Display system for a vehicle

Abstract

Display system for a vehicle, comprehensive - a windscreen (10) with an upper edge (O) and a lower edge (U), a transparent viewing area (D) and a display area (A) which is arranged in an opaque masking area (M) located between the viewing area (D) and the lower edge (U), comprising an outer pane (1) with an outer surface (I) and an inner surface (II) and an inner pane (2) with an outer surface (III) and an inner surface (IV) which are connected to each other via an intermediate layer, and - an imaging unit (20) directed towards the display area (A) and emitting p-polarized radiation, wherein - the windscreen (10) in the display area (A) is equipped with a reflective layer (4) which is suitable to reflect the radiation from the imaging unit (20) to generate a display image, - in the display area (A) the distance between the outer pane (1) and the inner pane (2) increases in a direction from the viewing area (D) to the lower edge (U).

Description

[0001] The invention relates to a display system for a vehicle and a vehicle equipped therewith.

[0002] Windshields for vehicles, especially passenger cars, are designed as laminated glass (laminated safety glass), consisting of an outer pane and an inner pane laminated together with a thermoplastic interlayer. They typically feature an opaque masking area, which forms a continuous border and surrounds a central 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 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 created by a black printed overprint on the surface of the outer pane facing the interlayer.

[0003] It has been proposed to use the opaque masking area as a display surface for a display system. For this purpose, the display area is coated with a reflective layer and illuminated by an imaging unit, such as a screen or projector. The image projected onto the reflective layer of the imaging unit is perceptible to a user, particularly the driver, as a display image. Examples include DE102009020824A1, WO2022073894A1, and WO2022073860A1.

[0004] In this way, displays for the driver, which were previously located on the dashboard, can be projected directly onto the windshield. This is not only aesthetically pleasing but also improves driving safety, as the driver has to take their eyes off the road less to read the display. Examples of such displays include vehicle speed, time, engine speed, navigation system information, speed limit information (traffic sign recognition), a rear-view camera image, and various vehicle status indicators.

[0005] To ensure a high-intensity display, the display area is often coated with a reflective layer designed to reflect the radiation from the imaging unit. This reflective layer can be located on the inner surface of the windshield. However, this is an exposed surface of the windshield where the reflective layer is subject to chemical and mechanical influences and can be damaged.

[0006] The reflective layer can alternatively be embedded inside the windshield, for example, applied to the outer surface of the inner pane facing the intermediate layer. The radiation from the imaging unit then passes through another reflective interface before reaching the reflective layer: the air-glass interface of the inner pane's surface facing the interior. This results in a second reflection, which appears to the viewer as a ghost image displaced from the main image. This problem is often addressed by operating the imaging unit with p-polarized radiation and selecting an angle of incidence that corresponds to (or only slightly deviates from) the Brewster angle.Since p-polarized radiation is not reflected at the Brewster angle, reflection at the inner surface of the inner disc is eliminated (or only minimally present), and the ghost image can be avoided (or at least its intensity greatly reduced). This principle has been applied particularly in head-up displays; EP3187917A2 and WO2021104800A1 are just two examples.

[0007] To achieve convincing results, the imaging unit must illuminate the inner windshield as precisely as possible at the Brewster angle. However, this is often not possible. Firstly, structural limitations within the vehicle can prevent this. More importantly, the vehicle manufacturer is not entirely free in positioning the imaging unit, as it must be ensured that the displayed image (a virtual image behind the reflective plane) appears within the driver's field of vision. If the imaging unit is moved to achieve the Brewster angle, this can result in the virtual displayed image being shifted out of the driver's field of vision, which is obviously unacceptable. It has been shown that problems can arise in this regard, particularly with very shallow windshields (large installation angle to the vertical), which are becoming increasingly common.

[0008] Therefore, there is a need for improved display systems for vehicles of the type mentioned above, which have a higher number of degrees of freedom, so that on the one hand the windshield can (ideally) be illuminated exactly at the Brewster angle and on the other hand the display image appears at a desired location in the driver's field of vision.

[0009] The present invention is based on the objective of providing such an improved display system.

[0010] The object of the present invention is solved according to the invention by a display system according to claim 1. Preferred embodiments are set forth in the dependent claims.

[0011] The display system according to the invention for a vehicle comprises a windshield and an imaging unit. The windshield has an upper edge and a lower edge, a transparent viewing area, and a display area. The display area is arranged in an opaque masking area located between the viewing area and the lower edge. The windshield is designed as a laminated glass and comprises an outer pane and an inner pane, each having an outer surface and an inner surface, respectively, and which are bonded together via an intermediate layer (preferably a polymeric intermediate layer). The imaging unit is directed towards the display area. The imaging unit emits p-polarized radiation and illuminates the display area with it.

[0012] The windshield is equipped with a reflective layer, at least in the display area. This reflective layer is capable of reflecting (at least partially) the radiation from the imaging unit, thereby generating a display image that a user, particularly the driver of the vehicle, can perceive.

[0013] According to the invention, (at least) in the display area the distance between the outer pane and the inner pane increases in a direction from the viewing area (or from the upper edge) to the lower edge.

[0014] The inventive design of the windshield provides the skilled person with an additional degree of freedom for designing the display system. The position of the imaging unit can be selected so that the displayed image appears at the desired location in the viewer's field of vision. Due to the increasing distance between the outer and inner panes, the angle of incidence of the inner pane in the display area can be designed independently of the installation angle. In particular, the angle of incidence can be selected, depending on the position of the imaging unit, such that the angle of incidence of the radiation from the imaging unit onto the inner pane corresponds to Brewster's angle. If the imaging unit is operated with p-polarized radiation, reflection does not occur at the surface of the inner pane, but only at the reflective coating. A ghost image can thus be avoided. This is the major advantage of the present invention.

[0015] The windshield is designed for a vehicle and can therefore also be referred to as a vehicle windshield. In a preferred embodiment, it is the windshield of a motor vehicle, in particular a passenger car or truck.

[0016] The windshield is typically designed as a laminated glass pane, comprising an outer pane and an inner pane bonded together by a polymeric interlayer. The windshield is intended to separate the interior (vehicle interior) from the external environment in the forward-facing window opening of a vehicle (relative to the direction of travel). For the purposes of this invention, the term "inner pane" refers to the pane of the windshield facing the interior. The term "outer pane" refers to the pane facing the external environment.

[0017] 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. The outer and inner panes, in particular, each have a constant thickness.

[0018] The outer pane and the inner pane each have an outer and an inner surface (main surfaces) and a circumferential side edge surface extending between them. For the purposes of the invention, the outer surface refers to the main surface that is intended to face the external environment when installed. For the purposes of the invention, the inner surface refers to the main surface that is 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 intermediate layer.

