Composite pane with partially applied heated reflective layer

Abstract

Composite disk (100), in particular for at least one projection arrangement, comprising at least - an outer pane (1) with an outer surface (I) and an inner surface (II), - a thermoplastic intermediate layer (3), - an inner pane (2) with an outer surface (III) and an inner surface (IV), - a masking layer (4), - an adhesive layer (5), - a glass pane (6) with an outer surface (V) and an inner surface (VI) and a thickness of 20 µm to 500 µm, wherein the thermoplastic intermediate layer (3) is arranged between the outer disc (1) and the inner disc (2), the masking layer (4) is arranged between the outer pane (1) and the inner pane (2) in an area of ​​the composite pane (100), the adhesive layer (5) is arranged between the inner pane (2) and the glass pane (6), a reflective layer (7) for reflecting light is arranged on the outer surface (V) of the glass pane (6) and / or on the inner surface (VI) of the glass pane (6), and wherein the glass pane (6) is arranged in an area of ​​the laminated pane (100) which, when viewed perpendicularly through the laminated pane (100), lies entirely within the area in which the masking layer (4) is arranged, and wherein an electrically conductive coating (8, 7E) is arranged on the outer surface (V) of the glass pane (6) which is connected to terminals to a voltage source to form a current path for a heating current.

Description

[0001] The invention relates to a composite pane with a partially applied, heatable reflective layer and a projection arrangement.

[0002] HMIs (Human Machine Interfaces) and displays are essential and significant topics and functionalities in the automotive sector. The size and number of displays and display systems, especially in the cockpit of motor vehicles, are constantly increasing. For example, the display and playback of navigation, safety, and telecommunications information, as well as additional infotainment, is now almost indispensable. Efforts are underway to replace cluster displays, at least partially, with space-saving, energy-efficient solutions, thereby increasing design freedom.

[0003] In addition to the familiar cluster displays placed in the interior of motor vehicles, head-up displays (HUDs) are increasingly being used today. Using a projector, typically located in the dashboard area, images are projected onto the windshield, reflected there, and perceived by the driver as a virtual image 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 make a significant contribution to improving road safety.

[0004] HUD projection assemblies consisting of a projector and a windshield with a wedge-shaped thermoplastic intermediate layer and / or wedge-shaped panes are frequently used. A wedge angle is provided to avoid double images. The radiation from HUD projectors is typically essentially s-polarized due to the windshield's better reflection characteristics compared to p-polarization. However, if the viewer wears polarization-selective sunglasses that only transmit p-polarized light, the HUD image will at best be perceived in a dimmed form. One solution to this problem is the use of projection assemblies that use p-polarized light. DE102014220189A1 discloses a head-up display projection assembly operated with p-polarized radiation, wherein the windshield has a reflective structure that reflects p-polarized radiation toward the viewer.US20040135742A1 also discloses a head-up display projection arrangement using p-polarized radiation having a reflective structure.

[0005] Head-up displays often have the problem that the area of ​​the windshield intended to reflect the light projected by the projector must have a high transparency of at least 70%. The reflected light from the projector is therefore overlaid by light from the outside environment, which, depending on the lighting conditions, can lead to a reduction in the contrast of the virtual image and thus to poorer visual perception for the driver. Adequate visual perception of safety-relevant information, such as lane departure warnings, speedometer, or engine speed, must be ensured in all weather and lighting conditions.When designing a display based on head-up display technology, the projector must therefore have sufficient power to ensure the projected image is sufficiently bright, especially in sunlight, and easily visible to the viewer. This requires a certain size of the projector and entails a corresponding power consumption.

[0006] In addition to or as an alternative to the HUDs known and used to date, it would be desirable to have a projection system based on head-up display technology that eliminates unwanted secondary images and is relatively easy to set up while maintaining good visibility and sufficient brightness and contrast of the displayed image information. To achieve this, it is necessary to increase the contrast in the reflective area of ​​the windshield. The contrast increase can be achieved, for example, by making the background of the reflective area largely or completely opaque. However, such solutions require that a reflective layer be applied only in a locally limited area of ​​the windshield.

[0007] The application of metallic, reflective coatings to glass panes is usually achieved by sputtering, particularly magnetron sputtering. During sputtering, atoms are released from a target, for example a metallic material, by bombardment with ions. Using physical vapor deposition, the glass pane is coated with the atoms released from the target in an evacuated chamber. The atoms are guided by electric fields through the chamber toward the glass pane. They therefore move from the cathode, on which the target is arranged, to the anode. Due to the arrangement of the glass pane between the cathode and anode, a layer forms on the glass pane. In the case of magnetron sputtering, an additional magnetic field is arranged behind the cathode, which leads to faster layer growth and a denser, i.e., less porous, layer.Methods in which sputtering is used to coat glass panes are known, for example, from WO 9900528A1, DE 10126868C1 and WO 2017198363A1.

[0008] Magnetron sputtering is also suitable for coating glass panes because, unlike many other coating technologies, it can also be used on curved glass panes, as is the case with panes intended for the automotive sector, for example. However, a disadvantage of sputtering is that, without special precautions, it cannot be used to selectively coat specific surface areas, but only the entire surface. Selective coating of only specific surface areas can be achieved, for example, by complex masking of the areas that are not to be coated.

[0009] Cold gas spraying is also a suitable method for coating glass panes and is a coating process generally known to those skilled in the art. It involves applying a metallic powder to a substrate at very high speed. Methods for coating using cold gas spraying are known, for example, from WO 2010 / 003396 A1, EP 3 845 685 A1, and EP 2 902 530 A1.

[0010] Another major challenge when driving is heating the windshield to prevent icing or fogging, which obstructs visibility. This obstruction of visibility then also affects the windshield as a projection surface for displays based on HUD technology. The windshield is usually heated using heated air that is blown onto the windshield via inlets. This type of heating is summarized under the Heating, Ventilation and Air Conditioning (HVAC) method. In addition to the enormous energy consumption, the inlets through which the hot air is transported and blown onto the windshield require a lot of space. Furthermore, the outlet nozzles must be positioned in a specific geometric relationship to the windshield, which in turn significantly limits design and construction freedom.

[0011] Alternatively, the pane itself can have an electrical heating function. For example, DE 103 52 464 A1 discloses a laminated glass pane in which electrically heated wires are inserted between two glass panes. The specific heating output can be adjusted by the ohmic resistance of the wires. For design and safety reasons, the number and diameter of the wires must be kept as small as possible. The wires must be invisible or barely perceptible in daylight and at night under headlights.

