Display system for vehicle having two different operating modes

Abstract

The invention relates to a display system for a vehicle, comprising: a windshield (10) having a transparent see-through region (D) and an opaque shading region (M); and a screen (20) directed towards the display area (A) located in the shading area (M), in which: the windshield (10) is equipped in the display area (A) with a reflective layer (4) adapted to reflect radiation from the screen (20) in order to generate a display image; the screen (20) is adapted to operate in a first mode of operation and in a second mode of operation; in the first mode of operation, the screen emits light within a first angular range (beta1), and in the second mode of operation, the screen emits light within a second angular range (beta2), the first angular range (beta1) being smaller than the second angular range (beta2).

Description

Technical Field

[0001] The present invention relates to a display system for a vehicle and a vehicle equipped with such a display system. Background Art

[0002] The windshield of a vehicle, in particular a motor vehicle such as a passenger car, is designed as a composite glass pane (laminated safety glass) consisting of an outer glass pane and an inner glass pane, which are laminated to each other via a thermoplastic interlayer. The windshield typically has an opaque masking area, which is designed as a circumferential edge area and surrounds a central see-through area. The opaque masking area is mainly used to protect the adhesive for attaching the windshield to the vehicle body from UV radiation. If the windshield is equipped with an electrical function (e.g., a heating function), the required electrical connections can also be hidden in the masking area. The masking area is typically formed by a black covering imprint on the surface of the outer glass 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 provided with a reflective layer and irradiated with an imaging unit (e.g., a screen or a projector). The user, in particular the driver, can perceive this phenomenon on the reflective layer of the imaging unit as a display image. By way of example, reference is made to DE102009020824A1, WO2022073894A1, and WO2022073860A1.

[0004] In this way, the display for the driver, which was previously located in the dashboard area, can be displayed on the windshield itself. This is aesthetically pleasing on the one hand and improves driving safety on the other hand, since the driver does not have to divert their gaze from the road in order to read the display. Examples of such displays are the driving speed, the time of day, the engine speed, the display of the navigation system, information about speed limits (traffic sign recognition), an image from a rear camera, and various status indicators regarding the vehicle status.

[0005] In a development, such a display system can also be provided for the front seat passenger. For them, for example, entertainment content can be displayed on the windshield. However, there is a risk that the display system for the front seat passenger interferes with or distracts the driver, which impairs driving safety. Therefore, there is a need for a display system of the type mentioned at the beginning, which displays information for the front seat passenger without distracting the driver as a result.

[0006] WO2019034557A1 discloses a screen that can be operated in two different operating modes, specifically a free viewing mode and a restricted viewing mode. In the free viewing mode, light from the screen is emitted over a wider angular range than in the restricted viewing mode. The screen is an LCD screen that includes two planar backlights with different radiation angular ranges. The user can turn on one of the two backlights to activate the desired operating mode. Summary of the Invention

[0007] The object of the present invention is to provide an improved display system for a vehicle. The display system will be suitable for implementing a display for the front seat passenger of a vehicle without distracting or otherwise interfering with the driver. However, conversely, the display for the front row passenger is intended to be visible to the driver if this is desired.

[0008] According to the present invention, the object of the present invention is achieved by the display system according to claim 1. Preferred embodiments result from the dependent claims.

[0009] The display system for a vehicle according to the present invention includes a windshield and (at least) one screen. The windshield has a transparent viewing area and an opaque shielding area. The screen is directed towards a display area that is arranged in the shielding area of the windshield. The windshield is equipped with a reflective layer in the display area that is suitable for (at least partially) reflecting the radiation of the screen, thereby generating a display image.

[0010] According to the present invention, the screen is suitable for operating in a first operating mode and in a second operating mode. In the first operating mode, the screen emits light within a first angular range; in the second operating mode, the screen emits light within a second angular range. The first angular range is smaller than the second angular range.

[0011] The user can switch between the first operating mode and the second operating mode of the screen. In the first operating mode, due to the smaller angular range, a restricted viewing mode is provided, while in the second operating mode, due to the larger angular range, a free or unrestricted viewing mode is provided. If the display system is assigned to the front seat passenger, the first operating mode can be selected in cases where the display will not distract the driver and is therefore only intended to be visible to the front seat passenger. However, if the driver also wants to see the display, the second operating mode can be selected. These are significant advantages of the present invention.

[0012] The windshield is provided for a vehicle and can therefore also be referred to as a vehicle windshield. In a preferred embodiment, the windshield is the windshield of a motor vehicle, particularly a passenger car or a truck.

[0013] The windshield is typically designed as a laminated glass pane and includes an outer glass pane and an inner glass pane, which are connected to each other via a thermoplastic interlayer. The windshield is provided for separating the interior (the vehicle interior) from the external environment in a window opening of the vehicle facing forward (with respect to the driving direction). In the context of the present invention, the inner glass pane means the glass pane of the windshield facing the interior. The outer glass pane means the glass pane facing the external environment.

[0014] The windshield has an upper edge and a lower edge and two side edges extending therebetween. The upper edge means the edge intended to point upward in the installed position. The lower edge means the edge intended to point downward in the installed position. The upper edge is often also referred to as the roof edge, and the lower edge is often also referred to as the engine edge.

[0015] The outer glass pane and the inner glass pane each have an outer surface and an inner side surface and a circumferential side edge surface extending therebetween. In the sense of the present invention, the outer surface means the main surface intended to face the external environment when installed. In the sense of the present invention, the inner side surface means the main surface intended to face the interior when installed. The inner side surface of the outer glass pane and the outer surface of the inner glass pane face each other and are connected to each other via a thermoplastic interlayer.

[0016] The outer glass pane and the inner glass pane are preferably glass panes, particularly preferably made of soda-lime glass, as is customary for window glass panes. However, one or both of the glass panes can also be made of other types of glass, such as quartz glass, borosilicate glass or aluminosilicate glass, or made of rigid transparent plastics, such as polycarbonate or polymethyl methacrylate. These glass panes can be transparent, or can also be tinted or colored. The thicknesses of the outer glass pane and the inner glass pane are preferably, independently of each other, from 0.5 mm to 5 mm, particularly preferably from 1 mm to 3 mm.

[0017] The thermoplastic interlayer (except for any embedded functional film often formed based on PET) is preferably formed based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or polyurethane (PU), or formed from a mixture, copolymer, or derivative thereof, particularly preferably based on PVB. The interlayer is usually formed by at least one thermoplastic film (bonding film), particularly a film based on PVB, EVA, or PU. This means that the film consists largely of the polymer (proportion greater than 50% by weight). In addition to the polymer, the film can also contain additional additives, particularly plasticizers. If the reflective layer is designed as a reflective film and embedded in the interlayer, then in addition to the reflective film, the interlayer will preferably also include at least two bonding layers (an inner bonding layer and an outer bonding layer, where the inner bonding layer faces the inner glass pane and the outer bonding layer faces the outer glass pane), where each of the bonding layers is usually formed by at least one bonding film, particularly a bonding film based on PVB, EVA, or PU. The reflective film is arranged between the bonding layers. The thickness of the bonding film (or each bonding film, if there are several) is preferably from 0.2 mm to 1 mm. For example, PVB films with a standard thickness of 0.38 mm or 0.76 mm can be used. Instead of a film, a polymer coating can also be used, particularly if the thermoplastic layer under discussion will be formed very thin, for example, with a thickness from 0.005 mm to 0.1 mm or from 0.02 mm to 0.07 mm.

