Glazing for a projection assembly with p-polarized radiation

Abstract

The invention relates to a glazing (100) for a projection assembly (101), comprising a pane (1) having an interior-side surface (IV) and an exterior-side surface (III) and comprising a reflective coating (2) for p-polarized radiation (6), the reflective coating being applied at least in a display region (A), preferably only in a display region (A), on the interior-side surface (IV) of the pane (1) and having, in the specified sequence starting from the interior-side surface (IV) of the pane (1), an optically highly refractive layer (2.1) with a refractive index which is greater than or equal to 2.0, a reflection-increasing layer (2.2) which is based on silver, a second optically highly refractive layer (2.3) with a refractive index which is greater than or equal to 2.0, and an optically low-refractive layer (2.5) with a refractive index which is less than or equal to 1.6. The glazing is characterized in that the reflection-increasing layer (2.2) is a discontinuous layer. The invention also relates to a projection assembly comprising the glazing and to an imaging unit.

Description

[0001] SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0002] Glazing for a projection arrangement with p-polarized radiation

[0003] The invention relates to a glazing for a projection arrangement and a projection arrangement with such glazing.

[0004] Vehicle windows, especially those in passenger cars, typically feature an opaque masking area, which forms a circumferential border surrounding a central viewing area. The primary purpose of this opaque masking area is to protect the adhesive used to bond the vehicle window to the vehicle body from UV radiation. This masking area is typically created by a black printed overprint.

[0005] Modern vehicles are increasingly equipped with so-called head-up displays (HUDs). A projector, typically located in the dashboard area, projects images onto the windshield's viewing area, where they are reflected and perceived by the driver as a virtual image (from their perspective) behind the windshield. This allows important information to be projected into the driver's field of vision, such as current speed, navigation instructions, or warnings, which the driver can see without taking their eyes off the road. Head-up displays can thus significantly contribute to improving road safety.

[0006] HUD projectors typically illuminate the windshield at an angle of incidence of approximately 65°, which is close to Brewster's angle for an air-to-glass interface (57.2° for soda-lime glass). This can be exploited for a clear HUD projection: if the HUD projector uses p-polarized radiation, it will hardly reflect the radiation at the external glass surfaces of the windshield. Instead, the windshield is coated with a reflective coating suitable for reflecting the p-polarized radiation to generate the displayed image. Since there is only one significant plane of reflection—the reflective coating—a clear display image is produced without ghosting (or with only faint ghosting, which is due to residual reflection at the external glass surfaces if the angle of incidence deviates slightly from Brewster's angle).For example, reference is made to DE102014220189A1, EP3187917B1 and W02021104800A1. SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT.

[0007] It has also been proposed to use the opaque masking area as a display surface for a display system. For this purpose, a display area within the masking area is illuminated by an imaging unit such as a screen. Examples include DE102009020824A1, WO2022073894A1, and W02022073860A1. In this way, displays for the driver, which were previously located on the dashboard, can be projected directly onto the windshield. 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. These display systems within the masking area are also preferably operated using p-polarized radiation to avoid reflections from the glass surfaces and the resulting ghost images.

[0008] The reflective coating for a display area in the see-through region must have high transparency to avoid critically restricting the view through the windshield. This typically limits the reflectance towards p-polarized radiation. This limitation does not apply to a display area in the masking region, as the masking region is opaque by nature. Here, reflective coatings with a higher reflectance can be used, resulting in a more intense display image. For this reason, different reflective coatings are typically used for a display in the see-through region (head-up display, HUD) and a display in the masking region. However, for both HUDs and displays in the masking region, the benefits and costs must be in an economically viable balance, which is why unnecessary material consumption should be avoided.

[0009] Providing different reflective coatings presents challenges for glass manufacturers because it increases production costs. This is especially true when a vehicle is equipped with both a transparent and a masked display area, requiring the same windshield to be coated with both types of coatings in certain sections. Therefore, there is a need for reflective coatings that can be used for both transparent and masked displays and that largely eliminate ghosting regardless of the display type. SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT

[0010] CN113031276A discloses a display system wherein the interior surface of the inner disc is provided with a reflective coating comprising at least a sequence of a dielectric high refractive index (refractive index > 1.8) and a dielectric low refractive index (refractive index < 1.6).

[0011] WO2022253659A1 discloses a reflective coating for p-polarized radiation with high-refractive-index and low-refractive-index layers arranged alternately and comprising at least one layer of absorbing material having an average refractive index greater than 1 and an average extinction coefficient greater than 0.1.

[0012] The invention is based on the objective of providing an improved glazing, in particular vehicle glazing, for a projection arrangement that ensures a clear and high-intensity display, regardless of whether the display area is located in the transmission area or in the masking area. The glazing is to be provided with an improved reflective coating that exhibits a high reflectance of p-polarized radiation with minimal ghosting.

[0013] The object of the present invention is achieved according to the invention by a glazing according to claim 1 and a projection arrangement according to claim 11. Preferred embodiments are described in the dependent claims.

[0014] The glazing according to the invention for a projection arrangement comprises a pane with an interior surface and an exterior surface, as well as a circumferential edge surface that connects the two surfaces. A reflective coating for p-polarized visible radiation is applied to the interior surface of the pane. The reflective coating is arranged in at least one display area of ​​the pane. Preferably, the reflective coating is arranged only in one display area. However, the reflective coating can also be arranged in other areas of the pane, for example, in another display area. It is also possible for the reflective coating to extend over the entire interior surface of the pane. This variant simplifies the application, as the pane does not need to be masked before the reflective coating is applied.

[0015] The display area is preferably a portion of the inner surface of the disc, but it can also extend over the entire inner surface. SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT

[0016] The display area is designed to be illuminated by at least one imaging unit in order to display a virtual image or virtual images to a viewer.

[0017] The reflective coating comprises, in the following order starting from the inner surface of the disc, at least the following layers: a first optically high-refractive-index layer with a refractive index greater than or equal to 2.0, a reflection-enhancing layer based on silver, a second optically high-refractive-index layer with a refractive index greater than or equal to 2.0, and an optically low-refractive-index layer with a refractive index less than or equal to 1.6.

[0018] According to the invention, the reflection-enhancing layer is a discontinuous layer. A discontinuous layer is a layer consisting of individual islands or particles based on silver that are not interconnected. A discontinuous layer is therefore understood to be a layer that has interruptions, i.e., uncoated areas. The reflection-enhancing layer thus has areas coated with a silver-based material, as well as uncoated areas. The coated areas can also be referred to as coated regions. The uncoated regions can also be referred to as interruptions or uncoated regions. In particular, the coated and uncoated regions are irregularly distributed, i.e., not arranged in a regular geometric pattern.

[0019] In the reflective coating, the described uncoated areas can remain as voids or, alternatively, be filled by the material of the dielectric layer directly above them. Whether the uncoated area remains empty or is filled by the overlying layer can vary from one uncoated area to the next. In other words, the discontinuous reflection-enhancing layer can have uncoated areas that function as voids and uncoated areas that are filled by the overlying layer. The metallic layer according to the invention thus consists of discontinuously distributed areas coated with a silver-based material, as well as areas that are coated with dielectric material or empty, wherein said dielectric material is identical to that of the dielectric layer directly above it.SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT.