[0012] Transparent electrically conductive coatings, particularly silver-based ones, are also known. Such electrically conductive coatings can be used as coatings with reflective properties for the infrared range or as heatable coatings. WO 03 / 024155 A2, for example, discloses an electrically conductive coating with two silver layers. Such coatings typically have flat resistances in the range of 3 ohms / square.

[0013] One problem with electrically conductive coatings is their frequently high sheet resistance, which, especially for large dimensions of the windshield to be heated or for long current paths, requires a high operating voltage, which is certainly higher than the usual on-board voltages in vehicles. WO 2013 / 104439 A1 and EP 2803246 B1 disclose an electrically conductive coating for heating a windshield, which consists of different layers. At least one of these layers contains a highly refractive material with a refractive index greater than or equal to 2.1. The sheet resistance of the electrically conductive coating can be significantly reduced as a result and is thus preferably below 1 ohm / square.

[0014] The publication "Glass meets flexibility: Challenges in manufacturing of thin films on flexible glass" by M. Junghähnel et al., published in Vakuum in Forschung und Praxis, Vol. 26, No. 5, pp. 35-39, discusses the production of thin films on flexible glass.

[0015] DE 10 2009 020824 A1 discloses a virtual image system comprising a windshield with a matte black material on at least one of the windshield surfaces and an image source, wherein the image source emits image rays that are reflected at the windshield and provide an image.

[0016] WO 2022 / 161894 A1 describes a vehicle window for a head-up display comprising at least one transparent window and at least one masking strip in the edge region of the window, wherein the masking strip is arranged on or in a carrier film, the carrier film is connected to the transparent window and a light-directing device or an image display device is arranged in the region of the first masking strip on the vehicle interior side of the masking strip.

[0017] The present invention is based on the object of providing an improved composite pane with a partially applied reflective layer, which can be combined with a head-up display and which can be protected from fogging and icing and the associated visual impairment, particularly in the area of ​​the reflective layer. In particular, the composite pane should be easy to manufacture.

[0018] The object of the present invention is achieved by a composite pane according to claim 1. Preferred embodiments emerge from the subclaims and the independent claims.

[0019] The composite pane according to the invention comprises an outer pane, a thermoplastic intermediate layer, a masking layer, an inner pane, an adhesive layer, and a glass pane. The thermoplastic intermediate layer is arranged between the outer pane and the inner pane, and the adhesive layer is arranged between the inner pane and the glass pane. According to the invention, the masking layer is arranged in a region of the composite pane, and the glass pane is arranged in a region of the composite pane which, when viewed perpendicularly through the composite pane, lies entirely in the region in which the masking layer is arranged. Furthermore, according to the invention, an electrically conductive coating is arranged on the outer surface of the glass pane, which coating is connected to lines, in particular busbars, for connection to a voltage source to form a current path for a heating current.

[0020] The composite pane is designed to separate the interior of a vehicle's window opening from the exterior. For the purposes of the invention, the "inner pane" refers to the pane of the composite pane facing the vehicle interior. The "outer pane" refers to the pane facing the exterior.

[0021] The laminated glass has, in particular, an upper edge and a lower edge, as well as two side edges running between them. The upper edge refers to the edge that is intended to face upwards in the installed position. The lower edge refers to the edge that is intended to face downwards in the installed position. In the case of a windshield, the upper edge is often referred to as the roof edge, and the lower edge as the engine edge.

[0022] The outer pane, the inner pane, and the glass pane each have an outer surface and an inner surface, and a circumferential side edge running between them. For the purposes of the invention, the "outer surface" refers to the main surface intended to face the outside environment in the installed position. For the purposes of the invention, the "interior surface" refers to the main surface intended to face the interior in the installed position. The interior surface of the outer pane and the outer surface of the inner pane face each other and are connected by the thermoplastic intermediate layer.

[0023] The outside surface of the outer pane is called Side I. The inside surface of the outer pane is called Side II. The outside surface of the inner pane is called Side III. The inside surface of the inner pane is called Side IV. The outside surface of the glass pane is called Side V. The inside surface of the glass pane is called Side VI.

[0024] It is understood that the inner pane is arranged between the outer pane and the glass pane. The interior surface of the outer pane and the exterior surface of the inner pane face each other. The interior surface of the inner pane and the exterior surface of the glass pane face each other.

[0025] According to the invention, the glass pane has a thickness of 20 µm (micrometers) to 500 µm. The glass pane is thus made of ultra-thin glass. Such a pane of ultra-thin glass is flexible and can be adapted to the curvature of a pane, as is common in the automotive sector.

[0026] In a preferred embodiment of the composite pane according to the invention, the glass pane has a thickness of 30 µm to 300 µm, preferably from 50 µm or 100 µm to 250 µm, for example up to 150 µm, for example 70 µm.

[0027] In addition, according to the invention, a reflective layer for reflecting light is arranged on the outside surface of the glass pane and / or on the inside surface of the glass pane.

[0028] When the laminated pane is installed in a vehicle, the reflective layer is at a shorter distance from the vehicle interior than the masking layer.

[0029] Because the glass pane is arranged in an area of ​​the composite pane which, when viewed perpendicularly through the composite pane, lies entirely in the area in which the masking layer is arranged, the reflective layer applied to the glass pane is also arranged in an area which, when viewed perpendicularly through the composite pane, lies entirely in the area in which the masking layer is arranged. Thus, when viewed perpendicularly through the composite pane or in orthogonal projection through the composite pane, the reflective layer is arranged in registration or overlap with the masking layer. The reflective layer therefore has no section which does not overlap with the masking layer, i.e. the reflective layer is only formed where it is located in front of the masking layer when viewed from the inside of the composite pane.

[0030] As described above, the reflective layer is a reflective layer for reflecting light. The reflective layer is preferably opaque or partially translucent, which in the sense of the invention means that it has an average transmission (according to ISO 9050:2003) in the visible spectral range of preferably at most 80%, particularly preferably at most 50%, and in particular less than 10%. The reflective layer preferably reflects at least 10%, particularly preferably at least 50%, very particularly preferably at least 80%, and in particular at least 90% of the light incident on the reflective layer in the spectral range from 380 nm to 780 nm. This value is also referred to as the reflectance. The reflective layer preferably reflects p-polarized and s-polarized light in equal proportions, but it can also reflect p-polarized light and s-polarized light to different degrees.