[0019] The windshield also has an outer surface, an inner surface, and a circumferential side edge surface running between them. The outer surface of the outer pane preferably forms the outer surface of the windshield. The inner surface of the inner pane preferably forms the inner surface of the windshield. The side edge surface is formed by the side edge surfaces of the outer pane, the intermediate layer, and the inner pane.

[0020] The windshield typically has a rectangular base, i.e., it is rectangular in shape, or in the case of passenger cars, in particular trapezoidal or trapezoidal-like, with the sides (base and legs) being curved, unlike a simple trapezoid. The side edge surface can therefore be conceptually divided into four sections, with adjacent sections separated from each other by one of the four corners: an upper edge (actually the upper edge surface), a lower edge (actually the lower edge surface), and two intermediate side edges (actually side edge surfaces, which, to distinguish them from the already introduced circumferential side edge surface, can also be referred to as lateral edge surfaces). For the purposes of the invention, the upper edge refers to the edge (edge ​​surface) that is intended to point upwards in the installed position.The bottom edge refers to the edge (edge ​​surface) that is designed to face downwards when installed. The top edge is often also called the roof edge, and the bottom edge the motor edge. The side edges run between the top and bottom edges and can be referred to as the right and left side edges.

[0021] Terms such as "above", "below", "above", "below", "over", "under", and "sideways" are to be understood in the context of the present invention in the same way as the terms "top edge", "bottom edge", and "side edge". If a first element is arranged above or over a second element, it has a smaller distance to its top edge than the second element. If a first element is arranged below or under a second element, it has a smaller distance to its bottom edge than the second element. If two elements are arranged laterally from one another, they are offset from each other in the dimension extending between their side edges (width dimension).

[0022] For the purposes of this invention, the height of the windshield is understood to be the dimension between its upper and lower edges. The width of the windshield is understood to be the dimension between its side edges. A height section is an area that comprises a certain portion of the windshield's height, but not its entire height. The height section may extend over the entire width of the windshield or only over a portion of the width (a width section). A width section is an area that comprises a certain portion of the windshield's width, but not its entire width. The width section may extend over the entire height of the windshield or only over a portion of the height (a height section). The display area is typically arranged in a height section and a width section of the windshield.

[0023] The windshield has an opaque masking area and a transparent viewing area. For the purposes of this invention, the term "masking area" refers to an area of ​​the windshield through which visibility is not possible. The light transmission of the masking area is less than 5%, preferably less than 2%, and most preferably essentially 0%. For the purposes of this invention, the term "viewing area" refers to an area of ​​the windshield that allows visibility through the windshield and is intended for viewing. The viewing area is therefore transparent. The light transmission of the viewing area is preferably at least 70%. "Light transmission" here refers to the total transmission, determined by the method for testing the light transmittance of motor vehicle windows specified in ECE-R 43, Annex 3, Section 9.1.

[0024] 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 the perimeter of the windshield and borders the side edge of the windshield. Therefore, in a preferred embodiment, the masking area is arranged in a perimeter of the windshield and surrounds the central viewing area.

[0025] The frame-like masking area can be conceptually divided into four sections: - A first section is assigned to the bottom edge. It extends along the bottom edge and is positioned between the viewing area and the bottom edge. - A second section is assigned to the right side edge. It extends along the right side edge and is positioned between the viewing area and the right side edge. - A third section is assigned to the top edge. It extends along the top edge and is positioned between the viewing area and the top edge. - A fourth section is assigned to the left side edge. It extends along the left side edge and is positioned between the viewing area and the left side edge.

[0026] The display area according to the invention is arranged in the aforementioned first section of the masking area, which is associated with the lower edge, is located between the viewing area and the lower edge, and in particular borders the lower edge of the windshield. The display area is thus arranged between the viewing area and the lower edge of the windshield.

[0027] The distance between the outer and inner panes increases from top to bottom in the viewing area between them. This distance increases in a direction defined by the curve from the top edge to the bottom edge, or from the viewing area to the bottom edge. This curve can also be described as vertical – it is the curve between the top and bottom edges, running essentially perpendicular to these edges. On a rectangular windshield, all possible lines defining this direction run parallel to the side edges. However, typical vehicle windshields are approximately trapezoidal, with the top edge being shorter than the bottom edge.A specific line, defining the direction in question, runs from a point on the upper edge to a point on the lower edge, with the distance of these points from the same side edge corresponding to the same fraction of the total length of the respective edge (upper edge, lower edge). The direction is thus defined, for example, by the line running from a point on the upper edge that is 20% of the total length of the upper edge from the right side edge to a point on the lower edge that is 20% of the total length of the lower edge from the right side edge. All possible lines are distributed across the windshield in a fan-like or radial pattern. Across the entire width of the display area, the distance between the outer and inner panes increases in a direction from the viewing area, or from the upper edge, to the lower edge, with the direction at each point being determined as described above.

[0028] At least within the display area, the outer and inner panes are not parallel to each other, and the thickness of the intermediate layer is not constant but increases from top to bottom in the aforementioned direction. The area with the non-parallel panes may be limited to the display area. However, it may also extend above, below, and / or laterally beyond it. In particular, it is possible that the distance between the outer and inner panes increases across the entire width of the windshield in a vertical section that includes the display area. This can be advantageous because it requires a less complex curvature of the glass. Alternatively, it is also possible that the distance between the outer and inner panes increases only across a portion of the width (i.e., only in a horizontal section) of the windshield, specifically in a vertical section that includes the display area.

[0029] In the remaining areas of the windshield, the outer and inner panes are preferably arranged parallel to each other, and the intermediate layer has a constant thickness. This applies in particular to the viewing area and the sections of the masking area that are located at the top and side edges.

[0030] It is conceivable to incorporate configurations in which, in addition to the display system according to the invention with the display area in the masking area, a so-called head-up display (HUD) is used with a further display area in the viewing area D. If this HUD is generated with s-polarized radiation (by irradiating the display area with an s-polarized projector), it is customary to arrange the outer and inner panes at specific angles to each other, so that the reflections from the outer surface of the outer pane and the inner surface of the inner pane are superimposed, thus preventing a displaced ghost image. This is typically achieved by using a wedge-shaped thermoplastic film as an intermediate layer. In this case, the outer and inner panes are therefore not parallel to each other even in the viewing area, and the distance between them is not constant.However, such a change in distance is clearly distinguishable from the change in distance according to the invention in the masking area between the viewing area and the lower edge: firstly, the change in distance is less pronounced than that according to the invention, and secondly, it proceeds in the opposite direction – the distance between the outer and inner panes increases from bottom to top (i.e., in a direction from the lower edge to the upper edge), whereas, according to the invention, the distance between the outer and inner panes in the masking area increases from top to bottom (i.e., in a direction from the upper edge to the lower edge). For the sake of simplicity, when the following refers to an area in which the outer and inner panes are constant, this serves to distinguish it from the area containing the display area, which is affected by the increase in the pane distance from top to bottom according to the invention.The case where a wedge-shaped foil is used as an intermediate layer in the area, meaning the discs are not completely parallel but their distance increases from bottom to top, is not excluded and is included in each case.

