Composite pane comprising a heatable, transparent film and a reflective layer for p-polarised radiation

Abstract

The present invention relates to a composite pane (100) comprising at least, in the following order: an outer pane (1) having an outer surface (I) and an inner surface (II); a first thermoplastic intermediate layer (3); a heatable, transparent film (4); a second thermoplastic intermediate layer (5); an inner pane (2) having an outer surface (III) and an inner surface (IV); and a reflective layer (6) on the outer surface (III) of the inner pane (2) or on the inner surface (IV) of the inner pane (2), wherein the reflective layer (6) is suitable for reflecting p-polarised radiation.

Description

[0001] Composite pane with heatable, transparent film and reflective layer for p-polarized radiation

[0002] The invention relates to a composite pane with a heatable, transparent film and a reflection layer for p-polarized radiation, a display system comprising the composite pane, a method for producing the composite pane and the use of the composite pane.

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

[0004] HUD projectors typically illuminate the windshield at an angle of incidence of approximately 65%, which is close to the Brewster angle for an air-to-glass interface (57.2° for soda-lime glass). This circumstance can be exploited to ensure a clear HUD projection: if the HUD projector is operated with p-polarized radiation, the radiation is barely reflected by the external glass surfaces of the windshield. Instead, the windshield is equipped with a reflective layer suitable for reflecting the p-polarized radiation to generate the display image. Since there is only a single significant reflection plane, namely the reflective layer, a clear display image is produced without ghost images (or with only weak ghost images due to residual reflection from the external glass surfaces if the angle of incidence deviates slightly from the Brewster angle).For example, reference is made to DE102014220189A1, EP3187917B1 and WO2021104800A1.

[0005] It is desirable to provide a composite pane suitable for HUD projection that is also heatable to prevent fogging of the composite pane or to facilitate defrosting of a frozen composite pane. A transparent, conductive film is known, for example, from WO 2016 / 172315 A1, WO 2020 / 102392 A1, and WO 2022 / 081756 A1.

[0006] WO 2023 / 066378 A1 describes a HUD glass that may include an electrically conductive layer.

[0007] WO 2022 / 106315 A1 describes a projection arrangement for HUD with p-polarized radiation, which comprises heating wires.

[0008] WO 2022 / 050388 A1 describes a laminated glass, wherein a functional layer is arranged between the outer glass pane and the inner glass pane and a bonding layer for fixing the functional layer is arranged between the two glass panes.

[0009] The present invention is based on the object of providing a heatable composite pane with high transmission in the visible spectral range, which is suitable for HUD projection using p-polarized radiation.

[0010] The object of the present invention is achieved by a composite pane according to claim 1. Preferred embodiments are set out in the subclaims. The invention also relates to a display system comprising the composite pane, a method for producing the composite pane, and the use of the composite pane as interior or exterior glazing in a vehicle or a building.

[0011] The composite pane according to the invention comprises at least in the following order: an outer pane with an outer surface and an inner surface, a first thermoplastic intermediate layer, a heatable, transparent film, a second thermoplastic intermediate layer, an inner pane with an outer surface and an inner surface, and a reflective layer on the outer surface of the inner pane or on the inner surface of the inner pane, wherein the reflective layer is suitable for reflecting p-polarized radiation. The outer pane and the inner pane, as described above, each have an outer surface, i.e. an outer surface, and an interior surface, i.e. an inner surface, and a circumferential side edge running between them. In the sense of the invention, the term outer surface refers to the main surface which is intended to face the external environment in the installed position.For the purposes of the invention, the "inner surface" refers to the main surface intended to face the interior in the installed position. The inner surface of the outer pane and the outer surface of the inner pane face each other in the composite pane according to the invention.

[0012] The surfaces of the composite pane are typically referred to as follows:

[0013] The outer surface of the outer pane is called Side I. The inner surface of the outer pane is called Side II. The outer surface of the inner pane is called Side III. The inner surface of the inner pane is called Side IV.

[0014] If the composite pane is intended to separate an interior space from the exterior environment in a window opening of a vehicle or building, the inner pane, within the meaning of the invention, refers to the pane facing the interior (vehicle interior). The outer pane refers to the pane facing the exterior environment.

[0015] It is understood that visibility through the laminated glass means visibility from the outside environment or visibility from the interior.

[0016] The outer pane and inner pane are preferably made of glass, particularly preferably soda-lime glass, as is common for window panes. However, the panes can also be made of other types of glass, such as quartz glass, borosilicate glass, or aluminosilicate glass, or of rigid, clear plastics, such as polycarbonate or polymethyl methacrylate. The panes can be clear, tinted, or colored. If the laminated pane is used as a windshield, the outer pane and inner pane should have sufficient light transmission in the central viewing area, preferably at least 70% in the main viewing area A according to ECE-R43. The outer pane and inner pane are preferably curved, meaning they have a bend. The thickness of the outer pane and inner pane can vary widely and can thus be adapted to individual requirements.The outer pane and the inner pane preferably each have a thickness of 0.5 mm to 5 mm, particularly preferably 1 mm to 3 mm, and most preferably 1.6 mm to 2.1 mm. For example, the outer pane has a thickness of 2.1 mm and the inner pane has a thickness of 1.6 mm. However, the outer pane or, in particular, the inner pane can also be thin glass with a thickness of, for example, 0.55 mm.

[0017] According to the invention, the composite pane comprises a first thermoplastic intermediate layer and a second thermoplastic intermediate layer. Preferably, the first thermoplastic intermediate layer and the second thermoplastic intermediate layer independently contain at least polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), thermoplastic polyurethane (PU), or mixtures or copolymers, for example block copolymers, or derivatives thereof, particularly preferably polyvinyl butyral (PVB), very particularly preferably polyvinyl butyral (PVB), and additives known to those skilled in the art, such as plasticizers.

[0018] Plasticizers are chemical compounds that make plastics softer, more flexible, more supple, and / or more elastic. They shift the thermoelastic range of plastics towards lower temperatures, so that the plastics exhibit the desired more elastic properties near the application temperature. Preferred plasticizers are carboxylic acid esters, particularly low-volatility carboxylic acid esters, fats, oils, plastic resins, and camphor. Other plasticizers are preferably aliphatic diesters of tri- or tetraethylene glycol. Particularly preferred plasticizers are 3G7, 3G8, or 4G7, where the first digit indicates the number of ethylene glycol units and the last digit indicates the number of carbon atoms in the carboxylic acid moiety of the compound. 3G8, for example, stands for triethylene glycol bis(2-ethylhexanoate), i.e., a compound with the formula C4H9CH(CH2CH3)CO(OCH2CH2)3O2CCH(CH2CH3)C4H9.

