Composite pane for a projection assembly

Abstract

The invention relates to a composite pane (10) for a projection assembly (100), at least comprising: - a first pane (1), - a second pane (2), - a thermoplastic intermediate layer (3), wherein the first pane (1) is connected to the second pane (2) via an intermediate layer (3) in order to form a composite pane (10), the first pane (1) has a first surface (IV) facing away from the thermoplastic intermediate layer (3) and a second surface (III) facing the thermoplastic intermediate layer (3), and the second pane (2) has a first surface (II) facing the thermoplastic intermediate layer (3) and a second surface (I) facing away from the thermoplastic intermediate layer (3), and - a mirror structure (4) with electrically switchable optical properties, said mirror structure (4) being arranged in front of an opaque masking strip (7, 7') in a viewing direction through the composite pane (10).

Description

[0001] Composite panel for a projection arrangement

[0002] The invention relates to a composite pane for a projection arrangement and a projection arrangement.

[0003] Motor vehicles have head-up displays (HUDs) in their interiors that project vehicle and traffic information onto a windshield. This information can be read by the driver without losing sight of the flowing traffic. Vehicle windshields typically consist of two panes of glass laminated together with at least one thermoplastic film. The radiation from a HUD projector is typically predominantly s-polarized. This is due to the windshield's better reflection characteristics for s-polarized light compared to p-polarized light. However, if the driver wears polarization-selective sunglasses, which only transmit p-polarized light, they will barely be able to perceive the HUD image, if at all. Therefore, there is a need for HUD projection systems that are compatible with polarization-selective sunglasses.A solution to the problem in this context is therefore the use of projection arrangements that use p-polarized light.

[0004] DE 102014220189A1 discloses a HUD projection system that operates with p-polarized radiation to generate a HUD image. Since the angle of incidence is typically close to the Brewster angle and p-polarized radiation is therefore only slightly reflected by the glass surfaces, the windshield has a reflective structure that can reflect p-polarized radiation toward the driver. A single metallic layer with a thickness of 5 nm to 9 nm, for example, made of silver or aluminum, is proposed as the reflective structure. This layer is applied to the outer side of the inner pane facing away from the interior of the car.

[0005] When designing a projection system based on HUD technology, it is also important to ensure that the projected image is clearly visible to the viewer. Adequate visual perceptibility of safety-relevant information, such as lane departure warnings, speedometers, or engine speed, should be ensured in all weather and lighting conditions. It would be desirable to have a projection system based on head-up display technology that does not produce unwanted secondary images and whose arrangement is relatively easy to implement, while ensuring good visibility and sufficient brightness and contrast of the displayed image information. Furthermore, the projection system should be simple and cost-effective to manufacture.

[0006] DE 10 2006 006 690 B4 discloses an anti-glare device designed as a sun visor, which is movably mounted on an object in the interior of a vehicle. The anti-glare device has a translucent portion with a functional layer whose translucency can be adjusted.

[0007] WO 2021 / 139995 A1 discloses a vehicle glazing and display system within a bus for projecting images onto a partition window of the bus.

[0008] The object of the present invention is to provide an improved composite pane for a projection arrangement.

[0009] This object is achieved by the invention defined in the independent claims. Preferred embodiments are set forth in the subclaims.

[0010] The composite pane according to the invention for a projection arrangement comprises at least a first pane, a second pane, and a thermoplastic intermediate layer, wherein the first pane is connected to the second pane via the intermediate layer to form a composite pane. The first pane has a first surface (IV) facing away from the thermoplastic intermediate layer and a second surface (III) facing the thermoplastic intermediate layer. Likewise, the second pane has a first surface (II) facing the thermoplastic intermediate layer and a second surface (I) facing away from the thermoplastic intermediate layer. Furthermore, the composite pane comprises a mirror structure with electrically switchable optical properties. In particular, the mirror structure has reflective properties that are electrically switchable. For this purpose, the mirror structure can have two flat control electrodes.The composite pane's mirror structure ensures good image reproduction with high contrast. The images reflected by the mirror structure appear bright and therefore very easily recognizable.

[0011] The mirror structure can be arranged on the first pane. The mirror structure can be attached between the first pane and the thermoplastic intermediate layer. Alternatively, the mirror structure can be attached to the first surface (IV) of the first pane, which enables particularly simple production. The arrangement here refers to both the direct arrangement of the mirror structure on the pane and an indirect arrangement on the pane. For example, at least one further layer can be arranged between the pane and the mirror structure. By arranging the mirror structure on the first pane, the light from an image display device directed onto the first pane can be reflected very well.

[0012] In a preferred embodiment, the mirror structure can be arranged in an edge region of the composite pane. If the mirror structure is arranged in an edge region, then preferably near an edge, in particular the lower edge, of the composite pane. The distance between the mirror structure and the edge of the first pane is preferably from 0.1 cm to 30 cm, particularly preferably from 1 cm to 15 cm and in particular from 5 cm to 10 cm. The arrangement of the mirror structure in an edge region is particularly suitable since, in many possible uses of composite panes, the see-through region is usually located in a central region of the composite pane. Thus, even when a mirror structure is switched on in a semi-transparent (partially reflective) or fully reflective state, visibility is not impaired.

