Composite pane having a reflective coating provided in parts

Abstract

The present invention relates to a composite pane (100) at least comprising: an outer pane (1) and an inner pane (2), which are connected to one another by means of a thermoplastic intermediate layer (3); a masking layer (4) provided in a first sub-region (A) of the composite pane (100); and a reflective coating (5) provided on the interior-side surface (IV) of the inner pane (2), wherein the reflective coating (5) is provided in a second sub-region (B) of the composite pane (100) which, in a perpendicular view through the composite pane (100), lies completely in the first sub-region (A). Starting from the interior-side surface (IV) of the inner pane (2), the reflective coating (5) consists, in the specified order, of: a base layer (6) having a refractive index of greater than 1.9 and a thickness of 30 nm to 100 nm; a functional layer (7) consisting of, in an alternating layer sequence, optically high-refraction layers (9) having a refractive index of greater than 1.9 and a thickness of between 50 nm and 150 nm and optically low-refraction layers (10) having a refractive index of less than 1.6 and a thickness of 50 nm to 150 nm; and a cover layer (8) having a refractive index of less than 1.6 and a thickness of 10 nm to 150 nm, the cover layer being based on silicon oxide, doped silicon oxide, magnesium fluoride or potassium fluoride. The alternating layer sequence of the functional layer (7) begins with an optically high-refraction layer (9) immediately adjacent to the base layer (6) and ends with an optically low-refraction layer (10) immediately adjacent to the cover layer (8), and the functional layer (7) comprises at least three optically high-refraction layers (9) and at least three optically low-refraction layers (10).

Description

[0001] Composite pane with area-by-area reflective coating

[0002] The invention relates to a composite disc with a reflective coating arranged in certain areas and its use, as well as a projection arrangement.

[0003] To display navigation information on windshields, projection systems known as head-up displays (HUDs) are frequently used. These consist of an image display device and a windshield with a wedge-shaped thermoplastic interlayer and / or wedge-shaped lenses. A wedge angle is necessary to prevent double images. The projected image appears as a virtual image at a certain distance from the windshield, so that the driver perceives, for example, the projected navigation information as being directly in front of them on the road. The radiation from HUD image display devices is typically s-polarized due to the windshield's superior reflective properties compared to p-polarization.However, if the viewer is wearing polarization-selective sunglasses that do not transmit s-polarized light, they will perceive the HUD image only as dimly lit, if at all. One solution to this problem is the use of projection setups that utilize p-polarized light.

[0004] DE 10 2014 220 189 A1 discloses a head-up display projection arrangement that operates with p-polarized radiation, wherein the windshield has a reflective structure that reflects p-polarized radiation towards the viewer. US 20040135742 A1 also discloses a head-up display projection arrangement using p-polarized radiation that has a reflective structure. WO 96 / 19347A3 proposes a multilayer polymer layer as the reflective structure.

[0005] WO 2021 / 122848 A1 discloses a HUD system comprising a light source projecting p-polarized light onto a glazing, wherein the glazing comprises an outer glass pane with a first surface and a second surface and an inner glass pane with a first surface and a second surface, wherein the second surface of the inner glass pane comprises a reflective coating, both panes are joined by at least one layer of interlayer material, the reflective coating comprising at least one high refractive index layer with a thickness of 50 to 100 nm and at least one low refractive index layer with a thickness of 70 to 160 nm, wherein the at least one high refractive index layer comprises at least one of an oxide of Zr, Nb, Sn, a mixed oxide of Ti, Zr, Nb, Si, Sb, Sn, Zn, In, a nitride of Si, Zr and a mixed nitride of Si, Zr.

[0006] WO 2021 / 145387 A1 discloses a HUD system wherein the composite lens is provided in certain areas with a reflective element for p-polarized light. The reflective element can be a reflective film for p-polarized light, which is attached to the inner surface of the inner lens by means of an adhesion promoter layer, or a reflective coating for p-polarized light arranged on the inner surface of the inner lens, wherein the reflective coating comprises at least one layer of a material with a high refractive index and at least one layer of a material with a low refractive index.

[0007] CN 114035322 A discloses a head-up display glass comprising laminated glass, wherein the laminated glass comprises a first surface and a second surface opposite each other, the second surface comprising a display area and a non-display area, wherein the display area is provided with a first nanofilm having at least one first layer with a high refractive index and at least one first layer with a low refractive index stacked successively from the second surface outwards, wherein the refractive index of the first layer with the high refractive index is 1.9 to 2.7 and the refractive index of the first layer with the low refractive index is 1.3 to 1.8.

[0008] CN 117289468 A discloses a head-up display glass consisting of laminated glass and a transparent nanofilm, wherein the transparent nanofilm can reflect p-polarized light and the outermost protective layer of the transparent nanofilm is a SiZrO₂ x -layer or a SiZrMOy layer.

[0009] EP 4 265 411 A1 discloses a head-up display glass and a head-up display system. The head-up display glass consists of an outer surface and an inner surface opposite the outer surface. A transparent nanofilm, used to reflect p-polarized light, is arranged on the inner surface. The transparent nanofilm comprises a first layer with a high refractive index, a second layer with a high refractive index, a first layer with a low refractive index, a third layer with a high refractive index, and a second layer with a low refractive index, stacked successively on the inner surface.A refractive index of the first high-refractive-index layer, the second high-refractive-index layer, and the third high-refractive-index layer is each greater than 1.8, and a refractive index of the first low-refractive-index layer and the second low-refractive-index layer is each less than or equal to 1.8.

[0010] WO 2022 / 253659 A1 discloses a coated substrate comprising a transparent substrate provided with a p-polarized light-reflecting coating, a laminated glazing and a head-up display system comprising the coated substrate.

[0011] Reflective coatings can have the disadvantage of exhibiting low reflectivity for p-polarized light. When designing a display based on head-up display technology, it is also essential to ensure that the image display device has sufficient power so that the projected image, especially in sunlight, is bright enough and clearly visible to the viewer. This necessitates a larger image display device and entails correspondingly higher power consumption.

[0012] WO 2022 / 073894 A1 discloses a vehicle windscreen for a head-up display with an outer surface facing an external environment when installed and an inner surface facing a vehicle interior, comprising at least one transparent screen, at least one masking strip in an edge area of ​​the screen and at least one reflective layer applied by printing for reflecting light, which is arranged in the area of ​​the masking strip on the vehicle interior side of the masking strip.