[0019] According to one embodiment, the first thermoplastic intermediate layer and the second thermoplastic intermediate layer independently contain at least 3 wt.%, for example at least 5 wt.%, at least 20 wt.%, at least 30 wt.%, and at least 40 wt.% of a plasticizer. More preferably, the first thermoplastic intermediate layer and the second thermoplastic intermediate layer independently contain at least 60 wt.%, particularly preferably at least 70 wt.%, in particular at least 90 wt.%, and for example at least 97 wt.% of polyvinyl butyral.

[0020] The thickness of the first thermoplastic intermediate layer and the second thermoplastic intermediate layer is independently of one another preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm, for example 0.38 mm or 0.76 mm.

[0021] According to the invention, the laminated pane comprises a heatable, transparent film. The heatable, transparent film allows the laminated pane to be heated efficiently, as the heatable, transparent film itself can be heated quickly and homogeneously without adversely affecting the transmission in the visible spectral range of the laminated pane.

[0022] For the purposes of the present invention, "transparent film" means that the film has a transmission in the visible spectral range from 380 nm to 750 nm of at least 75%, preferably of at least 80%, more preferably of at least 85%. The transmission can be measured using a spectrophotometer (for example, PerkinElmer Lambda 900 UV / VIS / NIR) with illuminant D65. The use of the heatable, transparent film does not adversely reduce the transmission in the visible spectral range of the laminated pane.

[0023] The heatable, transparent film preferably extends over at least 5%, particularly preferably over at least 10%, very particularly preferably over at least 50%, in particular over at least 90% of the surface of the composite pane. The heatable, transparent film can also extend over the entire composite pane or essentially the entire surface, i.e. the entire surface minus a peripheral edge area of, for example, 20 mm, which is generally covered by a frame-like dark cover print. A full-surface or essentially full-surface arrangement of the heatable, transparent film offers advantages in production and in the heatability of the entire composite pane.

[0024] The thickness of the heatable, transparent film is not particularly limited. Preferably, the heatable, transparent film has a thickness in a range of 50 μm to 350 μm. This ensures advantageous transparency and mechanical stability of the heatable, transparent film.

[0025] In a preferred embodiment, the heatable, transparent film is provided with busbars that are connected to the poles of a voltage source. Preferably, at least two outer busbars intended for connection to a voltage source are connected to the heatable, transparent film in such a way that a current path for a heating current is formed between the busbars. The material for the busbars is not particularly limited, as long as it allows the formation of the current path.

[0026] In a preferred embodiment of the invention, the heatable, transparent film comprises a polymer film. The polymer film can serve as a substrate of the heatable, transparent film and support a structure that makes the heatable, transparent film heatable. The polymer of the polymer film is not particularly limited as long as the corresponding polymer film is transparent and mechanically stable. For example, the polymer of the polymer film comprises a polymer selected from the group consisting of polyethylene terephthalate, polycarbonate, polyarylate, polyethersulfone, polypropylene, polytetrafluoroethylene, and polyimide. Preferably, the polymer of the polymer film comprises or consists of polyethylene terephthalate or polycarbonate. A polymer film comprising such a polymer has particularly advantageous transparency and mechanical stability.

[0027] The polymer film preferably has a thickness in a range from 55 pm to 300 pm, more preferably from 75 pm to 150 pm, whereby good mechanical stability of the heatable, transparent film can be achieved.

[0028] In a preferred embodiment of the invention, the heatable, transparent film comprises a metal mesh layer or a layer with metal nanowires. The metal mesh layer or the layer with metal nanowires imparts electrical conductivity and thus heatability to the heatable, transparent film.

[0029] Preferably, the metal mesh layer consists of a maximum of 40%, more preferably a maximum of 25%, even more preferably a maximum of 10%, metal in a plan view. "Plan view" here means the viewing direction in the direction of the surface normal of the metal mesh layer. This means that the remaining portion of the metal mesh layer not occupied by the metal represents a free surface. This makes it possible to achieve advantageous transparency of the heatable, transparent film compared to a metal layer applied over the entire surface. Preferably, the metal mesh layer consists of a maximum of 1%, more preferably at least 2%, even more preferably at least 3%, metal in a plan view, whereby good electrical conductivity can be achieved.

[0030] Preferably, the metal mesh layer has a thickness in a range from 0.5 pm to 10 pm, more preferably from 1 pm to 6 pm, so that a good transparency of the heatable, transparent film can be achieved.

[0031] In a preferred embodiment of the invention, the metal mesh layer is formed from metal lines. According to the invention, “metal lines” means an elongated segment made of metal. The line width of a metal line is preferably from 1 pm to 7 pm, more preferably from 2 pm to 6 pm. According to the invention, the “line width of the metal line” refers to the extent of the metal line that is perpendicular to the length of the metal line in the extension direction and perpendicular to the thickness of the metal line. The thickness of the metal line is the extent of the metal line parallel to the direction of the thickness of the heatable, transparent film. Preferably, a metal line has a thickness in a range from 0.5 pm to 10 pm, more preferably from 1 pm to 6 pm. According to one embodiment, the thickness of the metal line corresponds to the thickness of the metal mesh layer. The distance between two metal lines is preferably from 200 pm to 400 pm, more preferably from 250 pm to 350 pm.This geometric arrangement and the corresponding dimensions allow a mechanically stable metal mesh layer to be obtained, while exhibiting advantageous transparency.

[0032] In a preferred embodiment of the invention, the metal lines are arranged in a pattern. Preferably, the metal lines are arranged in a diamond pattern, which allows for easy adjustment of the transparency and electrical conductivity of the metal mesh layer.

[0033] Preferably, the layer with metal nanowires in plan view consists of at most 40%, more preferably at most 25%, even more preferably at most 10%, of metal nanowires. "Top view" here means the viewing direction in the direction of the surface normal of the layer with metal nanowires. This means that the remaining portion of the layer with metal nanowires that is not occupied by the metal nanowires represents a free area or is occupied by a material that is different from the metal nanowires. This makes it possible to achieve an advantageous transparency of the heatable, transparent film compared to a metal layer applied over the entire surface. Preferably, the layer with metal nanowires in plan view consists of at least 1%, more preferably at least 2%, even more preferably at least 3%, of metal nanowires, whereby good electrical conductivity can be achieved.