[0031] The light reflected by the reflective layer is preferably visible light, i.e. light in a wavelength range of approximately 380 nm to 780 nm. The reflective layer preferably has a high and uniform reflectance (over different angles of incidence) with respect to p-polarized and / or s-polarized radiation, so that a high-intensity and color-neutral image representation is ensured.

[0032] The reflectance describes the proportion of the total incident radiation in the specified spectral range that is reflected. The reflectance always refers to a specific spectral range, for example, the visible spectral range from 380 nm to 780 nm or, for example, the ultraviolet range. It is expressed 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. The information on the reflectance or reflection spectrum refers to a reflection measurement with a light source that radiates uniformly in the spectral range under consideration with a normalized radiation intensity of 100%.

[0033] The term "reflectance" is used in accordance with the DIN EN 410 - 2011-04 standard. Reflectance always refers to the coating-side reflectance, which is measured when the substrate with the coated areas—here, the glass pane arranged on the inner pane—is facing the light source and the detector. Transparent elements, such as the glass pane, may be interposed to separate the coated substrate from the light source and the detector.

[0034] The reflectance is measured at an angle of incidence of 8° (unless otherwise stated) to the coated surface normal (the coated surface of the inner pane). The spectral range from 380 nm to 780 nm was used to characterize the reflection properties.

[0035] In another preferred embodiment, the reflection layer on the glass pane can preferably reflect p-polarized light.

[0036] 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.

[0037] In other words, the polarization, in particular the proportion of p- and s-polarized radiation, is determined at a point in the area irradiated by the image display device, preferably at the geometric center of the irradiated area. Since composite panes can be curved (for example, when designed as a windshield), which affects the plane of incidence of the image display device radiation, slightly different polarization components may occur in the remaining areas, which is unavoidable for physical reasons.

[0038] In a preferred embodiment, the reflective layer is an electrically conductive reflective layer that simultaneously forms the electrically conductive coating on the outer surface of the glass pane, which is intended to be used as a heating layer. In other words, this layer can perform and combine both functions: reflecting the light from a projector for the display function, as well as the heating function to prevent obstruction of vision due to fogging and icing of the pane. This has the advantage that an additional layer can be omitted, making the production of the laminated pane simpler and more cost-effective.

[0039] In one embodiment of the invention, the reflective layer is a metallic layer, i.e. a layer that contains or consists of at least one metal, a metal alloy or a transparent conductive metal oxide, in particular indium tin oxide (ITO). The reflective layer preferably contains or consists of at least one metal selected from a group consisting of titanium, hafnium, niobium, tantalum, chromium, molybdenum, tungsten, cobalt, iron, manganese, zirconium, cerium, scandium, yttrium, ruthenium, nickel, palladium, platinum, aluminum, magnesium, tin, indium, silver, copper or gold and / or mixtures thereof. Aluminum, titanium and / or nickel can, for example, have a high reflection for p-polarized or s-polarized light.At the same time or as an independent layer, the electrically conductive layer may equally comprise or consist of a coating of metal, a metal alloy or a transparent conductive metal oxide or mixtures thereof.

[0040] The reflection layer preferably has a thickness of 10 nm (nanometers) to 150 µm (micrometers), preferably up to 100 µm, particularly preferably from 50 nm to 50 µm, in particular from 100 nm to 5 µm.

[0041] Methods for measuring the thickness of the reflective layer are known to those skilled in the art. The thickness of the reflective layer can be determined using common methods for determining the thickness of thin films, for example, spectroscopic reflectometry, confocal microscopy, white light interferometry, or ellipsometry. These methods enable non-destructive measurement, and corresponding measuring instruments are commercially available. Ellipsometers are commercially available, for example, from Sentech. White light interferometry, profilometry, for example, confocal profilometry, or ellipsometry are preferred.

[0042] 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, chromium, titanium, and / or aluminum. The electrically conductive layer based on 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, chromium, titanium, and / or aluminum. The conductive layer preferably contains at least 90% by weight of nickel, chromium, titanium, and / or aluminum, more preferably at least 99% by weight of aluminum, and most preferably at least 99.9% by weight of nickel, chromium, titanium, and / or aluminum.The layer based on aluminum, chromium, nickel and / or titanium can contain dopants, for example palladium, gold, copper or silver. Materials based on aluminum, chromium, nickel and / or titanium are particularly suitable for reflecting light, particularly preferably p-polarized light. Furthermore, they are very chemically stable. The use of nickel, chromium, titanium and / or aluminum in metallic coatings has proven particularly advantageous for reflecting light. Aluminum, chromium, nickel and / or titanium are significantly cheaper than many other metals such as gold or silver. The individual layers of the thin-film stack preferably have a thickness of 10 nm to 1 µm. The thin-film stack preferably has 2 to 20 individual layers and in particular 5 to 10 individual layers.

[0043] In a preferred embodiment of the composite pane, the reflective layer has at least one electrically conductive coating with a surface resistance of less than 3 ohms / square, preferably less than 1 ohm / square.

[0044] The sheet resistance of the electrically conductive coating can be determined using methods known to those skilled in the art, for example, the van der Pauw measurement method or the four-point method. Suitable measuring instruments are commercially available.

[0045] In addition, in another embodiment, an electrically conductive coating can be arranged on the outside of the inner pane in some areas or over the entire surface and used as a heating layer.

[0046] As described above, in the composite pane according to the invention, a masking layer is arranged in one of the regions of the composite pane. Preferably, the masking layer is arranged in an edge region of the composite pane, which typically borders the edge of the pane. The great advantage of this arrangement arises when the composite pane is used in a vehicle as a windshield, since the masking layer, when arranged in an edge region, lies outside the driver's primary field of vision.

[0047] The masking layer is preferably arranged at least along the lower edge and adjacent to the lower edge. This results in a rectangular opaque strip arranged along the lower edge in a plan view of the laminated pane.

[0048] In a particularly preferred embodiment of the composite pane according to the invention, the masking layer is formed in a frame-like manner and extends all the way around. In a section in which the glass pane and thus also the reflective layer applied thereto are arranged in overlap with the masking layer, the frame-shaped masking layer is preferably provided with a widened portion, i.e., it has a greater width (dimension perpendicular to the extension) than in other sections. In this way, the masking layer can be suitably adapted to the dimensions of the glass pane with the reflective layer applied thereto.

[0049] In one embodiment, the masking layer is thus formed in a frame-like manner and has a greater width, in particular in a section which overlaps the glass pane, than in sections different therefrom.