[0013] WO 2022 / 073860 A1 discloses a vehicle windscreen for a head-up display with an outer surface facing an external environment when installed and an inner surface facing the vehicle interior, comprising at least one transparent pane, at least one masking strip in an edge region of the pane, and at least one light-directing device for directing light into the vehicle interior or at least one image display device for displaying image information, which is arranged in the area of ​​the masking strip, on the vehicle interior side of the masking strip. DE 10 2009 020 824 A1 discloses a virtual image system for windscreens that enables the reflection of an image source on the windscreen so that a virtual image free of ghosting is visible to the driver.Either a matte black material is applied to a windshield glass pane on any of the windshield surfaces of the outer glass pane, or on the windshield surface of the inner glass pane, or a black glossy layer is otherwise arranged on a windshield surface at the windshield frit, thereby providing the virtual image for any image source with real image rays incident on the windshield surface.

[0014] CN 117465203 A discloses a composite screen for a head-up display in which a functional reflective element is arranged in the area of ​​a masking, on the vehicle interior side of the masking.

[0015] The present invention is based on the objective of providing an improved composite disc with a reflective coating and an improved projection arrangement comprising such a composite disc.

[0016] The object of the present invention is achieved according to the invention by a composite disk and a projection arrangement according to the dependent claims. Preferred embodiments are described in the subclaims.

[0017] The composite disc according to the invention comprises an outer disc, a thermoplastic intermediate layer, a masking layer, an inner disc, and a reflective coating. The thermoplastic intermediate layer is arranged between the outer disc and the inner disc.

[0018] The laminated glass is designed to separate the interior of a vehicle from the outside environment within a window opening. For the purposes of this invention, the term "inner glass" refers to the pane of the laminated glass facing the vehicle interior. The term "outer glass" refers to the pane facing the outside environment.

[0019] The laminated glass pane has, in particular, a top edge and a bottom edge, as well as two side edges running between them. The top edge is the edge that is intended to point upwards when installed. The bottom edge is the edge that is intended to point downwards when installed. In the case of a windshield, the top edge is often also referred to as the roof edge and the bottom edge as the engine edge.

[0020] The outer pane and the inner pane each have an outer and an inner surface, and a circumferential side edge running between them. For the purposes of the invention, the outer surface is defined as the main surface intended to face the external environment when installed. The inner surface is defined as the main surface intended to face the interior when installed. The inner surface of the outer pane and the outer surface of the inner pane face each other and are connected by the thermoplastic intermediate layer.

[0021] The outer surface of the outer pane is designated as Side I. The inner surface of the outer pane is designated as Side II. The outer surface of the inner pane is designated as Side III. The inner surface of the inner pane is designated as Side IV.

[0022] According to the invention, the masking layer is arranged in a first sub-area of ​​the composite disc and the reflective coating is arranged in a second sub-area of ​​the composite disc, wherein the second sub-area lies completely within the first sub-area when viewed perpendicularly through the composite disc.

[0023] The masking layer is located between the outer pane and the inner pane, or on the outer surface of the outer pane.

[0024] According to the invention, the reflective coating is arranged on the interior surface of the inner pane.

[0025] Thus, when the laminated glass is installed in a vehicle, the reflective coating is closer to the vehicle interior than the masking layer. According to the invention, starting from the interior-facing surface of the inner pane, the reflective coating consists, in the specified order, of a base layer, a functional layer, and a top layer.

[0026] The base layer has a refractive index greater than 1.9 and a thickness of 30 nm to 100 nm.

[0027] The top layer has a refractive index of less than 1.6 and a thickness of 10 nm to 150 nm and is based on silicon oxide, doped silicon oxide, magnesium fluoride or calcium fluoride.

[0028] The silicon oxide can be doped with materials such as aluminum, zirconium, titanium, boron, or hafnium. Doping allows for the modification of the coating's optical, mechanical, and chemical properties.

[0029] According to the invention, the functional layer arranged between the base layer and the top layer consists of optically high-refractive-index layers with a refractive index greater than 1.9 and a thickness between 50 nm and 150 nm and optically low-refractive-index layers with a refractive index less than 1.6 and a thickness of 50 nm to 150 nm, arranged in an alternating layer sequence. The functional layer is arranged between the base layer and the top layer such that the alternating layer sequence of the functional layer begins with an optically high-refractive-index layer arranged immediately adjacent to the base layer and ends with an optically low-refractive-index layer arranged immediately adjacent to the top layer.

[0030] According to the invention, the functional layer has at least three optically high refractive index layers and at least three optically low refractive index layers.

[0031] The functional layer is thus a stack of n optically high-refractive-index layers with a refractive index greater than 1.9 and a thickness between 50 nm and 150 nm, and n optically low-refractive-index layers with a refractive index less than 1.6 and a thickness of 50 nm to 150 nm, where n is a natural number greater than or equal to 3, and where the stack begins with an optically high-refractive-index layer and ends with an optically low-refractive-index layer. In a preferred embodiment, the functional layer consists of three optically high-refractive-index layers and three optically low-refractive-index layers.

[0032] In an alternative preferred embodiment, the functional layer consists of four optically high refractive index layers and four optically low refractive index layers.

[0033] In an alternative preferred embodiment, the functional layer consists of five optically high refractive index layers and five optically low refractive index layers.

[0034] The functional layer can also consist of more than five optically high-refractive layers and more than five optically low-refractive layers, where the number of optically high-refractive layers always corresponds to the number of optically low-refractive layers and vice versa.

[0035] The refractive index of the optically low-refractive-index layers of the functional layer is preferably at most 1.5, particularly preferably at most 1.45. For example, the refractive index of the optically low-refractive-index layers is 1.45. This value has proven to be particularly advantageous with regard to the reflection properties of the composite disk.

[0036] The individual low-refractive-index layers of the functional layer can be based on different materials or all on the same material. Suitable materials include, for example, silicon dioxide, doped silicon dioxide, magnesium fluoride, or calcium fluoride. Preferably, the low-refractive-index layers of the functional layer are all based on silicon dioxide, doped silicon dioxide, magnesium fluoride, or calcium fluoride. The silicon dioxide can be doped with, for example, aluminum, zirconium, titanium, boron, or hafnium. Doping allows for the adjustment of the optical, mechanical, and chemical properties of the coating. Preferably, the individual low-refractive-index layers of the functional layer are all on the same material.

[0037] The individual optically low-refractive-index layers of the functional layer can have different thicknesses or all be the same thickness. Preferably, the individual optically low-refractive-index layers of the functional layer all have substantially the same thickness. According to the invention, three or more layers have substantially the same thickness if the thicknesses of the individual layers differ from each other by no more than 5%.

[0038] The base layer preferably has a thickness of 50 nm to 80 nm.

[0039] In a preferred embodiment, the base layer contains or consists of silicon nitride, a silicon-zirconium mixed nitride, or titanium oxide. The silicon nitride, silicon-zirconium mixed nitride, or titanium oxide can be undoped or doped, for example with aluminum, zirconium, titanium, boron, or hafnium.