[0020] If a layer of the reflective coating is based on a material, the layer consists predominantly of this material in addition to any impurities or dopants (preferably with a proportion of less than 5 wt.%).

[0021] The core of the invention is a glazing with an improved reflective coating. This coating is corrosion-resistant and stable against mechanical stress, allowing it to be applied to an exposed surface of the glass. This results in a particularly clear display image with only a very faint ghost image if the angle of incidence of the imaging unit does not exactly match Brewster's angle. This ghost image is caused by a certain amount of residual reflection on the outer surface of the glass, or, if another pane is present, on the outer surface of that additional pane, which is further attenuated by the light passing through the reflective coating.Furthermore, the reflective coating exhibits a high reflectivity towards the p-polarized radiation of the imaging unit, thus ensuring a high-intensity display image. The reflective coating is equally suitable for projection setups with a display area in the transmission zone and those with a display area in the masking zone. The discontinuous, reflection-enhancing layer has the significant advantage of only slightly reducing light transmission through the lens (particularly relevant for automotive glazing) while simultaneously increasing the reflection of p-polarized radiation. This ensures that the transmission through the transmission zone is not significantly impaired and allows for the display of a high-intensity virtual image. The discontinuous metal layer can be produced by vapor deposition, sputtering, printing, or other methods.These are major advantages of the present invention.

[0022] The high reflectance towards p-polarized radiation, combined with high transparency, is therefore primarily due to the influence of the discontinuous, silver-based reflectance-enhancing layer. The inventors surprisingly discovered that positioning this reflectance-enhancing layer results in a synergistic effect on transparency and reflectance for p-polarized radiation. Optimal properties are achieved when the reflectance-enhancing layer is positioned between two optically high-refractive-index layers. SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0023] The glazing can be single glazing with exactly one monolithic pane. However, the glazing is preferably a laminated pane comprising a second pane and a thermoplastic interlayer. The first pane with the reflective coating according to the invention and the second pane are bonded together over their entire surface via the thermoplastic interlayer. The thermoplastic interlayer is thus arranged between the first and second panes. The interior surface of the first pane is preferably oriented away from the thermoplastic interlayer, so that the reflective coating is located on a surface of the laminated pane exposed to the environment.

[0024] In a particularly preferred embodiment of the invention, the glazing is a vehicle window, in particular a windshield. The vehicle window is designed to separate the interior (vehicle interior) from the external environment. Specifically, the windshield is designed to separate the interior (vehicle interior) from the external environment in the forward-facing window opening of a vehicle. The interior surface of the window is designed to be the surface exposed to the vehicle interior, so that no further panes of glazing are arranged between the reflective coating and the vehicle interior. In this context, the pane is preferably the inner pane of a glazing assembly designed as a vehicle window. The further pane is correspondingly preferably the outer pane of the glazing assembly designed as a vehicle window.The glazing in this case is a laminated pane. For the purposes of the invention, the inner pane refers to the pane of the vehicle window facing the interior. The outer pane refers to the pane facing the external environment.

[0025] For the purposes of the invention, the term "outer surface" refers to the main surface of a disc which, when installed, is intended to face the external environment. The term "inner surface" refers to the main surface of a disc which, when installed, is intended to face the interior.

[0026] In a preferred embodiment of the invention, the reflection-enhancing layer is based on silver nanoparticles; preferably, the reflection-enhancing layer consists entirely of silver nanoparticles. When using silver nanoparticles, the reflectance for p-polarized radiation is further increased relative to the light transmittance. SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT

[0027] Particularly advantageous values ​​for light transmittance and reflectance are obtained when the reflection-enhancing layer is based on silver nanoparticles having, on average, a lateral extent of less than or equal to 100 nm, preferably less than or equal to 50 nm, and particularly preferably less than or equal to 20 nm. For the purposes of the invention, the lateral extent means that the silver nanoparticles extend along the x- and y-axes, which are parallel to the surface of the disk. It thus describes the size of the silver nanoparticles in the plane. The extent along the z-axis thus defined is the nominal extent, which indicates the thickness of the reflection-enhancing layer and therefore the thickness of the individual silver nanoparticles (geometric thickness). Unless otherwise specified, the specification of layer thicknesses or thicknesses generally refers to the geometric thickness of a layer.The lateral extent largely determines how strongly the silver nanoparticles reflect or scatter the light striking the coating. The smaller the lateral extent of the silver nanoparticles, the lower the reflection and the higher the light transmission through the coating. This can be advantageous for achieving high light transmittance of the pane while simultaneously providing good thermal insulation. At the specified values, a particularly favorable ratio of light transmittance to reflection is achieved for p-polarized radiation, which was completely surprising and unexpected for the inventors.

[0028] The lateral or nominal extent of nanoparticles can be measured or calculated using various methods. One option is atomic force microscopy (AFM), which scans the surface structure of the coating with a fine tip, thus determining the size and shape of the silver nanoparticles. Another option is transmission electron microscopy (TEM), which illuminates the coating with an electron beam, revealing the morphology of the silver nanoparticles. A further option is spectroscopic ellipsometry (SE), which analyzes the reflected light from different angles to determine the thickness and refractive index of the coating. From these data, the lateral and / or nominal extent of the silver nanoparticles can be derived using appropriate models.

[0029] In contrast to continuous, homogeneous metallic layers, the discontinuous reflection-enhancing layer made of nanoparticles according to the invention exhibits fundamentally different electronic and optical properties. Compared to continuous layers, whose optical and electronic properties are essentially determined by a conduction band according to the physical band model, SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0030] Nanoparticles are characterized by a higher surface-to-volume ratio, and their optical properties are determined by so-called plasmon resonance. In this process, free electrons are collectively excited to plasma vibrations against the ion cores (plasmons). This generates surface waves with longitudinal electronic vibrations parallel to the surface of a nanocrystal (surface plasmons). The required wavelength depends primarily on the size of the nanoparticles. This offers the advantageous possibility of precisely tailoring the optical properties of the glazing, particularly light reflection and transmission, to the specific requirements of the application by appropriately selecting the size of the nanoparticles. They exhibit high light transmission, and due to the small size of the nanocrystals, disruptive scattering effects occur only minimally or not at all.

[0031] The reflection-enhancing layer preferably has a thickness of 1 nm to 20 nm, particularly preferably 1 nm to 10 nm, most preferably 2 nm to 5 nm, and especially 2 nm to 4 nm. These thicknesses are sufficient to significantly increase the reflectivity of the reflective coating and, on the other hand, do not reduce the light transmission of the glazing to a critical extent.

[0032] The refractive index is specified within the scope of the present invention with reference to a wavelength of 550 nm, unless explicitly stated otherwise. The refractive index is fundamentally independent of the measurement method. It can be determined, for example, by ellipsometry. Ellipsometers are commercially available, for example from Sentech.