[0013] The mirror structure is arranged in front of an opaque masking strip extending from the first pane in the viewing direction through the composite pane. The opaque masking strip acts as an opaque background and is arranged in regions on at least one of the surfaces (III, IV) of the first pane and / or the surfaces (I, II) of the second pane. This achieves a good, high-contrast image representation of images projected onto the composite pane. The images reflected by the mirror structure are reflected particularly brightly and are therefore very easily recognizable.

[0014] The mirror structure and the opaque masking strip can be separated by the intermediate layer and / or the first pane. The distance between the mirror structure and the masking strip can be less than 3 millimeters. A distance of less than 3 millimeters results in very clear reflection images.

[0015] In a further preferred embodiment, the mirror structure has a protective layer. In other words, a hydrophobic film is arranged as a protective layer at least on the first surface (IV) of the first pane and seals the surface of the mirror structure coated therewith from the surrounding atmosphere. The provided protective layer thus forms, at least in the region of the mirror structure, the first, outer surface of the composite pane facing an interior in the installed position and advantageously protects this, in particular the mirror structure, from external influences, in particular contamination. The protective layer as a hydrophobic film is a coating with good resistance to deposits, for example of liquids, salts, grease and dirt, and is advantageously particularly easy to clean. For example, the formation of fingerprints when touched by an occupant / user can be prevented.Hydrophobic films suitable for the invention, as well as their design and production, are described, for example, in WO2005 / 084943, WO2007 / 012779, or WO2010 / 079299. Such hydrophobic coatings are already in use, for example, on the outside of vehicle windshields. Such hydrophobic films exhibit a good durability of two or more years in this application. The hydrophobic coating allows water droplets on the glazing to simply slide off, which can provide a driver with better visibility through a windshield when it rains. Advantageously, the inventive use of the hydrophobic coating on the mirror structure of the composite pane means that the mirror structure is not directly exposed to the weather or friction from windshield wipers, thus extending its service life. Advantageously, the coating according to the invention is also easy to renew.

[0016] In another embodiment, the mirror structure is formed as a continuous surface. This has the advantage that the associated water- and dirt-repellent properties of the hydrophobic film can also be provided over the entire surface. Furthermore, the production of such a full-surface seal facing an interior space is simple, efficient, and cost-effective.

[0017] The mirror structure preferably has a variable reflection. The reflectivity of the mirror structure can correspond to that of a metal / glass mirror when switched on, and there is almost no reflection when switched off. The mirror structure according to the invention can be switched from a, in particular optically, transparent state (i.e., a "non-reflective" state) to a semi-transparent state or reflective state (reflective state). The semi-transparent state is an intermediate state between the transparent and reflective states, so that the mirror structure is dimmable. This allows the brightness of the reflected images to be varied. For this purpose, an electrical voltage is applied to two connection points of the mirror structure. The mirror structure is therefore particularly suitable as a mirror whose reflectivity should be variable, such as in a vehicle mirror or architectural glazing.Preferably, the state of the mirror structure can be selected by a user (e.g., a vehicle occupant) according to their wishes or requirements. A switch or dimmer can be used for this purpose. However, the mirror structure can also be switched automatically.

[0018] The mirror structure is preferably designed as a mirror foil. This has the advantage that the mirror foil is particularly easy to use and handle in the manufacturing process of the composite pane.

[0019] The opaque masking strip, which is arranged in regions on at least one of the surfaces (I, II, III, IV) of the first pane, can in principle be arranged on either side of the first or second pane. In the composite pane according to the invention, it is preferably applied to the first surface (II) of the second pane, where it is protected from external influences. Alternatively or additionally, a marking strip can preferably be provided on the first surface (IV) of the first pane.

[0020] The masking strip is preferably a coating consisting of one or more layers. Alternatively, it can also be an opaque element, such as a film, embedded in the laminated pane.

[0021] According to a preferred embodiment of the composite pane, the masking strip consists of a single layer. This has the advantage of particularly simple and cost-effective production of the composite pane, since only a single layer needs to be formed for the masking strip.

[0022] In the case of windshields in particular, the masking strip is used to mask an adhesive bead used to bond the windshield to a vehicle body. This means that it prevents the adhesive bead, which is usually applied irregularly, from being seen from the outside, creating a harmonious overall impression of the windshield. The masking strip also serves as UV protection for the adhesive material used. Continuous exposure to UV light damages the adhesive material and would, over time, loosen the bond between the windshield and the vehicle body. In the case of windshields with an electrically controllable mirror structure, the masking strip can, for example, also be used to cover bus bars and / or connecting elements. The masking strip is printed onto the second pane and / or the first pane, in particular using a screen printing process. The printing ink is printed onto the glass pane through a fine-mesh fabric.The printing ink is pressed through the mesh using, for example, a rubber squeegee. The mesh has areas that are permeable to the printing ink, alongside areas that are impermeable to the printing ink, which determine the geometric shape of the print. The mesh thus acts as a stencil for the print. The printing ink contains at least one pigment and glass frits, suspended in a liquid phase (solvent), for example water or organic solvents such as alcohols. The pigment is typically a black pigment, for example pigment black (carbon black), aniline black, bone black, iron oxide black, spinel black, and / or graphite.