[0040] The individual high-refractive-index layers of the functional layer can be based on different materials or all be made of the same material. Suitable materials include silicon nitride, silicon-zirconium mixed nitride, or titanium oxide. The silicon nitride, silicon-zirconium mixed nitride, or titanium oxide can be undoped or doped, for example, with aluminum, zirconium, titanium, boron, or hafnium. Preferably, the individual high-refractive-index layers of the functional layer are all made of the same material.

[0041] The individual optically high-refractive-index layers of the functional layer can have different thicknesses or all be the same thickness. Preferably, the individual optically high-refractive-index layers of the functional layer all have essentially the same thickness.

[0042] The base layer and / or the optically high-refractive layers can therefore independently contain or consist of silicon nitride, a silicon-zirconium mixed nitride or titanium oxide, which may be undoped or doped.

[0043] Preferably, the top layer has a thickness of 20 nm to 140 nm.

[0044] Refractive indices are generally specified within the scope of the present invention with reference to a wavelength of 550 nm. Methods for determining refractive indices are known to those skilled in the art. The refractive indices specified within the scope of the invention can be determined, for example, by ellipsometry, using commercially available ellipsometers. Unless otherwise specified, the specification of layer thicknesses or thicknesses refers to the geometric thickness of a layer. The reflective coating is preferably applied substantially in the form of a quadrilateral, more preferably in the form of a rectangle, a parallelogram, or a trapezoid, extending in a region near the lower edge between the two side edges of the composite disk. More preferably, the edges of the reflective coating do not extend to the side edges and the lower edge of the composite disk, but are, for example, spaced 2 cm to 5 cm away from them.

[0045] The reflective coating is arranged in a second sub-area of ​​the composite pane, as described above. The reflective coating therefore does not extend over the entire composite pane. Consequently, the reflective coating is smaller in its external dimensions, i.e., its width and length, than the outer and inner panes of the composite pane. The reflective coating preferably extends over a maximum of 30%, and more preferably over a maximum of 20%, of the composite pane.

[0046] As described above, in the composite glass according to the invention, a masking layer is arranged in a first sub-area of ​​the composite glass. Preferably, the masking layer is arranged in an edge region of the composite glass, which typically borders the edge of the glass. The major advantage of this arrangement arises when the composite glass is used in a vehicle as a windshield, since the masking layer, when arranged in an edge region, lies outside the driver's main field of vision.

[0047] The masking layer is preferably arranged at least along and adjacent to the lower edge. In one embodiment, this results in a rectangular strip arranged along the lower edge when viewed from above. The shape of the masking layer is not limited to a rectangular shape; it can also have other shapes.

[0048] In a particularly preferred embodiment of the composite disc according to the invention, the masking layer is formed in a frame-like circumferential shape. In a section where the reflective coating is arranged in overlap with the masking layer, the frame-shaped masking layer is preferably provided with a widening, i.e., it has a greater width (dimension perpendicular to its extent) than in other sections. In this way, the masking layer can be suitably adapted to the desired dimensions of the reflective coating.

[0049] In one embodiment, the masking layer is thus formed in a frame-like circumferential shape and has a greater width, in particular in a section that overlaps the reflective coating, than in sections different from this.

[0050] A frame-shaped, circumferential masking layer is preferably used to mask the bonding of the laminated glass, for example, as a windshield in a vehicle body. This ensures a harmonious overall appearance of the laminated glass when installed. Furthermore, such a masking layer provides UV protection for the adhesive material used.

[0051] An advantage of the invention is that the reflective coating is applied to the interior surface of the inner pane. Thus, with the exception of the interior surface of the inner pane, the surface on which the masking layer is to be placed can be freely selected according to customer requirements. In contrast, a reflective coating applied to the exterior surface of the inner pane or the interior surface of the outer pane could be obscured by a masking print located further towards the vehicle interior. This is avoided by the design according to the invention.

[0052] The masking layer according to the invention is a layer that prevents visibility through the composite pane. The masking layer allows a transmission of at most 5%, preferably at most 2%, particularly preferably at most 1%, and especially at most 0.1% of the visible spectrum light. The masking layer is therefore opaque, preferably black.

[0053] The masking layer is preferably a coating consisting of one or more layers. Alternatively, the masking layer can also be a colored area of ​​the thermoplastic intermediate layer. According to a preferred embodiment of the laminated glass, the masking layer consists of a single layer. This has the advantage of particularly simple and cost-effective manufacturing of the laminated glass, since only a single layer needs to be formed for the masking layer. 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 designed as an opaque covering print arranged on the interior surface of the outer pane, in particular made of a dark, preferably black, enamel.

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

[0056] In an alternative preferred embodiment, the masking layer is designed as an opaque cover print arranged on the outer surface of the outer disc, in particular made of a dark, preferably black, enamel.

[0057] In an alternative preferred embodiment, the masking layer is formed as an opaquely colored region of the thermoplastic interlayer. In one embodiment, the thermoplastic interlayer is formed in one piece and is opaquely colored in one region. A masking layer formed as an opaquely colored region of the thermoplastic interlayer can also be realized by using a thermoplastic interlayer composed of an opaque thermoplastic film and a transparent thermoplastic film. The opaque thermoplastic film and the transparent thermoplastic film are preferably arranged offset from one another so that the two films do not overlap when viewed through the laminated glass. The transparent and the opaque thermoplastic film are made of the same plastic or preferably contain the same plastic.The materials on which the opaque thermoplastic film and the transparent thermoplastic film can be based are those also described for the thermoplastic interlayer. The opaque thermoplastic film is preferably a colored film, which can have various colors, especially black.

[0058] The composite disc according to the invention is preferably curved in one or more directions in space, as is common for automotive windshields, with typical radii of curvature ranging from about 10 cm to about 40 m. However, the composite disc can also be flat, for example, if it is intended as a windshield for buses, trains, or tractors.

[0059] The thermoplastic interlayer, which connects the outer pane to the inner pane, contains at least one thermoplastic polymer, preferably ethylene vinyl acetate (EVA), polyvinyl butyral (PVB), or polyurethane (PU), or mixtures, copolymers, or derivatives thereof, particularly preferably PVB. The thermoplastic interlayer is typically formed from a thermoplastic film (bonding film). The thickness of the thermoplastic interlayer is preferably from 0.2 mm to 2 mm, particularly preferably from 0.3 mm to 1 mm, for example, 760 pm or 848 pm. The thermoplastic interlayer can be formed from a single film or from more than one film. The thermoplastic interlayer can also be a film with functional properties, for example, a film with acoustic damping properties.

[0060] 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.

[0061] The outer and inner panes can be clear and colorless, or tinted or colored. The outer and inner panes can be independently unstressed, partially stressed, or stressed. If at least one pane is to have a prestress, this can be thermal or chemical.