[0034] The layer with metal nanowires preferably has a thickness in a range of 0.1 μm to 5 μm. The metal nanowires have a diameter in a range of 10 nm to 100 nm and a length in a range of 5 μm to 30 μm. This ensures advantageous transparency of the heatable, transparent film. The metal nanowires are preferably arranged randomly in the layer.

[0035] In a preferred embodiment of the invention, the metal of the metal mesh layer or the layer with metal nanowires is selected from copper, silver, or aluminum. The metal of the metal mesh layer or the layer with metal nanowires is preferably copper or silver, as this allows particularly good electrical conductivity of the heatable, transparent film to be achieved. According to a more preferred embodiment, the metal of the metal mesh layer is copper. According to another more preferred embodiment, the metal of the metal nanowires is silver.

[0036] Preferably, the metal mesh layer or the layer with metal nanowires is arranged on the polymer film. Thus, the metal mesh layer or the layer with metal nanowires can be advantageously mechanically stabilized by the polymer film.

[0037] According to a preferred embodiment, the metal of the metal mesh layer covers at most 40%, more preferably at most 25%, even more preferably at most 10%, of the surface of the polymer film in the plan view of the heatable, transparent film or polymer film, whereby advantageous transparency of the heatable, transparent film can be ensured. "Plan view" here means the viewing direction in the direction of the surface normal of the heatable, transparent film or polymer film. Preferably, the metal of the metal mesh layer covers at least 1%, more preferably at least 2%, even more preferably at least 3%, of the surface of the polymer film in the plan view of the heatable, transparent film or polymer film, whereby good electrical conductivity can be achieved.According to a further preferred embodiment, the metal nanowires of the layer comprising metal nanowires cover at most 40%, more preferably at most 25%, even more preferably at most 10%, of the surface of the polymer film in the plan view of the heatable, transparent film or polymer film, thereby ensuring advantageous transparency of the heatable, transparent film. "Plan view" here means the viewing direction in the direction of the surface normal of the heatable, transparent film or polymer film. Preferably, the metal nanowires of the layer comprising metal nanowires cover at least 1%, more preferably at least 2%, even more preferably at least 3%, of the surface of the polymer film in the plan view of the heatable, transparent film or polymer film, thereby achieving good electrical conductivity.

[0038] In a preferred embodiment of the invention, the heatable, transparent film comprises a layer of electrically conductive fibers that at least partially covers the metal mesh layer or the layer of metal nanowires. The layer of electrically conductive fibers preferably fills the free area of ​​the metal mesh layer not occupied by the metal of the metal mesh layer on the surface of the polymer film, or the free spaces between the metal nanowires of the layer of metal nanowires. This can increase the electrical conductivity of the heatable, transparent film.

[0039] Preferably, the layer with electrically conductive fibers has a thickness in a range of 5 pm to 70 pm.

[0040] In a preferred embodiment of the invention, the metal mesh layer or the layer with metal nanowires is arranged between the polymer film and the layer with the electrically conductive fibers. In a preferred embodiment, the layer with the electrically conductive fibers comprises a binder.

[0041] In a preferred embodiment of the invention, the electrically conductive fibers are carbon nanotubes, in particular single-walled carbon nanotubes with a diameter of 0.7 nm to 1.4 nm and a length of 0.3 pm to 3 pm. The use of carbon nanotubes can particularly advantageously stabilize the metal mesh layer or the layer with metal nanowires and, moreover, improve the electrical conductivity of the heatable, transparent film. The carbon nanotubes can be provided, in particular, according to the method described in WO 2022 / 081756 A1.

[0042] According to the invention, the composite pane comprises a reflective layer on the outer surface of the inner pane or on the inner surface of the inner pane, wherein the reflective layer is suitable for reflecting p-polarized radiation.

[0043] In a preferred embodiment of the invention, the reflective layer is arranged on the inner surface of the inner pane. The arrangement of the reflective layer on the inner surface of the inner pane is advantageous in that a particularly clear representation of the display image with only a very weak ghost image can be achieved in the event that the angle of incidence of the imaging unit does not exactly correspond to the Brewster angle. This ghost image is caused by a certain residual reflection on the outer surface of the outer pane, which is further attenuated by the passage through the reflective layer.

[0044] In another embodiment, the reflective layer is arranged on the outer surface of the inner pane. Since the reflective layer is protected in this arrangement by the layer between the outer pane and the inner pane, materials that are susceptible to corrosion can also be used for the reflective layer.

[0045] The reflective layer reflects the p-polarized light incident on the reflective layer with a reflectance of preferably 30% or more, more preferably 50% or more, very particularly 70% or more, and in particular 90% or more. The reflectance describes the proportion of the total incident radiation that is reflected. It is specified as a percentage (based on 100% incident radiation) or as a unitless number from 0 to 1 (normalized to the incident radiation). Plotted as a function of wavelength, it forms the reflection spectrum. In the context of the present invention, the statements regarding the reflectance with respect to p-polarized radiation refer to the reflectance measured at an angle of incidence of 65° to the interior surface normal.The information on the reflectance or the reflection spectrum refers to a reflection measurement with a light source that radiates uniformly in the considered spectral range with a standardized radiation intensity of 100%. According to one embodiment, the reflective layer comprises at least one metal selected from the group consisting of aluminum, tin, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, manganese, iron, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, and gold, or alloys thereof. The reflective layer may contain silicon oxide independently or additionally.

[0046] In one embodiment of the invention, the reflective layer is a reflective coating comprising a thin-film stack, i.e., a sequence of thin individual layers. According to one embodiment, this thin-film stack contains one or more electrically conductive silver-based layers. The electrically conductive silver-based layer according to this embodiment imparts the basic reflective properties to the reflective coating, as well as an IR-reflecting effect and electrical conductivity. The electrically 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 electrically conductive silver-based layer may contain dopants, for example, palladium, gold, copper, or aluminum. Silver-based materials are particularly suitable for reflecting p-polarized light.The use of silver in reflective coatings has proven particularly advantageous for reflecting p-polarized light. The reflective coating preferably has a thickness of 5 pm to 50 pm, more preferably 8 pm to 25 pm.

[0047] According to a further embodiment, the reflection layer is formed as a reflective film that reflects p-polarized light.

[0048] The reflective layer may be a reflective coating. According to another embodiment, the reflective layer may be a reflective polymer film.