[0031] The area where the distance between the outer and inner panes increases can extend to the bottom edge. However, there can also be another area between the area with the increasing pane distance and the bottom edge. In this area, the distance between the panes can remain constant (i.e., the panes are parallel) or the distance between the panes can even decrease again towards the bottom edge. The latter can be advantageous because the widened gap between the panes is effectively closed again, which can offer process-related advantages during filling and saves filling material. It is also conceivable that below the area with the increasing pane distance, there is an area with a decreasing pane distance (for example, down to the original pane distance), and below that, another area with a constant pane distance extends to the bottom edge.

[0032] In other words, the distance between the outer pane and the inner section increases from top to bottom along a certain vertical section of the windshield. This vertical section contains the display area. This vertical section is bounded at the top by a boundary line, preferably located within the masking area (between the viewing area and the display area). It can be bounded at the bottom by the lower edge or by a boundary line spaced apart from the lower edge.

[0033] The windshield is installed in the vehicle at a specific installation angle. The installation angle refers to the angle that the windshield forms with the vertical. The windshield is typically curved, at least in passenger cars. In this case, the installation angle is determined at the geometric center of the windshield (which is typically located in the viewing area), using the tangent plane of the outer surface of the windshield. The invention is particularly advantageous for windshields with a relatively shallow profile because, with such an installation position, it is especially challenging to position the display image at the desired location in the viewer's field of vision while simultaneously ensuring an angle of incidence that corresponds to Brewster's angle.

[0034] The increasing distance between the outer and inner panes is achieved primarily by the inner pane having a greater curvature, at least locally, than the outer pane. This effectively bends the inner pane away from the outer pane, towards the vehicle interior and the imaging unit. In its installed position, the inner pane is oriented at a steeper angle than the outer pane in the display area, meaning it has a smaller angle of attack. The angle of attack is measured relative to the vertical in the same way as the installation angle. In the case of a curved windshield, the tangent plane of the outer surface of the outer pane is used to determine its angle of attack, while the tangent plane of the inner surface is used to determine its angle of attack.The inner disc has a smaller angle of attack than the outer disc, particularly at every point in the display area. The total angle of attack of the inner and outer discs within the display area can then be determined at the geometric center of the display area.

[0035] In a first embodiment, the inner disc has a region (vertical section) with a greater curvature than the outer disc, which is located (entirely) above the display area. Below this region, the curvature of the inner disc is equal to the curvature of the outer disc. The inner disc is effectively bent in this region, causing the underlying portion of the inner disc to bend away from the outer disc. The increase in the distance between the outer and inner discs, as well as the increase in the thickness of the intermediate layer, is linear (first-order increase in distance).

[0036] In a second embodiment, the inner disc exhibits a greater curvature than the outer disc across the entire area with increasing disc spacing (especially in the display area), so that the inner disc is, as it were, continuously bent away from the outer disc. The increase in the distance between the outer and inner discs, as well as the increase in the thickness of the intermediate layer, is not linear, but becomes more pronounced with decreasing distance to the bottom edge (higher-order increase in distance).

[0037] A greater curvature generally corresponds to a smaller radius of curvature.

[0038] The intermediate layer is preferably polymeric. It typically comprises at least one thermoplastic layer, which is preferably formed from at least one thermoplastic film. In the transparent area and in the sections of the masking area associated with the top and side edges, where the outer and inner panes are preferably arranged parallel to each other, the intermediate layer is preferably formed from said thermoplastic layer. In these areas, the intermediate layer is particularly composed of the at least one thermoplastic film, i.e., a single thermoplastic film or a plurality of thermoplastic films stacked on top of each other, with the option of optionally embedding functional films or electrical functional elements between two thermoplastic films.Examples include PET carrier films with IR-reflective or heated coatings, functional films with electrically controllable optical properties (such as SPD, PDLC or electrochromic films), light-emitting diodes or sensors (such as light sensors, rain sensors or temperature sensors).

[0039] The thermoplastic layer or film is typically based on polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), or polyurethane (PU), or on mixtures, copolymers, or derivatives thereof, particularly preferably on PVB. This means that the layer or film consists largely of the aforementioned polymer (proportion greater than 50% by weight). In addition to the polymer, the layer or film may contain other additives, especially plasticizers. The thickness of each 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.

[0040] The area with the increasing distance between the outer and inner panes (from top to bottom) widens the space between the panes compared to the areas above. This creates a region with an expanded space between the panes, encompassing at least the area with the increasing pane distance and potentially also a region below it (if such a region exists below the area with the increasing pane distance where the pane distance remains constant or even decreases). This expanded space between the panes is filled with additional polymeric filler material.The intermediate layer therefore comprises, in the area with the enlarged gap between the panes (especially also in the display area), a polymeric filler material whose thickness increases in one direction from the viewing area to the lower edge (corresponding to the increasing pane distance), preferably a cured adhesive or a prefabricated polymer insert. The filler material is bonded directly or via an adhesion-promoting layer to the outer and inner panes.

[0041] In a first embodiment, the aforementioned additional polymeric filler material is a liquid polymeric filler, in particular a cured adhesive. The adhesive is poured into the enlarged space between the glass panes in liquid or flowable form and then cured. Curing depends on the type of adhesive and can be achieved, for example, by UV radiation, thermal activation, or a chemical reaction (two-component adhesive). Any adhesive can be used as long as it exhibits adhesive properties towards the adjacent layers of the windshield. The adhesive can be, for example, an acrylate, polyurethane, or silicone adhesive.

[0042] Instead of an adhesive, a liquid polymer precursor can also be poured into the enlarged space between the glass panes. This precursor does not have adhesive properties to the adjacent layers of the windshield. The precursor is then cured (in particular, polymerized) directly on site. Adhesion-promoting layers should already be present in the glass composite, which will then bond the resulting filler material securely to the glass panes.

