Projection layout with two display areas on one composite screen

Description

[0001] The invention relates to a projection arrangement, a method for its manufacture and its use.

[0002] Modern cars are increasingly equipped with so-called head-up displays (HUDs). A projector, typically located in the dashboard area, projects images onto the windshield's viewing area, where they are reflected and perceived by the driver as a virtual image (from their perspective) behind the windshield. This allows important information to be projected into the driver's field of vision, such as current speed, navigation instructions, or warnings, which the driver can see without taking their eyes off the road. Head-up displays can thus significantly contribute to improving road safety.

[0003] It is also known to equip the windshield with a reflective coating that allows visibility but still reflects the projector's radiation to a significant degree. The angle of incidence of the projector's radiation on the windshield is typically around 65°, which is close to Brewster's angle for an air-to-glass interface (56.5° for soda-lime glass). If the projector uses s-polarized radiation, it is reflected off the outer surfaces of the windshield. In this case, an additional reflective coating can be used to increase the intensity of the displayed image. If the projector uses p-polarized radiation, it is not significantly reflected off the windshield surfaces. In this case, a reflective coating is essential to implement the HUD.A coating with at least one metallic layer, particularly a silver layer, can be used as a reflective layer. The windshield typically consists of an outer and an inner pane bonded together by a thermoplastic interlayer. This coating can be applied, for example, to the surface of the outer or inner pane facing the interlayer, or to a PET carrier film embedded within the interlayer. Head-up displays (HUDs) with p-polarized radiation and reflective layers are known, for example, from DE102014220189A1, WO2019046157A1, and US2017242247A1. However, purely dielectric reflective films are also known, composed of a plurality of individual layers with alternating high and low refractive indices, where the reflective effect is generated by optical interference.Such films can also be embedded in the interlayer. A laminated glass pane with such a functional film is known, for example, from WO03099553A1.

[0004] Windshields, in addition to the transparent viewing area, have an opaque masking area through which no visibility is possible. This masking area is typically located around the perimeter of the windshield and surrounds the viewing area. The primary purpose of this opaque masking area is to protect the adhesive used to bond the windshield to the vehicle body from UV radiation. If the laminated windshield is equipped with electrical functions (such as a heating function), the necessary electrical connections can also be concealed within the masking area. The masking area is typically formed by a black printed covering on the surface of the outer pane facing the interlayer.

[0005] It is possible to generate a display in the masking area, essentially using the same principle as a HUD. The masking area is illuminated by a projector, reflected, and thus a display is created for the driver. For example, information previously displayed on the dashboard, such as the time, speed, engine speed, or navigation system data, or even the image from a rear-facing camera (replacing traditional side or rearview mirrors), can be displayed directly on the windshield in a practical and aesthetically pleasing way, for instance, in the section of the masking area adjacent to the lower edge of the windshield. A projection arrangement of this type is known, for example, from DE102009020824A1.WO2021 / 106690A1 discloses a projection arrangement in which both a masking area and a viewing area of ​​the windshield are irradiated by a projection unit.

[0006] When a reflective layer is used for a HUD, a compromise must be found regarding its optical properties. For the intensity of the displayed image, it is advantageous if the reflectance in the visible spectral range is as high as possible. However, since the reflective layer also reflects light entering from the outside through the windshield, thereby reducing the light transmission of the visible area, there are limits to the level of reflectance that can be achieved. If such a reflective layer is also used in the masking area, where light transmission is irrelevant, the intensity of the displayed image will not be optimal.

[0007] The present invention aims to provide an improved projection arrangement with a display area in the transmission area and a display area in the masking area. The display in the masking area is intended to exhibit improved image intensity.

[0008] The object of the present invention is achieved according to the invention by a projection arrangement according to claim 1. Preferred embodiments are described in the dependent claims.

[0009] The projection arrangement according to the invention comprises a laminated glass pane. The laminated glass pane comprises an outer pane and an inner pane, which are bonded together via a thermoplastic intermediate layer. The laminated glass pane is intended to separate the interior (in particular the vehicle interior) from the external environment in a window opening (for example, the window opening of a vehicle). For the purposes of the invention, the inner pane refers to the pane of the laminated glass facing the interior. The outer pane refers to the pane facing the external environment. The laminated glass pane is preferably a vehicle window, for example, a window pane of a motor vehicle, rail vehicle, ship, or aircraft. The laminated glass pane is particularly preferably the windshield of a vehicle, preferably a motor vehicle, in particular a passenger car or truck.However, it can also be another vehicle window, for example the rear window or side window, if displays are desired on these windows. Likewise, it can also be used in buildings, for example as a window pane, glass facade or glass door in exterior or interior areas, or even in furniture or other furnishings.

[0010] The laminated glass pane has 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 vehicle windshields, the top edge is often also referred to as the roof edge and the bottom edge as the engine edge.

[0011] 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.

[0012] The laminated glass pane according to the invention has an opaque masking area and a transparent viewing area. For the purposes of the invention, a masking area is defined as an area of ​​the laminated glass pane through which visibility is not possible. The light transmission of the masking area is preferably essentially 0%. For the purposes of the invention, a viewing area is defined as an area of ​​the laminated glass pane that allows visibility through the glass pane and therefore exhibits a certain degree of transparency or at least translucency. The light transmission of the viewing area is preferably at least 10%, more preferably at least 20%, and most preferably at least 50%.The light transmission is preferably at least 70%, especially when the laminated glass is used as a windshield of a vehicle for which a total transmission greater than 70% is required (determined by the procedure for testing the light transmission of motor vehicle windows laid down in ECE-R 43, Annex 3, § 9.1).

[0013] In a typical embodiment, the masking area surrounds the viewing area like a frame. The masking area is thus arranged all the way around the viewing area. Typically, the masking area forms at least part of the edge region of the laminated glass. This means that the masking area borders at least a section of the side edge of the laminated glass. Often, the masking area forms the entire surrounding edge region of the laminated glass, particularly in the case of windshields, roof windows, and rear windows of vehicles. Therefore, in a preferred embodiment, the masking area is arranged in a surrounding edge region of the laminated glass and surrounds the viewing area.

[0014] The projection arrangement according to the invention comprises, in addition to the composite screen, at least one imaging unit. The at least one imaging unit generates a head-up display (HUD) in the transmission area and a further display area in the masking area, which, for the purposes of the invention, is referred to as the secondary display area.

[0015] The imaging unit can be, for example, a projector or an electronic display, such as an LCD, LED, or TFT display.

[0016] As is typical for HUDs, the imaging unit illuminates an area of ​​the composite windscreen (more precisely, its viewing area), where the radiation is reflected towards the viewer (driver), thereby creating a virtual image that the viewer perceives as if it were behind the composite windscreen. The area of ​​the viewing area that can be illuminated by the imaging unit is referred to as the HUD area for the purposes of this invention. The beam direction of the imaging unit can typically be varied by mirrors, particularly vertically, to adapt the projection to the viewer's height. The area in which the viewer's eyes must be located for a given mirror position is called the eyebox window. This eyebox window can be shifted vertically by adjusting the mirrors, with the entire area thereby accessible (i.e., the superposition of all possible eyebox windows) being referred to as the eyebox.A viewer located within the eyebox can perceive the virtual image. This means, of course, that the viewer's eyes must be within the eyebox, not their entire body.