[0049] 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 reflective layer is preferably a reflective coating that represents a dielectric layer sequence with alternating refractive indices. By using a reflective coating that represents a dielectric layer sequence with alternating refractive indices, the transmission in the visible spectral range of the composite pane is not adversely reduced.In particular, the combination of the heatable, transparent film and this type of reflective layer, which is a reflective coating consisting of a sequence of dielectric layers with alternating refractive indices, can produce a composite pane with very high transmission in the visible spectral range. In contrast, the use of a metal-based layer can reduce the transmission in the visible spectral range of the composite pane. The dielectric layers can be based, for example, on silicon nitride, zinc oxide, tin-zinc oxide, silicon-metal mixed nitrides such as silicon zirconium nitride, silicon oxide, zirconium oxide, niobium oxide, hafnium oxide, tantalum oxide, tungsten oxide, or silicon carbide. These oxides and nitrides can be deposited stoichiometrically, substoichiometrically, or superstoichiometrically.The dielectric layers may contain dopants, for example, aluminum, zirconium, titanium, or boron. If the reflective layer is arranged on the inner surface of the inner pane, the dielectric layer sequence preferably comprises, starting from the inner surface of the inner pane and arranged one above the other in this order, at least one optically high-refractive-index layer with a refractive index of greater than or equal to 1.7 and one optically low-refractive-index layer with a refractive index of less than or equal to 1.6. Methods for determining refractive indices are known to those skilled in the art. Refractive indices can be determined, for example, by means of ellipsometry, for which commercially available ellipsometers can be used.The layers of the dielectric layer sequence can be applied using physical or chemical vapor deposition, i.e., using PVD or CVD processes (PVD: physical vapor deposition, CVD: chemical vapor deposition). Corresponding dielectric layer sequences with alternating refractive indices are known, for example, from WO 2023 / 052065A1.

[0050] According to one embodiment, the reflective polymer film comprises or consists of at least one dielectric polymer layer. The dielectric polymer layer preferably contains polyethylene terephthalate or polycarbonate. If the reflective layer is formed as a reflective film, it is preferably 30 μm to 300 μm thick, more preferably 50 μm to 200 μm thick, and even more preferably 100 μm to 150 μm thick. For example, the reflective layer is a reflective film that functions based on synergistically interacting prisms and reflective polarizers. Such reflective films for use as a reflective layer are commercially available, for example, from the 3M Company.The invention further relates to a display system for a vehicle, comprising the composite pane according to the invention, wherein the composite pane has at least one display area, and at least one imaging unit which is directed onto the display area and irradiates it with p-polarized radiation.

[0051] As is usual with display systems of this type, the imaging unit irradiates an area of ​​the composite pane where the radiation is reflected towards the viewer (driver), creating a virtual image which the viewer perceives from behind the composite pane. The area of ​​the composite pane that can be irradiated or is irradiated by the imaging unit is referred to as the display area. The composite pane has at least one such display area. The at least one imaging unit is therefore directed at the at least one display area. During operation, the at least one imaging unit emits p-polarized radiation and irradiates the at least one display area with this p-polarized radiation.

[0052] The display system according to the invention is operated with p-polarized radiation. This means that the radiation from the at least one imaging unit is predominantly p-polarized, i.e., has a proportion of p-polarized radiation of more than 50%, preferably at least 80%, particularly preferably at least 95%. In particular, the radiation is essentially purely p-polarized—the p-polarized radiation proportion is therefore 100% or deviates only insignificantly therefrom. The direction of polarization 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 spanned by the incidence vector and the surface normal of the composite pane at a point within the display area, preferably in the geometric center of the display area. Due to the pane curvature common in the automotive sector, which affects the plane of incidence and thus the definition of polarization, the polarization components (in particular the ratio of p-polarized radiation to s-polarized radiation or vice versa) can differ from this reference point at other locations. To generate the desired polarized radiation, a polarization filter or a polarizing beam splitter, for example, can be arranged between the imaging unit and the composite pane in the beam path if the imaging unit itself does not already provide radiation of the desired polarization direction.

[0053] The imaging unit is preferably a projector or a screen ("display", electronic display). In principle, any type of screen can be used for the display system according to the invention, for example a field emission display (FED), a liquid crystal display (LCD), a thin-film transistor display (TFT-LCD), a cathode ray tube display (CRT), a plasma display, an organic light-emitting diode (OLED), a (true) LED display, or a surface-conduction electron emitter display (SED). OLED and LCD screens are particularly common. Projectors are particularly common and preferred for head-up displays.

[0054] In HUD projectors, the beam direction can typically be varied using mirrors, particularly vertically, to adapt the projection to the viewer's height. The area in which the viewer's eyes must be located for a given mirror position is called the eyebox window. This eyebox window can be moved vertically by adjusting the mirrors, with the entire accessible area (i.e., the superimposition of all possible eyebox windows) being referred to as the eyebox. A viewer located within the eyebox can perceive the virtual image. This, of course, means that the viewer's eyes must be within the eyebox, not their entire body. The technical terms used here from the field of HUDs are generally familiar to those skilled in the art.For a detailed description, please refer to the dissertation “Simulation-based measurement technology for testing head-up displays” by Alexander Neumann at the Institute of Computer Science at the Technical University of Munich (Munich: University Library of the TU Munich, 2012), in particular to Chapter 2 “The head-up display”.

[0055] The at least one imaging unit is directed at the at least one display area of ​​the windshield. It is arranged on the interior side of the laminated pane and irradiates the laminated pane via the inner surface of the inner pane. When the display system is in operation, the radiation emitted by the imaging unit irradiates the display area to generate the projection or display image. The radiation from the imaging unit lies in the visible spectral range of the electromagnetic spectrum, in particular in the spectral range from 450 nm to 650 nm - typical imaging units operate with wavelengths of 473 nm, 550 nm, and 630 nm (RGB). The angle of incidence of the radiation onto the laminated pane is preferably from 45° to 70°, particularly preferably from 60° to 70°, for example approximately 65°. These angles of incidence deviate only slightly from the Brewster angle.The Brewster angle for an air-glass transition in the case of soda-lime glass, which is generally used for window panes, is 57.2° (with a refractive index of soda-lime glass of 1.55 at a wavelength of 550 nm). The angle of incidence can also be referred to as the angle of incidence. It is the angle between the incidence vector of the radiation and the interior-side surface normal (i.e. the surface normal to the inner surface of the inner pane) determined at a point in the display area, preferably in the geometric center of the display area. If the angle of incidence corresponds exactly to the Brewster angle, only s-polarized radiation is reflected, not p-polarized radiation. In an advantageous embodiment, the angle of incidence deviates from the Brewster angle by a maximum of 10°.