[0033] The reflective coating is, in particular, a transparent coating made of thin films (thin-film stack, thin-film sequence). A transparent coating is understood to be one that has an average transmission in the visible spectral range of at least 70%, meaning it does not significantly impair visibility through the pane. Generally, it is sufficient if the reflective coating is only present in the display area on the inner surface of the pane. However, for manufacturing reasons and to ensure a homogeneous appearance, preferably at least 80%, and particularly preferably at least 90%, of the inner surface of the pane is provided with the reflective coating.In particular, the reflective coating is applied across the entire interior surface of the pane, optionally with the exception of a perimeter border and / or local areas intended to ensure the transmission of electromagnetic radiation through the glazing as communication, sensor, or camera windows (SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT). The perimeter uncoated border, if present, has a width of up to 20 cm. It may, for example, be used for bonding the glazing to the vehicle body or window frame, allowing the adhesive and any sealing elements to be applied directly to the interior surface of the pane.

[0034] In a further preferred embodiment of the invention, a further reflection-enhancing layer is arranged between the second optically high-refractive-index layer and the optically low-refractive-index layer. This further reflection-enhancing layer is preferably silver-based and discontinuous. The reflectance can be increased even further by this additional reflection-enhancing layer. While the transmission is not reduced to the same extent, such a reflective coating is particularly suitable for positioning in a masking area of ​​the glazing.

[0035] In a further preferred embodiment, the additional reflection-enhancing layer is based on silver nanoparticles; preferably, the additional reflection-enhancing layer consists of silver nanoparticles. Particularly preferably, the reflection-enhancing layer is based on silver nanoparticles which have an average lateral extent of less than or equal to 100 nm, preferably less than or equal to 50 nm, and most preferably less than or equal to 20 nm.

[0036] The reflection-enhancing layer and / or the further reflection-enhancing layer preferably have a thickness of 1 nm to 20 nm, particularly preferably 1 nm to 10 nm, most preferably 2 nm to 5 nm, and especially 2 nm to 4 nm. These thicknesses are sufficient to significantly increase the reflectance of the reflective coating and, on the other hand, do not reduce the light transmission of the glazing to a critical extent.

[0037] According to the invention, the optically high-refractive layer has a refractive index of at least 2.0, particularly preferably at least 2.1, most preferably from 2.1 to 2.5, and in particular from 2.1 to 2.3.

[0038] In an advantageous embodiment of the invention, the optically high-refractive-index layer and / or the second optically high-refractive-index layer is based on a dielectric SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0039] The coating is formed from a material preferably based on silicon nitride, a silicon-metal mixed nitride (preferably silicon zirconium nitride, silicon titanium nitride, or silicon hafnium nitride), aluminum nitride, niobium oxide, or titanium oxide. Good results are achieved with these materials. They have a suitably high refractive index and are easy to deposit. Silicon nitride, silicon-metal mixed nitride (preferably silicon zirconium nitride, silicon titanium nitride, or silicon hafnium nitride), and aluminum nitride are particularly preferred. In addition to a suitably high refractive index, these materials have the advantage that thin films based on them are bendable. The coated inner disc can therefore be subjected to a bending process to bring it into a shape commonly used in the automotive sector (usually spherical) without cracks or haze forming in the coating.

[0040] Silicon-metal mixed nitrides are particularly preferred because the metal content allows the refractive index to be increased and, in particular, adjusted to a desired value. Silicon-zirconium nitride is especially preferred. The zirconium content is preferably between 5 and 45 wt.%, and particularly preferably between 10 and 30 wt.%.

[0041] However, titanium oxide can also be preferred, especially because of its advantageously high refractive index. Particularly with discs that are only slightly curved, the lower bendability may be acceptable.

[0042] The first optically high-refractive layer and / or the second optically high-refractive layer may contain dopants, preferably aluminum or boron.

[0043] If a dielectric layer contains metallic additives, these are referred to as doping within the meaning of the invention if their proportion is less than 5 wt.%. From a proportion of 5 wt.%, a layer is referred to as a mixture, for example as a silicon-metal mixed nitride.

[0044] The first optically high-refractive layer and / or the second optically high-refractive layer preferably have a layer thickness of 10 nm to 100 nm, particularly preferably of 10 nm to 50 nm, and most preferably of 20 nm to 35 nm.

[0045] If a first layer is arranged above a second layer, this means, in the sense of the invention, that the first layer is located further away from the interior surface of the SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0046] The first layer is arranged further away from the inner surface of the disc than the second layer. If a first layer is arranged below a second layer, this means, in the sense of the invention, that the second layer is arranged further away from the inner surface of the disc than the first layer.

[0047] It is possible to subject the reflective coating to heat treatment after deposition, for example, as part of a glass bending process. This regularly improves the optical properties of the coating, particularly increasing light transmission. Partial oxidation of the reflection-enhancing layer may occur during this process.

[0048] According to the invention, the optically low-refractive-index layer has a refractive index of at most 1.6. The refractive index is preferably less than 1.6, i.e., less than 1.6, particularly preferably from 1.3 to 1.6, and especially from 1.4 to 1.6.

[0049] In an advantageous embodiment, the optically low refractive index layer is based on silicon oxide, magnesium fluoride or calcium fluoride, particularly preferably silicon oxide.

[0050] The optically low refractive index layer may contain dopings or mixed compositions, preferably aluminum, titanium, hafnium, zirconium.

[0051] The optically low-refractive-index layer preferably has a thickness of at least 80 nm, particularly preferably at least 90 nm. The thickness of the low-refractive-index layer is preferably at most 200 nm. In preferred embodiments, the thickness of the low-refractive-index layer can be from 100 nm to 200 nm, particularly from 100 nm to 150 nm. This applies especially if the optically low-refractive-index layer is the only layer above the reflection-enhancing layer.

[0052] The nitrides (silicon nitride, silicon-metal mixed nitride, aluminum nitride), oxides (silicon oxide) and fluorides (magnesium fluoride, calcium fluoride) listed as preferred dielectric materials can be deposited stoichiometrically, substoichiometrically or superstoichiometrically with respect to nitrogen, oxygen or fluorine content.

[0053] In principle, several optically high-refractive-index layers (i.e., an optically high-refractive-index layer sequence) can also be placed below the at least one reflection-enhancing SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT

[0054] A layer may be present and / or several optically low-refractive-index layers (i.e., an optically low-refractive-index layer sequence) above the reflection-enhancing layer and, if present, the further reflection-enhancing layer. However, preferably no optically low-refractive-index layer is present below the reflection-enhancing layer. The optically low-refractive-index layer is preferably the uppermost layer of the reflective coating, and no optically high-refractive-index layers occur above the low-refractive-index layer.

[0055] The preferred geometric configurations specified within the scope of the present invention are advantageous for the reflection properties of the reflective coating with respect to p-polarized radiation. In particular, they result in the maximum of the reflection spectrum lying approximately in the middle of the visible spectral range, especially around 550 nm. This allows for a high reflectance and a comparatively color-neutral representation.

[0056] In principle, it is also possible that the reflective coating has further sequences of alternating optically high and low refractive index layers, with or without intervening reflection-enhancing layers.

