Laminated glazing unit for a head-up display

Abstract

The invention relates to a laminated glazing unit (10) for a head-up display, the glazing unit comprising an outer glass sheet (12), an inner glass sheet (14), a lamination adhesive interlayer (16) arranged between the outer glass sheet (12) and the inner glass sheet (14), an anti-reflection coating (18), wherein the anti-reflection coating (18) is deposited on an inner face (26) of the inner glass sheet (14), and a functional stack (72) configured to reflect p-polarised light (28), wherein the functional stack (72) is deposited on an inner face (22) of the outer glass sheet (12) or on an outer face (24) of the inner glass sheet (14), and wherein the anti-reflection coating (18) comprises a first anti-reflection module which comprises, from the inner face (26) of the inner glass sheet (14), a high-refractive-index layer and a low-refractive-index layer.

Description

DESCRIPTION TITLE: LAMINATED GLASS FOR HEAD-UP DISPLAYS technical field

[0001] This presentation concerns laminated glass for head-up display. Previous technique

[0002] Modern vehicles are now equipped with display systems or devices called "head-up display", also known as HUD according to the English acronym for Head-Up Display.

[0003] These systems or devices include a projector, usually located near the vehicle's dashboard, configured to project an image onto a specific area of ​​the vehicle's windshield. The projected image appears to the driver as a virtual image behind the windshield, displaying information such as vehicle speed, navigation instructions, or warnings directly within their field of vision. The driver no longer needs to take their eyes off the road to view this information and can remain alert to events occurring outside the vehicle. HUD systems or devices thus contribute to improved road safety.

[0004] Most HUD devices rely on the emission of electromagnetic radiation polarized with an s-type polarization and an angle of incidence of approximately 65° relative to the normal to the windshield. This angle is close to Brewster's angle for a glass-air interface, which is approximately 56.5° for soda-lime glass. The projected image is then reflected by the two main outer surfaces of the windshield. In addition to the main image, a secondary image also appears, more or less offset and partially overlapping the main image. This secondary image is called a "ghost image," "double image," or simply "ghost image."

[0005] To mitigate this unwanted ghosting effect, it is common practice to position the main surfaces of the windshield at different angles by inserting a laminated interlayer of varying thickness so as to causing the ghost image and the main image to overlap. This type of glazing is generally known as "wedge glazing" or "wedge windshield".

[0006] As an example, EP 0 420 228 describes a windscreen comprising a laminated interlayer whose thickness gradually decreases between a first and a second windscreen side so that the two sheets of glass in adhesive contact with said interlayer have two different angles of inclination with respect to the projector.

[0007] However, this type of glazing is expensive to manufacture, limited to certain viewing angles of the projected image, and does not prevent the formation of a ghost image when the glazing includes a functional coating.

[0008] It is common alternative practice to use HUD devices whose implementation relies on the emission of electromagnetic radiation polarized according to a p-type polarization and on a windshield comprising a functional coating adapted to the formation of a new reflective interface within said windshield for this type of radiation.

[0009] When p-polarized electromagnetic radiation is emitted towards the windshield at an angle of incidence close to Brewster's angle, it is weakly reflected by the glass-air interfaces. Reflection occurs only at the reflective interface formed by the functional coating. Various types of functional coatings can be used.

[0010] WO 2005 / 017600 describes a polarizing optical film comprising a plurality of individual layers having different optical refractive indices. The film is intended to be laminated into laminated glass to form a head-up display windshield comprising an area that predominantly reflects visible light polarized according to p-polarization. The film can also reflect infrared radiation to reduce greenhouse gas emissions in a vehicle.

[0011] DE 102014220189 describes a laminated glazing comprising a metallic functional layer based on silver or aluminium and with a thickness between 5 nm and 9 nm. The metallic functional layer allows the reflection of visible light polarized according to a p polarization.

[0012] WO 2016 / 058474, WO 2021 / 104800, WO 2019 / 046157, WO 2020 / 094422 describe laminated glazing for head-up displays with a functional coating comprising one or more functional layers metallic, especially silver-based, allowing the reflection of visible light polarized according to a p polarization. The functional coating may also include dielectric layers which, possibly combined with the metallic functional layers, confer other properties such as solar control properties and / or color neutralization of the coating in transmission and / or reflection. Description of the invention

[0013] The present presentation aims to remedy at least some of these drawbacks.

[0014] For this purpose, the present presentation concerns laminated glass for head-up displays comprising: - an outer sheet of glass; - an internal sheet of glass; - an intermediate adhesive layer of lamination placed between the outer glass sheet and the inner glass sheet; - an anti-reflective coating, the anti-reflective coating being deposited on an inner face of the inner glass sheet, the inner face being opposite the adhesive intermediate layer of lamination; and - a functional stack configured to reflect p-polarized light, the functional stack being deposited on an inner face of the outer glass sheet, the inner face being adjacent to the intermediate adhesive lamination layer, or on an outer face of the inner glass sheet, the outer face being adjacent to the intermediate adhesive lamination layer; the anti-reflective coating comprising a first anti-reflective module comprising, from the inner face of the inner glass sheet, a high refractive index layer and a low refractive index layer, the refractive index of the low refractive index layer being less than 1.9 at 550 nm and the refractive index of the high refractive index layer being greater than 2.1 at 550 nm.

[0015] The anti-reflective coating allows for a reflected image of polarized light p by functional stacking of satisfactory quality and superior to known head-up displays.

[0016] Indeed, since the coating is an anti-reflective coating, most of an incident ray of light will be diffracted.