[0023] After the printing ink has been applied, the glass pane undergoes a thermal treatment, during which the liquid phase is expelled by evaporation and the glass frits are melted and permanently bonded to the glass surface. The thermal treatment is typically carried out at temperatures in the range of 450°C to 700°C. The pigment remains as a masking strip in the glass matrix formed by the molten glass frit. The masking strip preferably has a thickness of 5 μm to 50 μm, particularly preferably 8 μm to 25 μm.

[0024] As already described, the masking strip can, in principle, be arranged on either side of the first pane or the second pane. In a composite pane according to the invention, it is preferably applied in the installed position to the first surface (inner side) II of the second pane (outer pane), where it is protected from external influences.

[0025] Another embodiment provides that, alternatively or additionally, a masking strip is arranged as a ceramic black print on the first surface (IV) of the first pane, which can particularly improve the application of adhesive layers and the quality of bonds, especially during installation of the composite pane according to the invention, for example, in a vehicle. In other words, the opaque masking strip is preferably arranged as a ceramic black print on the first surface (IV) of the first pane at least in one edge region, for example, as a peripheral edge region, of the composite pane.

[0026] Alternatively, the masking strip is a colored or pigmented, preferably black-pigmented, thermoplastic composite film, preferably based on polyvinyl butyral (PVB), ethyl vinyl acetate (EVA), or polyethylene terephthalate (PET), preferably PVB. The coloring or pigmentation of the composite film is freely selectable, but is preferably black. The colored or pigmented composite film is preferably arranged between the first pane and the second pane. The colored or pigmented thermoplastic composite film preferably has a thickness of 0.25 mm to 1 mm. The colored or pigmented composite film preferably extends over a maximum of 50% and particularly preferably a maximum of 30% of the area of ​​the composite pane.To avoid thickness differences in the composite pane, a further transparent thermoplastic composite film is preferably arranged between the first pane (e.g., an inner pane) and the second pane (e.g., an outer pane), extending over at least 50%, preferably at least 70%, of the surface of the composite pane. The colored or pigmented composite film is offset from the transparent thermoplastic composite pane in the surface plane of the composite pane, so that they do not overlap or cover each other.

[0027] The masking strip can also be provided by a partially pigmented or colored thermoplastic composite film. In this case, the mirror structure is spatially arranged in front of the pigmented or colored area of ​​the thermoplastic composite film in the viewing direction through the composite pane. The pigmentation or coloring of the composite film preferably extends over a maximum of 50% and particularly preferably a maximum of 30% of the surface of the composite pane. The remaining part of the partially pigmented or colored thermoplastic composite film is transparent, i.e., has no pigmentation or coloring. The partially pigmented or colored thermoplastic composite film preferably extends over the entire surface of the composite pane.Designing the masking strip as a pigmented or dyed thermoplastic composite film, or as a partially pigmented or dyed thermoplastic composite film, simplifies the production of the composite pane and improves its stability. It is very advantageous if the first pane (inner pane) or the second pane (outer pane) do not need to be coated beforehand to create an opaque background. This increases the stability of the composite pane and further improves process efficiency.

[0028] The terms "first pane" and "second pane" are chosen to distinguish between the two panes in a composite pane according to the invention. These terms do not imply any statement about the geometric arrangement. For example, if the composite pane according to the invention is intended to separate the interior from the exterior in an opening, for example, in a vehicle or a building, the first pane can face the interior or the exterior.

[0029] The first pane and second pane preferably contain or consist of glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass, alumino-silicate glass, or clear plastics, preferably rigid clear plastics, in particular polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, polystyrene, polyamide, polyester, polyvinyl chloride and / or mixtures thereof.

[0030] The first pane and second pane may have other suitable coatings known per se, for example anti-reflective coatings, non-stick coatings, anti-scratch coatings, photocatalytic coatings, electrically conductive coatings, or sun protection coatings or low-E coatings.

[0031] The thickness of the individual panes (first pane and second pane) can vary widely and be adapted to the requirements of the individual case. Preferably, panes with standard thicknesses of 0.5 mm to 5 mm and more preferably of 1.0 mm to 2.5 mm are used. The size of the panes can vary widely and depends on the application. The composite pane can have any three-dimensional shape. Preferably, the first pane and second pane have no shadow zones so that they can be coated, for example, by cathode sputtering. Preferably, the first pane and second pane are flat or slightly or strongly curved in one or more directions of space.