[0057] In particularly preferred embodiments, the reflective coating consists only of the following layers, in the specified order starting from the inner surface of the inner disk: a first optically high refractive index layer with a refractive index greater than or equal to 2.0, a discontinuous reflection-enhancing layer which is based on silver, preferably on silver nanoparticles, a second optically high refractive index layer with a refractive index greater than or equal to 2.0, preferably a further discontinuous reflection-enhancing layer which is based on silver, preferably on silver nanoparticles, and comprises an optically low refractive index layer with a refractive index less than or equal to 1.6.

[0058] In other words, the reflective coating according to the invention, in a preferred embodiment, comprises a maximum of four or five layers and no other layers. SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT

[0059] The invention further extends to a projection arrangement comprising the glazing according to one of the preceding embodiments and at least one imaging unit. The at least one imaging unit is directed towards the display area and, during operation, illuminates it at least partially, preferably predominantly, with p-polarized radiation.

[0060] As is typical for projection arrangements of this type, the imaging unit illuminates an area of ​​the glazing where the radiation is reflected towards the viewer (e.g., the driver), thereby creating a virtual image that the viewer perceives as being behind the glazing. The area of ​​the glazing that can be illuminated by the imaging unit is called the display area. The glazing has at least one such display area. The at least one imaging unit is therefore directed at the at least one display area. During operation, the at least one imaging unit emits at least partially, preferably predominantly, p-polarized radiation and illuminates the at least one display area with this p-polarized radiation.

[0061] The luminous transmittance values ​​given here can be determined, for example, according to ISO 9050:2003. With regard to the determination of luminous transmittance according to ISO 9050:2003 (see section 3.3 in the standard), the relative spectral distribution of illuminant D65 and / or the relative spectral distribution of illuminant A can be used for the determination (see, for example, ISO 11664-2:2007). In other words, the described luminous transmittance range applies to determination using illuminant A and / or illuminant D65.

[0062] The glazing preferably has a transparent viewing area and an opaque masking area. The viewing area is intended for viewing. For the purposes of the invention, a masking area is defined as an area of ​​the glazing through which viewing is not possible. The light transmittance of the masking area is less than 5%, preferably less than 2%, and most preferably essentially 0%. The masking area is typically formed by an opaque coating on a surface of the pane or, if present, of the additional pane, preferably on the interior surface of the additional pane. The coating is in particular formed from an enamel containing glass frits and a pigment, which is printed using screen printing or digital printing and then fired into the pane surface. The pigment is typically a SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT.

[0063] Black pigment, for example carbon black, aniline black, bone black, iron oxide black, spinel black, and / or graphite. The masking layer preferably has a thickness of 5 pm to 50 pm, particularly preferably 8 pm to 25 pm. Alternatively, opaque films can also be used in the intermediate layer to form the masking area. The latter is possible, for example, if the glazing comprises a laminated pane.

[0064] In a preferred embodiment, the masking area surrounds the viewing area like a frame. The masking area is thus arranged all the way around the viewing area. This is common, for example, in vehicle windows, especially windshields. Typically, the masking area forms the perimeter of the glazing and borders the side edge of the glazing. Therefore, in a preferred embodiment, the masking area is arranged in a perimeter of the glazing and surrounds the central viewing area.

[0065] The opaque element forming the masking area (in particular, the masking print or the opaque polymer film) is positioned behind the reflective coating in the direction of view from the interior to the external environment, so that the latter can be illuminated by the imaging unit. The reflective coating is therefore closer to the imaging unit and the interior than the opaque element, and farther from the external environment.

[0066] The glazing has a top edge and a bottom edge, as well as two side edges running between them. The top edge is the edge that is intended to point upwards when installed. The bottom edge is the edge that is intended to point downwards when installed. If the glazing is a vehicle window, the top edge is often also referred to as the roof edge and the bottom edge as the engine edge.

[0067] In one embodiment of the invention, the at least one display area is arranged within the field of vision. This creates a display directly in the user's (especially the driver's and / or vehicle occupants') field of vision, which they can see without having to take their eyes off, for example, the road. Such display systems are also known as head-up displays (HUDs). SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT

[0068] In a further embodiment of the invention, the display area is arranged within the masking area. It is preferred that the display area is positioned between the viewing area and the lower edge of the glazing. The glazing is preferably also designed as a windshield. In this way, displays can be shown in the display area that are conventionally located on the dashboard. This is aesthetically pleasing, and the driver does not have to take their eyes off the road as much, which can be advantageous for driving safety. Such display systems can also be referred to as black-print displays.

[0069] A combination of the two aforementioned embodiments is also possible. In a further embodiment of the invention, the glazing therefore has two display areas, wherein

[0070] - a first display area is arranged in the masking area and

[0071] - a second display area is arranged within the viewing area.

[0072] This configuration corresponds to the combination of a head-up display with a black print display. The invention unfolds its advantages particularly well because the reflective coating is suitable for both display areas. Thus, only a single coating is required, which ensures the reflection of the radiation from the imaging unit in both the first and second display areas. It is not necessary to provide a separate reflective coating or reflective element for each display area. In this configuration, the display system preferably comprises two imaging units, wherein a first imaging unit (in particular a screen) is directed at and illuminates the first display area, and wherein a second imaging unit (in particular a projector) is directed at and illuminates the second display area.Both imaging units predominantly emit p-polarized radiation during operation.

[0073] In embodiments of the invention, it may be preferred if the display area is arranged in the masking area. Additionally, a second display area may optionally be provided in the viewing area.

[0074] The glazing provided with the reflective coating preferably has a reflectance of at least 10%, and preferably at least 15%, towards p-polarized radiation. This reflectance is measured with an angle of incidence of 65° and the standard light source A. The reflectance is determined as the integrated reflectance, where the viewing angle corresponds to the angle of incidence. If the glazing SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT is designed as a windshield, then the light transmittance of the windshield in the viewing area is preferably at least 70%. In this context, light transmittance refers to the total transmittance, determined by the procedure for testing the light transmittance of motor vehicle windows specified in ECE-R 43, Annex 3, Section 9.1.

[0075] The projection arrangement according to the invention is operated with p-polarized radiation. This means that the radiation from the at least one imaging unit has at least a partial p-polarized component, preferably a predominantly p-polarized component, i.e., more than 50%. The radiation from the at least one imaging unit is preferably predominantly p-polarized, more preferably at least 80%, and more preferably at least 95%. In particular, the radiation is essentially purely p-polarized – the p-polarized component is therefore 100% or deviates only insignificantly from this. The polarization direction is specified as being relative to the plane of incidence of the radiation on the composite disk. P-polarized radiation is defined as radiation whose electric field oscillates in the plane of incidence.S-polarized radiation is defined as radiation whose electric field oscillates perpendicular to the plane of incidence. The plane of incidence is defined by the incidence vector and the surface normal of the glazing at a point within the display area, preferably at the geometric center of the display area. Due to the curvature of the glass, common in vehicles, which affects the plane of incidence and thus the definition of polarization, the polarization components (especially the ratio of p-polarized to s-polarized radiation or vice versa) can differ from this reference point at other locations. To generate the desired polarized radiation, a polarizing filter or a polarizing beam splitter can be placed in the beam path between the imaging unit and the glazing, unless the imaging unit itself already provides radiation of the desired polarization direction.