[0017] Because the inner surface of the internal glass sheet is coated with an anti-reflective coating, the light ray diffracted at the interface between the coating and the inner glass sheet is more intense than the intensity of the light ray diffracted without the coating. This reduces the formation of a so-called "ghost image" caused by the reflection of the diffracted light ray at the interface between the coating and the inner glass sheet. The light ray diffracted at the interface between the coating and the inner glass sheet is then reflected by the functional stack to form the head-up display image, with a portion of the light ray diffracted at the interface between the coating and the inner glass sheet being diffracted by the functional stack.The portion of light reaching the interface between the outer glass sheet and the atmosphere is even weaker when reflected at this interface. This reduces the formation of a so-called "ghost image" caused by the reflection at the interface between the outer glass sheet and the atmosphere of the light diffracted at the interface between the anti-reflective coating and the inner glass sheet.

[0018] By “light transmission”, TL, we mean the light transmission, denoted TL, as defined and measured and / or calculated in the ISO 13837:2021 standard.

[0019] By "solar factor", TTS, we mean the solar factor as defined according to ISO 13837:2021 - It is equal to the sum of the direct solar transmittance, TE, and the secondary heat flux, qi.

[0020] By “direct solar transmittance”, TE, we mean the direct solar transmittance as defined and calculated according to ISO 13837:2021.

[0021] By "solar selectivity", SE, we mean the ratio between light transmission, TL, and direct solar transmittance, TE.

[0022] By "selectivity", s, we mean the ratio of light transmission, TL, to the solar factor TTS.

[0023] By “light reflection” R, we mean light reflection as defined and measured and / or calculated in ISO 13837:2021.

[0024] In some embodiments, the anti-reflective coating comprises a second anti-reflective module comprising, from the inner face of the inner glass sheet, a layer with a high refractive index and a low refractive index layer, the refractive index of the low refractive index layer being less than 1.9 at 550 nm and the refractive index of the high refractive index layer being greater than 2.1 at 550 nm, the first anti-reflection module being disposed between the inner face of the inner glass sheet and the second anti-reflection module.

[0025] In some embodiments, the anti-reflection coating comprises a third anti-reflection module comprising, from the inner face of the inner glass sheet, a first nitride-based dielectric layer, an oxide-based layer having a refractive index having a minimum between 800 and 1600 nm and an extinction coefficient increasing monotonically with the wavelength of light and a second nitride-based dielectric layer, the third anti-reflection module being disposed between the inner face of the inner glass sheet and the first anti-reflection module.

[0026] It is understood that the anti-reflective coating may not include a second anti-reflective module, the anti-reflective coating including the first anti-reflective module and the third anti-reflective module.

[0027] The refractive index of the oxide-based layer passes through a minimum and the extinction coefficient increases with the wavelength of the light.

[0028] By modifying the deposition conditions of the oxide-based layer, it is possible to modify the characteristics of the anti-reflective coating.

[0029] It is understood that the refractive index of the oxide-based layer passes through a minimum, and the value of the refractive index increases with the wavelength of light after passing through the minimum value.

[0030] The presence of the first nitride-based dielectric layer and the second nitride-based dielectric layer sandwiching the oxide-based layer helps to limit, or even prevent, the oxidation of the oxide-based layer and thus to preserve the properties of the oxide-based layer by avoiding the oxidation of the oxide-based layer.

[0031] In some embodiments, the refractive index of the oxide-based layer has a difference between the minimum and a value at 400 nm greater than or equal to 0.8, in particular greater than or equal to 1.0.

[0032] In some embodiments, the extinction coefficient is less than 0.2, or even 0.1 at 500 nm and less than 2.0, or even less than 1.5 at 1200 nm.

[0033] In some embodiments, the extinction coefficient is greater than or equal to 0.5 at 1600 nm.

[0034] In some embodiments, the extinction coefficient has a difference between 400 nm and 1200 nm greater than or equal to 0.5.

[0035] Selectivity can thus be favorably increased.

[0036] In some embodiments, the oxide is a substoichiometric tungsten oxide, preferably with the chemical formula WO X , x being between 2.55 and 2.98.

[0037] In some embodiments, a physical thickness of the substoichiometric tungsten oxide-based layer is greater than or equal to 20 nm and less than or equal to 100 nm, preferably greater than or equal to 40 nm and less than or equal to 80 nm.

[0038] In some embodiments, the first and / or second nitride-based dielectric layer is a silicon nitride-based dielectric layer and has a physical thickness greater than or equal to 5 nm.

[0039] In some embodiments, the low refractive index layer is silica-based.

[0040] In some embodiments, the low refractive index layer is silica-based, comprising alumina.

[0041] In some embodiments, the low refractive index layer has a physical thickness greater than or equal to 5 nm and less than or equal to 140 nm.

[0042] In some embodiments, the high refractive index layer is based on sub-stoichiometric titanium oxide.

[0043] In some embodiments, the substoichiometric titanium oxide-based layer has a physical thickness greater than or equal to 5 nm and less than or equal to 30 nm, preferably greater than or equal to 5 nm and less than or equal to 20 nm.

[0044] In some embodiments, the functional stack is a solar control functional stack.

[0045] In some embodiments, the functional stack includes at least one metallic functional layer.

[0046] In some embodiments, the metallic functional layer is silver-based, preferably silver.

[0047] In some embodiments, the metallic functional layer has a physical thickness less than or equal to 20 nm.

[0048] In some embodiments, the functional stack comprises two metallic functional layers.

[0049] In some embodiments, a physical thickness of a first metallic functional layer is strictly less than a physical thickness of a second metallic functional layer.

[0050] The first metallic functional layer is arranged between the inner face of the inner glass sheet and the second metallic functional layer.

[0051] In some embodiments, the functional stack includes dielectric layers surrounding each metallic functional layer.

[0052] It is understood that each metallic functional layer is sandwiched between dielectric layers.

[0053] By way of non-limiting examples, the dielectric layer may include a dielectric layer in particular with a barrier function, a dielectric layer in particular with a stabilizing function, a dielectric layer in particular with a smoothing function and / or a dielectric layer in particular with a blocking function.