[0032] According to the invention, the first pane and the second pane are preferably transparent. For the purposes of the present invention, "transparent" means that the total transmission of the composite pane complies with the legal requirements, for example, for windshields (e.g., the European Union Directive ECE-R43), and preferably has a visible light transmittance of more than 50% and in particular more than 60%, for example, more than 70%. "Transparent pane" thus means that the first pane and the second pane are so transparent that the view through a see-through area of ​​the composite pane complies with the legal requirements for the intended use, for example, for windshields. Accordingly, "opaque" means a light transmission of less than 10%, preferably less than 5%, and in particular 0%.If a layer is formed on the basis of a material, the layer consists predominantly of this material, in particular essentially of this material in addition to any impurities or dopants.

[0033] The thermoplastic intermediate layer (adhesive layer) contains or consists of at least one thermoplastic, preferably polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), and / or polyurethane (PU), or copolymers or derivatives thereof, optionally in combination with polyethylene terephthalate (PET). However, the thermoplastic intermediate layer can also contain, for example, polypropylene (PP), polyacrylate, polyethylene (PE), polycarbonate (PC), polymethyl methacrylate, polyvinyl chloride, polyacetate resin, casting resin, acrylate, fluorinated ethylene-propylene, polyvinyl fluoride, and / or ethylene-tetrafluoroethylene, or a copolymer or mixture thereof.

[0034] The thermoplastic intermediate layer is preferably formed as at least one thermoplastic composite film and contains or consists of polyvinyl butyral (PVB), particularly preferably polyvinyl butyral (PVB), and additives known to those skilled in the art, such as plasticizers. The thermoplastic intermediate layer preferably contains at least one plasticizer. Plasticizers are chemical compounds that make plastics softer, more flexible, more pliable, and / or more elastic. They shift the thermoelastic range of plastics toward lower temperatures, so that the plastics exhibit the desired more elastic properties near the application temperature. Preferred plasticizers include, for example, carboxylic acid esters, particularly low-volatility carboxylic acid esters, fats, oils, soft resins, and camphor.

[0035] The PVB-based thermoplastic intermediate layer preferably contains at least 3 wt.%, preferably at least 5 wt.%, particularly preferably at least 20 wt.%, even more preferably at least 30 wt.%, and especially at least 35 wt.% of a plasticizer. The plasticizer contains or consists, for example, of triethylene glycol bis(2-ethylhexanoate).

[0036] The thermoplastic intermediate layer can be formed by a single film or by more than one film. The thermoplastic intermediate layer can be formed by one or more thermoplastic films arranged flat one above the other, wherein the thickness of the thermoplastic intermediate layer is preferably from 0.25 mm to 1 mm, typically 0.38 mm or 0.76 mm. The thermoplastic intermediate layer can also be a functional thermoplastic intermediate layer, in particular an intermediate layer with acoustically dampening properties, an infrared radiation-reflecting intermediate layer, an infrared radiation-absorbing intermediate layer and / or a UV radiation-absorbing intermediate layer. For example, the thermoplastic intermediate layer can also be a bandpass filter film that blocks narrow bands of visible light.

[0037] The invention further comprises a projection arrangement comprising a composite pane according to the invention as described above in various embodiments, wherein the composite pane has a mirror structure with electrically switchable optical properties. The projection device further comprises an image display device associated with the composite pane and having an image display directed onto the composite pane. The image display device is directed onto the composite pane and irradiates it with light, in particular p-polarized light. At least the region of the composite pane that at least partially encompasses the mirror structure is irradiated by the image display device.

[0038] The polarization direction refers to the plane of incidence of the radiation on the composite pane. P-polarized radiation refers to radiation whose electric field oscillates in the plane of incidence. S-polarized radiation refers to radiation whose electric field oscillates perpendicular to the plane of incidence. The plane of incidence is defined by the incidence vector and the surface normal of the composite pane at the geometric center of the irradiated area.

[0039] According to the invention, the mirror structure preferably reflects more than 10%, preferably at least 30% or more, preferably 50% or more, and in particular 70% or more, of the light incident on the mirror structure, in particular p-polarized light, preferably in a wavelength range of 450 nm to 650 nm and angles of incidence of 50 to 80°, for example, from 55° to 75°. This is advantageous in order to achieve the greatest possible brightness of an image emitted by the image display device and reflected by the mirror structure.

[0040] The term p-polarized light refers to light from the visible spectral range that predominantly consists of light with p-polarization. The p-polarized light preferably has a p-polarization component of >50%, preferably >70%, particularly preferably >90%, and in particular approximately 100%. The image display device serves as a light source to emit an image. A projector, a display, or another device known to those skilled in the art can be used as the image display device. The image display device is preferably a display, particularly preferably an LCD, LED display, OLED display, or electroluminescent display, in particular an LCD. Displays have a low installation height and are thus easy and space-saving to integrate into the dashboard of a vehicle. Furthermore, displays are significantly more energy-efficient to operate than projectors.The comparatively lower brightness of displays is entirely sufficient in combination with the inventive mirror structure and the opaque cover layer behind it. The radiation from the image display device preferably strikes the composite pane at an angle of incidence of 55° to 80°, preferably 62° to 77°, in the area of ​​the mirror structure. The angle of incidence is the angle between the incidence vector of the radiation from the image display device and the surface normal at the geometric center of the reflective layer.