[0076] In a preferred embodiment, the radiation of the imaging unit is purely p-polarized. In this case, reflection from the external disk surfaces is negligible, and the display relies essentially solely on reflection from the reflective coating, thus avoiding ghosting. In a further preferred embodiment, the radiation exhibits both p-polarized and s-polarized components. The proportion of s-polarized radiation can, for example, range from 5% to 80%, preferably from 10% to 40%, and most preferably from 20% to 30%. SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT

[0077] This allows the intensity of the displayed image to be increased because the s-polarized radiation components are reflected by the disk surfaces, which then contributes to the overall intensity of the displayed image.

[0078] The imaging unit is preferably a projector or a screen (“display”, electronic display). In principle, any type of screen can be used for the projection arrangement 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. Projectors are especially common and preferred for head-up displays, and screens for black-print displays.

[0079] In HUD projectors, the beam direction can typically be varied using mirrors, particularly vertically, to adjust the projection to the viewer's height. The area in which the viewer's eyes must be positioned for a given mirror position is called the eyebox window. This eyebox window can be shifted vertically by adjusting the mirrors, with the entire accessible area (i.e., the superposition of all possible eyebox windows) being referred to as the eyebox. A viewer located within the eyebox can perceive the virtual image. This means, of course, that the viewer's eyes must be within the eyebox, not their entire body. The technical terms used here from the field of HUDs are generally known to those skilled in the art.For a detailed description, please refer to the dissertation “Simulation-based measurement technology for testing head-up displays” by Alexander Neumann at the Institute of Computer Science of the Technical University of Munich (Munich: University Library of the TU Munich, 2012), in particular to chapter 2 “The Head-Up Display”.

[0080] The at least one imaging unit is directed at the at least one display area of ​​the glazing. It is located on the inside of the pane and, during operation, illuminates the reflective coating in the display area of ​​the glazing. The inside surface of the pane, on which the reflective coating is located and which is preferably the exposed inside surface of the glazing (in particular, the inside surface of the inner pane in the case of a laminated pane), is therefore oriented towards the imaging unit. The radiation from the imaging unit is in the visible spectrum. SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT

[0081] Spectral range of the electromagnetic spectrum (380 nm to 780 nm), particularly in the spectral range of 450 nm to 650 nm – typical imaging units operate at wavelengths of 473 nm, 550 nm, and 630 nm (RGB). The angle of incidence of the radiation on the glazing is preferably from 45° to 80°, particularly preferably from 60° to 75°, and especially from 65° to 70°, for example, approximately 65°. These angles of incidence deviate only slightly from the Brewster angle. 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 soda-lime glass of 1.55 at a wavelength of 550 nm). The angle of incidence can also be referred to as the angle of incidence.The angle between the incident radiation vector and the interior surface normal (i.e., the surface normal to the interior surface of the disk) is determined at a point in the display area, preferably at the geometric center of the display area. If the angle of incidence exactly matches the Brewster angle, only s-polarized radiation is reflected, not p-polarized radiation. In an advantageous embodiment, the angle of incidence deviates from the Brewster angle by at most 10°.

[0082] Since the angle of incidence typically does not deviate significantly from Brewster's angle, p-polarized radiation is generally not reflected, or only to a very small extent, by the external surfaces of the glazing (the outer surface of any additional pane and the inner surface of the pane). Reflection at the inner surface of the pane is practically solely due to the reflective coating. No (significant) further reflection occurs at the outer surface of any additional pane that would result in a ghost image when using s-polarized radiation. Therefore, it is not necessary to position the external surfaces at an angle to each other, as is common practice when using s-polarized radiation, in order to superimpose or, as far as possible, align the two reflections.

[0083] Besides avoiding ghost images, the use of p-polarized radiation also has the advantage that the displayed image is recognizable for wearers of polarization-selective sunglasses, which typically only allow p-polarized radiation to pass through and block s-polarized radiation.

[0084] The pane and / or the additional pane are preferably made of glass, in particular soda-lime glass, which is common for window panes. However, the pane and / or the additional pane can also be made of other types of glass (for example, SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT).

[0085] The sheet can be made of borosilicate glass, quartz glass, aluminosilicate glass, or transparent plastics (for example, polymethyl methacrylate or polycarbonate). The thickness of the sheet and / or the additional sheet can vary widely. Preferably, sheets with a thickness in the range of 0.8 mm to 5 mm, more preferably from 1.1 mm to 2.9 mm, are used, for example, with standard thicknesses of 1.6 mm or 2.1 mm.

[0086] The disc and / or, if present, the thermoplastic interlayer and / or the additional disc can be clear and colorless, or tinted or colored. The disc and / or the additional disc can be independently unstressed, partially stressed, or stressed (thermally or chemically).

[0087] The glazing is preferably curved in one or more directions, for example, when used as a windshield for motor vehicle windows (especially windows of passenger cars), with typical radii of curvature ranging from about 10 cm to about 40 m. However, the glazing can also be flat, for example, when intended as a windshield for buses, trains, or tractors.

[0088] If the glazing comprises a laminated pane with another pane and a thermoplastic interlayer, as described above, then the thermoplastic interlayer preferably contains at least one thermoplastic polymer, preferably polyvinyl butyral (PVB), ethylene vinyl acetate (EVA), or polyurethane (PU), or mixtures, copolymers, or derivatives thereof, particularly preferably PVB. The interlayer is typically formed from at least one thermoplastic film (bonding film), preferably based on one of the aforementioned polymers, especially PVB. In the context of the invention, this means that the film contains the aforementioned material predominantly (a proportion greater than 50% by weight) and may optionally contain other components, such as plasticizers, stabilizers, or UV or IR absorbers. The thickness of the interlayer is preferably from 0.2 mm to 2 mm, particularly preferably from 0.5 mm to 1 mm.

[0089] The reflective coating is preferably applied to the disk by physical vapor deposition (PVD), particularly preferably by cathode sputtering, and most preferably by magnetic field-assisted cathode sputtering (magnetron sputtering). However, the coating can also be applied, for example, by chemical vapor deposition (CVD), such as plasma-assisted SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT.

[0090] The materials can be deposited by vapor deposition (PECVD), evaporation, or atomic layer deposition (ALD). By appropriately selecting the process conditions, the formation of continuous thin films can be prevented, and the formation of discontinuous layers, preferably nanoparticle layers, can be promoted. These conditions include high pressure and a low deposition rate (low voltage). These effects are generally known to those skilled in the art, for example, from S. Sardana et al., Applied Surface Science 347 (2015) pp. 651-656 or P. Asanithi et al., Journal of Nanomaterials (2012) (Article ID 963609). The process conditions required in each individual case can be determined by those skilled in the art through simple preliminary tests and / or simulations.

[0091] The discontinuous reflection-enhancing layer, preferably based on nanoparticles, can be produced in various ways, with two fundamentally different approaches to be distinguished:

[0092] The upstream production of (nano)particles, which are then deposited onto the surface of the glass pane, involves the following steps: the particles can be generated in a solution using known methods, such as chemical reduction of metal ions or laser ablation. The particles are stabilized by dissolved ligands, and their size can be influenced by the ligand concentration. Subsequently, the particles are applied to the pane surface, for example, using a wet chemical process by applying the solution and then evaporating the solvent. Alternatively, the particles can be produced by mechanical decomposition, whereby the silver-based material is mechanically ground (e.g., using a ball mill) or crushed until individual particles are obtained, and then applied to the surface.