[0056] Since the angle of incidence typically does not deviate significantly from the Brewster angle, p-polarized radiation is generally not reflected, or only reflected to a small extent, by the external surfaces of the composite pane (outer surface of the outer pane and inner surface of the inner pane). The reflection at the inner surface of the inner pane is due almost exclusively to the reflective layer, insofar as this is arranged there according to a preferred embodiment. No (significant) further reflection occurs at the outer surface of the outer pane, which would lead to a ghost image when using s-polarized radiation. It is therefore not necessary to arrange the external surfaces at an angle to one another, as is common when using s-polarized radiation, in order to superimpose the two reflections or, if possible, to align them.Instead, the composite pane and its components (outer pane, inner pane, intermediate layers) preferably have a constant thickness. The outer surface of the outer pane and the inner surface of the inner pane are preferably aligned parallel to one another. The use of relatively expensive wedge films or wedge-shaped panes can be dispensed with. However, it is not excluded that a wedge film can still be used, for example to align a low-intensity ghost image, caused by reflection on the outer surface of the outer pane as a result of a deviation from the Brewster angle, with the main image. In addition to avoiding ghost images, the use of p-polarized radiation also has the advantage that the displayed image is visible to wearers of polarization-selective sunglasses, which typically only allow p-polarized radiation to pass through and block s-polarized radiation.

[0057] The invention further relates to a method for producing a composite pane according to the invention, wherein at least a) a layer stack is provided which comprises at least in the following order: an outer pane with an outer surface and an inner surface, a first thermoplastic intermediate layer, a heatable, transparent film, a second thermoplastic intermediate layer, an inner pane with an outer surface and an inner surface, and a reflective layer on the outer surface of the inner pane or on the inner surface of the inner pane, and b) the layer stack is connected by lamination.

[0058] The heatable, transparent film can be provided as described in WO 2016 / 172315 A1, WO 2020 / 102392 A1 and / or WO 2022 / 081756 A1 and arranged in the layer stack.

[0059] If, according to one embodiment, the reflective layer is formed as a reflective coating, it is preferably applied to the outer surface of the inner pane or to the inner surface of the inner pane by physical vapor deposition (PVD), particularly preferably by cathode sputtering (“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), for example plasma-enhanced vapor deposition (PECVD), by vapor deposition, or by atomic layer deposition (ALD). The coating is preferably applied to the inner pane before lamination. If, according to a further embodiment, the reflective layer is a coated, reflective film, the CVD or PVD coating process can also be used for production.

[0060] The layer stack can be laminated using common lamination processes. For example, so-called autoclave processes can be carried out at an elevated pressure of approximately 10 bar to 15 bar and temperatures of 130 °C to 145 °C for approximately 2 hours. Alternatively, autoclave-free processes are also possible. Conventional vacuum bag or vacuum ring processes, for example, operate at approximately 200 mbar and 80 °C to 110 °C. The layer stack can also be pressed into a composite pane in a calender between at least one pair of rollers. Systems of this type are known for the production of composite panes and usually have at least one heating tunnel upstream of a press. The temperature during the pressing process can range, for example, from 40 °C to 150 °C. Combinations of calender and autoclave processes have proven particularly successful in practice. Alternatively, vacuum laminators can be used.These consist of one or more heatable and evacuatable chambers in which the outer pane and the inner pane are laminated within, for example, about 60 minutes at reduced pressures of 0.01 mbar to 800 mbar and temperatures of 80 °C to 170 °C.

[0061] The embodiments described above in connection with the composite pane according to the invention also apply in the same way to the method according to the invention.

[0062] The invention further relates to the use of the laminated pane according to the invention as interior glazing or exterior glazing in a vehicle or a building, in particular as a vehicle pane in means of transport for traffic on land, in the air or on water, in particular in motor vehicles and in particular as a windshield which serves as a projection surface.

[0063] The various embodiments of the invention can be implemented individually or in any combination. In particular, the features mentioned above and those to be explained below can be used not only in the specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention. The invention is explained in more detail 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. They show:

[0064] Fig. 1 is a plan view of an embodiment of a composite pane 100 according to the invention,

[0065] Fig. 2 shows a cross section through the embodiment of a composite pane 100 according to the invention shown in Fig. 1 along the dashed line XX',

[0066] Fig. 3 shows a cross section through an embodiment of a heatable, transparent film 4 according to the invention,

[0067] Fig. 4 shows a cross section through a further embodiment of a heatable, transparent film 4 according to the invention,

[0068] Fig. 5 is a plan view of an embodiment of a metal mesh layer 8 according to the invention,

[0069] Fig. 6 shows a cross section through a further embodiment of a heatable, transparent film 4 according to the invention,

[0070] Fig. 7 shows a cross section through a further embodiment of a heatable, transparent film 4 according to the invention,

[0071] Fig. 8 shows a cross section through an embodiment of a display system 200 according to the invention, which comprises a composite pane 100 according to Figure 2, and

[0072] Fig. 9 shows an embodiment of a method according to the invention using a flow chart.

[0073] Fig. 1 shows a plan view of an embodiment of a composite pane 100 according to the invention, and Fig. 2 shows the cross-section through the embodiment of a composite pane 100 according to the invention shown in Fig. 1 along the section line XX'. In the embodiment shown in Fig. 1, the composite pane 100 has an upper edge O, a lower edge U and two side edges S. As shown in Fig. 2, the composite pane 100 comprises in this order an outer pane 1 with an outer surface I and an inner surface II, a first thermoplastic intermediate layer 3, a heatable, transparent film 4, a second thermoplastic intermediate layer 5, an inner pane 2 with an outer surface III and an inner surface IV, and a reflective layer 6 on the inner surface IV of the inner pane 2. In the embodiment shown in Fig.In the embodiment shown in Figures 1 and 2, the heatable, transparent film 4 is arranged over the entire surface between the first thermoplastic intermediate layer 3 and the second thermoplastic intermediate layer 5, and the reflective layer 6 is arranged over the entire surface of the inner surface IV of the inner pane 2. According to alternative embodiments, however, the heatable, transparent film 4 and the reflective layer 6 can each be formed only in sections.

[0074] For example, the outer pane 1 is made of soda-lime glass and is 2.1 mm thick. The inner pane 2 is made of soda-lime glass and is 1.6 mm thick.

[0075] In the embodiment shown in Figs. 1 and 2, the first thermoplastic intermediate layer 3 and the second thermoplastic intermediate layer 5 are formed, for example, from a polyvinyl butyral (PVB) film and are each 0.38 mm thick.