[0054] The external and / or internal glass sheet is preferably colorless, non-opaque and non-translucent in order to minimize light absorption and thus maintain maximum light transmission in the visible electromagnetic spectrum.

[0055] Laminated glazing has a light transmission greater than or equal to 71% and is color neutral in reflection and transmission.

[0056] In some embodiments, the internal and / or external glass sheet is a mineral glass tinted throughout.

[0057] Coloration can generally be achieved by adding coloring oxides to the chemical composition of glass. Examples of coloring oxides include iron(II) oxide, copper oxide, chromium oxide, nickel oxide, gold oxide, manganese oxide, cobalt oxide, uranium oxide, neodymium oxide, and erbium oxide. Mixtures of oxides such as copper and tin oxide, or ionic complexes such as iron-sulfur or cadmium-sulfur complexes, can also be used.

[0058] In some embodiments, the anti-reflective coating includes a protective coating for the anti-reflective coating disposed opposite the inner glass sheet, in particular the inner face of the inner glass sheet.

[0059] The protective coating may include several layers of protection.

[0060] In some embodiments, the selectivity of the laminated glazing is greater than or equal to 1.25, in particular greater than or equal to 1.35.

[0061] In some embodiments, the ratio of the light reflection of the functional stack to the light reflection of an external face of the external glass sheet is greater than or equal to 15, or even greater than or equal to 20.

[0062] The higher the ratio, the better the quality of the head-up display will be, meaning that the "ghost" image will be of very low intensity compared to the image reflected by the functional stack.

[0063] In some embodiments, the ratio of light reflection of the functional stack to the light reflection of the anti-reflective coating is greater than or equal to 20, or even greater than or equal to 25.

[0064] The higher the ratio, the better the quality of the head-up display will be, meaning that the "ghost" image will be of very low intensity compared to the image reflected by the functional stack.

[0065] In some embodiments, the outer glass sheet and / or the inner glass sheet has a thickness of between 0.4 and 1.1 mm, in particular between 0.4 and 0.7 mm.

[0066] In some embodiments, the intermediate adhesive layer of lamination comprises one or more layers of thermoplastic material.

[0067] Examples of thermoplastic materials include polyurethane, polycarbonate, polyvinyl butyral (PVB), polymethyl methacrylate (PMMA), ethylene vinyl acetate (EA), or an ionomer resin.

[0068] In some embodiments, the adhesive intermediate layer of lamination has acoustic properties.

[0069] In some embodiments, the intermediate adhesive layer of lamination is UV-resistant. Brief description of the drawings

[0070] Other features and advantages of the object of this presentation will emerge from the following description of embodiments, given by way of non-limiting examples, with reference to the attached figures.

[0071] [Fig. 1] Figure 1 is a schematic view of laminated glazing according to one embodiment.

[0072] [Fig. 2] Figure 2 is a schematic cross-sectional view of an internal glass sheet provided with an anti-reflective coating according to one embodiment.

[0073] [Fig. 3] Figure 3 is a schematic cross-sectional view of an internal glass sheet provided with an anti-reflective coating according to another embodiment.

[0074] [Fig. 4] Figure 4 is a schematic cross-sectional view of an internal or external glass sheet equipped with a functional stacking according to one embodiment.

[0075] [Fig. 5] Figure 5 is a schematic cross-sectional view of an internal or external glass sheet equipped with a functional stack according to another embodiment.

[0076] [Fig. 6] Figure 6 is a graph representing the refractive index (unitless) as a function of the wavelength of light (in nm).

[0077] [Fig. 7] Figure 7 is a graph representing the extinction coefficient (unitless) as a function of the wavelength of light (in nm).

[0078] Across all figures, common elements are identified by identical numerical references. Detailed description

[0079] In what follows, the elements common to the different embodiments are identified by the same numerical references.

[0080] Figure 1 is a schematic cross-sectional view of laminated glazing according to one embodiment.

[0081] In the embodiment of Figure 1, the laminated glass 10 is laminated glass for head-up displays. The laminated glass 10 comprises an outer glass sheet 12 and an inner glass sheet 14. The laminated glass 10 includes an adhesive intermediate layer of lamination 16 disposed between the outer glass sheet 12 and the inner glass sheet 14. The outer glass sheet 12 has an outer face 20 and an inner face 22, and the inner glass sheet 14 has an outer face 24 and an inner face 26.

[0082] The outer face 20 of the outer glass sheet 12 is opposite the intermediate adhesive layer of lamination 16, i.e. the inner face 22 of the outer glass sheet 12 is closer to the intermediate layer of lamination 16 than the outer face 20 of the outer glass sheet 12.

[0083] The inner face 26 of the inner glass sheet 14 is opposite the intermediate adhesive layer of lamination 16, i.e. the outer face 24 of the inner glass sheet 14 is closer to the intermediate layer of lamination 16 than the inner face 26 of the inner glass sheet 14.

[0084] In this document, the terms "internal" and "external" are used in relation to laminated glass when it is installed on a motor vehicle, for example. The term "external" refers to an element closer to the exterior of the vehicle, and the term "internal" refers to an element closer to the interior of the vehicle.

[0085] In the embodiment of Figure 1, the inner face 26 of the inner glass sheet 14 is provided with an anti-reflective coating 18 and the inner face 22 of the outer glass sheet is provided with a functional stack 72. The functional stack 72 could alternatively be deposited on the outer face 24 of the inner glass sheet 14, the inner face 26 of the inner glass sheet 14 being provided with the anti-reflective coating 18 and the outer face 24 of the inner glass sheet 14 being provided with the functional stack 72. The functional stack 72 is configured to reflect polarized light p.