[0017] The technical terms used here from the field of HUDs are generally known to experts. For a detailed explanation, please refer to the dissertation "Simulation-based measurement technology for testing head-up displays" by Alexander Neumann at the Institute of Computer Science of the Technical University of Munich (Munich: University Library of the Technical University of Munich, 2012), in particular to Chapter 2 "The Head-Up Display".

[0018] The at least one imaging unit also illuminates a portion of the masking area of ​​the laminated windscreen. This radiation is also reflected towards the viewer (driver), thereby generating a further display image that the viewer perceives within the masking area. For the purposes of this invention, the portion of the masking area that can be illuminated by the imaging unit is referred to as the secondary display area.

[0019] The at least one imaging unit is thus directed at the HUD area located in the transmission area and at the secondary display area located in the masking area. It irradiates these areas with radiation in the visible range of the electromagnetic spectrum to generate two display images: a HUD image in the transmission area and a secondary display image in the masking area. The radiation is specifically in the spectral range of 450 nm to 650 nm, for example, with wavelengths of 473 nm, 550 nm, and 630 nm (RGB).

[0020] Two different imaging units can be used to generate the two display images: a first imaging unit (the "HUD imaging unit," for example, a "HUD projector") that is directed at and illuminates the HUD area, and a second imaging unit (the "secondary imaging unit," for example, a "secondary projector") that is directed at and illuminates the secondary display area. This allows the display images to be generated independently. The imaging units preferably emit similar radiation, i.e., radiation of the same wavelength(s) and polarization. Their radiation intensity can differ. However, it is also possible, in principle, to use a single imaging unit that illuminates both the HUD area and the secondary display area.

[0021] The composite screen is equipped with a reflective layer in both the HUD area and the secondary display area. These reflective layers are designed to reflect the radiation from the at least one imaging unit to generate the respective display image. According to the invention, the reflective layer in the secondary display area has a higher reflectance relative to the radiation from the imaging unit than the reflective layer in the HUD area. Thus, a single, homogeneous reflective layer covering both the HUD area and the secondary display area is not used; instead, the reflective layer is adapted to the requirements of each specific display area. A reflective layer with a lower reflectance is used in the HUD area.Because this also reduces the reflection of light passing through the laminated glass from the outside, high light transmission is ensured in the viewing area, which contains the HUD area. In contrast, a reflective layer with a higher reflectance is used in the masking area, which contains the secondary display area. This significantly increases the intensity of the secondary display image. The secondary display image is more easily perceptible to the viewer, or, if a separate imaging unit is used for the secondary display, it can be operated at a lower radiation intensity. These are significant advantages of the present invention.

[0022] The difference between the reflectance of the reflective layer in the secondary display area and the reflectance of the reflective layer in the HUD area with respect to the radiation of the imaging unit is preferably at least 10%, for example from 30% to 60%. This results in a significantly more intense secondary display image.

[0023] The reflective layer in the HUD area preferably has a reflectance of 10% to 50% relative to the radiation from the imaging unit directed at the HUD area, and particularly preferably 15% to 35%. Within this range, the reflectance is sufficiently high to allow for a HUD display with adequate intensity. At the same time, the light transmission of the transparent area is not reduced to a critical degree.

[0024] At least the reflective layer in the HUD area is preferably transparent, which in the sense of the invention means that it has an average transmission in the visible spectral range (380 nm to 780 nm) of at least 10%, preferably at least 50%, particularly preferably at least 70%, and most preferably at least 80%, and thus does not significantly restrict the view through the screen.

[0025] The reflective layer in the secondary display area preferably has a reflectance of 20% to 100% relative to the radiation from the imaging unit directed onto the secondary display area, and particularly preferably 35% to 70%. This is advantageous for high intensity and good quality of the secondary display image.

[0026] Reflectance describes the proportion of the total incident radiation that is reflected. It is expressed as a percentage (relative to 100% incident radiation) or as a dimensionless number from 0 to 1 (normalized to the incident radiation). Plotted as a function of wavelength, it forms the reflection spectrum. Within the scope of the present invention, the descriptions of reflectance refer to the reflectance measured at an angle of incidence of 65° to the interior surface normal, which corresponds approximately to the illumination by conventional imaging devices. The reflectance values ​​are based on a reflection measurement with a light source that emits uniformly across the considered spectral range at a normalized radiation intensity of 100%.

[0027] The reflective layers cover at least the respective display area (HUD area or secondary display area). However, they can also extend beyond the respective display area, thus covering adjacent areas of the composite screen. This can be advantageous to avoid the need for such precise positioning of the reflective layers or to prevent display errors at the edges of the image that could occur due to imperfect positioning of the reflective layers. Particularly in the case of the reflective layer in the HUD area, it is advantageous if it covers the entire viewing area. The edge of the reflective layer should preferably be located in the masking area so that the entire viewing area has homogeneous optical properties and the edge of the reflective layer is not visible.

[0028] The reflective layer in the HUD area and the reflective layer in the secondary display area are preferably arranged in the same plane of the composite lens. This offers particular advantages in terms of manufacturing.

[0029] In an advantageous embodiment of the invention, the reflective layers are each formed as a reflective film or from a reflective film. The reflective films preferably each have at least one layer based on polyethylene terephthalate (PET) and are embedded in the intermediate layer. Such PET-based films are commonly used as functional films for laminated glass. They can sometimes be purchased and are easily integrated into the intermediate layer. Since PET-based films do not exhibit adhesive properties towards the glass panes, they are typically arranged between at least one outer and at least one inner thermoplastic bonding layer. The at least one outer bonding layer is arranged between the outer pane and the reflective film, and the at least one inner bonding layer is arranged between the inner pane and the reflective film.The intermediate layer therefore has a multilayered structure, wherein the reflective film is connected to the outer pane via at least one outer thermoplastic bonding layer and to the inner pane via at least one inner thermoplastic bonding layer. The bonding layers are preferably each formed from a thermoplastic film (bonding film) or composed of several film sections. The bonding films are preferably based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or polyurethane (PU).

[0030] The reflective films have at least one layer based on or made of PET. The proportion of PET in said layer is preferably more than 90 wt.%, particularly preferably more than 95 wt.%. Preferably, said layer consists essentially of PET. For the purposes of the present invention, the reflective films can also be referred to as PET-based or PET-containing. The functional films preferably have a thickness of 20 µm to 200 µm, particularly preferably 25 µm to 75 µm.