[0076] In the embodiment shown in Figs. 1 and 2, the heatable, transparent film 4 consists, for example, of a heatable, transparent film that can be produced according to WO 2016 / 172315 A1, WO 2020 / 102392 A1, and / or WO 2022 / 081756 A1. In particular, the heatable, transparent film 4 preferably has a thickness in a range from 50 pm to 350 pm.

[0077] The embodiment of a composite pane 100 according to the invention shown in Figs. 1 and 2 can be used, for example, as a windshield of a vehicle.

[0078] Fig. 3 shows a cross section through an embodiment of a heatable, transparent film 4 according to the invention. The heatable, transparent film 4 shown comprises a polymer film 7 and a metal mesh layer 8, wherein the metal mesh layer 8 is arranged on the polymer film 7.

[0079] In this embodiment, the metal mesh layer 8 is depicted as a continuous surface for the sake of simplicity. However, the metal of the metal mesh layer 8 preferably covers at most 40%, more preferably at most 25%, of the surface of the polymer film 7 in the plan view of the heatable, transparent film 4 or polymer film, thereby ensuring advantageous transparency of the heatable, transparent film 4.

[0080] The metal mesh layer 8 preferably has a thickness in a range from 0.5 μm to 10 μm. The metal of the metal mesh layer 8 is selected, for example, from copper or silver, since this allows particularly good electrical conductivity to be achieved. The polymer film 7 preferably has a thickness in a range from 55 μm to 300 μm, whereby good mechanical stability of the heatable, transparent film 4 can be achieved. The polymer of the polymer film 7 is selected, for example, from polyethylene terephthalate or polycarbonate.

[0081] Fig. 4 shows a cross-section of a further embodiment of a heatable, transparent film 4 according to the invention. The heatable, transparent film 4 shown in cross-section in Fig. 4 differs from that shown in Fig. 3 in that it further comprises a layer with electrically conductive fibers 12 arranged on the metal mesh layer 8. Accordingly, in this embodiment, the metal mesh layer 8 is arranged between the polymer film 7 and the layer with the electrically conductive fibers 12. For the sake of simplicity, the metal mesh layer 8 and the layer with the electrically conductive fibers 12 are shown as continuous surfaces. However, according to a preferred embodiment, the layer with the electrically conductive fibers 12 fills the free area of ​​the metal mesh layer 8 that is not occupied by the metal of the metal mesh layer 8 on the surface of the polymer film 7.This can increase the electrical conductivity of the heatable, transparent film 4. In a preferred embodiment, the layer with the electrically conductive fibers 12 comprises a binder. The electrically conductive fibers 12 are preferably carbon nanotubes, in particular single-walled carbon nanotubes with a diameter of 0.7 nm to 1.4 nm and a length of 0.3 pm to 3 pm. By using carbon nanotubes, the metal mesh layer 8 can be particularly advantageously stabilized and, moreover, the electrical conductivity of the heatable, transparent film 4 can be improved.

[0082] Fig. 5 shows a plan view of an embodiment of a metal mesh layer 8 according to the invention. The metal mesh layer 8 shown is formed from metal lines 9 arranged in a diamond pattern 10. The metal mesh layer 8 preferably has a thickness in a range from 0.5 μm to 10 μm. This means that a metal line 9 also preferably has a thickness, i.e., a height, starting from the surface of the polymer film 7, in a range from 0.5 μm to 10 μm. The line width of a metal line 9 is preferably from 1 μm to 7 μm. The distance between two metal lines 9 is preferably from 200 μm to 400 μm. This geometric arrangement and the corresponding dimensions make it possible to obtain a mechanically stable metal mesh layer 8 while also having advantageous transparency. Fig. 6 shows a cross-section through a further embodiment of a heatable, transparent film 4 according to the invention.The heatable, transparent film 4 shown comprises a polymer film 7 and a layer with metal nanowires 11, wherein the layer with metal nanowires 11 is arranged on the polymer film 7.

[0083] In this embodiment, the layer with metal nanowires 11 is depicted as a continuous surface for the sake of simplicity. However, the metal nanowires 11 preferably cover at most 40%, more preferably at most 25%, of the surface of the polymer film 7 in the plan view of the heatable, transparent film 4 or polymer film, thereby ensuring advantageous transparency of the heatable, transparent film 4.

[0084] The layer with metal nanowires 11 preferably has a thickness in a range from 0.1 μm to 5 μm. The metal nanowires have a diameter in a range from 10 nm to 100 nm and a length in a range from 5 μm to 30 μm. This ensures advantageous transparency of the heatable, transparent film 4. The metal nanowires are preferably randomly arranged in the layer. The metal of the layer with metal nanowires 11 is selected, for example, from copper or silver, since this allows particularly good electrical conductivity to be achieved.

[0085] The polymer film 7 preferably has a thickness in a range of 55 μm to 300 μm, which allows good mechanical stability of the heatable, transparent film 4 to be achieved. The polymer of the polymer film 7 is selected, for example, from polyethylene terephthalate or polycarbonate.

[0086] Fig. 7 shows a cross-section of a further embodiment of a heatable, transparent film 4 according to the invention. The heatable, transparent film 4 shown in cross-section in Fig. 7 differs from that shown in Fig. 6 in that it further comprises a layer with electrically conductive fibers 12 arranged on the layer with metal nanowires 11. Accordingly, in this embodiment, the layer with metal nanowires 11 is arranged between the polymer film 7 and the layer with the electrically conductive fibers 12. For the sake of simplicity, the layer with metal nanowires 11 and the layer with the electrically conductive fibers 12 are shown as continuous surfaces. However, according to a preferred embodiment, the layer with the electrically conductive fibers 12 fills the free spaces between the metal nanowires of the layer with metal nanowires 11.This can increase the electrical conductivity of the heatable, transparent film 4. In a preferred embodiment, the layer with the electrically conductive fibers 12 comprises a binder. The electrically conductive fibers 12 are preferably carbon nanotubes, in particular single-walled carbon nanotubes with a diameter of 0.7 nm to 1.4 nm and a length of 0.3 pm to 3 pm. By using carbon nanotubes, the layer with metal nanowires 11 can be particularly advantageously stabilized and, moreover, the electrical conductivity of the heatable, transparent film 4 can be improved.

[0087] Fig. 8 shows a cross section through an embodiment of a display system 200 according to the invention, which comprises a composite pane 100 according to Figure 2, wherein the composite pane 100 has a display area A. The display system 200 also comprises an imaging unit 13, which is directed onto the display area A of the composite pane 100 and irradiates it with p-polarized radiation.