[0050] The glass pane with the reflective layer applied thereto preferably has a substantially rectangular shape extending in a region near the bottom edge between the two side edges. Particularly preferably, the edges of the glass pane do not extend to the side edges and the bottom edge, but are spaced from them, for example, by 2 cm to 5 cm.

[0051] The masking layer, within the meaning of the invention, is a layer that prevents visibility through the composite pane. The masking layer transmits a maximum of 5%, preferably a maximum of 2%, particularly preferably a maximum of 1%, in particular a maximum of 0.1%, of light of the visible spectrum. The masking layer is thus an opaque masking layer, preferably a black masking layer.

[0052] The masking layer is preferably a coating consisting of one or more layers. Alternatively, the masking layer can also be a colored region of the thermoplastic intermediate layer. According to a preferred embodiment of the composite pane, the masking layer consists of a single layer. This has the advantage of particularly simple and cost-effective production of the composite pane, since only a single layer needs to be formed for the masking layer.

[0053] The masking layer is in particular an opaque cover print made of a dark, preferably black, enamel.

[0054] In a preferred embodiment, the masking layer is formed as a first opaque cover print arranged on the interior-side surface of the outer pane, in particular made of a dark, preferably black, enamel.

[0055] In an alternative preferred embodiment, the masking layer is formed as a first opaque cover print arranged on the outer surface of the inner pane, in particular made of a dark, preferably black, enamel.

[0056] In an alternative preferred embodiment, the masking layer is formed as an opaque colored region of the thermoplastic intermediate layer.

[0057] In one embodiment, the thermoplastic intermediate layer is formed in one piece and is colored opaque in one area.

[0058] A masking layer formed as an opaque colored region of the thermoplastic intermediate layer can also be realized by using a thermoplastic intermediate layer composed of an opaque thermoplastic film and a transparent thermoplastic film. The opaque thermoplastic film and transparent thermoplastic film are preferably arranged offset from one another so that the two films do not overlap when viewed through the composite pane. The transparent and opaque films consist of the same plastic or preferably contain the same plastic. The materials on which the opaque film and the transparent film can be formed are those also described for the thermoplastic intermediate layer. The opaque film is preferably a colored film that can have various colors, in particular black.

[0059] The composite pane according to the invention can additionally have a second opaque cover print arranged on the interior-side surface of the inner pane, in particular at least in the area where the glass pane is arranged. Such a cover print on the interior-side surface of the inner pane improves the adhesion properties of the surface to an adhesive layer. The second opaque cover print is preferably frame-shaped.

[0060] In one embodiment of the composite pane according to the invention, a reflective layer for reflecting light is arranged on the interior-side surface of the glass pane and a protective layer is arranged on this reflective layer.

[0061] In a further preferred embodiment of the composite pane according to the invention, a reflective layer for reflecting light is arranged on both the interior surface of the glass pane and the exterior surface of the glass pane, and a protective layer is arranged on the reflective layer arranged on the interior surface of the glass pane. No protective layer is necessary for the reflective layer arranged on the exterior surface of the glass pane, since this reflective layer is bonded to the interior pane via the adhesive layer and is thus protected. Optionally, however, a protective layer can also be arranged on the reflective layer arranged on the exterior surface of the glass pane.

[0062] The protective layer is preferably transparent and applied flatly, in particular congruently, to the reflective layer. The protective layer is preferably a polymer based on polyacrylates, polyoximes, alkyd resins, polyurethanes, or mixtures thereof. The protective layer preferably has a thickness of 50 nm to 10 µm, and particularly preferably of 100 nm to 5 µm.

[0063] The protective layer protects the reflective layer from mechanical damage such as scratches. It can also serve to increase the durability of the reflective layer. With the protective layer, fewer metal particles separate over time, and the reflective layer of the glass pane retains its shape longer.

[0064] 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 remain on a surface when touching it and can have an unsightly effect.

[0065] The adhesive layer is preferably a thermoplastic layer or an optically clear adhesive (OCA). Suitable optically clear adhesives (OCAs) are known to those skilled in the art.

[0066] An adhesive layer formed as a thermoplastic layer contains at least one thermoplastic polymer, preferably ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB), or polyurethane (PU), or mixtures or copolymers or derivatives thereof, particularly preferably PVB. The thermoplastic layer is typically formed from a thermoplastic film (connecting film). The thickness of the thermoplastic layer is preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm, for example 760 µm. The thermoplastic layer can be formed by a single film or by more than one film.

[0067] The composite pane is preferably curved in one or more directions, as is common for automotive windows, with typical radii of curvature ranging from approximately 10 cm to approximately 40 m. However, the composite pane can also be flat, for example, if it is intended for use as a pane for buses, trains, or tractors.

[0068] The thermoplastic intermediate layer, via which the outer pane is connected to the inner pane, contains at least one thermoplastic polymer, preferably ethylene-vinyl acetate (EVA), polyvinyl butyral (PVB) or polyurethane (PU) or mixtures or copolymers or derivatives thereof, particularly preferably PVB. The thermoplastic intermediate layer is typically formed from a thermoplastic film (connecting film). The thickness of the thermoplastic intermediate layer is preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm, for example 760 µm. The thermoplastic intermediate layer can be formed by a single film or by more than one film. The thermoplastic intermediate layer can also be a film with functional properties, for example a film with acoustically dampening properties.

[0069] The outer pane and inner pane preferably contain or consist of glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, aluminosilicate glass, or clear plastics, preferably rigid clear plastics, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride and / or mixtures thereof.

[0070] The outer pane and the inner pane can be clear and colorless, but also tinted or colored. In a preferred design, the total transmission through the windshield in the main viewing area is greater than 70% (illuminant A). The term "total transmission" refers to the procedure for testing the light transmittance of motor vehicle windows specified in ECE-R 43, Annex 3, Section 9.1. The outer pane and the inner pane can independently be non-tempered, partially tempered, or toughened. If at least one of the panes is to be tempered, this can be thermally or chemically toughened.

[0071] The thickness of the outer pane and the inner pane can vary widely and thus be adapted to the requirements of the individual case. The outer pane and the inner pane preferably have thicknesses of 0.5 mm to 5 mm, more preferably of 1 mm to 3 mm, and most preferably of 1.6 mm to 2.1 mm. For example, the outer pane has a thickness of 2.1 mm and the inner pane a thickness of 1.6 mm. However, the outer pane or, in particular, the inner pane can also be made of thin glass with a thickness of, for example, 0.55 mm.