[0062] The composite glass according to the invention is preferably designed as a windshield. In a preferred embodiment, the total transmission through the windshield is greater than 70% in the main viewing area (light type A). The term total transmission refers to the method for testing the light transmittance of motor vehicle windows specified in ECE-R 43, Annex 3, Section 9.1.

[0063] It is understood that the first section of the laminated glass, in which the masking layer is located, is positioned outside the main viewing area of ​​the laminated glass. The outer and inner panes can have suitable coatings known per se, for example, anti-reflective coatings, non-stick coatings, anti-scratch coatings, photocatalytic coatings, solar control coatings, or low-E coatings.

[0064] The thickness of the outer and inner panes can vary widely and thus be adapted to the specific requirements. Preferably, the outer and inner panes have thicknesses of 0.5 mm to 5 mm, more 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 a thickness of 1.6 mm. However, the outer pane, or especially the inner pane, can also be made of thin glass with a thickness of, for example, 0.55 mm.

[0065] The composite pane according to the invention can comprise one or more additional intermediate layers, in particular functional intermediate layers. An additional intermediate layer can, in particular, be an intermediate layer with acoustic damping properties, an infrared radiation-reflecting intermediate layer, an infrared radiation-absorbing intermediate layer, a UV radiation-absorbing intermediate layer, an intermediate layer that is at least partially colored, and / or an intermediate layer that is at least partially tinted. If several additional intermediate layers are present, they can also have different functions. The additional intermediate layers are preferably arranged between the inner pane and the outer pane.

[0066] The invention also relates to a projection arrangement comprising at least a composite disk according to the invention and an imaging unit directed towards the reflective coating which emits p-polarized light, wherein the interior surface of the inner disk is the surface of the inner disk closest to the imaging unit.

[0067] According to the invention, a projection arrangement thus also comprises at least a composite disk, comprising at least

[0068] • an outer pane with an outer surface and an inner surface, and an inner pane with an outer surface and an inner surface, which are connected to each other via a thermoplastic intermediate layer,

[0069] • a masking layer arranged in a first sub-area of ​​the composite pane between the outer pane and the inner pane or on the outer surface of the outer pane, and

[0070] • a reflective coating arranged on the inner surface of the inner pane, wherein the reflective coating is arranged in a second sub-area of ​​the composite pane which, when viewed perpendicularly through the composite pane, lies entirely within the first sub-area, and the reflective coating is arranged in the specified sequence starting from the inner surface of the inner pane

[0071] - a base layer with a refractive index greater than 1.9 and a thickness of 30 nm to 100 nm,

[0072] - a functional layer consisting of optically high-refractive-index layers with a refractive index greater than 1.9 and a thickness between 50 nm and 150 nm arranged in an alternating layer sequence and optically low-refractive-index layers with a refractive index less than 1.6 and a thickness of 50 nm to 150 nm

[0073] - and a top layer with a refractive index of less than 1.6 and a thickness of 10 nm to 150 nm, which is based on silicon oxide, doped silicon oxide, magnesium fluoride or calcium fluoride, wherein the alternating layer sequence of the functional layer begins with an optically high refractive index layer arranged immediately adjacent to the base layer and ends with an optically low refractive index layer arranged immediately adjacent to the top layer, and the functional layer has at least three optically high refractive index layers and at least three optically low refractive index layers.

[0074] - and an imaging unit directed at the reflective coating, which emits p-polarized light, wherein the interior surface of the inner pane is the surface of the inner pane closest to the imaging unit. In particular, the combination of the reflective coating with the masking layer located behind it from the perspective of a vehicle occupant results in good image visibility in a projection arrangement according to the invention, even in external sunlight and when using low-luminosity imaging units. Even under these circumstances, the image generated by the imaging unit appears bright and is clearly recognizable. This allows for a reduction in the power consumption of the imaging unit and thus reduced energy consumption.

[0075] Because the reflective coating is located in a second sub-area of ​​the laminated glass, which, when viewed perpendicularly through the laminated glass, lies entirely within the first sub-area containing the opaque masking layer, the reflective coating has no section that is not overlapping with the masking layer. In other words, the reflective coating is only present where, when viewed through the laminated glass from the inside, it is located in front of the masking layer. From the perspective of a vehicle occupant, the reflective layer is thus spatially located in front of the masking layer. The area of ​​the laminated glass containing the reflective coating therefore appears opaque. The phrase "viewed perpendicularly through the laminated glass" means that the view is from the inside, i.e., the interior surface of the inner pane is the surface of the inner pane closest to the viewer.For the purposes of the present invention, "spatially further away" means that the reflective coating is arranged spatially further away from the outer surface of the outer pane than the masking layer. Preferably, the masking layer is widened at least in the area that overlaps with the reflective coating. This means that, viewed perpendicularly to the nearest section of the circumferential edge of the composite pane, the masking layer has a greater width in this area than in other sections.

[0076] The imaging unit serves to project an image and can therefore also be referred to as a projector, display device, or image display device. For example, a display or another device known to those skilled in the art can be used as the imaging unit. Preferably, the imaging unit is a display, particularly preferably an LCD display, LED display, OLED display, or electroluminescent display, especially an LCD display. Displays have a low profile and are thus easy and space-saving to integrate into the dashboard of a vehicle. Furthermore, displays are significantly more energy-efficient to operate compared to other imaging units. The comparatively lower brightness of displays is entirely sufficient in the combination of the reflective coating with the masking layer behind it, as described in the invention. The imaging unit emits p-polarized light.The radiation from the imaging unit preferably strikes the composite disk in the region of the reflective coating at an angle of incidence of 55° to 80°, more preferably 62° to 77°. The angle of incidence is the angle between the incident vector of the radiation from the imaging unit and the surface normal at the geometric center of the second sub-region of the composite disk, in which the reflective coating is arranged as described above.

[0077] The p-polarized light emitted by the imaging unit strikes the reflective coating and is reflected there. The light reflected by the reflective coating is predominantly visible light, i.e., light in a wavelength range of approximately 380 nm to 780 nm.

[0078] Preferably, the reflective element reflects at least 30%, particularly preferably at least 40%, and most preferably at least 45% of the p-polarized light incident on the reflective coating in a wavelength range of 450 nm to 650 nm and an angle of incidence of 65°.

[0079] The term p-polarized light refers to light from the visible spectral range that consists predominantly of light exhibiting p-polarization. The p-polarized light preferably has a p-polarization component of greater than or equal to 50%, more preferably greater than or equal to 70%, particularly preferably greater than or equal to 90%, and especially approximately 100%.