[0041] The invention also includes a vehicle, in particular a passenger car, with a composite pane according to the invention.

[0042] Furthermore, the invention can comprise a method for producing a composite pane according to the invention. The method comprises at least the following steps: providing the first pane, the thermoplastic intermediate layer, the mirror structure, and the second pane; arranging the first pane, the thermoplastic intermediate layer, the mirror structure, and the second pane, wherein the thermoplastic intermediate layer is arranged between the first pane and the second pane and the mirror structure is arranged on the first surface (IV) of the first pane facing away from the thermoplastic intermediate layer or between the first pane and the second pane; and laminating the layer stack to form a composite pane.

[0043] The layer stack is laminated under the influence of heat, vacuum and / or pressure, whereby the individual layers are bonded (laminated) to one another by at least one thermoplastic intermediate layer. Known processes for producing a composite pane can be used. For example, so-called autoclave processes can be carried out at an elevated pressure of approximately 10 bar to 15 bar and temperatures of 130°C to 145°C for approximately 2 hours. Known vacuum bag or vacuum ring processes operate, for example, at approximately 200 mbar and 130°C to 145°C. The first pane, the second pane and the thermoplastic intermediate layer can also be pressed into a composite pane in a calender between at least one pair of rollers. Systems of this type are known for producing composite panes and normally have at least one heating tunnel upstream of a pressing unit.The temperature during the pressing process, for example, ranges from 40°C to 150°C. Combinations of calendering and autoclaving processes have proven particularly effective in practice. Alternatively, vacuum laminators can be used. These consist of one or more heated and evacuatable chambers in which the outer and inner panes can be laminated within, for example, approximately 60 minutes at reduced pressures of 0.01 mbar to 800 mbar and temperatures of 80°C to 170°C.

[0044] In an advantageous embodiment of the method, after lamination of the layer stack, a protective layer in the form of a hydrophobic film is applied, for example, by liquid application, such as spraying, dipping, flooding, or even by application with a cloth. The hydrophobic film can alternatively be applied, for example, as a nanolayer system, using chemical or physical vapor deposition processes. According to the invention, the hydrophobic film forms the outer, exposed surface of the composite pane facing the interior, at least in the area of ​​the mirror structure.

[0045] The present invention further encompasses the use of the composite pane according to the invention in means of transport for land, air, or water traffic, in particular in trains, ships, and motor vehicles, for example as a windshield, roof window, rear window, and / or side window. The composite pane according to the invention is preferably used as a vehicle windshield. The composite pane according to the invention can also be used as a functional and / or decorative individual piece and as a built-in component in furniture, appliances, and buildings.

[0046] Within the scope of the present invention, all embodiments mentioned for individual features can also be freely combined with one another, provided they are not contradictory. The invention is explained in more detail below with reference to figures and exemplary embodiments. The figures are schematic representations and not to scale. The figures do not limit the invention in any way.

[0047] They show:

[0048] Figure 1 is a cross-sectional view of an embodiment of the projection arrangement according to the invention,

[0049] Figure 2 is a plan view of a composite pane of Fig. 1,

[0050] Figure 3 is a cross-sectional view of a first embodiment of the composite pane according to the invention in the region of a mirror structure,

[0051] Figure 4 is a cross-sectional view of a second embodiment of the composite pane according to the invention,

[0052] Figure 5 is a cross-sectional view of a third embodiment of the composite pane according to the invention,

[0053] Figure 6 is a cross-sectional view of a fourth embodiment of the composite pane according to the invention,

[0054] Figure 7 is an enlarged cross-sectional view of the first embodiment of the composite pane according to the invention in the region Z, and

[0055] Figure 8 is an enlarged cross-sectional view of another embodiment of the composite pane according to the invention.

[0056] Numerical values ​​are generally not to be understood as exact values, but also include a tolerance of + / - 1% to + / - 10%.

[0057] Figure 1 shows a cross-sectional view of an embodiment of the projection arrangement 100 according to the invention in a vehicle. The schematic representation is highly simplified. The cross-sectional view of Figure 1 corresponds to the section line AA' of the composite pane 10 from Figure 2.

[0058] A top view of the composite pane 10 is shown in Figure 2. Different embodiments of the composite pane 10 are shown in Figures 3 to 8. The composite pane 10 comprises a first pane 1 and a second pane 2 with a thermoplastic intermediate layer 3. The thermoplastic intermediate layer 3 connects the first pane 1 to the second pane 2. When installed, the composite pane 10 is a glazing unit of a vehicle or building. The composite pane 10 separates an interior space 12 from an external environment 13. For example, the composite pane 10 is the windshield of a motor vehicle.