[0072] The glass pane preferably contains or consists of aluminosilicate glass, borosilicate glass, or aluminoborosilicate glass. The glass pane can be tempered, semi-tempered, or toughened.

[0073] In one embodiment of the invention, a HUD element is arranged in at least one view-through area of ​​the composite pane between the inner side II of the outer pane and the outer side III of the inner pane. In other words, the HUD element extends at least into an area of ​​the composite pane that, when viewed through, does not overlap with an opaque background and has a functional area that does not overlap with the glass pane and the reflective layer arranged thereon. Advantageously, the HUD element and the reflective layer on the glass pane do not negatively influence each other's function and can be used in a complementary manner. The HUD element can also be incorporated into the composite pane either over the entire surface or in a locally limited manner. The HUD element can, for example, be a hologram, a p-pol coating, a reflective film, a HUD layer, or an active display.

[0074] A HUD layer preferably comprises at least one metal selected from the group consisting of aluminum, tin, titanium, copper, chromium, cobalt, iron, manganese, zirconium, cerium, yttrium, silver, gold, platinum and palladium, or mixtures thereof.

[0075] In another embodiment of the invention, the HUD layer is a coating containing 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 silver. The electrically conductive layer based on silver imparts the basic reflective properties to the reflective coating, as well as an IR-reflecting effect and electrical conductivity. The electrically conductive layer is based on silver. The conductive layer preferably contains at least 90 wt.% silver, more preferably at least 99 wt.% silver, most preferably at least 99.9 wt.% silver. The silver layer can contain dopants, for example, palladium, gold, copper, or aluminum. Silver-based materials are particularly suitable for reflecting p-polarized light.The use of silver has proven particularly advantageous for reflecting p-polarized light. The coating has a thickness of 5 nm to 50 nm, and preferably 8 nm to 25 nm.

[0076] If the HUD layer is formed as a coating, it is preferably applied to the inner or outer pane by physical vapor deposition (PVD), particularly preferably by cathode sputtering, and most preferably by magnetic field-assisted cathode sputtering (magnetron sputtering). In principle, however, the coating can also be applied, for example, by chemical vapor deposition (CVD), such as plasma-enhanced vapor deposition (PECVD), by vapor deposition, or by atomic layer deposition (ALD). The coating is applied to the panes before lamination.

[0077] The HUD layer can also be formed as a reflective film that reflects s- and / or p-polarized light. The HUD layer can be a carrier film with a reflective coating or a reflective polymer film. The reflective coating preferably comprises at least one metal-based layer and / or a dielectric layer sequence with alternating refractive indices. The metal-based layer preferably contains or consists of silver and / or aluminum. The dielectric layers can be formed, for example, from silicon nitride, zinc oxide, tin-zinc oxide, silicon-metal mixed nitrides such as silicon zirconium nitride, zirconium oxide, niobium oxide, hafnium oxide, tantalum oxide, or silicon carbide. The aforementioned oxides and nitrides can be deposited stoichiometrically, substoichiometrically, or superstoichiometrically. They can contain dopants, for example, aluminum, zirconium, titanium, or boron.The reflective polymer film preferably comprises or consists of dielectric polymer layers. The dielectric polymer layers preferably contain PET. If the HUD layer is formed as a reflective film, it is preferably 30 µm to 300 µm thick, particularly preferably 50 µm to 200 µm thick, and especially 100 µm to 150 µm thick.

[0078] If it is a coated, reflective film, the CVD or PVD coating processes can also be used for production.

[0079] According to a further preferred embodiment, the HUD layer is formed as a reflective film and arranged within the thermoplastic intermediate layer. The advantage of this arrangement is that the HUD layer does not have to be applied to the outer or inner pane using thin-film technology (e.g., CVD and PVD). This results in uses of the HUD layer with additional advantageous functions, such as more homogeneous reflection of p-polarized light at the HUD layer. Furthermore, the production of the composite pane can be simplified because the HUD layer does not have to be applied to the outer or inner pane using an additional process prior to lamination.

[0080] In a preferred embodiment of the composite pane according to the invention, the intermediate layer is formed by a wedge-shaped thermoplastic film, in particular a PVB film. This embodiment enables simple and cost-effective use in an additional and complementary HUD projection system that can be operated with mixed s- and p-polarized light.

[0081] The composite pane according to the invention can also comprise one or more additional intermediate layers, in particular functional intermediate layers. An additional intermediate layer can, in particular, be an intermediate layer with acoustically dampening properties, an infrared-reflecting intermediate layer, an infrared-absorbing intermediate layer, a UV-absorbing intermediate layer, an at least partially colored intermediate layer, and / or an at least partially tinted intermediate layer. If several additional intermediate layers are present, these can also have different functions.

[0082] The invention also relates to a projection arrangement comprising at least one composite pane according to the invention and an imaging unit directed onto the reflection layer.

[0083] According to the invention, a projection arrangement is thus also at least comprising - a composite pane, comprising at least an outer pane with an outside surface and an inside surface, a thermoplastic intermediate layer, an inner pane with an outside surface and an inside surface, a masking layer arranged in a region of the composite pane between the outer pane and the inner pane, an adhesive layer and a glass pane with an outside surface and an inside surface and a thickness of 10 µm to 500 µm, wherein the thermoplastic intermediate layer is arranged between the outer pane and the inner pane, the adhesive layer is arranged between the inner pane and the glass pane, a reflective layer for reflecting light is arranged on the outer surface of the glass pane and / or on the inner surface of the glass pane, and wherein the glass pane is arranged in a region of the composite pane which, when viewed perpendicularly through the composite pane, lies entirely in the region in which the masking layer is arranged, and wherein an electrically conductive coating is arranged on the outer surface V of the glass pane, which is connected to a voltage source to form a current path for a heating current - and an imaging unit directed at the reflective layer.

[0084] In particular, the combination of the reflective layer with the masking layer located behind it from the perspective of a vehicle occupant ensures good image visibility in this area in a projection arrangement according to the invention, even in external sunlight and when using low-light imaging units. Even under these conditions, the image generated by the imaging unit appears bright and is clearly recognizable. This enables a reduction in the power of the imaging unit and thus reduced energy consumption. The provided electrically conductive layer, which can assume the function of a heating layer, can prevent or eliminate fogging and icing, and the resulting visual impairment.