[0088] The display area A is arranged in the view-through area of ​​the composite pane 100. The imaging unit 13 is a projector operated with p-polarized radiation. The imaging unit 13 irradiates the display area A, whereby a display image is projected directly into the field of vision of the observer 14 (vehicle driver) as a virtual image on the side of the composite pane 100 facing away from them when their eyes are within the so-called eyebox E. Such a display system is also referred to as a "head-up display" (HUD). This allows the observer 14 to be shown, in particular, status information (e.g., driving speed), navigation instructions (e.g., speed limits or directions), or warning symbols without having to take their eyes off the road.

[0089] The imaging unit 13 irradiates the display area A at an angle of incidence α, measured relative to the interior surface normal of the inner pane. The angle of incidence α is, for example, 65°, which is comparatively close to the Brewster angle (approximately 57° for an air-soda-lime glass transition). The p-polarized radiation of the imaging unit 13 is therefore not significantly reflected by the glass surfaces.

[0090] Fig. 9 shows an embodiment of the method according to the invention for producing a composite pane 100 according to the invention using a flow diagram, wherein at least P1 a layer stack is provided which comprises at least in the following order: an outer pane 1 with an outer surface I and an inner surface II, a first thermoplastic intermediate layer 3, a heatable, transparent film 4, a second thermoplastic intermediate layer 5, an inner pane 2 with an outer surface III and an inner surface IV, and a reflective layer 6 on the outer surface III of the inner pane 2 or on the inner surface IV of the inner pane 2, and

[0091] P2 the layer stack is connected by lamination.

[0092] Examples

[0093] Example 1 : Heatability of the heatable, transparent film

[0094] A CHASM AgeNT®-1-G2 film from CHASM™ was used as the heatable, transparent film. This film comprises, in the following order: a polymer film 7 (made of polyethylene terephthalate, 100 μm thick), a metal mesh layer 8 (made of copper, with the metal mesh layer 8 formed of metal lines 9 in a diamond pattern 10, the thickness of the metal mesh layer 8 being 2 μm, the line width of a metal line 9 being 5 μm, and the distance between two metal lines 9 being 300 μm), and a layer of electrically conductive fibers 12 (containing single-walled carbon nanotubes).

[0095] The values ​​shown in Table 1 were determined for two different heating layouts for a voltage of 14 V and 42 V, respectively. The "engine edge to roof edge" heating layout means that the values ​​were measured at the edges of the film that are aligned toward the engine or the roof of the vehicle when the film is laminated into the laminated glass 100 mm. When measuring with the "A-pillar to A-pillar" heating layout, the values ​​were measured at the edges of the film that are aligned toward the A-pillars of the vehicle when the film is laminated into the laminated glass 100 mm. The values ​​shown in Table 1 were calculated for a windshield according to standard practice. The windshield had the following dimensions: Width (roof edge): 1264.09 mm Width (engine edge): 1482.43 mm

[0096] Height (center of roof edge to center of engine edge): 1005.28 mm

[0097] In particular, the specific heating output for the heating layout “engine edge to roof edge” is calculated as follows:

[0098] Pspec = U 2 / (R D ■ H 2 ) where P S p e z is the specific heating power, U is the voltage, R n is the sheet resistance and H is the height of the windshield between the upper busbar (“busbar”) and the lower busbar (i.e. busbar at the motor edge).

[0099] The total heating output for the heating layout “engine edge to roof edge” was calculated as follows:

[0100] Total heating output = heating surface ■ P spez with the

[0101] Heating area = | W(upper busbar) - W(lower busbar) | / 2 ■ H where W(upper busbar) is the width of the windshield along the upper busbar, W(lower busbar) is the width of the windshield along the lower busbar (ie busbar at the engine edge) and H is the height of the windshield between the two busbars.

[0102] The calculations for the heating layout “A-pillar to A-pillar” have been adjusted accordingly.

[0103] Table 1

[0104] As shown in Table 1, good heating performance can be achieved using CHASM AgeNT®-1-G2 foil with a sheet resistance of 1 Ω / n. For the 14 V application, for example, the heating power would be sufficient to prevent fogging of the laminated glass 100. At higher voltages, such as the 42 V used here, in combination with a DC / DC converter, very good heating performance is achieved.

[0105] Example 2: Laminated panes with heatable, transparent film

[0106] Laminated panes 1 to 4 were manufactured. They comprised, in the following order: an outer pane 1 (Planiclear® from Saint-Gobain Glass, soda-lime glass, light transmission TL of 91%, thickness: 2.1 mm), a first thermoplastic interlayer 3 (PVB, 0.38 mm), a heatable, transparent film 4 (as explained below), a second thermoplastic interlayer 5 (PVB, 0.38 mm), and an inner pane 2 (Planiclear® from Saint-Gobain Glass, soda-lime glass, light transmission TL of 91%, thickness: 2.1 mm).

[0107] The following heatable, transparent films were used as 4. One of these special films was laminated into each of the laminated panes 1 to 4.

[0108] Slides used:

[0109] CHASM AgENT®-1-G2 film from CHASM™:

[0110] Compare corresponding film under Example 1. CHASM AgeNT®-1-G3 film from CHASM™:

[0111] The CHASM AgeNT®-1-G3 film from CHASM™ is largely identical to the CHASM AgeNT®-1-G2 film from CHASM™ described above and differs from it in that the distance between two metal lines is 9,100 pm.

[0112] CHASM AgeNT™-30 film from CHASM™: a polymer film 7 (made of polyethylene terephthalate, 127 pm thick), a layer of metal nanowires 11 (silver nanowires, randomly arranged, layer thickness: 0.3 pm), and a layer of electrically conductive fibers 12 (containing single-walled carbon nanotubes).

[0113] CHASM AgeNT™-75 film from CHASM™: a polymer film 7 (made of polyethylene terephthalate, 127 pm thick), a layer of metal nanowires 11 (silver nanowires, randomly arranged, layer thickness: 0.2 pm), and a layer of electrically conductive fibers 12 (containing single-walled carbon nanotubes).

[0114] Table 2 shows the laminated panes 1 to 4 with the corresponding films:

[0115] Table 2

[0116] Additionally, a laminated pane was produced as a reference that did not include a heatable transparent film. The reference laminated pane comprised, in the following order: an outer pane 1 (Planiclear® from Saint-Gobain Glass, soda-lime glass, light transmission TL of 91%, thickness: 2.1 mm), a first thermoplastic interlayer 3 (PVB, 0.38 mm), a second thermoplastic interlayer 5 (PVB, 0.38 mm), and an inner pane 2 (Planiclear® from Saint-Gobain Glass, soda-lime glass, light transmission TL of 91%, thickness: 2.1 mm).