[0018] The windshield has an opaque masking area and a transparent viewing area. In the context of the present invention, the masking area means an area of the windshield through which it is not possible to view. The light transmittance of the masking area is less than 10%, preferably less than 5%, particularly preferably less than 2%, and very particularly preferably substantially 0%. In the context of the present invention, the viewing area is an area of the windshield that enables viewing through the windshield and is intended for viewing through the windshield. Thus, the viewing area is transparent. The light transmittance of the viewing area is preferably at least 70%. The light transmittance means the total transmittance determined by the method for testing the light transmittance of motor vehicle glass panes defined in Section 9.1 of Appendix 3 of ECE-R43.

[0019] In a typical embodiment, the masking area surrounds the viewing area in a frame-like manner. Thus, the masking area is arranged circumferentially around the viewing area. Usually, the masking area forms the circumferential edge area of the windshield and abuts the side edges of the windshield. In a preferred embodiment, the masking area is thus arranged in the circumferential edge area of the windshield and surrounds the viewing area.

[0020] In a preferred embodiment, the display area is arranged in a section of the shielding area that is contiguous with the lower edge of the windshield. Thus, the display area is arranged between the transparent area of the windshield and the lower edge. In the case of a frame-like shielding area in the circumferential edge area of the windshield, the section of the shielding area is contiguous with each edge (upper edge, lower edge, first side edge, and second side edge) in each case, and the display area is preferably arranged in the section contiguous with the lower edge.

[0021] The shielding area is preferably formed by an opaque, particularly black imprint (covering imprint) on at least one of the surfaces of the outer glass plate and / or the inner glass plate, particularly preferably on the inner side surface of the outer glass plate. The covering imprint is generally composed of enamel, which contains glass frit and a colorant (particularly a pigment) and is applied by a screen printing method and then dried by baking. Such covering imprints have been commonly used, particularly for vehicle glass plates. The pigment is usually a black pigment, such as pigment carbon black, aniline black, bone black, iron oxide black, spinel black, and / or graphite. The covering imprint preferably has a thickness of 5 μm to 50 μm, particularly preferably 8 μm to 25 μm.

[0022] The shielding area can alternatively be formed by an opaque polymer film, which is part of the intermediate layer and is arranged between the reflective layer and the outer glass plate. In the context of the present invention, an opaque film is understood to mean a film with a light transmittance of less than 5%, particularly 0%, in the visible spectral range.

[0023] The shielding area can also be formed completely or partially by a functional element that has electro-controllable properties and can be darkened. Such functional elements include an active layer or layer sequence located between two planar electrodes, by means of which a voltage can be applied to the active layer (sequence) to adjust its optical properties. Functional elements that can be darkened to form an opaque shielding area are particularly electrochromic functional elements and SPD functional elements (suspended particle devices). An opaque shielding area exists only when the functional element is in the darkened state. The functional element can be applied to one of the surfaces of the outer glass plate or the inner glass plate, particularly to the inner side surface of the outer glass plate or the outer surface of the inner glass plate. The functional element can alternatively be provided as a multilayer film and arranged between two layers of the intermediate layer.

[0024] In the development of the present invention, there are: permanent shielding areas, which are formed in particular by covering imprints (alternatively by opaque polymer films); and areas that extend from the shielding areas into the see-through areas and are provided with functional elements having electro-controllable properties (in particular electrochromic functional elements). The display area is arranged partly in the permanent shielding area and partly in the area with the functional elements. Depending on the switching state, the area with the functional elements belongs to the see-through area (when the functional elements have been switched to transparent) or the shielding area (when the functional elements have been darkened or switched to opaque). If a display is to be generated that is arranged completely or partly in the area with the functional elements, the functional elements will be darkened. On the other hand, if a display is to be generated that is arranged only in the permanent shielding area, the functional elements can be switched to transparent in order to increase the size of the see-through area.

[0025] The opaque element forming the shielding area (in particular the covering imprint, the opaque polymer film and / or the functional element with electro-controllable properties) is arranged behind the reflective layer in the viewing direction, such that the reflective layer can be irradiated by the screen. Thus, the reflective layer is at a shorter distance from the screen than the opaque element.

[0026] The screen is directed towards the display area and irradiates the display area in order to generate a display image. Thus, in the context of the present invention, the area of the windscreen that is irradiated (or can be irradiated) by the screen is the display area. In the display area of the windscreen, a reflective layer is arranged according to the present invention, which reflects the radiation of the screen in the direction of the user in order to generate a display image. The screen irradiates the display area with electromagnetic radiation in the visible spectral range in order to generate a display image, which the user perceives as being in the shielding area. The radiation is in particular in the spectral range from 450 nm to 650 nm, for example wavelengths of 473 nm, 550 nm and 630 nm (RGB).

[0027] The reflective layer preferably has a reflectivity of at least 10%, particularly preferably at least 15%, with respect to the radiation of the screen. This is conducive to achieving a high intensity and good quality of the secondary display image. The reflectivity is, for example, from 10% to 100% or from 15% to 30%. The reflectivity describes the proportion of the total incident radiation that is reflected. The reflectivity is indicated in % (based on 100% of the emitted radiation) or as a dimensionless number from 0 to 1 (normalized to the emitted radiation). When plotted as a function of the wavelength, the reflectivity forms a reflection spectrum. In the context of the present invention, the statements regarding the reflectivity relate to the reflectivity measured at an angle of incidence of 65° with respect to the normal of the inner side surface, which approximately corresponds to the irradiation by a conventional screen. The reflectivity values relate to reflection measurements carried out using a light source that radiates uniformly with a normalized radiation intensity of 100% in the spectral range under consideration.

[0028] The reflective layer covers at least the display area. However, the reflective layer can also extend beyond the display area, i.e., can also cover an adjacent area of the windshield. This can be advantageous in order to avoid the need for precise positioning of the reflective layer or in order to prevent display errors from occurring in the edge regions of the displayed image, which may occur due to imperfect positioning of the reflective layer.

[0029] The reflective layer can be designed in different ways. In a first preferred embodiment, the reflective layer is designed as a metal-containing coating. The metal-containing coating can be applied to the surface of the outer glass plate or the inner glass plate, for example to the inner side surface of the outer glass plate, the outer surface of the inner glass plate or the inner side surface of the inner glass plate. Alternatively, the coating can be provided on a carrier film, which is arranged between two layers of the thermoplastic interlayer. The carrier film together with the coating forms a reflective film. The carrier film is, for example, a film based on polyethylene terephthalate (PET), preferably consisting essentially of PET, having a thickness of 20 μm to 200 μm, preferably 25 μm to 75 μm.