[0085] From the perspective of a vehicle occupant, the reflective layer is arranged spatially in front of the masking layer when viewed through the inner pane. The area of ​​the composite pane in which the reflective layer is arranged therefore appears opaque. The expression "when viewed through the composite pane" means that the view through the composite pane starts from the interior-side surface of the composite pane. For the purposes of the present invention, "spatially in front" means that the reflective layer is arranged spatially further away from the outer surface of the outer pane than the masking layer. The masking layer is preferably widened at least in the area that overlaps with the reflective layer and in which the composite pane is used to display images.This means that the masking layer in this area, viewed perpendicular to the nearest section of the peripheral edge of the laminated pane, has a greater width than in other sections. The masking layer can thus be adapted to the dimensions of the reflective layer.

[0086] The imaging unit of the projection arrangement emits light and is arranged adjacent to the interior-side surface of the inner pane such that the imaging unit irradiates this surface, with the light being reflected by the reflective layer of the composite pane. The reflective layer preferably reflects at least 10%, more preferably at least 50%, most preferably at least 80%, and in particular at least 90% of the light incident on the reflective layer in a wavelength range from 400 nm to 700 nm and at angles of incidence from 55° to 80°. This is advantageous in order to achieve the greatest possible brightness of an image emitted by the imaging unit and reflected by the reflective layer.

[0087] The imaging unit is used to emit an image and can therefore also be referred to as a projector, display device, or image display device. A display or another device known to those skilled in the art can also be used as the imaging unit. The imaging unit is preferably a display, particularly preferably an LCD display, LED display, OLED display, or electroluminescent display, in particular an LCD display. Displays have a low installation height and are therefore easy and space-saving to integrate into the dashboard of a vehicle. Furthermore, displays are significantly more energy-efficient to operate than other imaging units. The comparatively lower brightness of displays is entirely sufficient in the inventive combination of the reflective layer and the masking layer behind it.The radiation of the imaging unit can, for example, strike the composite pane in the region of the reflective layer at an angle of incidence of 55° to 80°, preferably of 62° to 77°. The angle of incidence is the angle between the incidence vector of the radiation of the image display device and the surface normal in the geometric center of the reflective layer.

[0088] In a preferred embodiment, the imaging unit is operated with p-polarized light.

[0089] By arranging the reflective layer on the outside surface and / or the inside surface of a glass pane with a thickness of 20 µm to 500 µm bonded to the inside surface of the inner pane, the occurrence of a disturbing ghost image is avoided.

[0090] In a projection arrangement with a reflective layer applied to the interior surface of the glass pane, the desired virtual image is created by reflection from the reflective layer and no ghost image occurs.

[0091] In a projection arrangement with a reflective layer applied to the outside surface of the glass pane, the desired virtual image is created by reflection from the reflective layer and, in addition, a second virtual image, the so-called ghost image, is created by reflection from the inside surface of the glass pane.

[0092] In a projection arrangement with a reflective layer applied to the outside surface of the glass pane and a reflective layer applied to the inside surface of the glass pane, a first virtual image is generated by reflection from the reflective layer applied to the outside surface of the glass pane, and a second virtual image is additionally generated from the reflective layer applied to the inside surface of the glass pane. With the very small thicknesses for the glass pane provided according to the invention, however, the spatial offset between the first virtual image and the ghost image or between the first virtual image and the second virtual image is sufficiently small not to be noticeable. The effect is based on the typical angular acuity of the human eye: the thin glass pane according to the invention leads to an offset between the first virtual image and the ghost image orbetween the first virtual image and the second virtual image, which is no longer resolvable for the human eye.

[0093] The preferred embodiments of the composite pane according to the invention described above also apply accordingly to the projection arrangement according to the invention comprising a composite pane according to the invention and an imaging unit and vice versa.

[0094] A method for producing a composite pane according to the invention, comprising at least: a) providing a composite comprising an outer pane having an outer surface and an inner surface, a thermoplastic intermediate layer, and an inner pane having an outer surface and an inner surface, wherein the thermoplastic intermediate layer is arranged between the outer pane and the inner pane, and a masking layer is arranged in a region between the outer pane and the inner pane; b) Providing a glass pane with an outside surface and an inside surface, wherein a reflective layer for reflecting light is arranged on the outside surface of the glass pane and / or on the inside surface of the glass pane, and wherein an electrically conductive coating is arranged on the outside surface of the glass pane, which coating can be connected via connections, in particular via bus bars, to a voltage source for forming a current path for a heating current; c) bonding the glass pane to the inner pane of the composite pane via an adhesive layer to form a composite pane, such that the glass pane is arranged in a region of the composite pane which, when viewed vertically through the composite pane, lies entirely in the region in which the masking layer is arranged.

[0095] Steps a) and b) can be performed in the specified order, simultaneously, or in reverse order. Step c) is performed after steps a) and b).

[0096] As explained above, the glass pane is arranged in a region of the composite pane which, when viewed perpendicularly through the composite pane, lies entirely in the region in which the masking layer is arranged. Thus, the glass pane is smaller in terms of its external dimensions than the outer pane and the inner pane of the composite pane. The glass pane can be provided in step b) by applying a reflective layer over the entire surface of the interior and / or the exterior surface of an uncoated glass pane with the desired dimensions. Advantageously, the reflective layer can simultaneously be designed as the electrically conductive coating, thus combining both functions. This allows the manufacturing process to be carried out particularly efficiently. Alternatively, a separate electrically conductive coating can also be applied over the entire surface of the exterior surface of the glass pane.

[0097] Alternatively, the provision of the glass pane in step b) can also be carried out by applying a reflective layer and / or electrically conductive layer over the entire surface of the interior surface and / or the exterior surface of an uncoated glass pane which is larger than desired in terms of external dimensions, i.e. width and length, and then cutting out a section having the desired dimensions from such a coated glass pane, for example by means of a laser cutting process.

[0098] A reflective layer and an electrically conductive coating (layer) can be selectively arranged in an area of ​​the composite pane over the glass pane provided with the reflective layer.

[0099] The provision of the glass pane in step b) may additionally comprise the application of a protective layer to the reflective layer applied to the interior surface and / or the exterior surface. The protective layer is preferably applied to the reflective layer by spraying or squirting, for example, using a pressure atomizer.

[0100] If the laminated pane is to be curved, a curved outer pane and a curved inner pane are used during the preparation of the laminate in step a). The glass pane with the reflective coating is flexible due to its thinness and adapts to the curved inner pane of the laminate in step c). This is an advantage of the process. In this process, the reflective coating is applied to a flat substrate.