[0043] In the area with the enlarged disc gap, the interlayer can consist solely of the polymeric filling. In the areas without an enlarged disc gap, the interlayer is preferably designed as a thermoplastic layer (in particular, formed from a thermoplastic film), which, however, does not extend into the area with the enlarged disc gap but terminates before it. Optionally, a thermoplastic layer can also be present in the enlarged disc gap.Thus, it is possible that at least one thermoplastic layer (in particular formed by at least one thermoplastic film) is arranged over the entire surface between the outer pane and the inner pane, which forms the intermediate layer alone in the areas with an unexpanded gap between the panes and which abuts one of the panes in the area with an expanded gap between the panes, wherein the polymeric filling is arranged between the at least one thermoplastic layer and the other pane.It is also possible that at least two thermoplastic layers (in particular formed by at least two thermoplastic films) are arranged across the entire surface between the outer and inner panes, forming the intermediate layer in areas with an unexpanded gap between the panes. In areas with an expanded gap between the panes, at least one thermoplastic layer is in contact with one of the panes, and the polymeric filling is arranged between these two thermoplastic layers. The thermoplastic layers can, for example, act as adhesion-promoting layers if the polymeric filling itself does not exhibit adhesive properties to the panes.

[0044] In a second embodiment, the aforementioned additional polymeric filler material is a polymeric insert. Such an insert is a prefabricated component that is integrated into the windshield during its manufacture by being arranged in the layer stack and bonded or laminated to the adjacent layers. In one embodiment, the insert is connected to both the outer and inner panes via an adhesion-promoting layer. This is particularly necessary if the insert itself does not possess adhesive properties towards the panes. This adhesion-promoting layer can, in particular, be a thermoplastic layer or an adhesive layer.Preferably, two thermoplastic layers (in particular, each formed by a thermoplastic film) are arranged across the entire surface between the outer and inner panes. In areas with an unexpanded gap between the panes, these layers alone form the intermediate layer, while in areas with an expanded gap, they each abut one of the panes. The polymer insert is arranged between the two thermoplastic layers. The thermoplastic layers bond the insert to the panes. Alternatively, more than two thermoplastic layers can be used. In the area with the expanded gap between the panes, a stack of several thermoplastic layers abuts one pane, while a single thermoplastic layer or a stack of several thermoplastic layers abuts the other pane.

[0045] Alternatively, it is also possible that the at least one thermoplastic layer forming the intermediate layer in the areas with the unexpanded space between the panes does not extend into the area with the expanded space between the panes, and that the insert is bonded to the panes via adhesive layers. Likewise, it is also alternatively possible that (at least) one thermoplastic layer (in particular formed by (at least) a thermoplastic film) is arranged across the entire surface between the outer and inner panes, forming the intermediate layer alone in the areas with the unexpanded space between the panes, and in the area with the expanded space between the panes, it rests against one of the panes and bonds the insert to it, with the insert being bonded to the other pane via an adhesive layer.If the inlay itself has adhesive properties towards the glass panes (for example, if it is based on plasticized PVB), then one or both of the adhesion-promoting layers can optionally be omitted.

[0046] The polymer insert can be made of materials such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinyl butyral (PVB), acrylonitrile butadiene styrene (ABS), polyethylene (PE), polyurethane (PU) or polyvinyl chloride (PVC).

[0047] The intermediate layer therefore preferably consists of - a thermoplastic layer, in particular formed from at least one thermoplastic film, in the areas with non-expanded gaps, wherein functional films or electrical functional elements may optionally be integrated in the intermediate layer, - the polymeric filler material and optionally one or two adhesion-promoting layers, in particular independently selected from a thermoplastic layer and an adhesive layer, in the area with the enlarged disc gap.

[0048] According to the invention, the windshield is equipped, at least in the display area, with a reflective layer which is designed and suitable for reflecting the radiation from the imaging unit and for generating a display image. The reflective layer covers at least the entire display area. However, it can also extend beyond the display area, thus additionally covering adjacent areas of the windshield. This can be advantageous in order to avoid having to position the reflective layer so precisely or to prevent display errors in the edge area of ​​the display image that could occur as a result of imperfect positioning of the reflective layer.

[0049] In a preferred embodiment, the reflective layer is applied to or arranged on the outer surface of the inner disk. It is preferably deposited from the gas phase onto said surface. Since the radiation from the imaging unit then only has to pass through the inner disk before it encounters the reflective layer, the displayed image is particularly intense and exhibits high optical quality, thereby avoiding distortions that could occur when passing through polymeric material in the intermediate layer. Alternatively, it is also possible for the reflective layer to be embedded in the intermediate layer, for example, applied to a polyethylene terephthalate (PET) carrier film, or for the reflective layer to be applied to or arranged on the inner surface of the outer disk.

[0050] The reflective layer can have a smaller angle of inclination to the vertical in the display area than the outer pane.

[0051] The reflective layer preferably has a reflectance of at least 90%, and particularly preferably at least 95%, relative to the radiation from the imaging unit. The reflective layer is particularly preferably designed as a solid mirror that reflects the radiation from the imaging unit essentially completely (reflectance essentially 100%), with the exception of any minor absorbed radiation components, and allows no radiation components to pass through. This enables the realization of particularly high-intensity display images. In this embodiment, the reflective layer is preferably arranged exclusively in the masking area and does not extend into the transparent viewing area.

[0052] 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). Within the scope of the present invention, the descriptions of reflectance refer to the reflectance measured at an angle of incidence of 57° to the interior surface normal, which corresponds approximately to Brewster's angle of an air-soda-lime-glass interface and is preferred within the scope of the present invention as the angle of incidence of the radiation to the imaging unit. The reflectance values ​​refer to a reflection measurement with a light source that emits uniformly across the considered spectral range with a normalized radiation intensity of 100%.

[0053] In an advantageous embodiment, the reflective layer is formed as a metal-based layer. The metal is preferably aluminum or silver, but other metals can also be used, for example, magnesium, tin, indium, titanium, tantalum, niobium, tungsten, nickel, copper, chromium, cobalt, iron, manganese, zirconium, hafnium, cerium, scandium, yttrium, gold, platinum, palladium, or ruthenium, or mixtures or alloys thereof. The thickness of the reflective layer is preferably from 10 nm to 100 µm, particularly preferably from 50 nm to 50 µm, most preferably from 100 nm to 5 µm, and especially from 500 nm to 1.5 µm. This allows for the creation of highly reflective, fully reflective layers.