[0059] The first pane 1 and the second pane 2 are each made of glass, preferably thermally toughened soda-lime glass, and are transparent to visible light. The thermoplastic intermediate layer 3 consists of a thermoplastic material, preferably polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), and / or polyethylene terephthalate (PET).

[0060] The first pane 1 has a first surface IV facing away from the thermoplastic intermediate layer and a second surface III facing the thermoplastic intermediate layer. Likewise, the second pane 2 has a first surface II facing the thermoplastic intermediate layer and a second surface I facing away from the thermoplastic intermediate layer. The first surface II of the second pane 2 and the second surface III of the first pane 1 thus each face the intermediate layer 3. The second surface I of the second pane 2 is the exterior surface of the composite pane 10. The first surface IV of the first pane 1 is the interior surface of the composite pane 10.

[0061] Furthermore, the composite pane 10 has a frame-shaped, circumferential masking strip 7, 7' on the second pane 2. The masking strip 7, 7' is opaque, preferably black. The masking strip 7, 7' is designed to cover the adhesive bonds and connecting structures arranged on the inside of the composite pane 10. The masking strip 7, 7' can also be widened in the lower (for example, engine-side) section of the edge region 11. For this purpose, the section of the edge region 11 has a greater width than the upper (for example, roof-side) section of the edge region 11 of the composite pane 10. The width is understood to be the dimension of the masking strip 7, 7' perpendicular to its extension.

[0062] The composite pane 10 comprises a mirror structure 4, which is located on the first pane 1 and spatially in front of the masking strip 7, 7'. The opaque masking strip 7, 7' acts as an opaque background. The mirror structure 4 is, for example, a mirror film, with the masking strip 7, 7' completely covering the mirror film. The mirror structure 4 is electrically switchable. In particular, the mirror structure 4 has reflective properties that are electrically switchable. For this purpose, the mirror structure 4 can have two planar control electrodes. In other words, the reflectivity of the mirror structure 4 can be different in a first operating mode than in a second operating mode. The mirror structure 4 can be switched from a, in particular optically, transparent state (i.e., a "non-reflective" state) to a semi-transparent state or reflective state (reflective state).The semitransparent state is an intermediate state between the transparent and the reflective states, allowing the mirror structure 4 to be dimmed. When the composite pane 10 is irradiated with images in the area of ​​the mirror structure 4, these images are reflected. In front of the opaque masking strip 7, 7', the images reflected by the mirror structure 4 appear bright and clearly visible.

[0063] The mirror structure 4 is arranged on the first pane 1. The mirror structure 4 can be arranged between the first pane 1 and the thermoplastic intermediate layer 3. Alternatively, the mirror structure 4 can be attached to the first surface (IV) of the first pane 1.

[0064] The mirror structure 4 is arranged in an edge region 11 near the lower edge of the composite pane 10. The distance between the mirror structure 4 and an edge of the first pane 1 can be 6 cm, 8 cm, or 10 cm. Alternatively or additionally, the mirror structure 4 can be arranged in the upper section of the edge region 11 or on a lateral section of the edge region 11. An edge-side arrangement is naturally advantageous and expedient when the composite pane 10 is used and configured as a windshield in order to meet the required requirements for the driver's field of vision. The mirror structure 4 can be formed as a continuous surface, in particular as a single piece. The mirror structure 4 can extend along one edge, in particular the lower edge, of the composite pane 10, so that a circumferential image (from one side edge to an opposite side edge) can be generated.The mirror structure 4 extends in several, for example three or four, sections, which are arranged in the lower (for example motor-side) edge region 11.

[0065] The projection arrangement 100 further comprises an image display device 9 as an image generator. The image display device 9 can be arranged in a dashboard of a vehicle and irradiate the composite pane 10 with images. It serves to generate light, in particular p-polarized light 10, which is directed onto the composite pane 10 and the mirror structure 4. The mirror structure 4 reflects the light 10', for example, into the vehicle interior, where it can be seen by an observer (e.g., the driver). This allows important vehicle data (speed, engine speed, route information) to be displayed to the driver with particularly high contrast. The light 10 of the image display device 9 preferably strikes the composite pane 10 at an angle of incidence of 50° to 80°, in particular of 55° to 75°, for example of 60° to 70°, typically approximately 65°.The image display device 9 can alternatively or additionally be arranged in the A-pillar of a motor vehicle or on the roof in the vehicle interior. If multiple mirror structures 4 are provided, each mirror structure 4 can be assigned a separate image display device 9, i.e., multiple image display devices 9 can be arranged. The image display device 9 is, for example, a display such as an LCD, OLED display, EL display, or pLED display. It would also be possible, for example, for the composite pane 10 to be a roof pane, side pane, or rear pane of a vehicle.