[0101] The composite in step a) can be provided by means of lamination processes familiar to the person skilled in the art.

[0102] When providing the glass pane in step b), the application of the reflective layer and / or the electrically conductive coating can be carried out by means of generally known coating methods, such as magnetron sputtering or cold gas spraying.

[0103] The preferred embodiments of the composite pane according to the invention described above also apply accordingly to methods for producing a composite pane according to the invention.

[0104] The composite pane according to the invention is preferably used as a vehicle pane in means of transport for land, air, or water traffic, particularly in motor vehicles, and particularly as a windshield for a head-up display. The composite pane can advantageously incorporate both a conventional head-up display, for example, operated with mixed-polarized radiation, in the viewing area, and a projection arrangement comprising the glass pane with p-polarized radiation. For example, various cluster displays can be replaced in this way, and the space requirements and design freedom, particularly in vehicle cockpits, can be optimized.

[0105] The invention is explained in more detail below with reference to drawings and exemplary embodiments. The drawings are schematic representations and not to scale. The drawings do not limit the invention in any way.

[0106] They show: Fig. 1 a plan view of an embodiment of a composite pane according to the invention, Fig. 2 a cross-section through the Fig. 1 shown embodiment, Fig. 3 is a plan view of another embodiment of a composite pane according to the invention, Fig. 4 a cross-section through the Fig. 3 shown embodiment, Fig. 5 shows a cross section through an embodiment of a projection arrangement 101 according to the invention.

[0107] Fig. 1 shows a plan view of an embodiment of a composite pane 100 according to the invention (on its inner side IV) and in Fig. 2 is the cross section through the Fig. 1 is shown along the section line XX'. The composite pane 100 shown in the Fig. 1 and Fig. The composite pane 100 shown in Figure 2 has an upper edge O, a lower edge U, and two side edges S, and comprises an outer pane 1 with an outer surface I and an inner surface II, an inner pane 2 with an outer surface III and an inner surface IV, a thermoplastic intermediate layer 3, a masking layer 4, an adhesive layer 5, and a glass pane 6 with an outer surface V and an inner surface VI. The thermoplastic intermediate layer 3 is arranged between the outer pane 1 and the inner pane 2, the inner pane 2 is arranged between the outer pane 1 and the glass pane 6, and the adhesive layer 5 is arranged between the inner pane 2 and the glass pane 6. The outer pane 1, the thermoplastic intermediate layer 3, and the inner pane 2 are arranged one above the other with their entire surface.The masking layer 4 is arranged between the outer pane 1 and the inner pane 2 in a region of the composite pane 100. In the . Fig. 1 and Fig. 2, the masking layer 4 is formed as a first opaque masking print arranged on the interior-side surface II of the outer pane 1 and is arranged only in an edge region of the composite pane 100 bordering the lower edge U. The glass pane 6 is arranged in a region of the composite pane 100 which, when viewed perpendicularly through the composite pane 100, lies entirely in the region in which the masking layer 4 is arranged. The glass pane 6 is thus smaller in terms of its external dimensions than the inner pane 2. The outer surface V of the glass pane 6 is connected to the interior-side surface IV of the inner pane 2 via the adhesive layer 5. In the embodiment shown in the Fig. In the embodiment shown in Figure 2, a reflective layer 7 for reflecting light is arranged on the interior surface VI of the glass pane 6. An electrically conductive coating (layer) is arranged on the exterior surface V of the glass pane, which is connected via busbars 11, 11', so-called busbars (see Fig. 1) is connected to a voltage source to form a current path for a heating current. In this embodiment, the busbars 11, 11' are aligned substantially parallel to the side edges of the composite pane (100). The busbars 11, 11' are concealed toward the interior by the reflective layer 7 and toward the outside by the masking layer 4.

[0108] The glass pane 6 is made of aluminosilicate glass, for example, and has a thickness between 50 and 250 µm, for example, 70 µm, 100 µm, or 150 µm. The thermoplastic intermediate layer 3 contains PVB, for example, and has a thickness of 0.76 mm. The intermediate layer 3 can also be wedge-shaped, for example. The outer pane 1 is made of soda-lime glass, for example, and is 2.1 mm thick. The inner pane 2 is made of soda-lime glass, for example, and is 1.6 mm thick.

[0109] The adhesive layer 5, for example, is an optically clear adhesive.

[0110] The reflection layer 7 is, for example, a metallic layer with a thickness of 100 nm and contains, for example, aluminum.

[0111] The reflective layer can also be a transparent, conductive and reflective oxide layer, for example an indium tin oxide layer (ITO).

[0112] The electrically conductive layer 8 is applied to the outer surface V of the glass pane 6 and can, for example, be an ITO layer. Transition metal coatings are particularly advantageous because they have good stability, good conductivity, and also good reflection properties. The latter is of particular interest for embodiments such as in Fig. 4 in which the electrically conductive layer 8 is simultaneously formed as a reflection layer 7 or 7E.

[0113] In the in the Fig. 1 and Fig. In the embodiment shown in Figure 2, the masking layer 4 extends between the two side edges S of the composite pane 100 and, starting from the lower edge U of the composite pane 100, has a width of, for example, 30 cm.

[0114] It is understood that the composite pane 100 may have any suitable geometric shape and / or curvature. Typically, the composite pane 100 is a curved composite pane.

[0115] Fig. Figure 3 shows a plan view of another embodiment of a composite pane 100 according to the invention (on its inner side IV) and in Fig. 4 is the cross section through the Fig. 3 shown composite pane 100 along the section line Y-Y''. In contrast to the Fig. 1, the bus bars 11, 11' are formed parallel to the upper edge O and lower edge U. In the embodiment shown in Fig. 4, the reflective layer 7 is also an electrically conductive coating 7E on the outer surface V of the glass pane 6. In other words, this coating 7E can simultaneously perform both the heating function and serve as a reflective layer. This is particularly efficient and saves production costs. Optionally, the composite pane (100) can have further (not shown) functional layers, such as UV or IR radiation-reflecting layers or heat-insulating layers (low-E layers). For example, a heating layer can also be arranged in regions or over the entire surface of the outer surface III of the inner pane. In the embodiment shown, the intermediate layer 3 is a wedge-shaped intermediate layer 3, for example a PVB, which is available in particular for an additional HUD function in the see-through range, for example with an imaging unit with mixed s- and p-polarized radiation.In a preferred embodiment, the use of a wedge-shaped PVB intermediate layer 3 for the HUD function in combination with the (heatable) reflective layer 7, 7E for the additional HUD display function, also called a black print display, eliminates the need for an additional heating layer on the outer surface III of the inner pane. This saves production costs and also contributes to an optimized visual appearance of the laminated pane 100 in the transparent viewing area D.