[0086] As illustrated in Figure 1, an incident light ray 28 of p-polarized light is mainly diffracted by the anti-reflective coating 18 forming a diffracted light ray 56. Although the angle of the incident light ray 28 is oriented at about 65°, that is close to the Brewster angle, with respect to the bisector 34 of the angle formed between the incident light ray 28 and the secondary light ray 32B, that is to say the perpendicular to the inner face 26 of the inner glass sheet 14, the anti-reflective coating 18 reflects a very small part of the incident light ray 28 to form a secondary light ray 32B.

[0087] In the embodiment of Figure 1, the outer glass sheet 12, the inner glass sheet 14, and the intermediate adhesive lamination layer 16 have similar or even equal refractive indices. Therefore, the diffracted light ray 56 is only slightly deviated when passing through the interfaces between the inner glass sheet 14, the intermediate adhesive lamination layer 16, the functional stack 72, and the outer glass sheet 12.

[0088] When the diffracted light ray 56 reaches the interface between the adhesive laminate intermediate layer 16 and the functional stack 72, the diffracted light ray 56 is reflected by the functional stack 72 towards the inner glass sheet 14 (reflected light ray 58B). The reflected light ray 58B by the functional stack 72 is only slightly modified during its passage through the interfaces between the functional stack 72, the adhesive laminate intermediate layer 16, and the inner glass sheet 14. At the interface between the anti-reflective coating 18 and the internal atmosphere, the reflected light ray 58B is diffracted and forms a reflected light ray 30, which constitutes the main image of the head-up display.

[0089] The intensity of the secondary light ray 32B creates for an observer located on the side of the inner face 26 of the inner glass sheet 14, i.e. in the vehicle, a low intensity secondary image also called a ghost image or "ghost" which is superimposed on the image created by the light ray reflected 30 by the functional stack 72. The "ghost" images potentially created at the interfaces with the intermediate adhesive layer of lamination 16 are negligible compared to the light ray reflected 30 by the functional stack 72 and the secondary light ray 32B.

[0090] When the diffracted light ray 56 reaches the interface between the outer glass sheet 12 and the outside atmosphere, the light ray The diffracted ray 56 is reflected from the outer face 20 of the outer glass sheet 12 towards the inner glass sheet 14 (reflected light ray 58A). The reflected light ray 58A from the outer face 20 of the outer glass sheet 12 is only slightly modified when passing through the interfaces between the outer glass sheet 12, the functional stack 72, the adhesive intermediate layer of lamination 16, and the inner glass sheet 14. At the interface between the anti-reflective coating 18 and the inner atmosphere, the reflected light ray 58A is diffracted and forms a secondary light ray 32A. The intensity of the secondary light ray 32A creates for an observer located on the side of the inner face 26 of the inner glass sheet 14, i.e. in the vehicle, a secondary image of low intensity also called a ghost image or "ghost" which is superimposed on the image created by the light ray reflected 30 by the functional stack 72.The potentially created "ghost" images at the interfaces with the adhesive intermediate layer of lamination 16 are negligible compared to the light ray reflected 30 by the functional stack 72 and the secondary light ray 32A.

[0091] Figure 2 shows a schematic cross-sectional view of an inner glass sheet 14 equipped with an anti-reflective coating 18 according to one embodiment. The anti-reflective coating 18 comprises an anti-reflective module 38 including, from the inner face 26 of the inner glass sheet 14, a layer with a high refractive index 52A and a layer with a low refractive index 54A.

[0092] The anti-reflective coating 18 can comprise two anti-reflective modules 38, 40, a first anti-reflective module 38 and a second anti-reflective module 40, the first anti-reflective module 38 being disposed between the inner face 26 of the inner glass sheet 14 and the second anti-reflective module 40. Each anti-reflective module 38, 40 comprises, from the inner face 26 of the inner glass sheet 14, a layer of high refractive index 52A, 52B and a layer of low refractive index 54A, 54B.

[0093] The refractive index of the low refractive index layer 54A, 54B is less than 1.9 at 550 nm and the refractive index of the high refractive index layer 52A, 52B is greater than 2.1 at 550 nm.

[0094] Figure 3 is a schematic cross-sectional view of an internal glass sheet equipped with the anti-reflective coating 18 according to another embodiment.

[0095] In the embodiment of Figure 3, the anti-reflection coating 18 comprises three anti-reflection modules, a third anti-reflection module 36, the first anti-reflection module 38 and the second anti-reflection module 40.

[0096] The anti-reflective coating 18 can include two anti-reflective modules, the third anti-reflective module 36 and the first anti-reflective module 38.

[0097] The third anti-reflective module 36 is arranged between the inner face 26 of the inner glass sheet 14 and the first anti-reflective module 38. When the anti-reflective coating 18 comprises three anti-reflective modules, the first anti-reflective module 38 is arranged between the third anti-reflective module 36 and the second anti-reflective module 40.

[0098] The third anti-reflection module 36 comprises, from the inner face 26 of the inner glass sheet 14, a first nitride-based dielectric layer 44, an oxide-based layer 46, having a refractive index having a minimum between 800 and 1600 nm and an extinction coefficient increasing with the wavelength of light and a second nitride-based dielectric layer 48.

[0099] Figure 4 is a schematic cross-sectional view of an internal 14 or external 12 glass sheet equipped with the functional stacking 72 according to one embodiment.

[0100] In the embodiment of Figure 4, the functional stack 72 includes a metallic functional layer 80A.

[0101] In the embodiment of Figure 4, the metallic functional layer 80A is contained between dielectric layers.

[0102] In the embodiment of Figure 4, starting from the outer face 24 of the inner glass sheet 14 or from the inner face 22 of the outer glass sheet 12, the functional stack 72 comprises two dielectric layers 76AA, 78AA, the metallic functional layer 80A and four dielectric layers 82A, 78AB, 76AB, 74.