[0093] The formation of nanoparticles directly on the inner surface of the disk from atoms: individual atoms, particularly silver atoms, are deposited on the disk surface, which then migrate and form atomic aggregates that in turn grow into particles. At higher surface coverage, individual particles again aggregate into particle agglomerates. Vacuum-based methods such as physical vapor deposition (PVD), preferably sputtering, and especially magnetron sputtering, are particularly suitable for depositing the individual atoms. This variant is particularly advantageous because the same methods are typically also used for the formation of conventional continuous layers.The glass manufacturer can therefore easily integrate the production of the discontinuous layer into existing processes and production lines.

[0094] The glazing can be used as vehicle windows, building glazing, or furniture glazing, in particular as a motor vehicle windshield. The preferred configurations described above apply accordingly.

[0095] The glazing, in particular the projection arrangement, can be used, for example, in a vehicle on land, water or in the air, preferably a motor vehicle, rail vehicle, aircraft or ship, in particular a passenger car or truck.

[0096] The various embodiments of the invention can be implemented individually or in any combination. In particular, the aforementioned features can be used not only in the specified combinations, but also in other combinations or on their own, unless they are explicitly described as possible only as alternatives to one another without departing from the scope of the present invention.

[0097] The invention is explained in more detail below with reference to figures and exemplary embodiments. The figures are schematic and not to scale. The figures do not limit the invention in any way.

[0098] They show:

[0099] Fig. 1 shows a top view of a glazing according to the invention of a first embodiment, Fig. 2 shows a cross-section through a first embodiment of the projection arrangement according to the invention with the glazing from Figure 1 ,

[0100] Fig. 3 shows a top view of a glazing of a second embodiment according to the invention, Fig. 4 shows a cross-section through a second embodiment of the projection arrangement according to the invention with the glazing from Figure 3,

[0101] Fig. 5 shows a top view of a glazing according to the invention of a third embodiment, Fig. 6 shows a cross-section through a second embodiment of the glazing according to the invention.

[0102] Projection setup with the glazing from Figure 5,

[0103] Fig. 7 shows a cross-section through an embodiment of the glazing according to the invention, SAINT-GOBAIN SEKURIT FRANCE 2024247- WO- PCT

[0104] Figs. 8-9 are enlarged views of section Z from figure 7 in two embodiments according to the invention and

[0105] Fig. 10 shows a diagram illustrating the wavelength-dependent reflectance for p-polarized light for an example according to the invention and a generic comparative example.

[0106] Figures 1 and 2 each show a detail of a first embodiment of a glazing 100 according to the invention in a projection arrangement 101 for a vehicle. The projection arrangement 101 comprises the glazing 100, which is designed as a side window of a passenger car. The projection arrangement 101 also includes an imaging unit 5, which is directed onto a display area A of the glazing 100. Images can be generated in the display area A by the imaging unit 5, which are perceived by a viewer 6 (vehicle driver) as virtual images on the side of the glazing 100 facing away from him, provided his eyes are within the so-called eyebox E.

[0107] The glazing assembly 100 comprises a pane 1. The lower edge U of the glazing assembly 100 is oriented downwards towards the engine of the passenger car, and its upper edge O is oriented upwards towards the roof. The pane 1 is made of soda-lime glass with a thickness of 2.1 mm. For the sake of simplicity, the glazing assembly 100 is shown as planar, although real vehicle side windows typically have a spherical curvature.

[0108] The pane 1 has an outer surface III facing the external environment and an inner surface IV facing the vehicle interior. The glazing 100 has an opaque masking area M arranged in a circumferential edge region, which surrounds a transparent viewing area D like a frame. Such masking areas M are common in vehicle windows – they primarily serve to protect the adhesive used to bond the glazing 100 to the vehicle body from UV radiation. The masking area M is formed, for example, by a printed cover 7.

[0109] Display area A is located in the masking area M between the viewing area D and the lower edge U. Such a display system can also be referred to as a "black-print display". This display area A serves to show information for the vehicle occupants. This can include, in particular, vehicle status information (for example, the driving speed or a fuel gauge), navigation instructions, and more.

[0110] (for example, speed limits or directional information) or the image from a rear-facing camera. Entertainment content can also be displayed (for example, films, internet data, or computer games), particularly on the passenger side. A reflective coating 2 is applied to the display area A on the interior surface IV of the screen 1. The reflective coating 2 is limited to the display area A and does not extend beyond it. The reflective coating 2 is constructed, for example, as described for the configurations shown in Figures 8 and 9.

[0111] The imaging unit 4 is, for example, an LCD screen or a plurality of LCD screens arranged side by side. The imaging unit 5 irradiates the display area A with an angle of incidence α, which is measured relative to the interior surface normal of the inner pane. The angle of incidence α is, for example, 65°, which is relatively close to Brewster's angle (approximately 57° at an air-soda-lime glass interface). The radiation from the imaging unit 5 is at least partially p-polarized.

[0112] Figures 3 and 4 each show a detail of a second embodiment of a projection arrangement 101 according to the invention for a vehicle. The projection arrangement 101 again comprises a glazing 100, which here, however, is designed as a windshield of a passenger car, and an imaging unit 5. In this embodiment, the glazing 100 is designed as a laminated glass, as is usual for windshields. In addition to the glass 1, the glazing 100 comprises a second glass 3. The first glass 1 and the second glass 3 are also bonded together via a thermoplastic interlayer 4. In its installed position, the second glass 3 faces the outside environment, and the first glass 1 faces the vehicle interior. The second glass 3 is therefore the outer glass and the first glass 1 is the inner glass of the glazing 100. The first and second glass 1, 3 are made of soda-lime glass with a thickness of 2.1 mm.For the sake of simplicity, the glazing 100 is shown as flat, although real windshields typically have a spherical curvature.

[0113] The second pane 1 has an outer surface I facing the external environment and an inner surface II facing the vehicle interior. The first pane 1 also has an outer surface III facing the external environment and an inner surface IV facing the vehicle interior. The glazing 100 has an opaque SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0114] A masking area M is located in a surrounding border region and surrounds a transparent viewing area D in a frame-like manner. The masking area M is formed, for example, by a cover print 7.

[0115] The display area A is located within the visible area of ​​the glazing 100. The imaging unit 5 is a projector that operates with p-polarized radiation. The imaging unit 5 illuminates the display area A, projecting a display image directly into the field of vision of the viewer 6 (driver) – again as a virtual image on the side of the glazing 10 facing away from the viewer, when their eyes are within the so-called eyebox E. Such a display system is also known as a "head-up display" (HUD). This allows the viewer 6 to be shown status information (e.g., vehicle speed), navigation instructions (e.g., speed limits or directions), or warning symbols without having to take their eyes off the road. The reflective coating 2 is limited to the display area A and does not extend beyond it.The reflective coating 2, for example, is constructed as described for the designs shown in Figures 8 and 9.