[0117] In Table 3 is / are

[0118] R n the sheet resistance, measured with a four-point resistance meter;

[0119] TL(A) the integrated light transmission according to ISO 9050 (illuminant A);

[0120] TT905 the integrated light transmission according to ISO 9050 (illuminant A) at a wavelength of 905 nm;

[0121] TT1550 the integrated light transmission according to ISO 9050 (illuminant A) at a wavelength of 1550 nm;

[0122] RL(A)j is the integrated light reflection, measured on the interior side with an angle of incidence of 8° and an observation angle of 2° (illuminant A);

[0123] RL(A) a the integrated light reflection, measured externally with an angle of incidence of 8° and an observation angle of 2° (illuminant A);

[0124] TTS the total radiated solar energy measured according to ISO 13837;

[0125] Tr is the turbidity, measured with a turbidity meter;

[0126] L*j is the brightness and a* and b* are the values ​​of the reflected color in the L*a*b* color space, measured indoors with an angle of incidence of 8° and an angle of observation of 2° (illuminant A); and

[0127] L* a the brightness and a* a and b* a the values ​​of the reflection color in the L*a*b* color space, measured externally with an angle of incidence of 8° and an observation angle of 2° (illuminant A).

[0128] As shown in Table 3, all laminated glass units 1 to 4 exhibit favorable optical properties. In particular, all laminated glass units 1 to 4 meet a light transmission of at least 70% according to ECE-R43, exhibit low haze, similar internal and external reflectance, and neutral color values ​​a* and b*.

[0129] By using the heatable, transparent film, the thermal properties of the laminated pane can also be improved, as shown in Table 3. In particular, laminated panes 1 to 4 exhibit lower TTS values ​​compared to the reference laminated pane. Table 3

[0130] List of reference symbols:

[0131] 1 outer pane

[0132] 2 inner pane

[0133] 3 first thermoplastic intermediate layer

[0134] 4 heatable, transparent film

[0135] 5 second thermoplastic intermediate layer

[0136] 6 reflective layer

[0137] 7 Polymer film

[0138] 8 metal mesh layer

[0139] 9 metal lines

[0140] 10 diamond patterns

[0141] 11 layer with metal nanowires

[0142] 12 electrically conductive fibers

[0143] 13 imaging unit

[0144] 14 viewers / vehicle drivers

[0145] 100 composite panes

[0146] 200 display system

[0147] I Outer surface of the outer pane 1

[0148] II Inner surface of the outer pane 1

[0149] III Outer surface of the inner pane 2

[0150] IV Inner surface of the inner pane 2

[0151] A display area

[0152] E Eyebox

[0153] O top edge

[0154] U bottom edge

[0155] S side edge a angle of incidence

[0156] XX' cutting line

Claims

Patent claims 1. Composite pane (100), at least comprising in the following order: an outer pane (1) with an outer surface (I) and an inner surface (II), a first thermoplastic intermediate layer (3), a heatable, transparent film (4), a second thermoplastic intermediate layer (5), an inner pane (2) with an outer surface (III) and an inner surface (IV), and a reflective layer (6) on the outer surface (III) of the inner pane (2) or on the inner surface (IV) of the inner pane (2), wherein the reflective layer (6) is suitable for reflecting p-polarized radiation.

2. Composite pane (100) according to claim 1, wherein the reflective layer (6) is a reflective coating which represents a dielectric layer sequence with alternating refractive indices.

3. Composite pane (100) according to claim 1 or 2, wherein the heatable, transparent film (4) comprises a polymer film (7).

4. Composite pane (100) according to one of claims 1 to 3, wherein the heatable, transparent film (4) comprises a metal mesh layer (8).

5. Composite pane (100) according to claim 4, wherein the metal mesh layer (8) is formed from metal lines (9) and the line width of a metal line (9) is from 1 pm to 7 pm.

6. Composite pane (100) according to claim 5, wherein the metal lines (9) are arranged in a diamond pattern (10).

7. Composite pane (100) according to one of claims 1 to 3, wherein the heatable, transparent film (4) comprises a layer with metal nanowires (11), wherein the metal nanowires have a diameter in a range of 10 nm to 100 nm and a length in a range of 5 pm to 30 pm.

8. Composite pane (100) according to one of claims 4 to 7, wherein the heatable, transparent film (4) comprises a layer with electrically conductive fibers (12) which at least partially covers the metal mesh layer (8) or the layer with metal nanowires (11).

9. Composite pane (100) according to one of claims 4 to 8, wherein the metal of the metal mesh layer (8) or the layer with metal nanowires (11) is selected from copper or silver.

10. Composite pane (100) according to one of claims 3 to 9, wherein the polymer of the polymer film (7) comprises polyethylene terephthalate or polycarbonate.

11. Composite pane (100) according to one of claims 8 to 10, wherein the electrically conductive fibers (12) comprise carbon nanotubes, preferably single-walled carbon nanotubes with a diameter of 0.7 nm to 1.4 nm and a length of 0.3 pm to 3 pm.

12. Composite pane (100) according to one of claims 1 to 11, wherein the reflective layer (6) is arranged on the inner surface (IV) of the inner pane (2).

13. A display system (200) for a vehicle, comprising the composite pane (100) according to any one of claims 1 to 12, wherein the composite pane (100) has at least one display area (A) and at least one imaging unit (13) directed onto the display area (A) and irradiating it with p-polarized radiation.

14. A method for producing a composite pane (100) according to one of claims 1 to 12, wherein at least a) a layer stack is provided which comprises at least in the following order: an outer pane (1) with an outer surface (I) and an inner surface (II), a first thermoplastic intermediate layer (3), a heatable, transparent film (4), a second thermoplastic intermediate layer (5), an inner pane (2) with an outer surface (III) and an inner surface (IV), and a reflection layer (6) on the outer surface (III) of the inner pane (2) or on the inner surface (IV) of the inner pane (2), and b) the layer stack is connected by lamination.

15. Use of a composite pane (100) according to one of claims 1 to 12 as interior glazing or exterior glazing in a vehicle or a building, in particular as a vehicle pane in means of transport for traffic on land, in the air or on water, in particular in motor vehicles and in particular as a windscreen which serves as a projection surface.

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