outer board (1).

5. A composite board (100) according to any one of claims 1 to 3, wherein the reflective element (4) is configured as a reflective coating of an outer side surface (III) of the inner board (2).

6. Composite board (100) according to claim 4 or 5, wherein the cladding is a layer stack or layer sequence comprising a plurality of conductive layers, in particular metal-containing layers, wherein each conductive layer is arranged between two dielectric layers or layer sequences, respectively.

7. A composite panel (100) according to any one of claims 1 to 3, additionally comprising a second thermoplastic intermediate layer (5) arranged between the outer panel (1) and the first thermoplastic intermediate layer (3) or between the inner panel (2) and the first thermoplastic intermediate layer (3), wherein the reflective element (4) is configured as a reflective film arranged between the first thermoplastic intermediate layer (3) and the second thermoplastic intermediate layer (5).

8. Composite board (100) according to claim 7, wherein the reflective film is a carrier film with a reflective coating or a metal-free reflective polymer film, preferably a polyethylene terephthalate (PET) based film coated with a copolymer layer stack based on PET and/or polyethylene naphthalate (PEN).

9. Projection device (101) for a head-up display (HUD) representing a virtual image (6) for an observer (8), said projection device comprising at least:

-a composite board (100) according to any one of claims 1 to 8, said composite board having a HUD area (B), and

A projector (7) aligned to said area (B),

wherein the radiation of the projector (7) has a p-polarized component of at least 70% and at least 5% of the p-polarized radiation emitted by the projector (7) and impinging on the reflective element (4) of the composite plate (100) is reflected by the reflective element (4) in the direction of the observer (8) for generating a virtual image (6) at a distance from the composite plate (100),

and wherein the thickness of the inner plate (2) is variable in the vertical direction at least in the region (B) with a maximum wedge angle (α) of less than 0.20 mrad.

10. Projection apparatus (101) according to claim 9, wherein the p-polarized radiation of the total radiation of the projector (7) has a component of 80%, preferably 100%.

11. Projection device (101) according to claim 9 or 10, wherein the radiation of the projector (7) impinges on the composite plate (100) with an angle of incidence of 55 ° to 80 °, preferably 55 ° to 75 °, particularly preferably 60 ° to 70 °.

12. Projection device (101) according to any one of claims 9 to 11, wherein 10% to 70%, preferably 15% to 60%, particularly preferably 20% to 50% of the p-polarized radiation emitted by the projector (7) and impinging on the reflective element (4) of the composite plate (100) is reflected by the reflective element (4) in the direction of the observer (8).

13. The projection device (101) according to any one of claims 9 to 12, wherein the virtual image (6) is at a distance of at least 2500 mm, preferably at least 3500 mm, completely particularly preferably at least 4500 mm, from the composite plate (100).

14. A method for manufacturing a composite board (100) according to any one of claims 1 to 8, wherein at least:

(a) Providing an outer plate (1), a first thermoplastic intermediate layer (3), a reflective element (4) adapted to reflect at least 5% of p-polarized radiation impinging on the reflective element (4), and an inner plate (2) having a thickness that is variable at least section by section in a vertical direction with a maximum wedge angle (α) of less than 0.20 mrad;

(b) Forming a stacking sequence, wherein the first thermoplastic intermediate layer (3) is arranged between the outer plate (1) and the inner plate (2), and the reflective element (4) is arranged between the outer plate (1) and the first thermoplastic intermediate layer (3) or between the inner plate (2) and the first thermoplastic intermediate layer (3);

(c) The stacking sequences are connected by lamination.

15. Use of a composite panel (100) according to any one of claims 1 to 8 as a vehicle panel in a vehicle, in particular in a motor vehicle, for land, air or water traffic and in particular as a wind deflector for use as a projection surface of a head-up display.

Images