[0116] Fig. 5 shows a cross section through an embodiment of a projection arrangement 101 according to the invention. Fig. The projection arrangement 101 shown in Figure 5 comprises a composite pane 100 and an imaging unit 10. List of reference symbols: 100 composite panes 101 Projection arrangement 1 outer pane 2 inner pane 3 thermoplastic intermediate layer 4 Masking layer 5 adhesive layer 6 glass pane 7 Reflective layer 7E electrically conductive reflective layer (reflection and heating) 8 electrically conductive coating (heating layer) 10 imaging unit 11, 11' Collector O Top edge of the composite pane 100 U Bottom edge of the laminated pane 100 S Side edge of the laminated pane 100 D See-through area I outside surface of the outer pane 1 II Interior surface of the outer pane 1 III outer surface of the inner pane 2 IV Interior surface of the inner pane 2 V outer surface of the glass pane 6 VI Interior surface of the glass pane 6 X'-X intersection line YY' cutting line QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 102014220189A1

[0004] US 20040135742A1

[0004] WO 9900528A1

[0007] DE 10126868C1

[0007] WO 2017198363A1

[0007] WO 2010 / 003396 A1

[0009] EP 3 845 685 A1

[0009] EP 2 902 530 A1

[0009] DE 103 52 464 A1

[0011] WO 03 / 024155 A2

[0012] WO 2013 / 104439 A1

[0013] EP 2803246 B1

[0013] DE 10 2009 020824 A1

[0015] WO 2022 / 161894 A1

[0016] Cited non-patent literature

[0000] Glass meets flexibility: Challenges in manufacturing of thin films on flexible glass” by M. Junghähnel et al., published in Vacuum in Research and Practice, Vol. 26, No. 5, pp. 35-39

[0014]

Claims

[1] Composite pane (100), in particular for at least one projection arrangement, comprising at least - an outer pane (1) with an outside surface (I) and an inside surface (II), - a thermoplastic intermediate layer (3), - an inner pane (2) with an outside surface (III) and an inside surface (IV), - a masking layer (4), - an adhesive layer (5), - a glass pane (6) with an outside surface (V) and an inside surface (VI) and a thickness of 20 µm to 500 µm, wherein the thermoplastic intermediate layer (3) is arranged between the outer pane (1) and the inner pane (2), the masking layer (4) is arranged between the outer pane (1) and the inner pane (2) in a region of the composite pane (100), the adhesive layer (5) is arranged between the inner pane (2) and the glass pane (6), a reflective layer (7) for reflecting light is arranged on the outside surface (V) of the glass pane (6) and / or on the inside surface (VI) of the glass pane (6), and wherein the glass pane (6) is arranged in a region of the composite pane (100) which, when viewed vertically through the composite pane (100), lies entirely in the region in which the masking layer (4) is arranged, and wherein an electrically conductive coating (8, 7E) is arranged on the outer surface (V) of the glass pane (6), which is connected to terminals of a voltage source to form a current path for a heating current. [2] Composite pane (100) according to claim 1, wherein the glass pane (6) has a thickness of 30 µm to 300 µm, preferably of 50 µm to 250 µm. [3] Composite pane (100) according to claim 1 or 2, wherein the reflection layer (7) reflects visible light to at least 10%, preferably to at least 50%, particularly preferably to at least 80% and in particular to at least 90%. [4] Composite pane (100) according to one of claims 1 to 3, wherein a reflection layer (7) is an electrically conductive reflection layer (7E) which simultaneously forms the electrically conductive coating (8) on the outer surface (V) of the glass pane (6). [5] Composite pane (100) according to one of claims 1 to 4, wherein the reflective layer (7, 7E) and / or the electrically conductive layer (8) contains or consists of at least one coating of metal, metal alloy or transparent conductive metal oxides, in particular indium tin oxide (ITO), titanium, zirconium, hafnium, niobium, tantalum, chromium, molybdenum, tungsten, nickel, chromium, palladium, platinum, aluminum, silver, copper or gold and / or mixtures thereof. [6] Composite pane (100) according to one of claims 1 to 5, wherein the reflection layer (7, 7E) has a layer thickness in the range of 10 nm to 150 µm, preferably a layer thickness of up to 100 µm. [7] Composite pane (100) according to one of claims 1 to 6, wherein the electrically conductive coating (8, 7E) is connected in an edge region of the glass pane (6) to two busbars (11, 11') provided for connection to a voltage source, so that a current path for a heating current is formed between the busbars (11, 11'). [8] Composite pane (100) according to one of claims 1 to 7, wherein the electrically conductive coating (8, 7E) has a surface resistance of less than 3 ohms / square, preferably less than 1 ohm / square. [9] Composite pane (100) according to one of claims 1 to 8, wherein the masking layer (4) is formed as a first opaque cover print arranged on the interior-side surface (II) of the outer pane (1) or the exterior-side surface (III) of the inner pane (2) or as an opaquely colored region of the thermoplastic intermediate layer (3). [10] Composite pane (100) according to one of claims 1 to 9, wherein the composite pane (100) additionally has, at least in the region in which the glass pane (6) is arranged, a second opaque cover print (9) arranged on the interior-side surface (IV) of the inner pane (2). [11] Composite pane (100) according to one of claims 1 to 10, wherein a reflective layer (7, 7E) for reflecting light is arranged on the interior-side surface (VI) of the glass pane (6), and wherein a protective layer (8) is arranged on the reflective layer (7, 7E) which is arranged on the interior-side surface (VI) of the glass pane (6). [12] Composite pane (100) according to one of claims 1 to 11, wherein the adhesive layer (5) is a thermoplastic layer or an optically clear adhesive (OCA). [13] Composite pane (100) according to one of claims 1 to 12, wherein the composite pane (100) has at least one HUD element, in particular a HUD layer, and / or a wedge-shaped intermediate layer (3) between the inner side (II) of the outer pane (1) and the outer side (III) of the inner pane (2) at least in one viewing area (D). [14] Projection arrangement (101) comprising at least - a composite pane (100) according to one of claims 1 to 13, - an imaging unit (10) directed onto the reflection layer (7).

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