[0031] In one embodiment, the reflective films comprise a carrier film based on or made of PET and an electrically conductive coating applied thereto. The electrically conductive coating comprises at least one layer based on a metal, in particular silver. The conductive layer preferably contains at least 90 wt.% silver, more preferably at least 99 wt.% silver, and most preferably at least 99.9 wt.% silver. The silver layer may contain dopants, for example, palladium, gold, copper, or aluminum. The thickness of the silver layer is typically from 5 nm to 20 nm. Such a coating exhibits (partially) reflective properties in the visible range, so that the reflective film can serve as a reflective surface for the display system. The coating is preferably transparent, at least in the case of the reflective film for the HUD area.The conductive coating does not significantly reduce the light transmission of the transparent area. For transparent coatings, typically only thin metallic layers (for example, up to 20 µm thick) and dielectric layers are used, which, among other things, serve to reduce the reflection of the metallic layers. In the case of the reflective film for the secondary display area, the coating does not need to be transparent. In this case, a thicker silver layer, similar to a mirror, can also be used, so that the reflectance relative to the radiation from the imaging unit is essentially 100%. Metallic coatings typically also exhibit IR-reflective properties. They can therefore be used as solar control coatings to reduce the transmission of infrared components of solar radiation through the laminated glass.This reduces the heating of the interior behind the laminated glass and thus improves thermal comfort.

[0032] The electrically conductive coating is preferably a thin-film stack, i.e., a sequence of thin individual layers. The desired reflection characteristics, in particular the reflectance relative to the radiation from the imaging unit and the light transmission, are achieved primarily by selecting the materials and thicknesses of the individual layers. The conductive coating can thus be suitably adjusted, which is common practice in the field and well known to those skilled in the art. The aforementioned at least one electrically conductive layer is primarily responsible for the reflective effect. By using several electrically conductive layers, the reflectance can be further increased without significantly reducing the light transmission.

[0033] Dielectric layers or sequences of layers are typically arranged above and below the electrically conductive layer. If the conductive coating comprises several conductive layers, each conductive layer is preferably arranged between two typically dielectric layers or sequences of layers, so that a dielectric layer or sequence of layers is arranged between adjacent conductive layers. The coating is therefore a thin-film stack with n electrically conductive layers and ( n + 1 ) dielectric layers or layer sequences, where n is a natural number and where a conductive layer and a dielectric layer or layer sequence alternately follow each lower dielectric layer or layer sequence. Such coatings are known as solar control coatings and heatable coatings.

[0034] Examples of common dielectric layers in such a thin-film stack are: Anti-reflective coatings, which reduce the reflection of visible light and thus increase the transparency of the coated disc, for example based on silicon nitride, silicon-metal mixed nitrides such as silicon zirconium nitride, titanium oxide, aluminum nitride or tin oxide, with layer thicknesses of, for example, 10 nm to 100 nm; matching layers, which improve the crystallinity of the electrically conductive layer, for example based on zinc oxide (ZnO), with layer thicknesses of, for example, 3 nm to 20 nm; smoothing layers, which improve the surface structure for the layers above, for example based on a non-crystalline oxide of tin, silicon, titanium, zirconium, hafnium, zinc, gallium and / or indium, in particular based on tin-zinc mixed oxide (ZnSnO), with layer thicknesses of, for example, 3 nm to 20 nm.

[0035] In addition to electrically conductive and dielectric layers, the reflective coating can also include blocker layers, which protect the conductive layers from degradation. Blocker layers are typically very thin, metal-containing layers based on niobium, titanium, nickel, chromium, and / or alloys, with layer thicknesses of, for example, 0.1 nm to 2 nm.

[0036] In a preferred embodiment, the reflective films are purely dielectric polymer films containing alternating layers with different refractive indices. The films have no metal-containing coatings. They are purely dielectric sequences of polymer layers with a higher and polymer layers with a lower refractive index, arranged alternately. At least one of the two layer types is PET-based. The other layer type can also be PET-based, with the different refractive indices achieved by suitable additives, based on a PET copolymer or on another polymer, for example, PMMA.By alternating layers with different refractive indices, optical interference effects are achieved that can be tailored to the specific application (in particular by selecting the layer thicknesses and refractive indices) to realize reflective properties in a desired spectral range. For example, reflective properties in the visible spectral range can be achieved to use the functional film as a reflective surface for a display system. The film's reflective properties can be optimized for reflecting the radiation from the imaging unit, allowing for precise adjustment of the desired reflectance and light transmission. Additionally, IR-reflective properties can be achieved to reduce the transmission of infrared components of solar radiation.

[0037] In principle, a combination of the two configurations described above is also conceivable, with one of the reflective films being designed as a PET carrier film with an electrically conductive coating and the other as a purely dielectric film. For example, a transparent, purely dielectric reflective film could be used for the HUD area and a carrier film with a silver coating, similar to a mirror, for the secondary display area. Alternatively, a purely dielectric reflective film could be used for the secondary display area and a carrier film with a transparent conductive coating for the view-through area to reduce the transmission of IR radiation.

[0038] In a preferred embodiment, the reflective film for the HUD area and the reflective film for the secondary display area are arranged such that their side edges directly abut each other along a line referred to as the contact line in accordance with the invention. This has the advantage that the reflective films are easier to position because they do not need to be positioned independently and precisely. In particular, it is possible to join the two reflective films into a single, continuous film along the contact line before the composite lens is manufactured, so that only this single, continuous film needs to be positioned in the layer stack. The contact line is preferably located in the masking area, as it could be distracting in the viewing area. The distance of the contact line from the edge of the masking area facing the viewing area is preferably at least 1 mm, and more preferably from 3 mm to 15 mm.In this area, the contact line is, on the one hand, far enough away from the viewing area so that it is well concealed by the masking area and is not visible in the viewing area even taking into account usual manufacturing tolerances, and on the other hand, it is not too far from the viewing area so that the reflective film for the HUD area would occupy too large an area of ​​the masking area, which would then no longer be available for the secondary display area.

[0039] The reflective layer does not necessarily have to be a reflective film. Electrically conductive coatings can also be used on one of the surfaces of the discs. These coatings preferably include at least one metal-based layer, particularly silver. They can be designed as transparent, partially reflective coatings, using only thin metallic layers (for example, up to 20 µm thick) and dielectric layers, which, among other things, serve to reduce the reflection of the metallic layers. The design of the coating is generally the same as described above for a conductive coating on a PET-based substrate. However, a thicker silver layer, similar to a mirror, can also be used for the secondary display area.The coatings are preferably arranged on one of the surfaces of the outer or inner pane facing the intermediate layer, i.e., on the inner surface of the outer pane or the outer surface of the inner pane. The coating is particularly well-suited to the outer surface of the inner pane because it is then easier to implement the masking area with an opaque element, which must be located further away from the inner pane than the reflective layer, as the latter would otherwise not be irradiated by the imaging unit. In this case, the thermoplastic intermediate layer can be formed from a single bonding film or from several bonding films.

[0040] The masking area can be formed by an opaque, particularly black, print (masking print) on the inner surface of the outer pane. The masking print typically consists of an enamel applied by screen printing and subsequently fired, containing glass frits and colorants (especially pigments). Such masking prints are commonly used, particularly for vehicle windows. The pigment is typically a black pigment, for example, carbon black, aniline black, bone black, iron oxide black, spinel black, and / or graphite. The masking print preferably has a thickness of 5 µm to 50 µm, and particularly preferably 8 µm to 25 µm.