[0054] In a further advantageous embodiment, the reflective layer is configured as a dielectric layer. The dielectric layer is particularly well-suited to be made of a material with a higher refractive index (measured at 550 nm) than the substrate on which it is applied (especially the inner disk). The reflective layer is, for example, based on titanium oxide, aluminum nitride, silicon nitride, zirconium nitride, silicon-zirconium mixed nitride, zirconium oxide, tin oxide, zinc oxide, tin-zinc mixed oxide, silicon oxide, titanium carbide, zirconium carbide, or silicon-zirconium-aluminum, most preferably on titanium oxide. The layer thickness is, for example, from 10 nm to 100 µm, or from 50 nm to 50 µm, or from 100 nm to 5 µm, or from 500 nm to 2 µm. Fully reflective layers can also be achieved with these thicknesses.

[0055] In principle, partially reflective coatings can also be used, which reflect only a portion of the radiation from the imaging unit and transmit the remainder. Such coatings can also extend into the transmission area, provided their light transmission is sufficiently high so that they do not critically reduce the transparency. In particular, they can also cover essentially the entire transmission area and fulfill an additional function there. For example, IR-reflective coatings can be used to prevent the transmission of IR components of solar radiation in the transmission area and function as a reflective coating in the display area. Partially reflective coatings are typically designed as thin-film coatings, i.e., as stacks of thin layers. The thickness of the individual thin layers is preferably less than 500 nm, and particularly preferably less than 200 nm.Coatings are known which contain at least one thin film based on a metal, in particular silver, in addition to dielectric thin films, for example, based on silicon nitride, silicon-metal mixed nitrides such as silicon zirconium nitride, titanium oxide, aluminum nitride, tin oxide, zinc oxide, or tin-zinc mixed oxide. Thin films based on a metal preferably have thicknesses of less than 50 nm, in particular less than 20 nm, to ensure the semi-transparent properties of the coating. Alternatively, purely dielectric coatings are also known which comprise exclusively dielectric thin films.In this process, layers with a higher refractive index (e.g., based on titanium oxide or silicon nitride) and layers with a lower refractive index (e.g., based on silicon oxide) are arranged alternately, and the reflective effect is achieved through interference effects and can be precisely controlled by selecting the layer thicknesses. Alternatively, purely dielectric reflective films are also known, which can be embedded in the intermediate layer to function as the reflective layer. The reflective film is a polymeric film containing alternating individual layers with different refractive indices. At least one of the two layer types is preferably PET-based. The other layer type can also be PET-based, with the different refractive indices achieved through suitable additives, based on a PET copolymer or another polymer, such as PMMA.By alternating layers with different refractive indices, optical interference effects are achieved which can be adjusted to suit the specific application (especially by choosing the layer thicknesses and the refractive indices) in order to realize reflective properties in a desired spectral range.

[0056] The masking area is preferably formed by an opaque, in particular black, print (masking print). The masking print typically consists of an enamel applied by screen printing and subsequently fired, which contains glass frits and colorants (in particular pigments). Such masking prints are commonly used, especially 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, particularly preferably 8 µm to 25 µm.

[0057] The masking print is preferably arranged on the inner surface of the outer pane. Alternatively, the masking print can be applied to the outer surface of the inner pane, with the reflective layer, if also applied to the outer surface of the inner pane, positioned between the inner pane and the masking print. It is also possible for the masking area to be formed by a masking print on the inner surface of the outer pane and for a further masking print to be applied to the side of the reflective layer facing away from the inner pane. This can be advantageous for improving the contrast of the displayed image.

[0058] The masking area can alternatively be formed by an opaque polymeric film, which is part of the intermediate layer and is arranged between the reflective layer and the outer pane.

[0059] The opaque element forming the masking area (in particular, the printed masking layer or the opaque polymer film) is positioned behind the reflective layer in the direction of view from the vehicle interior to the external environment, so that the latter can be illuminated by the imaging unit. The reflective layer is therefore closer to the imaging unit and the vehicle interior than the opaque element, and further away from the external environment.

[0060] The imaging unit is directed at the display area and illuminates it to generate a display image. The area of ​​the windshield illuminated (or irradiable) by the imaging unit is therefore the display area within the meaning of the invention. According to the invention, a reflective layer is arranged within the display area of ​​the windshield, which reflects the radiation from the imaging unit towards the user to generate the display image. The imaging unit illuminates the display area with electromagnetic radiation in the visible spectral range to generate the display image, which a user inside the vehicle can perceive within the masking area. The radiation is particularly in the spectral range of 450 nm to 650 nm, for example with wavelengths of 473 nm, 550 nm, and 630 nm (RGB).The imaging unit irradiates the windshield via the inner pane; it is therefore located on the inside side of the windshield and irradiates the windshield via the inside surface of the inner pane.

[0061] The imaging unit can be, for example, a projector or a screen (“display,” electronic display). In principle, any type of screen can be used for the display system according to the invention, for example, a field emission display (FED), a liquid crystal display (LCD), a thin-film transistor display (TFT-LCD), a cathode ray tube display (CRT), a plasma display, an organic light-emitting diode (OLED), a (true) LED display, or a surface conduction electron emitter display (SED). OLED and LCD screens are particularly common.

[0062] According to the invention, the radiation of the imaging unit is p-polarized. The imaging unit illuminates the display area with the p-polarized radiation. The radiation is, in particular, essentially purely p-polarized – the p-polarized radiation component is therefore 100% or deviates only insignificantly from this. The p-polarized radiation component is preferably at least 95%. The polarization direction is specified with respect to the plane of incidence of the radiation on the windshield. P-polarized radiation is defined as radiation whose electric field oscillates in the plane of incidence. S-polarized radiation is defined as radiation whose electric field oscillates perpendicular to the plane of incidence. The plane of incidence is defined by the incidence vector and the surface normal of the windshield. The polarization, and in particular the proportion of p- and s-polarized radiation, is determined at a point in the display area.If the windshield is curved, which is usually the case, this affects the plane of incidence of the radiation. Therefore, slightly different polarization components may occur in other areas, which is unavoidable for physical reasons. The proportion of p-polarized radiation is determined at the point in the display area where the highest proportion of p-polarized radiation occurs. Preferably, the display system is designed such that this point is located at the geometric center of the display area. To provide the p-polarized radiation, a polarizing filter or a polarizing beam splitter can, for example, be arranged in the beam path between the imaging unit and the windshield, if the imaging unit does not itself provide radiation of the desired polarization direction.