[0103] Figure 5 is a schematic cross-sectional view of an internal 14 or external 12 glass sheet equipped with the functional stacking 72 according to another embodiment.

[0104] In the embodiment of Figure 5, the functional stack 72 comprises at least one metallic functional layer 80A, 80B. The stack functions 72 can include one 80A metallic functional layer or two 80A, 80B metallic functional layers.

[0105] In the embodiment of Figure 5, each metallic functional layer 80A, 80B is sandwiched between dielectric layers. The dielectric layers separate the metallic functional layers from each other.

[0106] Arbitrarily, the functional stack 72 of Figure 5 is decomposed into two functional modules 84, 86, a dielectric layer 74A, 74B, 74C, being arranged on either side of each module 84, 86.

[0107] In the embodiment of Figure 5, starting from the outer face 24 of the inner glass sheet 14 or from the inner face 22 of the outer glass sheet 12, the functional stack 72 comprises a first dielectric layer 74A, a first functional module 84, a second dielectric layer 74B, a second functional module 86 and a third dielectric layer 74C.

[0108] In the embodiment of Figure 5, starting from the outer face 24 of the inner glass sheet 14 or from the inner face 22 of the outer glass sheet 12, the first functional module 84 comprises two dielectric layers 76A, 78AA, a metallic functional layer 80A and two dielectric layers 82A, 78AB.

[0109] In the embodiment of Figure 5, starting from the outer face 24 of the inner glass sheet 14 or from the inner face 22 of the outer glass sheet 12, the second functional module 86 comprises two dielectric layers 76B, 78BA, a metallic functional layer 80B and two dielectric layers 82B, 78BB.

[0110] As an example, the deposition of an anti-reflective coating and / or a functional stack comprising thin films on a glass substrate is achieved by successively depositing each thin film by passing the glass substrate through a succession of deposition cells adapted to deposit a given thin film.

[0111] Deposition cells can use deposition methods such as magnetic field-assisted sputtering (also called magnetron sputtering), ion beam-assisted deposition (IBAD), evaporation, chemical vapor deposition (CVD), chemical vapor deposition plasma-assisted vapor deposition (PECVD), low-pressure chemical vapor deposition (LPCVD), etc.

[0112] Magnetic field assisted spray deposition processes are particularly used.

[0113] The tungsten oxide target may in particular contain one or more dopant elements in the proportions as described for the doped tungsten oxide layer.

[0114] The tungsten oxide-based layer can be deposited by sputtering using the aforementioned target under a deposition atmosphere composed of 20 to 100% argon and 0 to 80% dioxygen, preferably 30 to 90% argon and 10 to 70% dioxygen.

[0115] The tungsten oxide-based layer can be deposited under a pressure of between 1 and 20 mTorr, preferably from 3 to 15 mTorr.

[0116] Preferably, the deposition can be carried out cold, i.e. at a temperature below 100°C, in particular between 20°C and 60°C, for the substrate.

[0117] The deposition can also be carried out hot, in particular at a temperature between 100°C and 400°C.

[0118] The inner glass sheet 14, equipped with the reflective coating 18, can undergo annealing heat treatment. The annealing temperature can range from 450°C to 800°C, particularly from 550°C to 750°C, or even from 600°C to 700°C. The annealing time can range from 5 to 30 minutes, particularly from 5 to 20 minutes, or even from 5 to 10 minutes. The same applies when the inner glass sheet 14 is equipped on its inner face 26 with the reflective coating 18 and on its outer face 24 with the functional stack 72.

[0119] The outer glass sheet 12, equipped with the functional stack 72, can undergo annealing heat treatment. The annealing temperature can be between 450°C and 800°C, particularly between 550°C and 750°C, or even between 600°C and 700°C. The annealing time can be between 5 and 30 minutes, particularly between 5 and 20 minutes, or even between 5 and 10 minutes.

[0120] In the examples below, thin films are deposited by magnetic field assisted sputtering.

[0121] For example 1 (Ex1), example 2 (Ex2), example 3 (Ex3), example 4 (Ex4), example 5 (Ex5), comparative example 1 (ExC1) and example Comparative 2 (ExC 2), the outer glass sheet 12 is a soda-lime-silica glass 1.6 mm thick, the intermediate adhesive lamination layer 16 is a PVB 0.76 mm thick, and the inner glass sheet 14 is a soda-lime-silica glass 2.1 mm thick. The inner face 26 of the inner glass sheet 14 has the reflective coating 18, and the inner face 22 of the outer glass sheet 12 has the functional stack 72.

[0122] Example 1

[0123] Anti-reflective coating 18

[0124] The anti-reflective coating 18 of example 1 is according to the embodiment of figure 2 and includes an anti-reflective module 38.

[0125] The high refractive index layer 52A, for example in substoichiometric titanium oxide TiO₂ w , is deposited using a titanium oxide target at a pressure of 2.10 -3 mbar in an atmosphere of argon and nitrogen with an Ar / (Ar+N2) ratio of 95 (in flight%). The titanium oxide obtained is stoichiometric or close to it (x equal to 2 or almost).

[0126] The low refractive index 54A layer, for example, is made of silica containing alumina. The target used is a Si:Al target comprising 92% silicon and 8% aluminum by weight. The layer is deposited at a pressure of 4.10 -3 mbar in an atmosphere of argon and dioxygen with an Ar / (Ar+Û2) ratio of 36 (in flight%).

[0127] After deposition of the high refractive index and low refractive index layers, the inner glass sheet 14 with the coating is annealed at 650°C for 10 min.

[0128] Functional stacking 72

[0129] The functional stack 72 of example 1 is according to the embodiment of figure 4 and includes a metallic functional layer 80A.

[0130] The dielectric layers 76AA and 76AB are aluminum-doped SiZrN. The target used is a Si:Zr:Al target comprising 78 at% Si, 17 at% Zr, and 5 at% Al. The layer is deposited at a pressure of 2 x 10⁻¹⁰ kJ. -3 mbar in an atmosphere of argon and nitrogen with an Ar / (Ar+N2) ratio of 45 (in flight%).