[0041] In a further development of the invention, the masking area is formed, at least in the secondary display area, by an opaque polymeric film, which is part of the intermediate layer and which is arranged between the reflective layers and the outer pane.

[0042] For the purposes of this invention, an opaque film is understood to be a film with a light transmission in the visible spectral range of less than 5%, in particular of 0%. A transparent film is understood to be a film with a light transmission of at least 10%, preferably at least 50%, particularly preferably at least 70%, and most preferably at least 80%.

[0043] This design is particularly advantageous when the reflective layer is a PET-based reflective film. The outer thermoplastic bonding layer (or at least one of the outer thermoplastic bonding layers if there are several) has a transparent area and an opaque area. It is composed of two different bonding films: a transparent bonding film and an opaque bonding film. The opaque bonding film contains colorants (pigments or dyes) in a concentration sufficient for opacity. The two films are joined, particularly flush with their side edges, so that they are arranged in one plane and together form a single layer. The transparent bonding film forms the transparent area of ​​the aforementioned outer bonding layer and is (at least partially) located in the transparent area of ​​the laminated panel.The opaque bonding film forms the opaque area of ​​the outer bonding layer and also at least part of the masking area of ​​the composite disc, which contains the secondary display area.

[0044] This means that the opaque connecting film of the outer connecting layer is the opaque element that causes a region of the laminated glass (namely, the masking region, or at least a portion of the masking region containing the secondary display area) to be opaque and prevent visibility through it. The opaque connecting film is thus located within the masking region of the laminated glass and prevents visibility through it (or at least through a portion of it), making it the opaque masking region. In other words, the outer connecting layer comprises a transparent viewing region formed by at least one transparent connecting film and an opaque masking region formed by at least one opaque connecting film. The masking region of the laminated glass is at least partially formed by the opaque masking region of the outer connecting layer.

[0045] It is possible that the opaque bonding film of the outer bonding layer forms the entire masking area of ​​the laminated glass. However, it is also possible that only a portion of the masking area is formed by the opaque bonding film, while the remaining portion is formed by another opaque element, in particular a printed cover (preferably on the inner surface of the outer glass). The portion of the masking area containing the secondary display area is formed by the opaque bonding film and preferably has no printed cover. Other portions of the masking area are formed by an opaque printed cover. In these areas, the bonding film is preferably transparent.

[0046] One problem with using PET-based films is that they exhibit different shrinkage behavior than typical bonding films, such as PVB films. This can lead to the so-called orange peel effect ( orange skin effectThis leads to distortions resulting from deformation at the interface between the reflective film and the adjacent bonding films. The orange peel effect causes optical distortions that are particularly visible in reflection and therefore reduce the quality of the secondary display image produced by reflection. The inventors have found that the orange peel effect caused by the reflective film is less noticeable against the background of the opaque bonding film than against the background of an opaque cover film. The appearance of the laminated panel is thus significantly improved because the orange peel effect is less distracting to the viewer. The inventors suspect that the roughness of conventional cover films intensifies the prominence of the orange peel effect, which can be avoided by replacing them with an opaque bonding film.

[0047] The outer bonding layer with the opaque bonding film can be the only outer bonding layer. However, additional outer bonding films, preferably transparent, may also be present. There may be a single inner bonding layer or several inner bonding layers, which are / are transparent. The following layer sequences, which form the composite disc in the specified order, are particularly noteworthy: Outer pane - outer bonding layer with opaque area - reflective films - transparent inner bonding layer - inner pane; the thickness of the first outer bonding layer is preferably from 0.3 mm to 2 mm, particularly preferably from 0.6 mm to 1.6 mm, particularly preferably from 0.7 mm to 1.0 mm. The thickness of the inner bonding layer is preferably from 0.005 mm to 0.55 mm, particularly preferably from 0.03 mm to 0.5 mm, most preferably from 0.035 mm to 0.4 mm; outer pane - outer bonding layer with opaque area - transparent further outer bonding layer - reflective films - transparent inner bonding layer - inner pane;This design offers particular advantages in terms of manufacturing: the outer bonding layer, the reflective films, and the inner bonding layer, each formed in one piece, can be joined to form an easy-to-handle multilayer film, which is inserted between the panes during the manufacture of the laminated glass, thereby positioning the three layers simultaneously; the thickness of the outer bonding layer with opaque area, the outer bonding layer, and the inner bonding layer is preferably from 0.005 mm to 0.55 mm, more preferably from 0.03 mm to 0.5 mm, and most preferably from 0.035 mm to 0.4 mm.

[0048] The layer sequences mentioned contain the layers mentioned. Further bonding layers, in particular transparent bonding layers, may be present between the reflective films and the outer pane and / or between the reflective films and the inner pane. Particularly preferably, the layer sequences mentioned consist only of the layers mentioned.

[0049] In an advantageous embodiment, the thickness of the outer thermoplastic bonding layer (or the sum of the thicknesses of all outer thermoplastic bonding layers, if several are present) is greater than the thickness of the inner thermoplastic bonding layer (or the sum of the thicknesses of all inner thermoplastic bonding layers, if several are present). This has the advantage of further improving the reflective optics of the composite disc and thus its appearance. The thin inner thermoplastic layer bonds the PET-based functional film very firmly to the inner disc, reducing shrinkage and resulting in a less pronounced orange peel effect. Since the composite disc is irradiated by the imaging unit via the inner disc, a thin inner thermoplastic layer is also advantageous for the quality of the displayed image.The inner thermoplastic bonding layer or sequence of bonding layers preferably has a thickness of 0.005 mm to 0.55 mm, particularly preferably 0.03 mm to 0.5 mm, and most preferably 0.035 mm to 0.4 mm. The outer thermoplastic bonding layer or sequence of bonding layers preferably has a thickness of 0.3 mm to 2 mm, particularly preferably 0.6 mm to 1.6 mm, and most preferably 0.7 mm to 1.0 mm. The thicker outer thermoplastic layer or sequence of layers improves the stability of the composite panel and the shielding against disturbing noise.

[0050] If the masking area is arranged in a circumferential edge region of the laminated glass, one area of ​​the masking area borders the lower edge of the laminated glass, another area borders the upper edge of the laminated glass, and two further areas border each of the side edges. In an advantageous embodiment, the secondary display area is arranged in the area of ​​the masking area adjacent to the lower edge. The secondary display area is thus located between the viewing area and the lower edge of the laminated glass. Status information that was previously typically displayed in the dashboard area can be shown in the secondary display area, such as the time, vehicle speed, engine speed, coolant temperature, interior or exterior temperature, information from the entertainment system (such as the currently playing radio station), or information from a navigation system.Similarly, the image from one or more rear-facing cameras can be displayed to supplement or replace conventional side or rearview mirrors. Displaying this information in the secondary display area has the advantage that the driver does not have to turn their gaze as far from their primary field of vision as with conventional displays. Furthermore, the display is aesthetically pleasing.