[0066] Figure 2 shows a plan view of a composite pane 10 from Figure 1. In the plan view of Figure 2, the mirror structure 4 is arranged extending along the lower section of the edge region 11 of the composite pane 10.

[0067] In this embodiment, the mirror structure 4 is in direct contact with the second surface (III) of the first pane 1. The mirror structure 4 is formed as a single piece. Alternatively, the mirror structure 4 can be divided into several sections. The number of sections can vary widely. The mirror structure 4 can be divided into 2, 4, 6, or 8 sections.

[0068] Figure 3 shows a cross-sectional view of a first embodiment of the composite pane 10 in the region of the mirror structure 4. The cross-sectional view of Figure 3 corresponds to the section line AA' (Figure 2) in the region of the mirror structure 4. The masking strip 7 is preferably applied to the first surface II of the second pane 2 as a ceramic black print. In the first embodiment, the masking strip 7 consists of a coating containing an opaque, electrically non-conductive material, for example, a black-colored screen printing ink that is baked.

[0069] In this embodiment, the mirror structure 4 and the masking strip 7 are separated from each other by the thermoplastic intermediate layer 3. The distance between the mirror structure 4 and the masking strip 7 can be less than 3 millimeters, for example, 0.76 millimeters or 0.38 millimeters. At a distance of less than 3 millimeters, very clear reflection images are achieved.

[0070] Figure 4 shows a second embodiment of the composite pane 10. The cross-sectional view of the

[0071] Figure 4 corresponds to the section line AA' (Figure 2) in the area of ​​the mirror structure 4. In contrast to the embodiment in Figure 3, the masking strip 7' (opaque background of the mirror structure 4) is not formed by a black print on the first surface (II) of the second pane 2, but rather by a colored thermoplastic intermediate layer 3, for example, a colored or tinted PVB film. One or more black prints can advantageously serve as additional layers as masking for adhesive bonds (not shown here).

[0072] Figure 5 shows a third embodiment of the composite pane 10. The cross-sectional view of Figure 5 corresponds to the section line AA' (Figure 2) in the region of the mirror structure 4. In contrast to the embodiment in Figure 3, the mirror structure 4 is not located between the first pane 1 and the thermoplastic intermediate layer 3, but rather on the first surface IV of the first pane 1. Furthermore, the mirror structure 4 is arranged spatially in front of the masking strip 7. A protective layer 5 is arranged on the surface of the mirror structure 4 facing the interior 12. The protective layer 5 seals the surface of the mirror structure 4 from the surrounding atmosphere. The provided protective layer 5 thus forms, at least in the region of the mirror structure 4, the first outer surface of the composite pane 10 facing the interior in the installed position and advantageously protects this and the mirror structure 4 from external influences and contamination.The protective layer 5 can be formed as a hydrophobic film, which is a coating with good resistance to deposits such as liquids, salts, grease, and dirt. For example, the formation of fingerprints when touched by a user can be prevented.

[0073] Figure 6 shows a fourth embodiment of the composite pane 10. The cross-sectional view of Figure 6 corresponds to the section line AA' (Figure 2) in the region of the mirror structure 4. In contrast to the embodiment in Figure 4, the mirror structure 4 is not located between the first pane 1 and the thermoplastic intermediate layer 3, but rather on the first surface (IV) of the first pane 1. The masking strip 7' (opaque background of the mirror structure 4) is not formed by a black print on the first surface (II) of the second pane 2 in this example, but rather by a colored thermoplastic intermediate layer 3, for example a colored or tinted PVB film. One or more black prints can advantageously serve as further additional layers as masking for adhesive bonds (not shown here).

[0074] In this embodiment, the mirror structure 4 and the masking strip T are separated from one another by the first pane 1. Figure 7 shows an enlarged cross-sectional view of the first embodiment of the composite pane 10 according to the invention in the region Z. The mirror structure 4 provided on the second surface III of the first pane 1 (for example, the inner pane) and the masking strip 7 applied in this region as an opaque background are, in this embodiment, preferably only locally limited to the lower edge region 11 of the composite pane 10 and do not influence the view-through region of the composite pane 10. The masking strip 7 is applied to the first surface II of the second pane 2, preferably as a ceramic black print. Because the mirror structure 4 is positioned on the second surface III of the first pane 1, it is protected there from environmental influences and contamination.

[0075] Figure 8 shows an enlarged cross-sectional view of a further embodiment of the composite pane 10 according to the invention in the region Z. A first thermoplastic intermediate layer 3 firmly connects the first pane 1 to the second pane 2. The mirror structure 4 provided on the second surface III of the first pane 1 (for example, the inner pane) is connected to the first pane 1 via a further, second thermoplastic intermediate layer 3'. In the edge region 11, the second pane 2 is connected to the mirror structure 4 via the masking strip 7 and via a further, third thermoplastic intermediate layer 3'. The thermoplastic intermediate layers 3 and 3' consist of a thermoplastic material, preferably polyvinyl butyral (PVB), ethylene vinyl acetate (EVA) and / or polyethylene terephthalate (PET).