[0030] The metal-containing coating can be a mirror-like metal layer that substantially reflects all of the radiation of the screen (with a radiation reflectivity relative to the screen of substantially 100%). Suitable metals are, for example, silver or aluminum. Suitable layer thicknesses are, for example, from 200 nm to 5 μm, particularly from 800 nm to 1.5 μm. The metal-containing coating can alternatively be formed from a plurality of thin layers, including at least one thin layer based on a metal, preferably based on silver. Due to their IR reflection and conductive properties, this type of coating is also commonly used as a sunscreen coating (solar control coating) or a heatable coating. The at least one layer based on a metal preferably contains at least 99% by weight of silver and has a thickness of, for example, 5 nm to 20 nm. This coating has (partial) reflection properties in the visible light range such that it can be used as a reflective surface for a display system. The coating preferably further comprises a dielectric thin film. The desired reflection characteristics, particularly the reflectivity relative to the radiation of the screen, are achieved in particular by selecting the materials and thicknesses of the individual layers. Thus, the conductive coating can be appropriately adjusted, which is customary in the technical field and is well known to those skilled in the art. The dielectric layer or layer sequence is typically arranged above and below the metal layer. If the coating comprises several metal layers, each metal layer will preferably be arranged between two generally dielectric layers or layer sequences such that the dielectric layer or layer sequence is arranged between adjacent metal layers in each case. Thus, the coating is a thin film stack having n metal layers and (n + 1) dielectric layers or layer sequences, where n is a natural number, and where the metal layers and the dielectric layers or layer sequences alternately follow the lower dielectric layer or layer sequence in each case. Common dielectric layers of such thin film stacks are, for example, formed based on silicon nitride, silicon-metal mixed nitrides (such as zirconium silicon nitride), titanium oxide, aluminum nitride, tin oxide, zinc oxide or tin-zinc mixed oxides and have a layer thickness of, for example, 3 nm to 200 nm. Barrier layers are also common, which protect the metal layer from degradation and are typically formed as very thin metal-containing layers based on niobium, titanium, nickel, chromium and / or their alloys, with a layer thickness of, for example, 0.1 nm to 2 nm.

[0031] In a second preferred embodiment, the reflective layer is designed as a pure dielectric coating. The dielectric coating can in turn be applied to the surface of the outer glass plate or the inner glass plate, for example, to the inner side surface of the outer glass plate, the outer surface of the inner glass plate or the inner side surface of the inner glass plate. Alternatively, the coating can be provided on a carrier film (reflective film) and embedded between two layers of the intermediate layer, as already described above in connection with the metal-containing coating. The dielectric coating preferably has a refractive index (measured at 550 nm) higher than that of the material layer (e.g., thin film) of the substrate (outer glass plate, inner glass plate or carrier film) to which the dielectric coating is applied. The layer is formed, for example, based on aluminum nitride, silicon nitride, zirconium nitride, silicon-zirconium mixed nitride, zirconium oxide, tin oxide, zinc oxide, tin-zinc mixed oxide, and particularly preferably based on titanium oxide. The layer thickness is, for example, from 100 nm to 5 μm or from 500 nm to 2 μm. More complex multilayer coatings can also be used, in which 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. The reflection effect is caused by an interference effect here and can be adjusted very specifically by selecting the layer thickness.

[0032] In a third preferred embodiment, the reflective layer is designed as a pure dielectric polymer film, which comprises alternating individual layers with different refractive indices. The dielectric reflective film is preferably arranged between two layers of the intermediate layer and is thus embedded in the intermediate layer. The film does not have a metal-containing coating. The film is a sequence of pure dielectric layers made of polymer layers with a higher refractive index and polymer layers with a lower refractive index, and these polymer layers are arranged alternately. At least one of these two layer types is preferably based on PET. The other layer type can also be based on PET, wherein the different refractive indices are achieved by means of suitable additives (based on PET copolymers or based on another polymer (e.g., PMMA)). By alternating the layers with different refractive indices, an optical interference effect is achieved, which can be appropriately adjusted for the corresponding application (in particular by selecting the layer thickness and refractive index) in order to achieve the reflection properties in the desired spectral range. In this way, the reflection properties in the visible spectral range can be achieved in order to use the film as a reflective surface of the display system according to the invention.

[0033] The screen irradiates the windshield with electromagnetic radiation in the visible spectral range via the inner glass plate in order to generate a display image, which can be perceived by a user located inside the vehicle. Therefore, the screen is arranged on the inner side of the windshield and irradiates the windshield via the inner side surface of the inner glass plate. The radiation of the screen is (partially) reflected at the reflective layer.

[0034] The screen can operate in two operating modes: operating in a first operating mode with a restricted viewing mode, in which the screen emits light within a first angular range; and operating in a second operating mode with a free or unrestricted viewing mode, in which the screen emits light within a second angular range. The first angular range is smaller than the second angular range, thereby implementing the restricted viewing mode of the first operating mode.

[0035] The user can switch between the first operating mode and the second operating mode. This can be done by manual or voice control input from the user. In development, it is also conceivable to implement the selection of the operating mode in an automated manner by a driver assistance system, where, for example, when the driver assistance system detects a critical situation, a switch from the second operating mode to the first operating mode occurs.

[0036] The display of the display system according to the invention is specifically provided for and assigned to the vehicle occupants (usually the front seat passengers). The first angular range is preferably selected in such a way that the vehicle occupant can see the display, while another vehicle occupant (usually the driver) who is laterally offset relative to the person cannot see the display. The second angular range is preferably selected such that both the vehicle occupant and another vehicle occupant who is laterally offset relative to the person can see the display.

[0037] The angular range (within which light is emitted) determines the viewing angle of the display - that is, it determines the range within which an observer who is laterally offset relative to the display area can look at the area and still see the display. The radiation emitted from a point on the screen is emitted in the form of a beam cone, and the angular range indicates the expansion of the beam cone. It can be quantitatively expressed as the angle between the lateral surface of the beam cone and the surface normal of the screen (determined at the point where the beam cone is emitted). In this way, the angular range is specified within the context of the present invention as follows: It is described as the angle between the peripheral rays of the beam cone (which limit the beam cone) and the surface normal. A screen that emits light only precisely vertically and exclusively along the surface normal and not in the form of a beam cone would have an angular range of 0°. The farther the beam cone extends, the larger the size of the angular range.

[0038] It is possible that the light is not emitted in the form of a rotationally symmetric beam cone, but the angular range is different in the horizontal and vertical directions. The terms "horizontal" and "vertical" refer to the representation shown on the windshield: the vertical angular range defines the extent of the illuminated area along the vertical direction of the windshield (the direction between the upper and lower edges of the windshield), and the horizontal angular range defines the extent of the illuminated area along the horizontal direction of the windshield (the direction between the lateral edges). As can be readily seen from the intended application, within the context of the present invention, the angular range in this case refers to the horizontal angular range. The angular range is described as the angle between the peripheral rays of the beam in the horizontal section and the surface normal, and these peripheral rays are emitted towards the lateral edges of the windshield. The horizontal section is the section that passes through the emitted light component that illuminates the windshield along the horizontal line between the lateral edges of the windshield.