[0131] The dielectric layers 78AA and 78AB are made of ZnO containing alumina. The target used is a Zn:Al target comprising 98% zinc by weight and 2% by weight of aluminum. The layer is deposited at a pressure of 1.8 x 10 -3mbar in an atmosphere of argon and oxygen with an Ar / (Ar+O2) ratio of 63 (in flight%).

[0132] The 80A metallic functional layer is silver. The target used is a silver target. The layer is deposited at a pressure of 8.10 -3 mbar in an argon atmosphere.

[0133] The dielectric layer 82A is made of NiCrOx. The target used is a Ni:Cr target comprising 80 at% nickel and 20 at% chromium in an argon atmosphere. The dielectric layer 82A is oxidized during the deposition of the next layer, in this example the second dielectric layer 78AB, and during the heat treatment of the functional stack 72.

[0134] The dielectric layer 74 is made of aluminum-doped silicon nitride. The target used is a Si:Al target comprising 92 wt% silicon and 8 wt% aluminum. The layer is deposited at a pressure between 3.2 x 10 -3 and 6.10 -3mbar in an atmosphere of argon and nitrogen with an Ar / (Ar+N2) ratio of 55 (in flight%).

[0135] After deposition of the functional stack 72, the outer glass sheet 12 equipped with the functional stack 72 is annealed at 650°C for 10 min.

[0136] Example 2

[0137] Anti-reflective coating 18

[0138] The anti-reflective coating 18 of example 2 is according to the embodiment of figure 2 and comprises the first anti-reflective module 38 and the second anti-reflective module 40.

[0139] High refractive index layers 52A, 52B, for example in substoichiometric titanium oxide TiO₂ w , are deposited using a titanium oxide target at a pressure of 2.10-3 mbar in an atmosphere of argon and nitrogen with an Ar / (Ar+N2) ratio of 95 (by volume%). The titanium oxide obtained is stoichiometric or close to it (x equal to 2 or almost).

[0140] The low refractive index layers 54A and 54B, for example, are made of silica containing alumina. The target used is a Si:Al target comprising 92% silicon and 8% aluminum by weight. The layer is deposited at a pressure of 4.10 -3 mbar in an atmosphere of argon and dioxygen with an Ar / (Ar+O2) ratio of 36 (in flight%).

[0141] After deposition of the high refractive index and low refractive index layers, the inner glass sheet 14 with the coating is annealed at 650°C for 10 min.

[0142] Functional stacking 72

[0143] The functional stack 72 of example 2 is according to the embodiment of 5 and comprises two metallic functional layers 80A, 80B.

[0144] The dielectric layers 74A, 74B, and 74C are made of aluminum-doped silicon nitride. The target used is a Si:Al target comprising 92% silicon and 8% aluminum by weight. The layer is deposited at a pressure between 3.2 and 10⁻¹¹ kJ / s. -3 and 6.10 -3 mbar in an atmosphere of argon and nitrogen with an Ar / (Ar+N2) ratio of 55 (in flight%).

[0145] The dielectric layers 76A and 76B are made of SnZnO. The target used is a Zn:Sn target comprising 64 at% Zn and 36 at% Sn. The layer is deposited at a pressure of 2 x 10⁻¹¹ kJ / cm². -3 mbar in an atmosphere of argon and oxygen with an Ar / (Ar+Û2) ratio of 50 (in flight%).

[0146] The dielectric layers 78AA, 78AB, 78BA, and 78BB are made of ZnO containing alumina. The target used is a Zn:Al target comprising 98% zinc and 2% aluminum by weight. The layer is deposited at a pressure of 1.8 x 10⁻¹¹ kJ / cm². -3mbar in an atmosphere of argon and oxygen with an Ar / (Ar+Û2) ratio of 63 (in flight%).

[0147] The 80A and 80B metallic functional layers are silver. The target used is a silver target. The layer is deposited at a pressure of 8.10 -3 mbar in an argon atmosphere.

[0148] The dielectric layers 82A and 82B are made of NiCrOx. The target used is a Ni:Cr target comprising 80 at% nickel and 20 at% chromium in an argon atmosphere. The dielectric layers 82A, 82B, and 82C are oxidized during the deposition of the next layer, in this example the second dielectric layers 78AB, 78BB, and 78CB, and during the heat treatment of the functional stack 72.

[0149] After deposition of the functional stack 72, the outer glass sheet 12 equipped with the functional stack 72 is annealed at 650°C for 10 min.

[0150] Example s

[0151] Anti-reflective coating 18

[0152] The anti-reflective coating 18 of example 3 is according to the embodiment of figure 3 and comprises the first anti-reflective module 38, the second anti-reflective module 40 and the third anti-reflective module 36.

[0153] The first dielectric layer, based on nitride 44, and the second dielectric layer, based on nitride 48, are aluminum-doped silicon nitride. The target used is a Si:Al target comprising 92% by weight silicon and 8% by weight aluminum. The layer is deposited at a pressure between 3.2 x 10⁻¹¹ kJ / s. -3 and 6.10 -3 mbar in an atmosphere of argon and nitrogen with an Ar / (Ar+N2) ratio of 55 (in flight%).

[0154] The oxide-based layer 46 is made of substoichiometric tungsten oxide WO X The target used is a tungsten target. The layer is deposited at a pressure of 12 mTorr in an atmosphere containing 60% by volume dioxygen.

[0155] High refractive index layers 52A, 52B, for example in substoichiometric titanium oxide TiO₂ w , are deposited using a titanium oxide target at a pressure of 2.10 -3 mbar in an atmosphere of argon and nitrogen with an Ar / (Ar+N2) ratio of 95 (in flight%). The titanium oxide obtained is stoichiometric or close to it (x equal to 2 or almost).