[0116] The imaging unit 5 illuminates the display area A as described for Figures 1 and 2 with an angle of incidence α, for example 65°. The p-polarized radiation from the imaging unit 5 is therefore not significantly reflected by the glass surfaces. This results in a clear display image without (or with only very faint) ghost images.

[0117] Figures 5 and 6 each show a detail of a third embodiment of a projection arrangement 101 according to the invention with a glazing 100. The third embodiment is essentially designed like the embodiment of Figures 3 and 4, so only the differences will be discussed here.

[0118] The projection arrangement 101 comprises a passenger car window 101 and an imaging unit 5. The window 100 has a first display area A in the masking area M and a second display area B in the transmission area D. The projection arrangement 101 includes a first imaging unit 5.1 directed at the first display area A, for example, an LCD screen or a plurality of adjacent LCD screens. The projection arrangement 101 also includes a second imaging unit 5.2 directed at the second display area B, for example, a projector. Both SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT imaging units 5.1 and 5.2 are operated, for example, with p-polarized radiation and irradiate the associated display areas A and B with an angle of incidence α of, for example, 65°.For reflection, the glazing 100 again has a reflective coating 2 according to the invention. A major advantage of the present invention is that the same reflective coating 2 is suitable for both a head-up display with a display area B in the transmission area D and for a black-print display with a display area A in the masking area M. Here, the reflective coating 2 extends over the entire interior surface IV of the first pane 1.

[0119] Figure 7 shows a cross-section through an embodiment of the glazing 100 according to the invention, comprising a first pane 1 (soda-lime glass, 2.1 mm), a second pane 3 (soda-lime glass, 2.1 mm), and a thermoplastic interlayer 4 (PVB, 0.76 mm). The masking area M is formed by a black masking print 7 on the inner surface 11 of the second pane 3. The masking print 7 consists of an enamel with glass frits and a black pigment, which is applied by screen printing and subsequently fired into the pane surface. The reflective coating 2 according to the invention is applied to the inner surface IV of the first pane 1. In this embodiment, the reflective coating 2 extends over the entire inner surface IV of the first pane.However, it is also possible that the reflective coating 2 extends only over at least one display area A of the first disc 1 (not shown here).

[0120] Figures 8 and 9 each show the section Z from Figure 7 in an enlarged view in two embodiments of the reflective coating 2 according to the invention.

[0121] Figure 8 shows a first embodiment of the reflective coating 2. The reflective coating 2 consists of a first optically high-refractive-index layer 2.1 with a refractive index greater than or equal to 2.0, a discontinuous reflection-enhancing layer 2.2, which is based on silver, preferably on silver nanoparticles, a second optically high-refractive-index layer 2.3 with a refractive index greater than or equal to 2.0, and an optically low-refractive-index layer 2.5 with a refractive index less than or equal to 1.6. SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0122] Layers 2.1, 2.2, 2.3, 2.5 are deposited in the specified order starting from the interior surface IV on the first disk 1, in particular by sputtering.

[0123] Figure 9 shows a second embodiment of the reflective coating 2. The reflective coating 2 consists of a first optically high-refractive-index layer 2.1 with a refractive index greater than or equal to 2.0, a discontinuous reflection-enhancing layer 2.2, which is based on silver, preferably on silver nanoparticles, a second optically high-refractive-index layer 2.3 with a refractive index greater than or equal to 2.0, a further discontinuous reflection-enhancing layer 2.4, which is based on silver, preferably on silver nanoparticles, and an optically low-refractive-index layer 2.5 with a refractive index less than or equal to 1.6.

[0124] Layers 2.1, 2.2, 2.3, 2.4, 2.5 are deposited in the specified order starting from the interior surface IV on the first disk 1, in particular by sputtering.

[0125] The layer sequences are shown schematically in Figures 8 and 9. The layer sequence of a glazing 100 with the reflective coating 2 on the interior surface IV of the pane 2, together with the materials and layer thicknesses of the individual layers, is shown in Table 1 for an example according to the invention and a generic, i.e., non-inventive, comparative example. The example according to the invention and the comparative example correspond to the structure shown in Figure 8, except that the comparative example does not have a low-refractive-index layer. Both the generic example and the example according to the invention have a reflection-enhancing layer 2.2 consisting of silver nanoparticles. These are real examples; the layers were applied consecutively to a soda-lime glass pane 1 by magnetron sputtering. SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0126] Table 1

[0127] The oxides SiO x and TiO x The deposits can be stoichiometric, substoichiometric, or superstoichiometric with respect to the oxygen content. Therefore, the variable "x" is indicated in the subscript of the chemical formulas in a way that is generally understandable to those skilled in the art. In the examples and the comparative example, however, the same stoichiometric ratio was chosen for layers based on the same material. The layers may also contain dopants and impurities. The doping levels in layers based on the same material were also the same in the examples and the comparative example. For example, the layer based on SiO₂ x doped with aluminum.

[0128] The reflective coating 2 of the inventive example and the comparative example differ in that the coating in the comparative example does not have a low-refractive-index layer. Otherwise, the reflective coatings are identical in structure, with a high-refractive-index titanium oxide layer 2.1 being applied to the disk 1 as the first layer. The first high-refractive-index layer 2.1 is followed by the reflection-enhancing layer 2.2, which consists of silver nanoparticles, and then by a further high-refractive-index layer 2.3 made of titanium oxide. The inventive reflective coating 2 also contains a low-refractive-index layer 2.5 made of silicon oxide. The dielectric layers 2.1, 2.3, and 2.5 have the following refractive indices at 550 nm: TiO₂ x (2.45), SiO x (1,45).

[0129] Table 2 shows the reflectance Rp- poi. The reflectance of glazing 100 against p-polarized radiation at an angle of incidence α of 65° and the reflectance against mixed-polarized radiation (50% s-polarized and 50% p-polarized) at an angle of incidence α of 8° are specified. An angle of incidence α of 65° corresponds to the configurations shown in Figures 1 to 6. Rp- po i. and R miX This indicates the integrated light reflection compared to p-polarized or mixed radiation, measured with a light source of luminous type A. The SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0130] The viewing angle corresponded to the angle of incidence in each case. Furthermore, the light transmittance TL through the glazing (100) is specified for both examples, assuming single-glazed glazing (100). The glazing (100) is therefore not a laminated pane. The light transmittance TL is the integrated light transmittance according to ISO 9050, measured with a light source of illuminant type A.

[0131] For both the reflection of p-polarized radiation at an angle of incidence α of 65° and the light transmittance λ, the color values ​​a* and b* from the LAB system (according to ISO 9050:2003) are also specified. The optical values ​​are further specified once for a glazing unit 100 with reflective coating 2 without post-treatment and once for a glazing unit 100 with reflective coating 2 that has been thermally tempered. Thermal tempering was carried out at 640 °C for 10 minutes. The example glazing units that have been post-treated in this way are marked with an asterisk (*).