[0039] The horizontal angular range can also be referred to as the lateral angular range. The lateral angular range of the screen determines the lateral angular range of the display. "Lateral" refers to the intended viewing situation, in which the observer is arranged on the inner side of the windshield and gazes at the inner side surface of the inner glass plate. The lateral angular range defines the range within which an observer positioned laterally offset relative to the display area can see the display. Thus, the angular range determines the lateral viewing angle of the display.

[0040] The angular range can be determined by an observer who looks at the viewing screen and moves laterally away from it. Starting from the position where the observer can no longer see the display, the angular range can be determined as the angle between the surface normal of the screen and the connecting line (between the position and the edge of the screen facing that position). To compare the angular ranges of different displays, these angular ranges of moving laterally away from the screen can be recorded, for example, using the same camera, where the camera remains pointed at the screen. In each case, when the display can no longer be seen in the camera recording, the limit of the angular range is reached.

[0041] The first angular range is typically in the range from 15° to 90°, for example from 15° to 60° or from 20° to 50° or from 20° to 40°. The second angular range is typically in the range from 30° to 90°, for example from 40° to 90° or from 50° to 90° or from 60° to 80°.

[0042] The screen is particularly designed as a backlight transmissive imager. The two operating modes are particularly achieved by using two different backlights that emit light with different angular ranges. The screen can

[0043] - be operated alternately using the first backlight or the second backlight, thus achieving the two operating modes, or

[0044] - be operated either only with the first backlight or with a combination of the two backlights, thus achieving the two operating modes.

[0045] In a preferred embodiment, the screen includes a first planar backlight, a second planar backlight, and a transmissive imager, which are arranged surface-to-surface in the given order one above the other. The transmissive imager faces the windshield, and the first planar backlight faces away from the windshield. These backlights are preferably at least as large as the transmissive imager such that the transmissive imager can be evenly illuminated. One of the two backlights emits light within a first angular range, and the other of the two backlights emits light within a second angular range. Since the light from the first backlight must pass through the second backlight to illuminate the transmissive imager, the second backlight is transparent. This means that the second backlight has a transmittance of at least 70% compared to the radiation of the first backlight. Similarly, the second backlight should not scatter the light of the first backlight too much - thus, the haze value of the second backlight is preferably less than 7%, particularly preferably less than 2%, as measured according to ASTM D1003.

[0046] The screen is preferably operated in such a way that the two backlights operate alternately. This means that in the first operating mode (restricted viewing mode), only the first backlight is operated while the second backlight is switched off; and in the second operating mode (free viewing mode), only the second backlight is operated while the first backlight is switched off. However, alternatively, it is also conceivable to continuously operate the first backlight with a smaller or limited angular range. In the first operating mode, the first backlight then becomes the sole light source, and in the second operating mode, the second backlight with a larger or unrestricted angular range is also switched on. This also achieves the free viewing mode in the second operating mode, whereby due to the additional light source, the radiation intensity within the first angular range is stronger, and thus the display appears brighter or stronger within the first angular range than in the remainder of the second angular range (i.e., the part that does not overlap with the first angular range). Therefore, at least the second backlight can be switched on and off. Preferably, both backlights can be switched on and off individually, with one backlight being switched on while the other is switched off.

[0047] In an advantageous embodiment, the first planar backlight emits light within a first angular range, and the second planar backlight emits light within a second angular range. Thus, the second operating mode is achieved by using the second backlight, which is arranged between the first backlight and the imager. The second backlight is preferably designed as a flat light guide, which is provided with lamps suitable for coupling light into the light guide via the lateral edges and decoupling devices suitable for decoupling light from the light guide via the surface facing the imager.

[0048] A planar light guide is a layered or plate-like object suitable for conducting light. It can also be referred to as a light guide plate and has two main surfaces and a peripheral edge surface extending therebetween, which peripheral edge surface can also be referred to as a lateral edge surface or simply a lateral edge. One of these main surfaces faces the imager and the other main surface faces the first backlight. Suitable materials for the light guide include, for example, glass or transparent plastics such as polymethyl methacrylate (PMMA), polyethylene terephthalate (PET) or polycarbonate (PC). The lamp is positioned in such a way that the light emitted by the lamp is coupled into the light guide via the lateral edge (at least a part of the lateral edge). There, the light propagates due to total internal reflection at the main surfaces of the light guide, thus forming the basis of the light conduction effect. The lamp is, for example, a light emitting diode or a plurality of light emitting diodes, which are positioned on the lateral edge of the light guide. The light guide is equipped with coupling-out devices, which cause light to be coupled out of the light guide via the surface facing the imager and then illuminate the imager. This does not mean that all the light must be coupled out only via this main surface - usually, a certain proportion of the light is coupled out via the opposite main surface facing the first backlight. This is not a problem, although this light proportion then naturally does not constitute the backlight of the imager and can be said to be lost. Therefore, it is advantageous for as large a proportion as possible of the light to be coupled out via the main surface facing the imager. The coupling-out devices can, for example, be designed as light scattering structures, which are formed on one of the main surfaces of the light guide and / or embedded in the light guide. Examples of this are local or full-surface roughening or structuring of at least one of the main surfaces, thus preventing total internal reflection and therefore causing light to be coupled out. The roughening or structuring is preferably provided on the main surface of the light guide facing the imager in order to optimize the emission in this direction. Instead of roughening, for example, microlenses, microprisms or diffraction structures (such as holograms or diffraction gratings) can be applied to or formed on the main surface. These elements can, for example, be applied to the main surface as prefabricated elements (e.g., by gluing them on), formed from a UV-cured or thermally cured varnish applied to the main surface, structured or imaged using a tool and then cured, or formed from the main surface of the light guide itself by machining it using a tool. Nanoparticles can, for example, be embedded in the light guide as embedded coupling-out devices, especially if the light guide consists of a polymer material (preferably having a particle size of 150 nm to 500 nm).

[0049] The first backlight preferably includes a planar base element (illuminating element, planar light emitter) that emits light, and a micro-louver film that causes the emission angle to be restricted to a first angular range. The micro-louver film is disposed between the base element and the second backlight, and is preferably applied to the main surface of the base element facing the second backlight. The micro-louver film is a polymer film in which parallel louvers with widths and gaps in the micrometer range are formed, and these widths and gaps limit the angular range through which light passes. The angular range can be adjusted by means of the depth of the lamellae and the gaps between adjacent lamellae. Such a micro-louver film is known per se and is used, for example, as a privacy filter on notebook monitors. In order to limit the lateral angular range of the display, the micro-louver film is arranged in such a way that the projection of the louvers onto the windshield extends substantially vertically between the upper and lower edges of the windshield.