[0063] Optimal results are achieved when the imaging unit irradiates the inner disk with an angle of incidence corresponding to the Brewster angle. In this case, no reflection of the p-polarized radiation occurs at the inner surface of the inner disk, and the displayed image is based solely on reflection at the reflective layer. Accordingly, a single, unobstructed image is displayed without any ghosting. Minor deviations from the calculated Brewster angle are acceptable. While some reflection does occur at the inner surface of the inner disk, it is so minimal that the resulting ghosting is not noticeable. In an advantageous embodiment, the imaging unit irradiates the inner disk with an angle of incidence equal to or deviating from the Brewster angle by no more than 2°, preferably by no more than 1°. The angle of incidence can also be referred to as the angle of incidence.It is the angle between the incident radiation vector and the interior surface normal (i.e., the surface normal to the interior surface of the inner pane) determined at a point in the display area, preferably at the geometric center of the display area. Thus, there exists at least one point (a location) in the display area that is irradiated with the aforementioned angle of incidence, preferably the geometric center of the display area. The Brewster angle for an air-glass interface in the case of soda-lime glass, which is commonly used for window panes, is 57.2° (with a refractive index of 1.55 at a wavelength of 550 nm).

[0064] The display system according to the invention can be manufactured by a method wherein the windshield according to the invention is manufactured and subsequently the imaging unit is directed onto the display area. The latter typically occurs during the installation of the windshield and imaging unit in a vehicle.

[0065] The reflective layer is preferably applied to the inner or outer disk by means of vapor deposition, in particular to the surface of the inner disk designated as the outer surface. Physical vapor deposition (PVD) is preferred, especially sputtering, and most preferably magnetron sputtering. However, the reflective layer 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).

[0066] The masking area is preferably formed by applying an opaque enamel printing ink to a surface of the panes, in particular the inner surface of the outer pane, especially by means of 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.

[0067] Typically, the outer and inner panes are bent, preferably before being joined to form a laminated glass pane. This involves a bending process to bring them into a cylindrical or spherical shape. 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. Preferably, the inner pane is bent more sharply in one area than the outer pane, so that the distance between the outer and inner panes increases, at least in the display area, in the finished laminated glass pane. Bending is preferably carried out after the deposition of the reflective coating and the application of the enamel printing ink.The bending then acts as a kind of heat treatment, which can improve the optical properties of the reflective layer and allows the enamel color to be baked into the disc surface.

[0068] In the manufacture of the laminated glass pane, the outer and inner panes are arranged congruently and over a flat surface, preferably with at least one thermoplastic film positioned between them. This thermoplastic film can cover the entire surface between the panes or be present only in a portion of the space between them, namely the area that is not widened due to the increasing distance between the panes.

[0069] If the reflective layer is not deposited on the surface of the discs, but rather on a carrier film or provided as a reflective film, it is also inserted into the layer stack at the required location. The same applies if the masking area is not formed by a printed cover layer, but by an opaque film. This can be a section of the thermoplastic film or an additional film specifically inserted for this purpose, for example, made of PET.

[0070] The stack of layers, consisting of the outer pane, the thermoplastic film, and the inner pane, is then laminated to form a composite pane. This is done in particular using methods known per se, 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.

[0071] The area with the enlarged gap between the panes, which is present at least in the display area due to the increasing pane spacing, is filled with a polymeric filler material. This filler material can be inserted into the layer stack as a pre-fabricated polymer insert before lamination, so that the filler material is directly laminated into the composite pane. The bond to the panes can be achieved independently of each other, preferably via an adhesive or a thermoplastic film. If the insert itself exhibits adhesive properties towards the panes, such an adhesion-promoting layer can be omitted.

[0072] Alternatively, the layer stacks can first be laminated to form a composite pane, leaving the enlarged space between the panes free. A polymeric filling in liquid or flowable form, preferably an adhesive, is then poured into this space and cured.

[0073] The invention further comprises a vehicle equipped with a display system according to the invention. The vehicle's windshield serves as the projection surface for the display system and is illuminated by the imaging unit. The vehicle is, in particular, a motor vehicle, preferably a passenger car or truck.

[0074] The display system according to the invention can be used in a vehicle, preferably a motor vehicle, in particular a passenger car. The imaging unit is typically arranged in the horizontal section of the dashboard facing the windshield. The display system is used in particular to show status information (such as the time, vehicle speed, engine speed, coolant temperature, interior or exterior temperature, or information from the entertainment system, for example, the currently playing radio station), information from a navigation system or other assistance systems (such as navigation instructions, directional arrows, speed limits, or other warnings), the image from a rear-facing camera, or entertainment content (such as a television program, videos, computer games, or internet data).

[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 windshield of a generic display system in a vehicle, Fig. 2 a cross-section through a conventional display system, Fig. 3 a cross-section through an embodiment of the display system according to the invention, Fig. 4 an enlarged view of section Z of the windshield made of Fig. 3, Fig. 5 an enlarged representation of section Z in a further embodiment of the windshield according to the invention, Fig. 6 an enlarged representation of section Z in a further embodiment of the windshield according to the invention, Fig. 7 a cross-section through a further embodiment of the display system according to the invention, Fig. 8 a cross-section through a further embodiment of the display system according to the invention.

[0077] Fig. Figure 1 shows a top view of a windscreen 10 of a generic display system. The windscreen 10 is installed in a vehicle, in particular a passenger car. The windscreen 10 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 windscreen 10 has an upper edge O pointing upwards (towards the vehicle roof) and a lower edge U pointing downwards (towards the engine compartment), and two side edges running between them. Such masking areas M are common in vehicle windscreens – they serve to protect the adhesive used to bond the windscreen 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.

[0078] The windshield 10 has a display area A in the masking area M between the viewing area D and the lower edge U. Display area A is therefore located in the section of masking area M adjacent to the lower edge U. This display area A serves to show information for the vehicle occupants. This can include, in particular, vehicle status information (for example, the vehicle speed or a fuel gauge), navigation instructions (for example, speed limits or directions), or the image from a rear-facing camera. Entertainment content (for example, films, internet data, or computer games) can also be displayed, especially on the passenger side.

[0079] Fig. Figure 2 shows a cross-section through a generic display system in which the windshield 10 is designed in a conventional manner. The cross-section runs through the windshield 10 along the in Fig. The section line X-X' is marked in section 1. The windshield 10 is a laminated glass consisting of an outer pane 1 and an inner pane 2, which are bonded together by a thermoplastic film 3. The outer pane 1 has an outer surface I facing the external environment and an inner surface II facing the vehicle interior. Similarly, the inner pane 2 has an outer surface III facing the external environment and an inner surface IV facing the vehicle interior.

[0080] The windshield 10 is installed in the vehicle at an angle to the vertical, which is, for example, 60°. For simplicity, the windshield 10 is shown as flat, whereas real windshields are typically curved, with the outer pane 1 and inner pane 2 having the same curvature and arranged parallel to each other.