[0051] The at least one imaging unit illuminates the reflective layers of the inner pane with electromagnetic radiation in the visible spectral range to generate a display image that a user inside the unit can perceive. The at least one imaging unit is therefore located on the inside side of the composite pane and illuminates the composite pane via the inner surface of the inner pane. The radiation from the imaging unit is (partially) reflected by the reflective layers. Preferably, the projection arrangement has two imaging units, with the first imaging unit illuminating the HUD area and the second imaging unit illuminating the secondary display area.

[0052] In a particularly advantageous embodiment, the at least one imaging unit (or both imaging units if two imaging units are used) emits p-polarized radiation. The radiation from the at least one imaging unit thus has a p-polarized component. The p-polarized radiation component is preferably more than 50%, particularly preferably more than 70%, and most preferably more than 90% of the radiation from the imaging unit. In a particularly advantageous embodiment, the radiation from the imaging unit is essentially purely p-polarized – the p-polarized radiation component is therefore 100% or deviates only insignificantly from this. 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 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 lens at the geometric center of the irradiated area. The polarization, and in particular the proportion of p- and s-polarized radiation, is determined at a point within the HUD area, preferably at its geometric center. If the composite lens is curved, which is typically the case with vehicle windshields, this affects the plane of incidence of the radiation from the imaging unit. Therefore, slightly different polarization proportions may occur in other areas, which is unavoidable for physical reasons.

[0053] The radiation from the imaging unit preferably strikes the laminated glass at an angle of incidence of 45° to 70°, particularly 60° to 70°. In an advantageous embodiment, the angle of incidence deviates from Brewster's angle by a maximum of 10°. The p-polarized radiation is then only minimally reflected from the surfaces of the laminated glass. As a result, the functional film represents the only significant reflective surface for the radiation from the imaging unit. If the radiation were also significantly reflected from the external surfaces of the laminated glass (air-glass interface), multiple images would be produced, which would be at least disturbing, if not completely unacceptable, for the user.The angle of incidence is the angle between the incident vector of the radiation from the imaging unit and the interior surface normal (i.e., the surface normal to the interior external surface of the laminated glass) at the geometric center of the HUD area. The Brewster angle for an air-to-glass interface in the case of soda-lime glass, which is commonly used for windows, is 56.5° (with a refractive index of 1.51 for soda-lime glass at 550 nm). Ideally, the angle of incidence should be as close as possible to this Brewster angle. However, angles of incidence of, for example, 65° can also be used, which are common for HUD projection setups, are easily implemented in vehicles, and deviate only slightly from the Brewster angle, so that the reflection of the p-polarized radiation increases only marginally.

[0054] Since the reflection of the p-polarized radiation from the imaging unit occurs primarily at the reflective layers and not at the external glass surfaces, it is unnecessary to arrange the external glass surfaces at an angle (wedge angle) to each other to avoid ghost images. Such wedge angles are common in projection setups with s-polarized radiation, which is reflected at both external glass surfaces. If these surfaces were arranged parallel, this would result in two offset display images (main image and ghost image). Therefore, the external surfaces of the windshield are preferably arranged essentially parallel to each other. The thermoplastic intermediate layer is preferably not wedge-shaped but has a substantially constant thickness, particularly in the vertical direction between the top and bottom edges of the windshield, as do the inner and outer glass panes.In contrast, a wedge-shaped intermediate layer would have a variable, and in particular increasing, thickness along the vertical path between the lower and upper edges of the windshield. This intermediate layer is typically made of at least one thermoplastic film. Since standard films are significantly less expensive than wedge-shaped films, windshield production becomes more cost-effective.

[0055] The thermoplastic interlayer, with the exception of any (PET-based) reflective films, is preferably based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or polyurethane (PU), or on mixtures, copolymers, or derivatives thereof, particularly preferably on PVB. The interlayer typically consists of at least one thermoplastic film (bonding film), especially based on PVB, EVA, or PU. This means that the film consists largely of the aforementioned polymer (proportion greater than 50% by weight). The film may contain other additives besides the polymer, particularly plasticizers.If the reflective layers are designed as reflective films, the intermediate layer comprises, in addition to these reflective films, at least two bonding layers (inner and outer bonding layer), each bonding layer typically consisting of at least one bonding film, in particular based on PVB, EVA, or PU. The thickness of each bonding film is preferably from 0.2 mm to 1 mm. For example, PVB films with standard thicknesses of 0.38 mm or 0.76 mm can be used. Instead of films, polymeric coatings can also be used, especially if the thermoplastic layer in question is to be very thin, for example, with a thickness of 0.005 mm to 0.1 mm or 0.02 mm to 0.07 mm.

[0056] The outer and inner panes are preferably made of glass, particularly preferably of soda-lime glass, as is common for window panes. However, one or both panes can also be made of other types of glass, for example, quartz glass, borosilicate glass, or aluminosilicate glass, or of rigid, clear plastics, for example, polycarbonate or polymethyl methacrylate. The panes can be clear, tinted, or colored. The thicknesses of the outer and inner panes are preferably from 0.5 mm to 5 mm, and particularly preferably from 1 mm to 3 mm, and are independent of each other.

[0057] The outer pane, the inner pane, and the thermoplastic interlayer can be clear and colorless, or tinted or colored. In a preferred embodiment, the total transmission through the laminated glass is greater than 70%, particularly if the laminated glass is a windshield. The term "total transmission" refers to the procedure for testing the light transmittance of motor vehicle windows as specified in ECE-R 43, Annex 3, Section 9.1. The outer pane and the inner panes can be independently unstressed, partially stressed, or stressed. If at least one of the panes is to have a stress, this can be a thermal or chemical stress.

[0058] The laminated glass is preferably curved in one or more spatial directions, as is common practice for automotive windshields. Typical radii of curvature range from approximately 10 cm to approximately 40 m. The inner surface of the inner pane is generally concave, while the outer surface of the outer pane is convex. However, the laminated glass can also be flat, for example, when used as a window for buses, trains, tractors, buildings, or furniture.

[0059] The invention also comprises a method for manufacturing a projection arrangement according to the invention, comprising at least: (a) Combining an outer pane and an inner pane via a thermoplastic intermediate layer to form a composite pane, wherein the composite pane is provided with an opaque masking area and a transparent viewing area, and wherein the composite pane is provided with a reflective layer in a HUD area located in the viewing area and in a secondary display area located in the masking area; and (b) Directing at least one imaging unit at the HUD area and the secondary display area.

[0060] According to the invention, the reflective layers are suitable for reflecting the radiation from the at least one imaging unit to generate a display image, wherein the reflective layer in the HUD area has a higher reflectance relative to the radiation from the at least one imaging unit than the reflective layer in the secondary display area.

[0061] The foregoing statements and preferred configurations relating to the projection arrangement apply equally to the procedure.