[0050] Similar to the second backlight, the base element can be designed as a flat light guide, which is provided with lamps suitable for coupling light into the light guide via the lateral edges, and extraction devices suitable for extracting light from the light guide via the surface facing the imager. For the first backlight, the lamps can also be arranged on the main surface of the light guide facing away from the imager, rather than on the lateral edges. Alternatively, for example, an electroluminescent film, a cold cathode tube, an LED panel (two-dimensional LED array), a planar OLED emitter or other floodlights can be used as the base element.

[0051] The first backlight can include additional elements well-known to those skilled in the art, such as diffusers, one or more light collimators or optical filters. For example, the first backlight can be constructed from the following elements in the order given: base element - diffuser - (multiple) light collimators - micro-louver filter.

[0052] The transmissive imager converts the light of the backlight into the desired display, which is then projected onto the windshield. Thus, when the light of the backlight passes through the imager, the imager can be said to supply information to the light. The transmissive imager is preferably a liquid crystal display element (LCD panel).

[0053] In a particularly advantageous embodiment, the radiation of the screen impinging on the windshield is p-polarized. The radiation is in particular substantially purely p-polarized - thus, the p-polarized radiation component is 100% or only insignificantly deviates from this value. The indication of the polarization direction here refers to the plane of incidence of the radiation on the windshield. P-polarized radiation is radiation whose electric field oscillates in the plane of incidence. S-polarized radiation is radiation whose electric field oscillates perpendicular to the plane of incidence. The incident vector and the surface normal of the windshield span the plane of incidence. The polarization (i.e., in particular, the ratio of p-polarized radiation and s-polarized radiation) is determined at a point in the display area, preferably at the geometric center of the display area. If the windshield is curved (which is usually the case), this has an impact on the plane of incidence of the radiation. For this reason, slightly deviating polarization components will occur in other areas, which are inevitable for physical reasons. To provide p-polarized radiation, a polarization filter or a polarization beam splitter can be arranged, for example, in the beam path between the screen and the windshield.

[0054] The radiation of the screen preferably impinges on the windshield at an angle of incidence of 45° to 70°, in particular 60° to 70°. In an advantageous embodiment, the angle of incidence deviates from the Brewster angle by at most 10°. Then, the p-polarized radiation is only insignificantly reflected at the surface of the windshield. As a result, the reflective layer represents the only significant reflection surface of the radiation. If the radiation is also significantly reflected at the inner side surface of the inner glass plate (air-glass transition), so-called ghosting will occur, which will at least interfere with the user (if not be completely unacceptable). The angle of incidence is the angle between the incident vector of the radiation and the inner side surface normal (i.e., the surface normal on the inner side outer surface of the windshield) at the geometric center of the display area. In the case of soda-lime glass (which is usually common for window glass plates), the Brewster angle for the air-glass transition is 57.2°. Ideally, the angle of incidence should be as close as possible to this Brewster angle. However, angles of incidence such as 65° can also be used (these angles are common for HUD projection arrangements), which are easy to implement in a vehicle and only slightly deviate from the Brewster angle, such that the reflection of the p-polarized radiation only increases insignificantly.

[0055] The windshield has at least one display area, which includes a screen with two operating modes according to the invention. The windshield can also have one or more additional display areas, specifically one or more display areas according to the invention (each display area being irradiated by a screen with two operating modes according to the invention) and / or one or more conventional display areas (each display area being irradiated by a conventional screen with only one operating mode). In an advantageous design, all display areas according to the invention are assigned to the passengers.

[0056] The windshield is preferably curved in one or more spatial directions, as is common in particular for motor vehicle glass panes. Typical radii of curvature are in the range from about 10 cm to about 40 m. The inner side surface of the inner glass pane is curved substantially concavely, and the outer side surface of the outer glass pane is curved substantially convexly. However, in principle, the windshield can also be flat.

[0057] The windshield can be produced by methods known per se. Here, the layer stack is produced by arranging the individual components (outer glass pane, (multiple) films of the intermediate layer, inner glass pane) flat on top of one another in the desired order. The layer stack is then laminated to form a composite glass pane. This is in particular carried out by methods known per se - for example by means of the autoclave method, the vacuum bag method, the vacuum ring method, the calender method, the vacuum laminator or a combination thereof. The outer glass pane and the inner glass pane are usually connected via the intermediate layer under the action of heat, vacuum and / or pressure.

[0058] If the reflective layer is a coating on the outer glass pane or the inner glass pane, the coating will preferably be applied to the respective glass pane surface by physical vapor deposition (PVD), particularly preferably by cathodic sputtering, very particularly preferably by magnetron-assisted cathodic sputtering ("magnetron sputtering"). However, in principle, the coating can also be applied, for example, by chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), by vapor deposition or by atomic layer deposition (ALD). The reflective layer is preferably applied to the glass pane surface, after which the glass panes are connected to form a composite glass pane (laminate).

[0059] On the other hand, if the reflective layer is provided as a reflective film (a metal-containing or pure dielectric coating on a carrier film or a pure dielectric polymer film), it will be arranged between two thermoplastic connecting layers and together with these two thermoplastic connecting layers form the intermediate layer. The connecting layers are preferably each provided in the form of at least one thermoplastic connecting film (in particular a PVB film). Reflective films can usually be purchased, for example a PET carrier film with a conductive coating or a pure dielectric reflective film with different individual layers, which individual layers alternately have a higher refractive index and a lower refractive index. The reflective film can be produced by depositing a conductive coating or a pure dielectric coating on a PET carrier film, in particular using the above-mentioned thin film coating methods or by coextrusion or multiple extrusion of two materials with different refractive indices in order to form a pure dielectric reflective film.

[0060] The shielding area can be formed by an opaque enamel printing ink applied to the surface of the glass plate, in particular the inner side surface of the outer glass plate (in particular by means of a screen printing method). The enamel printing ink is then baked into the glass plate surface, where it forms an opaque covering imprint that forms the shielding area. Alternatively, the shielding area can be formed by an opaque polymer film. In this case, one of the connecting layers is not formed by a single uniform connecting film, but consists of sections of an opaque connecting film and sections of a transparent connecting film. The connecting layer with the opaque connecting film is arranged between the reflective layer and the outer glass plate. If the shielding area (or at least a part thereof) is formed by a functional element with electro-switchable optical properties, either the layer system required for this purpose is applied before laminating onto one of the surfaces of the outer glass plate or the inner glass plate, or the functional element is provided as a prefabricated multilayer film and inserted between the two connecting layers before laminating.

[0061] If the windshield is curved, the outer glass plate and the inner glass plate will preferably be subjected to a bending process before laminating and preferably after any possible coating process in order to make them into a cylindrically or spherically curved shape. Preferably, the outer glass plate and the inner glass plate are bent uniformly together (i.e., simultaneously and with the same tool), as this optimally matches the shapes of the glass plates to each other for subsequent laminating. Typical temperatures for the glass bending process are, for example, 500 °C to 700 °C. At these temperatures, the glass plates become plastically deformable and can be brought into the desired shape by bending methods known per se (e.g., gravity bending, press bending, suction bending or combinations thereof).