[0156] The low refractive index layers 54A and 54B, for example, are made of silica containing alumina. The target used is a Si:Al target comprising 92% silicon and 8% aluminum by weight. The layer is deposited at a pressure of 4.10 -3 mbar in an atmosphere of argon and dioxygen with an Ar / (Ar+Û2) ratio of 36 (in flight%).

[0157] After deposition of the third anti-reflective module 36, the first anti-reflective module 38, and the second anti-reflective module 40, the inner glass sheet 14, equipped with the anti-reflective coating 18, is annealed at 650°C for 10 min. The substoichiometric tungsten oxide WO X presents an x ​​value of approximately 2.9.

[0158] Functional stacking 72

[0159] The functional stack-up 72 of example 2 is similar to that of example 1 and includes a metallic functional layer 80A.

[0160] After deposition of the functional stack 72, the outer glass sheet 12 equipped with the functional stack 72 is annealed at 650°C for 10 min.

[0161] Example 4

[0162] Anti-reflective coating 18

[0163] The anti-reflective coating 18 of example 4 is according to the embodiment of figure 3 and comprises the first anti-reflective module 38 and the third anti-reflective module 36.

[0164] The first dielectric layer, based on 42A and 42B nitrides, and the second dielectric layer, based on 46A and 46B nitrides, are aluminum-doped silicon nitride. The target used is a Si:Al target comprising 92 wt% silicon and 8 wt% aluminum. The layer is deposited at a pressure between 3.2 x 10⁻¹¹ kJ / m³. -3 and 6.10 -3 mbar in an atmosphere of argon and nitrogen with an Ar / (Ar+N2) ratio of 55 (in flight%).

[0165] The oxide-based layer 44A, 44B is made of cesium-doped tungsten oxide. The target used is a Cs / W / O ceramic target with a Cs / W ratio between 0.3 and 0.4. The layer is deposited at a pressure of 4 mTorr in an atmosphere containing 20% ​​oxygen by volume.

[0166] High refractive index layers 52A, 52B, for example in substoichiometric titanium oxide TiO₂ w , are deposited using a titanium oxide target at a pressure of 2.10-3 mbar in an atmosphere of argon and nitrogen with an Ar / (Ar+N2) ratio of 95 (by volume%). The titanium oxide obtained is stoichiometric or close to it (x equal to 2 or almost).

[0167] The low refractive index layers 54A and 54B, for example, are made of silica containing alumina. The target used is a Si:Al target comprising 92% silicon and 8% aluminum by weight. The layer is deposited at a pressure of 4.10 -3 mbar in an atmosphere of argon and dioxygen with an Ar / (Ar+Û2) ratio of 36 (in flight%).

[0168] After deposition of the third anti-reflective module 36 and the first anti-reflective module 38, the inner glass sheet 14, coated with the anti-reflective layer 18, is annealed at 650°C for 10 min. Cesium-doped tungsten oxide CsyWi-yOs has a y-value of approximately 0.05-0.06. (To be confirmed / modified - I understand that y is not the same for examples 1-3B and 1-3C)

[0169] Functional stacking 72

[0170] The functional stack-up 72 of example 4 is similar to that of example 1 and includes a metallic functional layer 80A.

[0171] After deposition of the functional stack 72, the outer glass sheet 12 equipped with the functional stack 72 is annealed at 650°C for 10 min.

[0172] Example s

[0173] Anti-reflective coating 18

[0174] The anti-reflective coating 18 of example 5 is similar to the anti-reflective coating of example 4.

[0175] After deposition of the third anti-reflective module 36 and the first anti-reflective module 38, the inner glass sheet 14, equipped with the anti-reflective coating 18, is annealed at 650°C for 10 min. Cesium-doped tungsten oxide CsyWi-yOs has a y value of approximately 0.05-0.06.

[0176] Functional stacking 72

[0177] The functional stack-up 72 of example 5 is similar to that of example 1 and includes a metallic functional layer 80A.

[0178] After deposition of the functional stack 72, the outer glass sheet 12 equipped with the functional stack 72 is annealed at 650°C for 10 min.

[0179] Comparative example 1

[0180] Comparative example 1 is a laminated glazing comprising a functional stack 72 on the inner face 22 of the outer glass sheet 12 and is devoid of anti-reflective coating 18. The functional stack 72 of comparative example 1 is similar to the functional stack of example 1.

[0181] Comparative example 2

[0182] Comparative example 2 is a laminated glazing comprising a functional stack 72 on the inner face 22 of the outer glass sheet 12 and is devoid of anti-reflective coating 18. The functional stack 72 of comparative example 2 is similar to the functional stack of example 2.

[0183] Table 1 gives the physical thicknesses of each layer, the thicknesses being expressed in nm, for example 1, example 2, example 3 and comparative example 1 and comparative example 2 as well as the values ​​of the selectivity, the ratio R30 / R32B 65° and the ratio R30 / R32A 65°.

[0184] R30 / R32A 65° represents the ratio between the light reflection of the reflected light ray 30 by the functional stack 72 and the secondary light ray 32A measured with an angle of the incident light ray 28 65° relative to the normal, i.e. bisector 34, to laminated glazing 10.

[0185] R30 / R32B 65° represents the ratio between the light reflection of the reflected light ray 30 by the functional stack 72 and the secondary light ray 32B measured with an angle of the incident light ray 28 of 65° with respect to the normal, i.e. the bisector 34, to the laminated glazing 10.