[0076] The mirror structure 4 is laminated into the two thermoplastic intermediate layers 3' between the two individual panes 1 and 2, thereby providing good protection for the mirror layer 4 from external influences. The lamination of the mirror structure 4 can be achieved by laminating the individual panes of a composite pane. Electrical contact, as well as the connection to the power source of the mirror structure 4, is realized by suitable connecting cables, for example, flat conductors or foil conductors. The electrical connection points of the mirror structure 4 can be electrically connected to a control unit (ECU) outside the composite pane 10. The control unit is then configured to apply an electrical voltage to control the mirror structure 4.

[0077] The masking strip 7 is preferably applied to the first surface II of the second pane 2 as a ceramic black print. In this embodiment (analogous to Figure 3), the masking strip 7 consists of a coating containing an opaque material, for example, a black-colored screen printing ink that is baked in. The masking strip 7, applied in this area as an opaque background, is limited in this embodiment of the composite pane 10, so that the mirror structure 4 protrudes beyond the area of ​​the masking strip 7.

[0078] Images and representations reflected on the composite pane 10 according to the invention as a glazing unit stand out from it with high contrast, thereby improving the readability of the operating data and images and thus increasing road safety.

[0079] List of reference symbols

[0080] 1 first slice

[0081] 2 second slice

[0082] 3, 3' thermoplastic intermediate layer

[0083] 4 Mirror structure

[0084] 5 protective layer

[0085] 7, 7' masking strip

[0086] 10 Composite pane

[0087] 11 Marginal area

[0088] 12 Interior

[0089] 13 external environment

[0090] 100 projection arrangement

[0091] I second surface (outside) of the second disc 2

[0092] II first surface (inside) of the second disc 2

[0093] III second surface (outside) of the first disc 1

[0094] IV first surface (inside) of the first disc 1

[0095] A-A' section line

[0096] Z enlarged area

Claims

Patent claims 1. Composite disk (10) for a projection arrangement (100), comprising at least: - a first disk (1), a second disk (2), a thermoplastic interlayer (3), wherein the first disk (1) is connected to a second disk (2) via an interlayer (3) to form a composite disk (10), and wherein the first disk (1) has a first surface (IV) facing away from the thermoplastic interlayer (3) and a second surface (III) facing the thermoplastic interlayer (3), and the second disk (2) has a first surface (II) facing the thermoplastic interlayer (3) and a second surface (I) facing away from the thermoplastic interlayer (3), and - a mirror structure (4) with electrically switchable optical properties, wherein the mirror structure (4) is arranged in the direction of transmission through the composite disk (10) in front of an opaque masking strip (7, 7').

2. Composite disc according to claim 1, wherein the mirror structure (4) is arranged on the first disc (1).

3. Composite disc according to one of claims 1 or 2, wherein the mirror structure (4) is arranged between the first disc (1) and the thermoplastic intermediate layer (3) or on the first surface (IV) of the first disc (1).

4. Composite disc according to one of claims 1 to 3, wherein the mirror structure is arranged in an edge region (11) of the composite disc (10).

5. Composite disc according to one of claims 1 to 4, wherein the distance of the mirror structure (4) to an edge of the first disc (1) is from 0.1 cm to 30 cm, preferably from 1 cm to 15 cm and particularly preferably from 5 cm to 10 cm.

6. Composite disc according to one of claims 1 to 5, wherein the mirror structure (4) and an opaque masking strip (7) are separated by the intermediate layer (3) and / or by the first disc (1).

7. Composite disc according to one of claims 1 to 6, wherein a protective layer (5) protecting the mirror structure (4) is provided. A laminated glass pane according to any one of claims 1 to 7, wherein the mirror structure (4) is formed as a continuous surface. A laminated glass pane according to any one of claims 1 to 8, wherein the mirror structure (4) has variable reflection. A laminated glass pane according to any one of claims 1 to 9, wherein the mirror structure (4) is switchable from a transparent state to a semi-transparent state or a reflective state. A laminated glass pane according to any one of claims 1 to 10, wherein the mirror structure (4) is formed as a mirror film. A laminated glass pane according to any one of claims 1 to 11, wherein the opaque masking strip (7, 7') is formed as a coating, preferably as a ceramic black print, or as an embedded opaque element, in particular a film. A laminated glass pane according to any one of claims 1 to 12, wherein the laminated glass pane is provided as a windshield, roof window, rear window and / or side window of a vehicle.Projection arrangement (100) comprising: a composite screen (10) according to any one of claims 1 to 13, an image display device (9) associated with the composite screen having an image display directed onto the composite screen (10), wherein the image display device (9) is directed onto the composite screen (10) and illuminates it with light, in particular p-polarized light, and wherein at least the area of ​​the composite screen (10) is illuminated by the image display device (9) which at least partially comprises the mirror structure (4). Vehicle, in particular passenger car, with a composite screen (10) according to any one of the preceding claims.

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