[0062] The application of reflective layers to the composite glass can be carried out in various ways. If the reflective layers are coatings on the outer or inner glass, they are preferably applied to the respective glass surface by physical vapor deposition (PVD), particularly preferably by sputtering, and most preferably by magnetron sputtering. In principle, however, the coatings can also be applied, for example, by chemical vapor deposition (CVD), such as plasma-enhanced chemical vapor deposition (PECVD), by evaporation, or by atomic layer deposition (ALD). atomic layer deposition,The reflective layers are preferably applied to a surface (interior surface of the outer pane or exterior surface of the inner pane, preferably the latter) before the panes are bonded together to form a laminated pane. In this case, the intermediate layer can consist of a single bonding film or several bonding films stacked on top of each other. A layer stack is thus created from the following elements in the specified order: outer pane - at least one bonding film - inner pane. This layer stack is then laminated to form the laminated pane.

[0063] In a preferred embodiment, the reflective layers are designed as reflective films. These are arranged between two thermoplastic bonding layers and together form the intermediate layer. The thermoplastic bonding layers are preferably arranged by positioning a corresponding thermoplastic bonding film at the appropriate location. Alternatively, one or both of the adjacent layers can be provided with a thin polymeric coating. The bonding layers are preferably provided in the form of at least one thermoplastic bonding film (in particular, a PVB film). Thus, a layer stack is created from the following elements in the specified order: outer pane - at least one bonding film - reflective films - at least one bonding film - inner pane. This layer stack is then laminated to form the composite pane.Reflective films can generally be purchased, for example as a PET carrier film with an electrically conductive coating or as a purely dielectric reflective film with different individual layers that alternately exhibit a higher and a lower refractive index. They can be manufactured by depositing an electrically conductive coating onto a PET carrier film, particularly using the thin-film coating processes mentioned above, or by co-extrusion or multi-extrusion of two materials with different refractive indices to form a purely dielectric reflective film.

[0064] The reflective film for the HUD area and the reflective film for the secondary display area can be securely bonded together before being arranged in the layer stack, particularly along their side edges following a contact line. This bonding can be achieved, for example, by gluing or fusing. This allows both reflective films to be handled like a single film and positioned together in the layer stack.

[0065] The masking area can also be created in different ways. It can be formed by applying an opaque enamel printing ink to a surface of the panes, particularly the inner surface of the outer pane, especially using a screen printing process. The enamel printing ink is then fired into the pane surface, forming an opaque cover print that creates the masking area.

[0066] In a preferred embodiment, the masking area is formed by an opaque polymeric film. In this case, one of the bonding layers is not formed by a single homogeneous bonding film, but is composed of a section of an opaque bonding film and a section of a transparent bonding film. The bonding layer with the opaque bonding film is arranged between the reflective layer and the outer pane. If reflective films are used as reflective layers, the bonding layer with the opaque bonding film is the one (or one of those) that is arranged between the reflective layers and the outer pane.

[0067] In an advantageous embodiment, a transparent bonding layer and the reflective films are first arranged on top of each other in a flat plane and permanently bonded to form a multilayer film (more precisely, a two-layer film, "bilayer"), for example by gluing or lamination (especially under the influence of temperature). The advantage of the multilayer film is that it can be handled like a single bonding film – the two layers are positioned together in the stack in one step and do not need to be arranged individually and sequentially. The transparent bonding layer is, in particular, formed in one piece from a transparent bonding film, so that the multilayer stack is comparatively easy to manufacture.

[0068] The outer pane, the composite bonding layer with the opaque bonding film, the two-layer film, and the inner pane are then arranged flat on top of each other in the specified order to form a layer stack, with the bonding layer of the multi-layer film facing the inner pane. However, it is also possible to insert further bonding layers between the two-layer film and the inner pane and / or between the two-layer film and the outer pane, particularly transparent bonding layers.

[0069] In a particularly advantageous embodiment, a transparent bonding layer, the reflective films, and another transparent bonding layer are first arranged one on top of the other in the specified sequence and permanently bonded to form a multilayer film (more precisely, a three-layer film, "trilayer"), for example, by gluing or lamination (especially under the influence of temperature). The reflective films are securely embedded in the multilayer film, and due to the outer bonding layers, it exhibits adhesive properties towards the discs and other bonding layers. The advantage of the multilayer film is that it can be handled like a single bonding film—the three layers are positioned together in the layer stack in one step and do not need to be arranged individually and sequentially in the layer stack.The transparent bonding layers are formed in one piece from a single transparent bonding film, making the multilayer stack relatively easy to manufacture.

[0070] The outer pane, the composite bonding layer with the opaque bonding film, the multilayer film, and the inner pane are then arranged on top of each other in the specified order to form a layer stack. The resulting laminated pane then consists of the following layers in the specified order: outer pane - outer bonding layer with opaque area - transparent outer bonding layer - reflective films - transparent inner bonding layer - inner pane. However, it is also possible to insert additional bonding layers between the three-layer film and the inner pane and / or between the three-layer film and the outer pane, particularly transparent bonding layers.

[0071] These multilayer films (two-layer film, three-layer film) are preferably supplied in large format, for example as rolls, with dimensions significantly larger than the surface area of ​​typical laminated glass panes. A suitable piece is then cut from this during the manufacturing of the laminated glass pane, as is common practice with simple bonding films.

[0072] Once the layer stack consisting of the outer pane, the components of the intermediate layer, and the inner pane, including the masking area and reflective layers, is produced, it is laminated to form a composite pane. This is done in particular using known methods, such as autoclave processes, vacuum bag processes, vacuum ring processes, calender processes, vacuum laminators, or combinations thereof. The bonding of the outer and inner panes via the intermediate layer typically occurs under the influence of heat, vacuum, and / or pressure.

[0073] If the laminated glass pane is to be curved, the outer and inner panes are preferably bent before lamination and preferably after any coating processes to bring them into a cylindrical or spherically curved shape. 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. At these temperatures, the glass panes become plastically deformable and can be bent into the desired shape using known bending methods, such as gravity bending, press bending, suction bending, or combinations thereof.

[0074] The invention further comprises the use of a projection arrangement according to the invention in a vehicle (in particular a motor vehicle), wherein the laminated glass is a window pane of the vehicle, preferably a windshield. However, the projection arrangement can also be used in buildings, furniture, or furnishings.

[0075] The invention is explained in more detail below with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and not to scale. The drawing does not limit the invention in any way.

[0076] They show: Fig. 1 a top view of a composite disk of a projection arrangement according to the invention, Fig. 2 a cross-section through a projection arrangement according to the invention with the composite disk made of Figure 1 , Fig. 3 a cross-section through the composite disc made of Figure 1, Fig. 4 a cross-section through a further embodiment of the composite disk of a projection arrangement according to the invention, Fig. 5 a cross-section through a further embodiment of the composite disk of a projection arrangement according to the invention.

[0077] Figure 1, Figure 2 and Figure 3 Each shows a detail of a projection arrangement according to the invention consisting of a composite disk 10 and two projectors P.1, P.2. Figure 1 shows a top view of the composite disc 10, Figure 2 a cross-section through the projection arrangement along the in Figure 1 marked section line XX' and Figure 3 a cross-section through the composite disk 10 along the same section line with a larger number of details.