[0081] To generate the display, an imaging unit 20 is directed at the display area A. The imaging unit is, for example, an LCD screen or a plurality of LCD screens arranged side by side. The imaging unit illuminates the display area A with an angle of incidence α, which is measured with respect to the surface normal of the inner disk on the interior side.

[0082] To generate a high-intensity display, a reflective layer (not shown) is arranged inside the windshield 10. This layer covers the display area A and reflects the radiation from the imaging unit 20 towards the viewer F, thus creating the display. It appears as a virtual image slightly behind the plane of reflection (from the viewer F's perspective). This reflective layer is, for example, an aluminum or silver layer with a thickness of 1 µm, which completely reflects the radiation from the imaging unit 20 (a perfect mirror). The reflective layer is, for example, arranged on the outer surface III of the inner pane 2. There, it is protected from damage inside the windshield 10.

[0083] To avoid further reflection at the interior surface IV of the inner disk 2, which would lead to a ghost image, the imaging unit 20 is operated with p-polarized radiation. If the angle of incidence α corresponds to the Brewster angle (approximately 57° at an air-soda-lime glass interface), no reflection occurs at the interior surface IV of the inner disk 2. The display relies solely on reflection at the reflective layer, and no disturbing ghost images appear.

[0084] With conventional windshields, however, it is not always possible to select an angle of incidence α that corresponds to Brewster's angle. The vehicle manufacturer is not entirely free regarding the positioning of the imaging unit 20. There may be structural limitations to the position of the imaging unit 20. More importantly, however, the position of the imaging unit 20 also determines the position of the virtual image in space. Thus, particularly with flat-mounted windshields, the problem often arises that the virtual image is no longer within the viewer's field of vision F if the imaging unit 20 is positioned so that the angle of incidence α corresponds to Brewster's angle.

[0085] Fig. Figure 3 shows, in comparison, a cross-section through a display system in which the windshield 10 is designed according to the invention. Section Z is in Fig. Figure 4 shows an enlarged view. The windshield 10 is also a laminated glass consisting of an outer pane 1 and an inner pane 2. The outer pane 1 is designed in the same way as in Fig. 2, in particular with the same curvature (not shown) common in the automotive sector. The outer pane is connected to the inner pane 2 via a polymeric intermediate layer, the design of which and the curvature of the inner pane 2 differ from the conventional design according to Fig. 2. Distinguish.

[0086] In the viewing area D and the sections of the masking area M bordering the side edges and the top edge O, the inner pane 2 is curved in the same way as the outer pane 1 and arranged parallel to it. The polymeric intermediate layer in this area is also formed from a thermoplastic film 3. However, in the section of the masking area M adjacent to the bottom edge U, where the display area A is located, the inner pane 2 is not arranged parallel to the outer pane 1. In this section of the masking area M, above the display area A, i.e., between viewing area D and display area A, the inner pane has a local area with a significantly greater curvature than the outer pane 1. Below this area, the curvature is again the same as that of the outer pane 1, with the same radii of curvature (shown here in plan view).The aforementioned local area with the sharp bend extends across the entire width of the inner pane 1. Within this area, the lower part of the inner pane 1 is effectively bent and curved away from the outer pane 1, towards the vehicle interior and the imaging unit 20. As a result, the distance between the outer pane 1 and the inner pane 2 increases linearly from the aforementioned local area with the sharp bend to the lower edge U. The lower portion of the inner pane 2 is significantly steeper than the corresponding portion of the outer pane 1 (smaller angle of attack to the vertical).

[0087] The area with the increasing distance from top to bottom between the outer pane 1 and the inner pane 2 provides the person skilled in the art with a further degree of freedom for designing the display system. The position of the imaging unit 20 can be selected such that the virtual display image appears at the desired location in the viewer's field of vision F. The curvature of the inner pane 2 in the aforementioned local area between the viewing area D and the display area A, and thus the angle of the area of ​​the inner pane 2 below it, can be selected depending on the position of the imaging unit 20 such that the angle of incidence α corresponds to Brewster's angle α. B This corresponds to the p-polarized radiation of the imaging unit 20, which is therefore not reflected at the interior surface IV of the inner disk 2 and a ghost image can be avoided.

[0088] Since the inner disc 2 is typically spherically curved in reality, the angle of incidence α is not the same at every point in the display area A. The display system is designed such that the angle of incidence α at a given point corresponds to Brewster's angle α. B This corresponds, in particular, to the geometric center of the display area A. A similar situation exists with regard to the polarization direction of the radiation from the imaging unit 20. Since the plane of incidence differs due to the spherical curvature of the inner disk 2, the polarization components also differ. The radiation is completely p-polarized at one point in the display area A, particularly at its geometric center, while small s-polarized radiation components may occur at other points. However, the reflection of these small s-polarized radiation components at the surface IV is typically so low that the resulting ghost image is not noticeable to the observer F.

[0089] The outer pane 1 and the inner pane 2 are each made of soda-lime glass, with the outer pane 1 having a thickness of, for example, 2.1 mm and the inner pane 1.6 mm. The thermoplastic film 3 is a commercially available PVB film with a thickness of 0.76 mm. It is applied across the entire surface of the inner surface II of the outer pane 1. In the areas where the outer pane 1 and the inner pane 2 are parallel, the thermoplastic film 3 forms the polymeric interlayer and bonds the outer pane 1 to the inner pane 2. In the lower area of ​​the windshield 10, where the gap between the panes increases from top to bottom, the space between the panes is wider. This wider space is filled with an adhesive 5, for example, a silicone adhesive.The layer of adhesive 5 thickens in a wedge shape from top to bottom and is located between the thermoplastic film 3 and the inner disc 2. The optical quality of the adhesive 5 is irrelevant, as it is located in the opaque masking area M anyway.

[0090] The adhesive 5 was poured in liquid form into the space between the panes after the lamination of the outer pane 1 and inner pane 2 over the film 3 and then cured.

[0091] The reflective layer 4, which serves to reflect the radiation from the imaging unit 20, is arranged on the outer surface III of the inner disk 2. The reflective layer 4 is itself an aluminum or silver layer with a thickness of 1 µm, which has been sputtered onto surface III. It completely covers the display area A and extends slightly beyond it all around, but is located entirely within the masking area M so as not to impair the view through the viewing area D.

[0092] The masking area M is formed by a black masking print 8 on the interior surface II of the outer pane 1. Such masking prints 8 are common in vehicle windows. They contain glass frits and a black pigment. The masking print 8 was applied to surface II as an enamel paste using a screen printing process and then fired.