[0080] The polarization direction is specified with respect to the plane of incidence of the radiation on the composite disk. P-polarized radiation is defined as radiation whose electric field oscillates in the plane of incidence. S-polarized radiation is defined as 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 disk at the geometric center of the irradiated area. In other words, the polarization, and in particular the proportion of P- and S-polarized radiation, is determined at a point within the area irradiated by the imaging unit, preferably at the geometric center of the irradiated area.Since composite discs can be curved (for example, when they are designed as a windshield), which affects the plane of incidence of the radiation from the imaging unit, slightly different polarization components may occur in the other areas, which is unavoidable for physical reasons.

[0081] The inventors have surprisingly discovered that reflective coatings consisting of a base layer with a refractive index greater than 1.9 and a thickness of 30 nm to 100 nm, a functional layer, and a top layer with a refractive index less than 1.6 and a thickness of 10 nm to 150 nm, which is based on silicon oxide, doped silicon oxide, magnesium fluoride, or calcium fluoride, wherein the functional layer consists of optically high-refractive-index layers with a refractive index greater than 1.9 and a thickness between 50 nm and 150 nm and optically low-refractive-index layers with a refractive index less than 1.6 and a thickness of 50 nm to 150 nm, wherein the alternating layer sequence of the functional layer begins with an optically high-refractive-index layer arranged immediately adjacent to the base layer and ends with an optically low-refractive-index layer arranged immediately adjacent to the top layer, and the functional layer has at least three optically high-refractive-index layers and at least three optically low-refractive-index layers, exhibiting higher average reflectances for p-polarized light, i.e., a higher reflectivity for p-polarized light, than reflective coatings with fewer than three optically high-refractive-index layers and fewer than three optically low-refractive-index layers arranged in an alternating layer sequence. Furthermore, the combination of the reflective coating with the masking layer behind it, from the perspective of a vehicle occupant, ensures good visibility of the image, even in external sunlight.This applies to occupants wearing sunglasses and when using low-light imaging units. Even under these circumstances, the image produced by the imaging unit appears bright and is clearly visible. This allows for a reduction in the imaging unit's power consumption and thus lower energy consumption.

[0082] The preferred embodiments of the composite disc according to the invention described above also apply accordingly to the projection arrangement according to the invention comprising a composite disc according to the invention and an imaging unit, and vice versa. The composite disc can be manufactured by methods known per se. The outer disc and the inner disc are laminated together via the intermediate layer, for example by autoclave processes, vacuum bag processes, vacuum ring processes, calender processes, vacuum laminators, or combinations thereof. The bonding of the outer disc and the inner disc is usually carried out under the influence of heat, vacuum, and / or pressure.

[0083] The application of the reflective coating layers—i.e., the base layer, the individual low-refractive-index layers, the high-refractive-index layers of the functional layer, and the top layer—can be carried out using well-known coating processes, such as magnetron sputtering or wet coating. Alternatively, application can also be carried out using a digital printing process.

[0084] In some embodiments, the top layer and / or the optically low refractive index layers of the functional layer can also be based on nanoporous silicon oxide and applied using a sol-gel process.

[0085] The reflective coating can be applied before or after lamination. Application before lamination and any bending processes is preferred, as coatings are easier to apply to flat substrates and result in better quality.

[0086] A partial coating can be achieved through masking techniques or by subsequently removing part of the coating (for example, by laser radiation or mechanical abrasion). In the case of a sol-gel coating, a partial coating is achieved by applying the sol only to the desired area, for example, by pad printing, screen printing, partial application using rollers or brushes, or by spray coating, or also by masking techniques. With digital printing processes, a partial coating is achieved by printing the layer only on the desired area. Therefore, masking techniques can generally be omitted in digital printing processes.

[0087] If the laminated glass is to be curved, the outer and inner panes are preferably bent before lamination and preferably after any coating processes. Preferably, the outer and inner panes are bent congruently together (i.e., simultaneously and using the same tool) because this ensures that the shape of the panes is optimally matched for the subsequent lamination. Typical temperatures for glass bending processes are, for example, 500°C to 700°C.

[0088] The preferred embodiments of the composite disk according to the invention described above also apply accordingly to methods for producing a composite disk according to the invention and vice versa.

[0089] The invention also relates to the use of a composite disc according to the invention as a vehicle window 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 for a head-up display.

[0090] 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.

[0091] They show:

[0092] Fig. 1 shows a top view of an embodiment of a composite disc according to the invention.

[0093] Fig. 2 shows a cross-section through the embodiment shown in Fig. 1,

[0094] Fig. 3 shows a cross-section through an embodiment of a functional layer,

[0095] Fig. 4 shows a cross-section through a further embodiment of a functional layer, Fig. 5 shows a cross-section through a further embodiment of a functional layer, Fig. 6 shows a cross-section through a further embodiment of a composite disc according to the invention,

[0096] Fig. 7 shows a cross-section through another embodiment of a composite disk according to the invention,

[0097] Fig. 8 shows a cross-section through another embodiment of a composite disk according to the invention,

[0098] Fig. 9 shows a top view of another embodiment of a composite disc according to the invention,

[0099] Fig. 10 shows a cross-section through the embodiment shown in Fig. 9, Fig. 11 shows a cross-section through a further embodiment of a composite disc according to the invention,

[0100] Fig. 12 shows a cross-section through another embodiment of a composite disk according to the invention,

[0101] Fig. 13 shows a cross-section through another embodiment of a composite disk according to the invention,

[0102] Fig. 14 shows a cross-section through an embodiment of a projection arrangement according to the invention,

[0103] Fig. 15 Reflection spectra of composite disks against p-polarized radiation at an incidence angle of 65°,

[0104] Fig. 16 Reflection spectra of composite disks against p-polarized radiation at an angle of incidence of 70°.

[0105] Fig. 1 shows a top view of an embodiment of a composite disc 100 according to the invention, and Fig. 2 shows the cross-section through the composite disc 100 shown in Fig. 1 along the section line X'-X. The composite disc 100 shown in Figs. 1 and 2 has a top edge O, a bottom edge U, and two side edges S and comprises an outer disc 1 with an outer surface I and an inner surface II, an inner disc 2 with an outer surface III and an inner surface IV, a thermoplastic intermediate layer 3, and a reflective coating 5 consisting of a base layer 6, a functional layer 7, and a top layer 8. The thermoplastic intermediate layer 3 is arranged between the outer disc 1 and the inner disc 2. The outer disc 1, the thermoplastic intermediate layer 3, and the inner disc 2 are arranged one above the other over their entire surface.The masking layer 4 is arranged between the outer pane 1 and the inner pane 2 in a first sub-region A of the composite pane 100. In the embodiment shown in Figures 1 and 2, the masking layer 4 is designed as an opaque covering print arranged on the inner surface II of the outer pane 1 and is located only in an edge region of the composite pane 100 bordering the lower edge U. For the sake of simplicity, the masking layer 4 is shown as patterned in Figure 1 instead of black. The reflective coating 5 is arranged in a second sub-region B of the composite pane 100, which, when viewed perpendicularly through the composite pane 100, lies entirely within the first sub-region A. The reflective coating 5 is therefore smaller in its external dimensions than the inner pane 2.Starting from the interior surface IV of the inner pane 2, the reflective coating 5 consists in the specified order of a base layer 6, a functional layer 7 and a top layer 8.