[0062] The invention also includes a vehicle having a driver's seat and a front passenger seat and equipped with a display system according to the invention. The windshield of the vehicle is used as a projection surface for the display system and is irradiated by at least one screen that can be operated in a first operating mode and a second operating mode.

[0063] The driver's seat and the front passenger seat are arranged particularly close to each other behind the windshield. The windshield can be imaginarily divided into two halves by a centrally arranged dividing line extending between the upper edge and the lower edge. One half is then assigned to the driver's seat and is arranged in front of the driver's seat (in the driving direction), while the other half is assigned to the front passenger seat and is arranged in front of the front passenger seat (in the driving direction). If the driver and the front passenger are looking straight ahead in the driving direction, each will view through the half of the windshield assigned to them.

[0064] In an advantageous embodiment, the display area according to the invention is assigned to the front seat passenger and is arranged in front of the front seat passenger seat. This means that a screen according to the invention with two operating modes is provided in order to generate a display for the front row passenger. Accordingly, the associated display area is arranged in the half of the windscreen assigned to the front seat passenger seat and on the side of the front seat passenger seat. The advantage of the display system according to the invention is particularly advantageous since the front row passenger can switch to the first operating mode with a restricted angular range if the driver is not to be distracted by the display.

[0065] Several display areas can also be assigned to the front seat passenger and arranged in front of the front seat passenger seat, each of these display areas being illuminated by a separate screen in each case. In this case, all the screens of the display areas preferably assigned to the front row passenger are designed according to the invention and are thus suitable for operating in two different operating modes.

[0066] In one embodiment of the invention, there is (at least) one further display area assigned to the driver and arranged in front of the driver's seat. A further screen is directed at this further display area in order to generate a display image by reflection at the reflective layer. Even several display areas can be assigned to the driver and arranged in front of the driver's seat, each of these display areas being illuminated by a separate screen.

[0067] In principle, the display area assigned to the driver can also be illuminated by a screen according to the invention with two operating modes. However, since driver display disturbing the front row passenger is less important, it is preferred to use a conventional screen which is only suitable for operating in a single operating mode (i.e., with a single angular range). Since conventional screens are generally less complex and thus less expensive, this is advantageous in terms of production costs. In said operating mode, the screen preferably emits light in the second angular range (free viewing mode) such that the front row passenger can also see the driver display. However, in principle, the screen then also emits light in the first angular range (restricted viewing mode).

[0068] Even several display areas can be assigned to the driver and arranged in front of the driver's seat, each of these display areas being illuminated by a separate screen. In this case, all the screens of the display areas assigned to the front row passenger preferably have a conventional design and are thus only suitable for operating in a single operating mode (preferably the operating mode with the second angular range and the free viewing mode).

[0069] In the development, it is also possible to use a screen such as the screen in WO2019034557A1. This screen has: a first region where the screen operates in two different operating modes with different angular ranges; and a second region where the screen operates only in one operating mode with a single angular range. Such a screen can be implemented, for example, with a first backlight and a second backlight, as described above, where the micro-louver film for restricting the angular range is only provided in the first region of the screen. In the second region, the first backlight then also emits light with a second angular range. Such a screen can be positioned, for example, in the area of the vehicle center console and irradiate a display area that is partially arranged in the half of the windshield associated with the driver's seat and partially arranged in the half of the windshield associated with the passenger's seat. The first region of the screen with two operating modes then preferably irradiates the part of the display area located in the half of the windshield associated with the passenger's seat, and the second region of the screen with only one operating mode then preferably irradiates the part of the display area located in the half of the windshield associated with the driver's seat.

[0070] In one or more display areas assigned to the front seat passenger, entertainment content such as TV programs, videos, computer games, or Internet data is preferably presented. In one or more display areas assigned to the driver, priority is given to displaying status information that was previously usually displayed in the dashboard area, such as the time of day, driving speed, engine speed, coolant temperature, internal or external temperature, information of the entertainment system (such as the currently used radio station), or information of the navigation system. Similarly, images from one or more rear cameras can be displayed for the driver to supplement or replace the classic exterior rearview mirror or rearview mirror. Displaying this information in the shaded area of the windshield has the advantage that the driver does not have to turn their line of sight out of the actual field of view as in the case of a conventional display, which is beneficial for safety reasons and ergonomic reasons. In semi-autonomous driving, the driver can gain control of the vehicle faster. A more flexible human-machine interface is provided, for example, where the user himself can determine the position of each display. The semi-virtual display image allows the eyes to refocus on the road faster. In addition, the display is aesthetically pleasing. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Hereinafter, the present invention will be explained in more detail with the aid of examples of the drawings and embodiments. The drawings are schematic representations and are not drawn to scale. The drawings do not limit the present invention in any way.

[0072] In the drawings:

[0073] Figure 1 is a plan view of the windshield of a display system according to the present invention in a vehicle,

[0074] Figure 2 is a cross-section of a windshield-equipped display system according to the present invention that passes through Figure 1 , and

[0075] Figure 3 is a cross-section of the windshield in Figure 1 ;

[0076] Figure 4 is a cross-section of another embodiment of the windshield of the display system according to the present invention,

[0077] Figure 5 is a cross-section of the screen of the display system from Figure 2 , and

[0078] Figure 6 is another cross-section of the screen of the display system from Figure 2 . DETAILED DESCRIPTION

[0079] Figure 1 , Figure 2 and Figure 3 each show details of a display system according to the present invention in a vehicle. The display system includes a windshield 10 and a screen 20. Figure 1 shows a plan view of the windshield 10, Figure 2 shows a cross-section of the display system passing through the cutting line X-X' marked in Figure 1 , and Figure 3 shows a cross-section of the windshield 10 passing through the same cutting line with a greater amount of detail.

[0080] The windshield 10 is installed in a vehicle, particularly a passenger vehicle. Figure 1 Also shown is a view of the windshield 10 from the interior of the vehicle. The vehicle is equipped with a driver's seat and a front passenger seat. In the illustration, the driver's seat is arranged behind the left half of the windshield 10, and the front passenger seat is arranged behind the right half. Thus, this is a so-called left-hand drive vehicle for right-hand traffic, as is common in continental Europe, the United States, and other places. The left half of the windshield 10 is assigned to the driver and is located in front of the driver's seat, and the right half is assigned to the front passenger and is located in front of the front passenger seat.

[0081] The windshield 10 has an opaque shielding area M, which is arranged in the circumferential edge area and surrounds the transparent viewing area D in a frame-like manner. The windshield 10 has an upper edge O pointing upward (towards the vehicle roof) and a lower edge U pointing downward (towards the engine compartment), as well as two side edges extending between them. Such shielding areas M are common in vehicle glass - they are used to protect the adhesive for bonding the windshield 10 to the vehicle body from UV radiation. Additionally, the side edges of any electrical connections or embedded functional films can be hidden within the shielding area M. For example, the windshield 10 has two display areas A, B. The two display areas A, B are arranged in a section of the shielding area M adjacent to the lower edge U. The display area A is assigned to the front seat passenger F and is arranged in the front half of the windshield 10 in front of them. This display area is intended to display a display for the front seat passenger F. This can particularly be entertainment content, such as movies, internet data, or computer games. The display area B is assigned to the driver and is arranged in the front half of the windshield 10 in front of them. This display area is intended to display a display for the driver. This can particularly be status information of the vehicle (e.g., driving speed), navigation information, or pictures from a rear camera.