[0132] Table 2

[0133] Ideally, the glazing should have low reflectance values ​​R. mix exhibit an angle of incidence α of 8°, as these can lead to unaesthetic and / or irritating reflections. As can be seen in Table 2, the reflective coating 2 according to the inventive example (Ex.) and the inventive example which has been thermally post-treated (Ex.*) shows significantly lower reflections for s- and p-polarized light than the generic reflective coating 2 according to the comparative example (Cf.-Ex.) and the comparative example which has been thermally post-treated (Cf.-Ex.*).

[0134] At the incidence angle a of 65°, which is particularly relevant for a projection arrangement, the thermally tempered glazing 100 with the reflective coating 2 according to the inventive example (Ex.*) exhibits a significantly higher reflection value Rp- poi. on than with SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT of the reflective coating 2 according to the comparative example (cf. example*). This is due to the influence of the optically low refractive index layer 2.5 in combination with the discontinuous silver layer of the reflection-enhancing layer 2.2. Both the comparative example and the example according to the invention exhibit high color neutrality regardless of the thermal treatment (a* and b*).

[0135] In the example according to the invention, regardless of the heat treatment, the light transmission was almost 90%, thus fulfilling the legal requirements for vehicle windows, in particular windshields. In the comparison example, a lower light transmission was observed, so this glazing 100 cannot be placed on the market. All values ​​in Table 2 were determined in the viewing area D of the glazing 100.

[0136] Figure 10 shows the wavelength-dependent reflectance of the example according to the invention and of a generic comparative example as specified in Table 1. The glazing 100 was thermally post-treated (tempered) in both cases. The angle of incidence α is 65° and the reflectance R p-poi The measurement was taken with a light source of type A whose emitted light is p-polarized. Figure 10 shows that the reflective coating 2 according to the invention exhibits a significantly higher reflectance over the entire visible spectral range (380 nm to 780 nm) than the generic reflective coating 2. The difference is particularly high in the wavelength range of 400 nm to 600 nm, which is very relevant for projection arrangements.

[0137] SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT

[0138] Reference symbol list

[0139] 1 (first) disc

[0140] 2 Reflective coating

[0141] 2.1 First optically high-refractive-index layer

[0142] 2.2 (first) reflection-enhancing layer

[0143] 2.3 Second optically high-refractive-index layer

[0144] 2.4 further (second) reflection-enhancing layer

[0145] 2.5 Optically low refractive index layer

[0146] 3 second disc

[0147] 4 thermoplastic intermediate layer

[0148] 5 imaging unit

[0149] 5.1 First imaging unit

[0150] 5.2 Second imaging unit

[0151] 6 viewers / drivers

[0152] 7 Cover print

[0153] O Top edge of the glazing 100

[0154] U bottom edge of the glazing 100

[0155] D Viewing area

[0156] M masking area

[0157] A (first) display area of ​​the glazing 100

[0158] B second display area of ​​the glazing 100

[0159] E Eyebox a angle of incidence

[0160] I outer surface of the second disc 3

[0161] II Interior surface of the second pane 3

[0162] III outer surface of the (first) disk 1

[0163] IV Interior surface of the (first) pane 1

[0164] X - X' Intersection line

[0165] Y -Y' Intersection line

[0166] Z - Z' Intersection line

[0167] Z enlarged section

Claims

SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT Patent claims 1. Glazing (100) for a projection arrangement (101), comprising a pane (1) with an interior surface (IV) and an exterior surface (III) and a reflective coating (2) for p-polarized radiation (6), which is applied to the interior surface (IV) of the pane (1) at least in one display area (A), preferably only in one display area (A), and which, starting from the interior surface (IV) of the pane (1), comprises in the specified order a first optically high refractive index layer (2.1) with a refractive index greater than or equal to 2.0, a reflection-enhancing layer (2.2) based on silver, a second optically high refractive index layer (2.3) with a refractive index greater than or equal to 2.0 and an optically low refractive index layer (2.5) with a refractive index less than or equal to 1.6, wherein the reflection-enhancing layer (2.2) is a discontinuous layer.

2. Glazing (100) according to claim 1, further comprising a further pane (3) and a thermoplastic intermediate layer (4), wherein the pane (1) and the further pane (3) are connected to each other over a planar area via the thermoplastic intermediate layer (4), wherein the interior surface (IV) of the pane (1) is arranged facing away from the thermoplastic intermediate layer (4).

3. Glazing (100) according to claim 1 or 2, wherein the reflection-enhancing layer (2.2) is based on silver nanoparticles, preferably consisting of silver nanoparticles.

4. Glazing (100) according to claim 3, wherein the silver nanoparticles have on average a lateral extent of less than or equal to 100 nm, preferably less than or equal to 50 nm, particularly preferably less than or equal to 20 nm.

5. Glazing (100) according to one of claims 1 to 4, wherein a further reflection-enhancing layer (2.4) is arranged between the second optically high refractive index layer (2.3) and the optically low refractive index layer (2.5), wherein the further SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT is a reflection-enhancing layer (2.4) based on silver and is a discontinuous layer.

6. Glazing (100) according to claim 5, wherein the further reflection-enhancing layer (2.4) has a layer thickness of 1 nm to 5 nm, preferably of 2 nm to 4 nm.

7. Glazing (100) according to any one of claims 1 to 6, wherein the first optically high refractive index layer (2.1) and / or the second optically high refractive index layer (2.3) is based on silicon nitride, on a silicon-metal mixed nitride, preferably silicon-zirconium nitride, silicon-titanium nitride or silicon-hafnium nitride, on an aluminum nitride, on a niobium oxide or on a titanium oxide basis.

8. Glazing (100) according to any one of claims 1 to 7, wherein the first optically high refractive index layer (2.1) and / or the second optically high refractive index layer (2.3) has a layer thickness of 10 nm to 50 nm, preferably of 20 nm to 35 nm.

9. Glazing (100) according to any one of claims 1 to 8, wherein the reflection-enhancing layer (2.2) has a layer thickness of 1 nm to 5 nm, preferably of 2 nm to 4 nm.

10. Glazing (100) according to any one of claims 1 to 8, wherein the optically low refractive index layer (2.5) has a layer thickness of at least 80 nm, preferably at least 90 nm, in particular 100 nm to 150 nm.

11. Glazing (100) according to one of claims 1 to 9, wherein the optically low refractive index layer (2.5) is based on silicon oxide, magnesium fluoride or calcium fluoride.

12. Projection arrangement (101) comprising a glazing (100) according to one of claims 1 to 10 and at least one imaging unit (5) which is directed towards the display area (A) and irradiates it with p-polarized radiation during operation.

13. Projection arrangement (101) according to claim 11, wherein the glazing (100) has a transparent viewing area (D) and an opaque masking area (M) and wherein the display area (A) is arranged in the viewing area (D). SAINT-GOBAIN SEKURIT FRANCE 2024247-WO-PCT 14. Projection arrangement (101) according to claim 11, wherein the glazing (100) has a transparent viewing area (D) and an opaque masking area (M), and wherein the display area (A) is arranged in the masking area (M).

15. Projection arrangement (101) according to any one of claims 11 to 13, wherein the at least one imaging unit (5) illuminates the display area (A) with an angle of incidence (a) of 60° to 75°, preferably of 65° to 70°.

Images