[0106] The thermoplastic interlayer 3 contains, for example, PVB and has a thickness of 0.76 mm. The outer pane 1 is made of, for example, soda-lime glass and is 2.1 mm thick. The inner pane 2 is made of, for example, soda-lime glass and is 1.6 mm thick.

[0107] Base layer 6 has a refractive index greater than 1.9 and a thickness of 30 nm to 100 nm. For example, base layer 6 consists of titanium dioxide and has a thickness of 55 nm. Base layer 6 can also be, for example, 52 nm or 45 nm thick.

[0108] The top layer 8 has a refractive index of less than 1.6 and a thickness of 10 nm to 150 nm and is based on silicon dioxide, doped silicon dioxide, magnesium fluoride, or calcium fluoride. For example, the top layer 8 is a 40 nm thick silicon dioxide layer. The top layer 8 can also be, for example, 120 nm or 132 nm thick.

[0109] The functional layer 7 consists of at least three optically high-refractive-index layers 9 with a refractive index greater than 1.9 and a thickness between 50 nm and 150 nm, and at least three optically low-refractive-index layers 10 with a refractive index less than 1.6 and a thickness of 50 nm to 150 nm, arranged in an alternating layer sequence. The functional layer 7 is arranged between the base layer 6 and the top layer 8 such that the alternating layer sequence of the functional layer 7 begins with an optically high-refractive-index layer 9 arranged immediately adjacent to the base layer 6 and ends with an optically low-refractive-index layer 10 arranged immediately adjacent to the top layer 8.

[0110] The functional layer 7 is configured, for example, as shown in Fig. 3, Fig. 4, or Fig. 5. In the embodiment shown in Figs. 1 and 2, the masking layer 4 extends between the two side edges S of the composite disc 100 and has a width of, for example, 30 cm from the lower edge U of the composite disc 100. It is understood that the composite disc 100 can have any suitable geometric shape and / or curvature. Typically, the composite disc 100 is a curved composite disc.

[0111] Fig. 3 shows a cross-section through an embodiment of a functional layer 7. In the embodiment shown in Fig. 3, the functional layer 7 consists of three optically high-refractive-index layers 9 and three optically low-refractive-index layers 10 in an alternating layer sequence. For example, the first optically high-refractive-index layer

[0112] 9.1, the second optically high refractive layer 9.2 and the third optically high refractive layer 9.3 each a titanium dioxide layer with a thickness of 65 nm and a refractive index of 2.45 and the first optically low refractive layer 10.1, the second optically low refractive layer 10.2 and the third optically low refractive layer 10.3 each a silicon dioxide layer with a thickness of 98 nm and a refractive index of 1.45.

[0113] Fig. 4 shows a cross-section through another embodiment of a functional layer 7. In the embodiment shown in Fig. 4, the functional layer 7 consists of four optically high-refractive-index layers 9 and four optically low-refractive-index layers 10 in an alternating layer sequence. For example, the first optically high-refractive-index layer

[0114] 9.1, the second high-refractive-index layer 9.2, the third high-refractive-index layer 9.3 and the fourth high-refractive-index layer 9.4 each a titanium dioxide layer with a thickness of 65 nm and a refractive index of 2.45 and the first low-refractive-index layer 10.1, the second low-refractive-index layer 10.2, the third low-refractive-index layer 10.3 and the fourth low-refractive-index layer 10.4 each a silicon dioxide layer with a thickness of 100 nm and a refractive index of 1.45.

[0115] Fig. 5 shows a cross-section through another embodiment of a functional layer 7. In the embodiment shown in Fig. 5, the functional layer 7 consists of five optically high-refractive-index layers 9 and five optically low-refractive-index layers 10 in an alternating layer sequence. For example, the first optically high-refractive-index layer

[0116] 9.1, the second high-refractive-index layer 9.2, the third high-refractive-index layer 9.3, the fourth high-refractive-index layer 9.4 and the fifth high-refractive-index layer 9.5 each a titanium dioxide layer with a thickness of 65 nm and a refractive index of 2.45 and the first low-refractive-index layer 10.1, the second low-refractive-index layer 10.2, the third low-refractive-index layer 10.3, the fourth low-refractive-index layer 10.4 and the fifth low-refractive-index layer 10.5 each a silicon dioxide layer with a thickness of 105 nm and a refractive index of 1.45.

[0117] Fig. 6 shows a cross-section through a further embodiment of a composite disc 100 according to the invention. The embodiment shown in cross-section in Fig. 6 differs from that shown in Fig. 2 only in that the masking layer 4 is not designed as an opaque covering print arranged on the inner surface II of the outer disc 1, but as an opaque covering print arranged on the outer surface III of the inner disc 2.

[0118] Fig. 7 shows a cross-section through another embodiment of a composite disc 100 according to the invention. The embodiment shown in cross-section in Fig. 7 differs from that shown in Fig. 2 only in that the masking layer 4 is not designed as an opaque covering print arranged on the inner surface II of the outer disc 1, but as an opaque covering print arranged on the outer surface I of the outer disc 1.

[0119] Fig. 8 shows a cross-section through another embodiment of a composite disc 100 according to the invention. The embodiment shown in cross-section in Fig. 8 differs from that shown in Fig. 2 only in that the masking layer 4 is not designed as an opaque covering print arranged on the inner surface II of the outer disc 1, but is designed as an opaquely colored area of ​​the thermoplastic intermediate layer 3.

[0120] Fig. 9 shows a top view of another embodiment of a composite disc 100 according to the invention, and Fig. 10 shows the cross-section through the composite disc 100 shown in Fig. 9 along the section line Y'-Y. The composite disc 100 shown in Figs. 9 and 10 has a top edge O, a bottom edge U, and two side edges S and comprises an outer disc 1 with an outer surface I and an inner surface II, an inner disc 2 with an outer surface III and an inner surface IV, a thermoplastic intermediate layer 3, a masking layer 4, and a reflective coating 5 consisting of a base layer 6, a functional layer 7, and a top layer 8. The thermoplastic intermediate layer 3 is arranged between the outer disc 1 and the inner disc 2. The outer disc 1, the thermoplastic intermediate layer 3, and the inner disc 2 are arranged one above the other over their entire surface.The masking layer 4 is arranged between the outer pane 1 and the inner pane 2 in a first sub-region A of the composite pane 100. In the embodiment shown in Figures 9 and 10, the masking layer 4 is designed as an opaque covering print arranged on the inner surface II of the outer pane 1 and is located in a circumferential edge region of the composite pane 100. This edge region has a greater width in a section overlapping the reflective coating 5 than in other sections. For the sake of simplicity, the masking layer 4 is shown as patterned in Figure 9 instead of black. The reflective coating 5 is arranged in a second sub-region B of the composite pane 100, which, when viewed perpendicularly through the composite pane 100, lies entirely within the first sub-region A. The reflective coating 5 is therefore smaller in its external dimensions than the inner pane 2.