[0082] To generate the display, the screen 20 is directed at the display area A irradiated by the screen. The display area B is similarly irradiated by another screen (not shown). The object of the present invention is to implement the display in the display area A in such a way that the driver is not disturbed by it. However, the driver is intended to be able to see the display in the display area A (if the driver so desires). For this purpose, according to the present invention, a projector 20 is used, which can be operated in two different operating modes, specifically: a first operating mode, in which the light of the screen 20 is emitted within a smaller angular range (restricted viewing mode); and a second operating mode, in which the light of the screen 20 is emitted within a larger angular range (free / unrestricted viewing mode). The driver or the front row passenger can set the operating mode in which the screen 20 operates. For the display area B, a conventional screen is used, which operates only in a single operating mode. This is particularly an operating mode with a larger angular range of emitted light, such that the front row passenger can also see the display. The screen is arranged below the respective display areas A and B.

[0083] The windshield 10 is constructed from an outer glass plate 1 and an inner glass plate 2, which are connected to each other via a thermoplastic interlayer 3. In the installation position, the outer glass plate 1 faces the external environment; the inner glass plate 2 faces the interior of the vehicle. For simplicity, the windshield 10 is shown as flat, although vehicle glass plates are usually curved, which is also preferred within the scope of the present invention. The outer glass plate 1 and the inner glass plate 2 are composed of soda-lime glass. The outer glass plate 1 has a thickness of, for example, 2.1 mm, and the inner glass plate 2 has a thickness of 1.6 mm.

[0084] The shielding area M is formed by a black covering imprint 8, which is applied to the inner side surface of the outer glass plate 1 facing the interlayer 3. In the automotive field, such a covering imprint 8 is usually standard: the enamel ink is printed onto the glass plate surface by means of screen printing. The enamel ink contains black pigments as well as glass frits, and the black pigments and glass frits are baked into the glass plate surface.

[0085] The interlayer 3 has a multi-layered structure. The interlayer has an outer connection layer 5 facing the outer glass plate 1 and an inner connection layer 6 facing the inner glass plate 2. The connection layers 5 and 6 are transparent and are made of commercially available PVB films, which also contain plasticizers. The outer connection layer 5 has a thickness of, for example, 0.76 mm, and the inner connection layer 6 has a thickness of 0.38 mm.

[0086] The reflective layer 4, which is designed as a reflective film, is arranged between the connection layers 5 and 6. Thus, the reflective layer 4 is connected to the outer glass plate 1 via the outer connection layer 5 and to the inner glass plate 2 via the inner connection layer 6. The reflective layer 4 is arranged in a section adjacent to the lower edge U of the shielding area M in such a way that it covers the two display areas A and B.

[0087] The screen 20 is arranged on the inner side of the windshield 10. Thus, the inner glass plate 2 of the windshield 10 faces the screen 20. The screen 20 irradiates the display area A in order to generate a display image. The radiation of the screen 20 onto the windshield 10 is substantially pure p-polarized. This is achieved, for example, by arranging a polarization filter between the screen 20 and the windshield 10. Since the screen 20 irradiates the windshield 10 at an incident angle of approximately 65° (which is close to the Brewster angle), the radiation of the screen 20 is only insignificantly reflected at the inner side surface of the windshield 10 facing away from the interlayer 3. The light of the screen 20 is reflected substantially only at the reflective layer 4, such that a clear display image is generated without any disturbing ghosting, which can be perceived by the observer (in this case the front seat passenger F).

[0088] The reflective layer 4 is, for example, a pure dielectric reflective film, which is in each case constructed from a series of individual polymer dielectric layers, where the individual layers alternately have a higher refractive index and a lower refractive index. Due to interference, the reflective film has reflective properties, in particular with respect to the radiation of the screen 20.

[0089] Figure 4 A cross-section through a further windscreen 10 which can be used for a display system according to the invention is shown. The outer glass plate 1, the inner glass plate 2, the outer connecting layer 5 and the inner connecting layer 6 with the covering stamp 8 are designed in the same way as in the Figure 3 example. The electrochromic film 7 is arranged between the outer connecting layer 5 and the inner connecting layer 6, specifically in the region extending from the marked area to the see-through area D. The electrochromic film 7 can be electrically darkened, thereby increasing the shielding area M so to speak. The reflective layer 4 is applied to the inner side surface of the inner glass plate 2 facing away from the intermediate layer 3 and thus covers the entire display area, in which case this display area is partly arranged in the static shielding area M formed by the covering stamp 8 and partly in the dynamic shielding area formed by the electrochromic film 7. The reflective layer 4 is, for example, a sputtered dielectric coating consisting of a titanium oxide thin film. Depending on the situation, thus if a larger display is to be shown and it is not necessary to be able to see completely through the actual see-through area D, the electrochromic film 7 can be used to enlarge the shielding area M and the display area A.

[0090] Figure 3 and Figure 4 The design of the reflective layer 4 in Figure 3 is only an example. Alternatively, the reflective layer 4 can be realized, for example, by a reflective film as in

[0091] Figure 5 which is provided as a PET carrier film with a metal-containing coating. Alternatively, a metal-containing coating can also be applied as the reflective layer 4 to the outer surface of the inner glass plate 2 facing the intermediate layer 3. The reflective layer 4 can have partial reflective properties with respect to the light of the screen 20 or be designed in a mirror-like manner and reflect substantially the entire radiation. Figure 2 A cross-section through the screen 20 of the display system in

[0092] The imager 23 is an LCD panel alternately illuminated by the first backlight 21 or the second backlight 22. The first backlight 21 emits light within a first angular range β1, and the second backlight 22 emits light within a second angular range β2. The angular range β1 is smaller than the second angular range β2. By using the first backlight 21 with a smaller angular range β1, an operating mode with a restricted viewing mode ( Figure 5 a) is achieved, and by using the second backlight 22 with a larger angular range β2, an operating mode with a free or unrestricted viewing mode ( Figure 5 b) is achieved.

[0093] The cross-sectional view shows a section of the emitted light component that illuminates the windshield along a horizontal line between the side edges of the windshield 10. Therefore, this radiation component is also referred to as the horizontal component. The angular ranges β1, β2 are determined as the angles between the peripheral rays (which laterally limit the beam cone originating from a point in the horizontal component) and the surface normal at that point. The angular ranges define the range within which an observer can laterally deviate from the actual expected observer position (directly in front of the display area 4) and still be able to see the display. When operating in the restricted viewing mode with a smaller angular range β1 ( Figure 5 a), if the range of lateral offset of the observer relative to the display area 4 is relatively small, the display can no longer be seen. This means that a driver who is significantly laterally offset relative to the display area 4 cannot see the display and is thus not disturbed or distracted thereby. When operating in the free viewing mode with a larger angular range β2 ( Figure 5 b), the display can still be clearly seen even from a laterally offset position. In this case, the driver can see the display in the display area 4.