[0186] [Table 1]

[0187] Figure 6 is a graph representing the refractive index (unitless) as a function of the wavelength of light (in nm). Curve 60 represents the evolution of the refractive index of sub-stoichiometric tungsten oxide as a function of the wavelength of light, curve 62 the evolution of the refractive index of cesium-doped tungsten oxide as a function of the wavelength of light, and curve 64 represents the evolution of the refractive index of stoichiometric tungsten oxide as a function of the wavelength of light. Curve 64 for stoichiometric tungsten oxide is provided for illustrative and comparative purposes. We observe that unlike curve 60 of sub-stoichiometric tungsten oxide and curve 62 of cesium-doped tungsten oxide, curve 64 of stoichiometric tungsten oxide does not pass through a minimum and varies little as a function of the wavelength of light.

[0188] Figure 7 is a graph representing the extinction coefficient (unitless) as a function of the wavelength of light (in nm). Curve 66 represents the evolution of the extinction coefficient of sub-stoichiometric tungsten oxide as a function of the wavelength of light, curve 68 the evolution of the extinction coefficient of cesium-doped tungsten oxide as a function of the wavelength of light, and curve 70 represents the evolution of the extinction coefficient of stoichiometric tungsten oxide as a function of the wavelength of light. Curve 70 for stoichiometric tungsten oxide is given for illustrative and comparative purposes. It can be seen that, unlike curve 66 for sub-stoichiometric tungsten oxide and curve 68 of cesium-doped tungsten oxide, curve 70 of stoichiometric tungsten oxide is not increasing but constant at 0.

[0189] Laminated glass 10 is particularly suitable for automotive glazing applications. It can also be adapted for certain building glazing applications, notably as laminated glass.

[0190] Although the present description has been made with reference to a specific embodiment, it is evident that various modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. Furthermore, individual features of the various embodiments mentioned can be combined in additional embodiments. Therefore, the description and drawings should be considered illustrative rather than restrictive.

Claims

DEMANDS

1. Laminated glass (10) for head-up display comprising: - an outer sheet of glass (12); - an internal sheet of glass (14); - an intermediate adhesive layer of lamination (16) disposed between the outer glass sheet (12) and the inner glass sheet (14); - an anti-reflective coating (18), the anti-reflective coating (18) being deposited on an inner face (26) of the inner glass sheet (14), the inner face (26) being opposite the adhesive intermediate lamination layer (16); and - a functional stack (72) configured to reflect p-polarized light (28), the functional stack (72) being deposited on an inner face (22) of the outer glass sheet (12), the inner face (22) being adjacent to the intermediate adhesive lamination layer (16), or on an outer face (24) of the inner glass sheet (14), the outer face (24) being adjacent to the intermediate adhesive lamination layer (16); the anti-reflective coating (18) comprising a first anti-reflective module (38) comprising, from the inner face (26) of the inner glass sheet (14), a high refractive index layer (52A) and a low refractive index layer (54A), the refractive index of the low refractive index layer (54A) being less than 1.9 at 550 nm and the refractive index of the high refractive index layer (52A) being greater than 2.1 at 550 nm.

2. Laminated glazing (10) according to claim 1, comprising a second anti-reflective module (40) comprising, from the inner face (26) of the inner glass sheet (14), a high refractive index layer (52B) and a low refractive index layer (54B), the refractive index of the low refractive index layer (52B) being less than 1.9 at 550 nm and the refractive index of the high refractive index layer (52B) being greater than 2.1 at 550 nm, the first anti-reflective module (38) being disposed between the inner face (26) of the inner glass sheet (14) and the second anti-reflective module (40).

3. Laminated glazing (10) according to claim 1 or 2, comprising a third anti-reflective module (36) comprising, from the inner face (26) of the inner glass sheet (14), a first layer a nitride-based dielectric (44), an oxide-based layer (46) having a refractive index having a minimum between 800 and 1600 nm and an extinction coefficient increasing monotonically with the wavelength of light and a second nitride-based dielectric layer (48), the third anti-reflection module (36) being disposed between the inner face (26) of the inner glass sheet (14) and the first anti-reflection module (38).

4. Laminated glazing (10) according to claim 3, wherein the oxide is a substoichiometric tungsten oxide, preferably of chemical formula WO X , x being between 2.55 and 2.

98.

5. Laminated glazing (10) according to claim 4, wherein a physical thickness of the substoichiometric tungsten oxide-based layer is greater than or equal to 20 nm and less than or equal to 100 nm, preferably greater than or equal to 40 nm and less than or equal to 80 nm.

6. Laminated glazing (10) according to any one of claims 3 to 5, wherein the first and / or second nitride-based dielectric layer is a silicon nitride-based dielectric layer and has a physical thickness greater than or equal to 5 nm.

7. Laminated glazing (10) according to any one of claims 1 to 6, wherein the low refractive index layer (54A, 54B) is silica-based.

8. Laminated glazing (10) according to claim 7, wherein the low refractive index layer (54A, 54B) is silica-based comprising alumina.

9. Laminated glazing (10) according to claim 8, wherein the low refractive index layer (54A, 54B) has a physical thickness greater than or equal to 5 nm and less than or equal to 140 nm.

10. Laminated glazing (10) according to any one of claims 1 to 9, wherein the high refractive index layer (52A, 52B) is based on sub-stoichiometric titanium oxide.

11. Laminated glazing (10) according to claim 10, wherein the substoichiometric titanium oxide-based layer has a physical thickness greater than or equal to 5 nm and less than or equal to 30 nm, preferably greater than or equal to 5 nm and less than or equal to 20 nm.

12. Laminated glazing (10) according to any one of claims 1 to 11, wherein the functional stack (72) comprises at least one metallic functional layer (80A, 80B).

13. Laminated glazing (10) according to claim 12, wherein the metallic functional layer (80A, 80B) has a physical thickness less than or equal to 20 nm.

14. Laminated glazing (10) according to claim 12 or 13, wherein a physical thickness of a first metallic functional layer (80A) is strictly less than a physical thickness of a second metallic functional layer (80B).

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