[0121] Starting from the interior surface IV of the inner pane 2, the reflective coating 5 consists in the specified order of a base layer 6, a functional layer 7 and a top layer 8.

[0122] The thermoplastic interlayer 3 contains, for example, PVB and has a thickness of 0.76 mm. The outer pane 1 is made of, for example, soda-lime glass and is 2.1 mm thick. The inner pane 2 is made of, for example, soda-lime glass and is 1.6 mm thick.

[0123] Base layer 6 has a refractive index greater than 1.9 and a thickness of 30 nm to 100 nm. For example, base layer 6 consists of titanium dioxide and has a thickness of 55 nm. Base layer 6 can also be, for example, 52 nm or 45 nm thick.

[0124] The top layer 8 has a refractive index of less than 1.6 and a thickness of 10 nm to 150 nm and is based on silicon dioxide, doped silicon dioxide, magnesium fluoride, or calcium fluoride. For example, the top layer 8 is a 40 nm thick silicon dioxide layer. The top layer 8 can also be, for example, 120 nm or 132 nm thick.

[0125] The functional layer 7 consists of at least three optically high-refractive-index layers 9 with a refractive index greater than 1.9 and a thickness between 50 nm and 150 nm, and at least three optically low-refractive-index layers 10 with a refractive index less than 1.6 and a thickness of 50 nm to 150 nm, arranged in an alternating layer sequence. The functional layer 7 is arranged between the base layer 6 and the top layer 8 such that the alternating layer sequence of the functional layer 7 begins with an optically high-refractive-index layer 9 arranged immediately adjacent to the base layer 6 and ends with an optically low-refractive-index layer 10 arranged immediately adjacent to the top layer 8.

[0126] The functional layer 7 is designed, for example, as shown in Fig. 3, Fig. 4 or Fig. 5.

[0127] It is understood that the composite disc 100 can have any suitable geometric shape and / or curvature. Typically, the composite disc 100 is a curved composite disc.

[0128] Fig. 11 shows a cross-section through another embodiment of a composite disc 100 according to the invention. The embodiment shown in cross-section in Fig. 11 differs from that shown in Fig. 10 only in that the masking layer 4 is not designed as an opaque covering print arranged on the inner surface II of the outer disc 1, but as an opaque covering print arranged on the outer surface III of the inner disc 2.

[0129] Fig. 12 shows a cross-section through another embodiment of a composite disc 100 according to the invention. The embodiment shown in cross-section in Fig. 12 differs from that shown in Fig. 10 only in that the masking layer 4 is not designed as an opaque covering print arranged on the inner surface II of the outer disc 1, but is designed as an opaquely colored area of ​​the thermoplastic intermediate layer 3.

[0130] Fig. 13 shows a cross-section through another embodiment of a composite disc 100 according to the invention. The embodiment shown in cross-section in Fig. 13 differs from that shown in Fig. 10 only in that the masking layer 4 is not designed as an opaque cover print arranged on the inner surface II of the outer disc 1, but rather as an opaque cover print arranged on the outer surface I of the outer disc 1. Fig. 14 shows a cross-section through an embodiment of a projection arrangement 101 according to the invention. The projection arrangement 101 shown in Fig. 14 comprises a composite disc 100 and an imaging unit 11. In the embodiment of a projection arrangement according to the invention shown in Fig. 14, the composite disc 100 is designed as shown in Fig. 2. It is understood that the composite disc can alternatively also be designed as shown in Figs.The projection arrangement 101 can be configured with 6, 7, 8, 10, 11, 12, or 13. The projection arrangement 101 includes an imaging unit 11. The imaging unit 11 serves to generate p-polarized light (image information), which is directed onto the reflective coating 5 and reflected by the reflective coating 5 into the vehicle interior, where it can be perceived by an observer, e.g., the driver. The light preferably strikes the reflective element at an angle of incidence of 55° to 80°, particularly 62° to 77°. The imaging unit 11 is, for example, a display, in particular an LCD display.

[0131] The invention is explained below with reference to examples and comparative examples. The reflection properties for p-polarized light of composite discs according to the invention and composite discs not according to the invention are compared below.

[0132] The layer sequence and layer thicknesses according to comparative examples C and D and the inventive examples E, F, and G are given in Tables 1 and 2. In inventive example E, the functional layer 7 was configured as shown in Fig. 3. In inventive example F, the functional layer 7 was configured as shown in Fig. 4. In inventive example G, the functional layer 7 was configured as shown in Fig. 5.

[0133] To simulate a masking layer, dark PVB was used as a thermoplastic intermediate layer 3 in comparison examples C and D and in the examples according to the invention E, F, and G. Table 1

[0134] Table 2

[0135] The reflectance, which is crucial for image quality, for p-polarized light is denoted as RL(A) p-pol. Reflectance describes the proportion of the total incident p-polarized radiation that is reflected. It is expressed as a dimensionless number from 0 to 1 (normalized to the incident radiation). Plotted as a function of wavelength, it forms the reflection spectrum. The reflectance values ​​refer to a reflection measurement with a light source of type A, emitting in the spectral range from 380 nm to 780 nm with a normalized irradiance of 1. The spectral range from 450 nm to 650 nm is particularly relevant for assessing reflectivity because typical imaging units 11 of a projection setup 101 use radiation in this range (RGB: 473 nm, 550 nm, 630 nm). Irradiation was achieved via the inner disk 2 (so-called internal reflection).The corresponding reflection spectra of comparison examples C and D and examples E, F, and G at an incidence angle of 65° are shown in Fig. 15. The corresponding reflection spectra of comparison example D and examples E, F, and G at an incidence angle of 70° are shown in Fig. 16.

[0136] As can be seen from Fig. 15, the reflectance at an angle of incidence of 65° for examples E, F, and G according to the invention is significantly higher at the wavelengths of 473 nm, 550 nm, and 630 nm commonly used by imaging units than the reflectance for comparison examples C and D at these wavelengths. The average reflectance over the spectral range from 450 nm to 650 nm is also higher in each case (0.45 for example E, 0.56 for example F, and 0.66 for example G) than the average reflectance over the same spectral range (0.17 for comparison example C and 0.25 for comparison example D).