[0094] Figure 6 is shown in more detail through Figure 5Another cross-section of the screen 20. The second backlight 22 is formed by a planar light guide 22a, which is made of, for example, glass or PMMA. The light guide 22a has: two main surfaces, one main surface facing the imager 23 and the other main surface facing the first backlight 21; and lateral edges (more precisely: lateral edge surfaces) extending therebetween. The lamp 22b is arranged on the lateral edge, for example, a plurality of LEDs. When the second backlight 22 is in operation, the light from the lamp is coupled into the light guide 22a via the lateral edge and propagates therein due to total internal reflection at the main surfaces. The main surface of the light guide 22a facing the imager 23 is provided with an outcoupling device 22c, such as a microprism or a diffraction structure. The outcoupling device 22c is schematically arranged over the entire main surface, but is usually only distributed over a locally restricted area with a uniform distribution. By means of the outcoupling device 22c, the light is (partially) outcoupled from the light guide 22a via the main surface facing the imager 23, as a result of which the imager 23 is backlit.

[0095] The first backlight 21 is formed by a planar illumination element 21a (base element, planar spotlight). The illumination element 21a can be formed by a light guide, for example, in a manner similar to the first backlight, via the lateral edge of which the light from the lamp is coupled in, where the light is outcoupled again via the main surface by means of an outcoupling device. However, other designs can also be envisaged, such as an electroluminescent film, an OLED or an LED arrangement. The microshutter film 21b is applied to the main surface of the base element 21a facing the second backlight 22 in order to achieve a restricted angular range β1 of the first backlight 21.

[0096] The screen can include additional components (not shown), such as components for beam shaping (such as collimators and / or diffusers) or optical filters (especially interference coatings) or other coatings (such as, for example, antireflection coatings).

[0097] List of reference numerals

[0098] (10) Windshield

[0099] (1) Outer glass plate

[0100] (2) Inner glass plate

[0101] (3) Thermoplastic interlayer

[0102] (4) Reflective layer

[0103] (5) Outer connection layer of intermediate layer 3

[0104] (6) Inner connection layer of intermediate layer 3

[0105] (7) Electrochromic film

[0106] (8) Cover imprint

[0107] (20) Screen

[0108] (22) First planar backlight of screen 20

[0109] (21a) Lighting element of first planar backlight 21

[0110] (21b) Micro-louver film of first planar backlight 21

[0111] (22) Second planar backlight of screen 20

[0112] (22a) Planar light guide of second planar flat backlight 22

[0113] (22b) Lamp of second planar backlight 22

[0114] (22c) Coupling-out device of second planar backlight 22

[0115] (23) Transmissive imager of screen 20

[0116] (F) Observer / front passenger

[0117] (M) Shielded area of windshield 10

[0118] (D) Transparent area of windshield 10

[0119] (A) Display area of windshield 10 (with two operating modes)

[0120] (B) Additional display area of windshield 10 (with one operating mode)

[0121] (O) Upper edge of windshield 10

[0122] (U) Lower edge of windshield 10

[0123] (β1) First angular range of screen 20

[0124] (β2) Second angular range of screen 20

[0125] X-X' section line

Claims

1. A display system for a vehicle, the display system comprising: - a windshield (10) having a transparent viewing area (D) and an opaque shielding area (M), and - a screen (20) directed towards a display area (A) arranged in the shielding area (M), wherein the windshield (10) is provided with a reflective layer (4) in the display area (A), the reflective layer being adapted to reflect the radiation of the screen (20) in order to generate a display image, and wherein the screen (20) is adapted to operate in a first operating mode and in a second operating mode, wherein, in the first operating mode, the screen emits light within a first angular range (β1), and in the second operating mode, the screen emits light within a second angular range (β2), wherein the first angular range (β1) is smaller than the second angular range (β2).

2. The display system according to claim 1, wherein, The screen (20) comprises: - a first planar backlight (21), - a second planar backlight (22), and - a transmissive imager (23), which are arranged surface-to-surface in a given order one on top of the other, wherein one of the two backlights (21, 22) emits light within the first angular range (β1), and the other of the two backlights (21, 22) emits light within the second angular range (β2).

3. The display system according to claim 2, wherein - the first planar backlight (21) emits light within the first angular range (β2), and - the second planar backlight (22) emits light within the second angular range (β2) and is designed as a planar light guide (22a), the planar light guide being provided with an illumination device (22b) adapted to couple light into the light guide (22a) via a lateral edge, and an outcoupling device (22c) adapted to couple the light out of the light guide (22a) via a surface facing the imager (23).

4. The display system according to any one of claims 2 or 3, wherein, The transmissive imager (23) is designed as a liquid crystal display element.

5. The display system according to any one of claims 2 to 4, wherein, The first planar backlight (21) comprises a planar illumination element (21a) and a micro-louver film (21b) arranged between the illumination element (21a) and the second planar backlight (22).

6. The display system according to any one of claims 1 to 5, wherein, The reflective layer (4) is designed as: - a metal-containing coating, or - a pure dielectric coating, or - a pure dielectric polymer film comprising alternating individual layers having different refractive indices.

7. The display system according to any one of claims 1 to 6, wherein The shielding area (M) is formed by: - a covering stamp (8), - an opaque polymer film which is part of the intermediate layer (3), and / or - a functional element with electro-controllable properties, in particular an electrochromic functional element.

8. The display system according to any one of claims 1 to 7, wherein - the windshield (10) has an upper edge (O), a lower edge (U), and two lateral edges extending therebetween, and - the display area (B) is arranged in a part of the shielding area (M) adjacent to the lower edge (U).

9. The display system according to any one of claims 1 to 8, wherein, The radiation of the screen (20) incident on the windshield (10) is p-polarized.

10. The display system according to any one of claims 1 to 9, wherein, The windshield (10) is a composite glass plate including an outer glass plate (1) and an inner glass plate (2), and the outer glass plate and the inner glass plate are connected to each other via a thermoplastic interlayer (3).

11. A vehicle having a driver's seat and a front passenger seat and equipped with the display system according to any one of claims 1 to 10.

12. The vehicle according to claim 11, wherein, The display area (A) is arranged in the upper half of the windshield (10) on the front passenger seat side.

13. The vehicle according to claim 12, wherein, The angular range (β1) is selected in such a way that the display of the display area (A) cannot be perceived from the driver's seat.

14. The vehicle according to any one of claims 12 or 13, wherein - an additional display area B is arranged in the upper half of the windshield (10) on the front passenger seat side, - another screen is directed to the additional display area (B), and - the additional screen is only suitable for operating in a single operation mode, in which the screen preferably emits light within the second angular range (β2).

Images