[0078] The laminated glass 10 is the windshield of a motor vehicle and has an opaque masking area M, which is arranged in a circumferential edge region and surrounds a transparent viewing area D in a frame-like manner. The laminated glass 10 has an upper edge O pointing upwards (towards the vehicle roof) and a lower edge U pointing downwards (towards the engine compartment), with two side edges running between them. Such masking areas M are common in vehicle windows – they serve to protect the adhesive used to bond the laminated glass 10 to the vehicle body from UV radiation. Furthermore, any electrical connections or the side edge of an embedded functional film can be concealed in the masking area M.

[0079] The projection arrangement also includes two projectors, P.1 and P.2. The first projector, P.1, is directed at an area of ​​the composite screen 10 in the viewing area D. In this area, which is referred to as the HUD area B for the purposes of the invention, the projector P.1 can generate images that are perceived by a viewer F (the driver) as virtual images on the side of the composite screen 10 facing away from him, provided his eyes are within the so-called eyebox E. The second projector, P.2, is directed at an area of ​​the composite screen 10 in the masking area M. In this area, which is referred to as the secondary display area S for the purposes of the invention, the projector P.2 can also generate images that are perceived by the viewer F.In HUD area B, a head-up display (HUD) is implemented, which allows information to be projected into the viewer's field of vision without requiring them to take their eyes off the road. In the secondary display area S, which is located in a section of the laminated glass 10 bordering the lower edge U, status displays can be shown, such as those conventionally displayed on the dashboard (e.g., vehicle speed, navigation system display, speed limits and other information about the current route, temperature or time), or the image(s) from one or more rear-facing cameras, which supplement or replace the conventional rear-view and / or exterior mirrors.

[0080] The laminated glass 10 consists of an outer pane 1 and an inner pane 2, which are bonded together via a thermoplastic intermediate layer 3. In its installed position, the outer pane 1 faces the external environment, and the inner pane 2 faces the vehicle interior. For simplicity, the laminated glass 10 is shown as flat, although vehicle windows are usually curved, which is also preferred within the scope of the present invention. The outer pane 1 and the inner pane 2 are made of soda-lime glass. The outer pane 1 has, for example, a thickness of 2.1 mm, and the inner pane 2 a thickness of 1.6 mm.

[0081] The masking area M is formed by a black masking print 8, which is applied to the interior surface of the outer pane 1 facing the intermediate layer 3. Such a masking print 8 is common in the automotive sector: an enamel-like paint is screen-printed onto the pane surface. It contains a black pigment and glass frits, which are baked into the pane surface.

[0082] The intermediate layer 3 has a multi-layered structure. It comprises an outer bonding layer 5, which faces the outer pane 1, and an inner bonding layer 6, which faces the inner pane 2. Bonding layers 5 and 6 are transparent and made of commercially available PVB film, which also contains plasticizers. The outer bonding layer 5 has a thickness of 0.76 mm, and the inner bonding layer 6 has a thickness of 0.38 mm.

[0083] Between the bonding layers 5 and 6 are two reflective layers 4-B and 4-S, which are designed as reflective foils. The reflective layers 4-B and 4-S are thus connected to the outer disk 1 via the outer bonding layer 5 and to the inner disk 2 via the inner bonding layer 6. The reflective layer 4-B extends over the entire viewing area D, and its side edges are located in the masking area M. The reflective layer 4-B is present in the HUD area B. The reflective layer 4-S is located in the section of the masking area M adjacent to the lower edge U. The reflective layer 4-S is also present in the secondary display area S. The reflective layers 4-B and 4-S are arranged in the same plane of the composite disk 10, namely between the bonding layers 5 and 6. They are arranged adjacent to each other, with sections of their side edges in direct contact along a contact line 4-k.The contact line 4-k is located in the section of the masking area M adjacent to the lower edge U and has a distance of, for example, 7 mm from the edge of the masking area M facing the viewing area D.

[0084] Projectors P.1 and P.2 are arranged on the inner side of the composite disk 10. The inner disk 2 of the composite disk 10 thus faces the projectors P.1 and P.2. Projector P.1 illuminates the HUD area B, and projector P.2 illuminates the secondary display area S, each to generate a display image. The radiation from projectors P.1 and P.2 is p-polarized, specifically essentially purely p-polarized. Since projectors P.1 and P.2 illuminate the composite disk 10 at an angle of incidence of approximately 65°, which is close to Brewster's angle, the radiation from projectors P.1 and P.2 is reflected only negligibly from the external surfaces of the composite disk 10 facing away from the intermediate layer 3.The double reflection at these external surfaces leads to a ghost image in s-polarized HUDs, which is usually aligned with the main image by arranging the surfaces at a wedge angle to each other (by using a wedge-shaped intermediate layer and / or at least one wedge-shaped disk). This is unnecessary in projection arrangements with p-polarized radiation. Instead, the composite disk 10 must be equipped with an additional reflective interface to reflect the p-polarized radiation. In this case, this function is fulfilled by the reflective layer 4-B for the HUD area B and the reflective layer 4-S for the secondary display area S.

[0085] The reflective layers 4-B and 4-S are purely dielectric reflective films, each composed of a sequence of polymeric dielectric layers, with the individual layers alternating between higher and lower refractive indices. At least one of the two layer types consists of PET. Due to interference, the reflective films exhibit reflective properties, particularly with respect to the radiation from projectors P.1 and P.2.

[0086] By using different reflective layers 4-B and 4-S for the HUD area B and the secondary display area S according to the invention, their properties can be specifically adjusted to the respective requirements. In this case, this is achieved in particular by adjusting the refractive index and / or thickness of the individual layers, thereby influencing optical interference. In the HUD area B, a reflective layer 4-B with a lower reflectance relative to the projector radiation is used than in the secondary display area S. This ensures that the light transmission of the viewing area D is not reduced to a critical degree. The reflective layer 4-S in the secondary display area S has a higher reflectance, which is easily possible since the light transmission in the masking area M is irrelevant. This allows the intensity of the secondary display image to be significantly increased.This is the great advantage of the present invention.

[0087] Although the invention is presented here by way of example with projectors P.1, P.2 as imaging units, alternatively, for example, electronic displays (screens, "displays") can be used as imaging units. This can be particularly advantageous in the case of the second imaging unit P.2 for the secondary display area S.

[0088] Figure 4 Figure 1 shows a cross-section through another composite disk 10, which can be used for a projection arrangement according to the invention. The outer disk 1, the inner disk 2, the inner bonding layer 6 and the reflective layers 4-B, 4-S are configured in the same way as in the example of Figure 1. Figures 1 to 3The outer pane 1 is not provided with a masking print 8. The masking area M is instead formed by an opaque film 5b. The outer bonding layer 5 is composed of this opaque film 5b in the masking area M and a transparent film 5a in the transmission area D. Both films 5a and 5b are 0.76 mm thick PVB films, with the opacity of film 5b being achieved by the addition of pigments.