[0137] As can be seen from Fig. 16, the reflectance at an angle of incidence of 70° for examples E, F, and G according to the invention is significantly higher at the wavelengths of 473 nm, 550 nm, and 630 nm commonly used by imaging units than the reflectance for comparative example D at these wavelengths. The average reflectance over the spectral range from 450 nm to 650 nm is also higher in each case (0.47 for example E, 0.52 for example F, and 0.63 for example G) than the average reflectance over the same spectral range (0.30) for comparative example D.

[0138] The high average reflectance (over various angles of incidence) with respect to p-polarized radiation ensures high-intensity image reproduction in projection arrangements according to the invention. This is an advantage of the composite lenses according to the invention. Composite lenses according to the invention enable a reduction in the power consumption of the imaging unit in projection arrangements according to the invention, and thus reduced energy consumption. Reference numerals:

[0139] 100 composite disc

[0140] 101 Projection setup

[0141] 1 outer pane

[0142] 2 inner disc

[0143] 3 thermoplastic intermediate layer

[0144] 4 masking layer

[0145] 5 Reflective coating

[0146] 6 Base layer

[0147] 7 Functional layer

[0148] 8 Top layer

[0149] 9 high-refractive-index layer

[0150] 9.1 First high-refractive layer

[0151] 9.2 second high-refractive layer

[0152] 9.3 third high-refractive layer

[0153] 9.4 fourth high-refractive layer

[0154] 9.5 fifth high-refractive layer

[0155] 10 low refractive index layer

[0156] 10.1 first low-refractive-index layer

[0157] 10.2 second low-refractive-index layer

[0158] 10.3 third low-refractive-index layer

[0159] 10.4 fourth low-refractive-index layer

[0160] 10.5 fifth low-refractive-index layer

[0161] 11 imaging unit

[0162] O Top edge of the composite disc 100

[0163] U lower edge of the composite disc 100

[0164] S Side edge of the composite disc 100

[0165] I outer surface of the outer pane 1

[0166] II Interior surface of the outer pane 1

[0167] III outer surface of the inner pane 2

[0168] IV Interior surface of the inner pane 2 A First sub-area

[0169] B second sub-area

[0170] X'-X Intersection line Y'-Y Intersection line

Claims

Patent claims 1. Composite disc (100), comprising at least - an outer pane (1) with an outer surface (I) and an inner surface (II) and an inner pane (2) with an outer surface (III) and an inner surface (IV), which are connected to each other via a thermoplastic intermediate layer (3), - a masking layer (4) arranged in a first sub-area (A) of the composite pane (100) between the outer pane (1) and the inner pane (2) or on the outer surface (I) of the outer pane (1), and - a reflective coating (5) arranged on the interior surface (IV) of the inner pane (2), wherein the reflective coating (5) is arranged in a second sub-area (B) of the composite pane (100) which, when viewed perpendicularly through the composite pane (100), lies entirely within the first sub-area (A), and the reflective coating (5) is arranged in the specified sequence starting from the interior surface (IV) of the inner pane (2) - a base layer (6) with a refractive index greater than 1.9 and a thickness of 30 nm to 100 nm, - a functional layer (7) consisting of optically high-refractive-index layers (9) with a refractive index greater than 1.9 and a thickness between 50 nm and 150 nm arranged in an alternating layer sequence and optically low-refractive-index layers (10) with a refractive index less than 1.6 and a thickness of 50 nm to 150 nm - and a cover layer (8) with a refractive index of less than 1.6 and a thickness of 10 nm to 150 nm, which is based on silicon oxide, doped silicon oxide, magnesium fluoride or calcium fluoride, wherein the alternating layer sequence of the functional layer (7) begins with an optically high refractive index layer (9) arranged immediately adjacent to the base layer (6) and ends with an optically low refractive index layer (10) arranged immediately adjacent to the cover layer (8) and the functional layer (7) has at least three optically high refractive index layers (9) and at least three optically low refractive index layers (10).

2. Composite disc (100) according to claim 1, wherein the functional layer (7) consists of three optically high refractive index layers (9) and three optically low refractive index layers (10).

3. Composite disc (100) according to claim 1, wherein the functional layer (7) consists of four optically high refractive index layers (9) and four optically low refractive index layers (10).

4. Composite disc (100) according to claim 1, wherein the functional layer (7) consists of five optically high refractive index layers (9) and five optically low refractive index layers (10).

5. Composite disc (100) according to one of claims 1 to 4, wherein the refractive index of the optically low refractive layers (10) is at most 1.5, preferably at most 1.

45.

6. Composite disc (100) according to one of claims 1 to 5, wherein the optically low refractive index layers (10) are formed on the basis of silicon dioxide, doped silicon oxide, magnesium fluoride or calcium fluoride.

7. Composite disc (100) according to any one of claims 1 to 6, wherein the base layer (6) has a thickness of 50 nm to 80 nm.

8. Composite disc (100) according to any one of claims 1 to 7, wherein the base layer (6) and / or the optically high refractive layers (9) independently contain or consist of silicon nitride, a silicon-zirconium mixed nitride or titanium oxide, which may be undoped or doped.

9. Composite disc (100) according to any one of claims 1 to 8, wherein the cover layer (8) has a thickness of 20 nm to 140 nm.

10. Composite disc (100) according to one of claims 1 to 9, wherein the masking layer (4) is formed in a frame-like circumferential manner.

11. Composite disc (100) according to claim 10, wherein the masking layer (4) has a greater width in the area which overlaps the reflective coating (5) than in sections different from it.

12. Composite disc (100) according to one of claims 1 to 11, wherein the masking layer (4) is formed as an opaque cover print arranged on the outer surface (I) of the outer disc (1), the inner surface (II) of the outer disc (1) or the outer surface (III) of the inner disc (2) or as an opaque colored area of ​​the thermoplastic intermediate layer (3).

13. Projection arrangement (101) comprising at least - a composite disc (100) according to one of claims 1 to 12, - an imaging unit (11) directed towards the reflective coating (5) which emits p-polarized light, wherein the interior surface (IV) of the inner disk (2) is the surface of the inner disk (2) closest to the imaging unit (11).

14. Projection arrangement (101) according to claim 13, wherein the imaging unit (11) is a display, preferably an LCD display, LED display, OLED display or electroluminescent display, particularly preferably an LCD display, and the p-polarized light preferably strikes the composite disc (100) at an angle of incidence of 55° to 80°, particularly preferably 62° to 77°.

15. Use of a composite disc (100) according to one of claims 1 to 12 as a vehicle disc 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 for a head-up display.

Images