[0093] Fig. Figure 5 shows section Z in a further embodiment of the windshield 10 according to the invention. It is constructed similarly to the windshield 10 in the Fig. 3 and Fig. 4, but differs from it in two aspects.

[0094] Firstly, the thermoplastic film 3 is not arranged across the entire surface of the laminated pane, but only in the areas where the outer pane 1 and inner pane 2 are parallel. It ends in the area with the stronger local curvature of the inner pane 2. Below this, in the area with the increasing pane spacing from top to bottom, the polymeric intermediate layer is formed solely by the adhesive 5.

[0095] Secondly, a further cover print 8 is arranged on the reflective layer 4 and surrounding areas of surface III. This can sometimes increase the contrast of the displayed image.

[0096] Fig. Figure 6 shows section Z in a further embodiment of the windshield 10 according to the invention. The outer pane 1 and the inner pane 2 are configured in the same way as in the previous embodiments. However, the polymeric intermediate layer is configured differently.

[0097] The polymeric interlayer comprises two thermoplastic films 3, for example, PVB films, each 0.38 mm thick. The first thermoplastic film 3 is arranged across its entire surface on the inner surface II of the outer pane 1, and the second thermoplastic film 3 is arranged across its entire surface on the outer surface III of the inner pane 2. In the areas where the outer pane 1 and the inner pane 2 are parallel, the films 3 lie flat against each other and together form the polymeric interlayer that connects the outer pane 1 to the inner pane 2. In the lower area of ​​the windshield 10, where the gap between the panes increases from top to bottom, the space between the panes is wider. There, a polymeric insert 6 is arranged between the films 3 and is connected to the outer pane 1 and the inner pane 2 via a film 3 each.The insert 6 is a prefabricated polymer component, for example made of polycarbonate. The insert 6 was arranged in the layer stack during the production of the composite window and integrated into the windshield 10 during lamination.

[0098] Fig. Figure 7 shows a cross-section through a further embodiment of the display system, in which the windshield 10 is designed according to the invention. It differs from the embodiment of the Fig. 3 by designing the area with the gap between the panes that increases from top to bottom. While the lower area of ​​the inner pane 2 in Fig. Since the inner pane 2 is only bent due to a local area of ​​greater curvature between the viewing area D and the display area A, it exhibits a greater curvature across its entire lower region than the outer pane 1. The inner pane 2 is thus continuously bent away from the outer pane 1 in its lower region. The increase in thickness of the space between the panes is not linear, but rather increases from top to bottom.

[0099] Fig.Figure 8 shows a cross-section through a further embodiment of the display system, in which the windshield 10 is designed according to the invention. In contrast to the previous embodiments, the distance between the outer pane 1 and the inner pane 2 does not increase up to the lower edge U. Instead, below the area with the increasing pane distance, in which the display area A is located, there is a further area in which the pane distance decreases again towards the lower edge U. The extended pane gap is thus effectively closed again at the lower edge. This saves material for the polymer filling of the extended pane gap. In addition, it can sometimes be easier to fill the pane gap, especially if a liquid adhesive 5 is used as the filling. List of reference symbols: 10 Windscreen 1 outer pane 2 inner disc 3 thermoplastic film 4 Reflective layer 5 Adhesive 6 polymer insert 8 Cover print 20 imaging units F viewer M Windscreen masking area 10 D Windscreen viewing area 10 A Display area of ​​the windshield 10 O Top edge of the windshield 10 U lower edge of the windshield 10 α Angle of incidence α B Brewsterwinkel I outer surface of the outer pane 1 II Interior surface of the outer pane 1 II outer surface of the inner pane 2 IV Interior surface of the inner pane 2 XX' Intersection line Z enlarged section QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] DE 102009020824A1

[0003] WO 2022073894A1

[0003] WO 2022073860A1

[0003] EP 3187917A2

[0006] WO 2021104800A1

[0006]

Claims

[1] Display system for a vehicle, comprising - a windshield (10) having an upper edge (O) and a lower edge (U), a transparent viewing area (D) and a display area (A) arranged in an opaque masking area (M) located between the viewing area (D) and the lower edge (U), comprising an outer pane (1) having an outside surface (I) and an inside surface (II) and an inner pane (2) having an outside surface (III) and an inside surface (IV), which are connected to one another via an intermediate layer, and - an imaging unit (20) which is directed towards the display area (A) and which emits p-polarized radiation, wherein - the windscreen (10) is provided in the display area (A) with a reflective layer (4) which is suitable for reflecting the radiation of the imaging unit (20) to generate a display image, - in the display area (A) the distance between the outer pane (1) and the inner pane (2) increases in a direction from the viewing area (D) to the lower edge (U). [2] Display system according to claim 1, wherein the inner pane (2) in the display area (A) has a smaller angle of incidence to the vertical than the outer pane (1). [3] Display system according to claim 1 or 2, wherein the inner pane (2) has a region with a greater curvature than the outer pane (1), which is arranged above the display region. [4] Display system according to claim 1 or 2, wherein the inner pane (2) has a greater curvature than the outer pane (1) in the entire display area (A). [5] Display system according to one of claims 1 to 4, wherein the imaging unit (20) irradiates the inner pane (2) with an angle of incidence (α) which corresponds to the Brewster angle (α B ) or deviates from it by a maximum of 2°, preferably by a maximum of 1°. [6] Display system according to one of claims 1 to 5, wherein the reflection layer (4) is applied to the outer surface (III) of the inner pane (2). [7] Display system according to one of claims 1 to 6, wherein the opaque masking area (M) is formed by an opaque masking print on the interior-side surface (II) of the outer pane (1). [8] Display system according to one of claims 1 to 7, wherein the reflection layer (4) is formed as a layer based on a metal, preferably aluminum or silver, and has a thickness of 100 nm to 5 µm, preferably of 500 nm to 1.5 µm. [9] Display system according to one of claims 1 to 8, wherein the reflection layer (4) has a reflectance with respect to the radiation of the imaging unit (20) of at least 90%, preferably at least 95%. [10] Display system according to one of claims 1 to 9, wherein the intermediate layer in the display area (A) comprises a polymeric filler material whose thickness increases in a direction from the see-through area (D) to the lower edge (U), preferably a cured adhesive (5) or a prefabricated polymeric insert (6), wherein the polymeric filler material is connected to the outer pane (1) and the inner pane (2) directly or via an adhesion-promoting layer, in particular selected from a thermoplastic film (3) and an adhesive layer. [11] Display system according to one of claims 1 to 10, wherein the imaging unit (20) is a projector or a screen, preferably an OLED or LCD screen. [12] Vehicle equipped with a display system according to one of claims 1 to 11, in particular a passenger car or a lorry.

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