[0089] The PET-based reflective layers 4-B and 4-S can cause a so-called orange peel effect, which is particularly visible in reflection and leads to optical distortions. The inventors have found that the orange peel effect is significantly less noticeable against the background of the opaque film 5b than against the background of the cover print 8. Optical distortions are less distracting, which is perceptible to the naked eye and can be used for a qualitative comparison (for example, with a lamp reflected off the laminated glass).

[0090] Figure 5 Figure 1 shows a cross-section through another composite disk 10, which can be used for a projection arrangement according to the invention. The outer disk 1, the inner disk 2, the inner bonding layer 6, and the reflective layers 4-B, 4-S are configured in the same way as in the examples of the Figures 1 to 3 as well as Figure 4 As in Figure 4The masking area is formed by an opaque film 5b, and the outer pane 1 is not provided with a cover print 8. In addition to the outer bonding layer 5, which is composed of the opaque film 5b and a transparent film 5a, there is another outer bonding layer 7, which is formed from a transparent PVB film. The reflective layers 4-B and 4-S are arranged between the transparent inner bonding layer 6 and the transparent outer bonding layer 7. The outer bonding layer 5 with the opaque film 5b is located between the outer bonding layer 7 and the outer pane 1. Both outer bonding layers 5 and 7 have a thickness of 0.38 mm.

[0091] This design has the advantage that the outer bonding layer 7, the reflective layers 4-B, 4-S, and the inner bonding layer 6 can be bonded together to form a pre-laminated multilayer film before the composite disc is manufactured. This makes the film easier to handle than if each individual layer had to be arranged separately in the layer stack between the discs 1 and 2. A multilayer film involving the multi-layered outer bonding layer 5, on the other hand, would be more complicated to manufacture. Reference symbol list:

[0092] (10) Composite disc (1) Outer pane (2) Inner pane (3) Thermoplastic intermediate layer (4-B) Reflective layer in HUD area B (4-S) Reflective layer in secondary display area S (4-k) Boundary line of reflective layers 4-B, 4-S (5) Outer bonding layer of intermediate layer 3 (5a) Transparent film of outer bonding layer 5 (5b) Opaque film of outer bonding layer 5 (6) Inner bonding layer (7) Further outer bonding layer (8) Cover print (P.1) first imaging unit / first projector (P.2) second imaging unit / second projector (E) eyebox (F) viewer / vehicle driver (M) Masking area of ​​the composite screen 10 (D) Viewing area of ​​the composite screen 10 (B) HUD area of ​​the composite screen 10 (S) Secondary display area of ​​the composite screen 10 (O) Top edge of the composite screen 10 (U) Bottom edge of the composite screen 10

Claims

1. Projection arrangement comprising at least - a composite pane (10), comprising an outer pane (1) and an inner pane (2), which are connected to one another via a thermoplastic intermediate layer (3), with an opaque masking region (M) and a transparent see-through region (D); and - at least one imaging unit (P.1, P.2), which is directed at an HUD region (B) arranged in the see-through region (D) and at a secondary display region (S) arranged in the masking region (M); wherein - the composite pane (10) is equipped in the HUD region (B) and in the secondary display region (S) in each case with a reflection layer (4-B, 4-S), which are suitable for reflecting the radiation of the at least one imaging unit (P.1, P.2) to generate a display image; and - the reflection layer (4-S) in the secondary display region (S) has a higher reflectance with respect to the radiation of the at least one imaging unit (P.1, P.2) than the reflection layer (4-B) in the HUD region (B).

2. Projection arrangement according to claim 1, having a first imaging unit (P.1) directed at the HUD region (B) and a second imaging unit (P.2) directed at the secondary display region (S).

3. Projection arrangement according to claim 1 or 2, wherein the difference between the reflectance of the reflection layer (4-S) in the secondary display region (S) with respect to the radiation of the at least one imaging unit (P.1, P.2) and the reflectance of the reflection layer (4-B) in the HUD region (B) with respect to the radiation of the at least one imaging unit (P.1, P.2) is at least 10%, preferably from 30% to 60%.

4. Projection arrangement according to one of claims 1 to 3, wherein the reflection layers (4-B, 4-S) are in each case formed as a reflection film with at least one layer based upon polyethylene terephthalate (PET), which are embedded in the intermediate layer (3).

5. Projection arrangement according to claim 4, wherein the reflection films are purely dielectric polymer films, which contain alternating individual layers with different refractive indices.

6. Projection arrangement according to claim 4 or 5, wherein the reflection films are arranged such that their side edges are directly adjacent to one another along a contact line (4-k), and wherein the contact line (4-k) is arranged in the masking region (M).

7. Projection arrangement according to claim 6, wherein the distance of the contact line (4-k) from the edge of the masking region facing the see-through region (D) is at least 1 mm, preferably from 3 mm to 15 mm.

8. Projection arrangement according to one of claims 1 to 7, wherein the masking region (M) is formed at least in the secondary display region (S) by an opaque polymer film (5b) that is part of the intermediate layer (3) and that is arranged between the reflection layers (4-B, 4-S) and the outer pane (1).

9. Projection arrangement according to one of claims 1 to 8, wherein the masking region (M) is arranged in a circumferential edge region of the composite pane (10) and surrounds the see-through region (D).

10. Projection arrangement according to claim 9, wherein - the composite pane (10) has an upper edge (O), a lower edge (U), and two side edges extending between them, and - the secondary display region (S) is arranged in the region, adjoining the lower edge (U), of the masking region (M).

11. Projection arrangement according to one of claims 1 to 10, wherein the at least one imaging unit (P.1, P.2) emits p-polarised radiation.

12. Projection arrangement according to one of claims 1 to 11, wherein the intermediate layer (3), with the exception of the potential reflection films, is formed on the basis of polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or polyurethane (PU).

13. Projection arrangement according to one of claims 1 to 12, wherein the outer pane (1) and the inner pane (2) are formed from soda-lime glass.

14. Method for producing a projection arrangement, comprising at least (a) connecting an outer pane (1) and an inner pane (2) via a thermoplastic intermediate layer (3) to form a composite pane (10), wherein the composite pane (10) is provided with an opaque masking region (M) and a transparent see-through region (D), and wherein the composite pane (10) is equipped in each case with a reflection layer (4-B, 4-S) in an HUD region (B), arranged in the see-through region (D), and in a secondary display region (S), arranged in the masking region (M); and (b) directing at least one imaging unit (P.1, P.2) at the HUD region (B) and the secondary display region (S); wherein the reflection layers (4-B, 4-S) are suitable for reflecting the radiation of the at least one imaging unit (P.1, P.2) to generate a display image, and wherein the reflection layer (4-B) in the HUD region (B) has a higher reflectance with respect to the radiation of the at least one imaging unit (P.1, P.2) than the reflection layer (4-S) in the secondary display region (S).

15. Use of a projection arrangement according to one of claims 1 to 13 in a vehicle, wherein the composite pane (10) is a window pane of the vehicle - preferably a windscreen.