Assembly glass unit with diffuse reflection

Abstract

The present invention relates to an assembly glass unit comprising a stack (40) of layers located between a lower substrate (20) and a transparent upper substrate (30). The stack of layers comprises: - two dielectric layers, a lower layer (41) and an upper layer (42), the lower layer comprising a first layer made of an adhesive material, referred to as a "first adhesive layer"; - an intermediate layer (43) made of a polymer material, in contact with the first adhesive layer, and having a refractive index substantially the same as that of the upper layer; - a central layer (44) in contact with each of the intermediate and upper layers at a textured interface, the central layer being configured such that the assembled glass has diffuse reflective properties.

Description

Background Technology

[0001] This invention belongs to the general field of manufacturing assembled glass units. More particularly, it relates to assembled glass units comprising a stack of layers located between two glass sheets, thereby possessing diffuse reflection properties. It also relates to methods of manufacturing such assembled glass units, and further to screens, systems, and projection methods using such assembled glass units. This invention is advantageously suited for a variety of industrial applications, for example, particularly, displaying information on assembled glass units in buildings or vehicles.

[0002] Known mounting glass units include standard transparent mounting glass units and translucent mounting glass units. The standard transparent mounting glass units cause specular transmission and reflection of radiation incident on the mounting glass units, while the translucent mounting glass units cause diffuse transmission and diffuse reflection of radiation incident on the mounting glass units.

[0003] Generally, when radiation incident on a glass element at a given angle of incidence is reflected by the glass element in multiple directions, the reflection is called scattering. When radiation incident on a glass element at a given angle of incidence is reflected by the glass element at a reflection angle equal to the angle of incidence, the reflection is called specular reflection. Similarly, when radiation incident on a glass element at a given angle of incidence is transmitted through the glass element at a transmission angle equal to the angle of incidence, the transmission through the glass element is called specular transmission.

[0004] One drawback of standard clear glass is that it reflects sharp reflections, like a mirror, which is undesirable in some applications. Therefore, when prefabricated glass units are used for architectural windows or display screens, it is preferable to limit the presence of reflections, which reduces visibility through the prefabricated glass unit. Sharp reflections on prefabricated glass units can also lead to glare risks, impacting safety, for example, when vehicle headlights reflect off glazed building facades. This problem is most particularly evident in airport prefabricated glass facades. Indeed, the risk of glare to pilots approaching the terminal must be limited as much as possible.

[0005] Semi-transparent mounting glass units have the advantage of not producing sharp reflections; however, they cannot be clearly seen through the mounting glass units.

[0006] To overcome these drawbacks, it is known from the prior art, including document WO2012104547A1, that transparent layered elements are used in the manufacture of assembled glass units, with the aim of imparting diffuse reflection properties to the assembled glass units while maintaining specular transmission properties.

[0007] The layered element can be inserted between two transparent substrates to form the assembled glass unit, or it can be added to the surface of an existing assembled glass unit, for example, by adhesive bonding. Each transparent substrate can be, for example, composed of a transparent polymer, transparent glass, or transparent ceramic.

[0008] More specifically, the layered element includes a so-called “center” layer inserted between two outer layers (lower and upper layers), the “center” layer being composed of a dielectric material having substantially the same refractive index.

[0009] The contact (i.e., the contact surface) between the central layer and each of the outer layers is based on a so-called “textured” interface (therefore each outer layer can be considered a textured layer). Conversely, each outer layer has a smooth surface relative to the textured interface that separates it from the central layer.

[0010] In detail, the core layer is formed from a single layer, which is a dielectric or metal layer with a refractive index different from that of the outer layers, or it is formed from a stack of layers including at least one dielectric or metal layer having a refractive index different from that of the outer layers. Each contact surface between two adjacent layers of the layered element (one of which is a dielectric and the other is a metal, or both are dielectric layers with different refractive indices) is textured and parallel to other textured contact surfaces between the two adjacent layers (one of which is a dielectric and the other is a metal, or both are dielectric layers with different refractive indices).

[0011] The production of such layered elements using appropriate manufacturing methods will not be reviewed here, but it should be understood that references can be made, in particular, to document WO2012104547A1 for more details. At least, it will be reviewed only that the central layer is deposited on the lower layer to conform to the textured surface of the lower layer (i.e., the single layer forming the central layer or each layer has a substantially uniform thickness over the entire extent of the textured surface).

[0012] For the overall description given herein, and unless otherwise stated, the terms and expressions referenced below refer to:

[0013] -Dielectric material or layer: A material or layer with a low conductivity of less than 100 S / m;

[0014] -Refractive index: Optical refractive index, measured at a wavelength of 550 nm;

[0015] - The two dielectric materials have essentially equal refractive indices: the absolute value of the difference between the refractive indices at 550 nm is less than or equal to 0.15, preferably less than 0.05, and more preferably less than 0.015.

[0016] - The difference in refractive index between the two dielectric materials: the absolute value of the difference in their refractive index at 550 nm is strictly greater than 0.15;

[0017] - Transparent elements: Elements (materials, substrates, etc.) that allow radiation to be transmitted through the specular surface of the element, at least within the wavelength range useful for its intended application. For example, when the element is used as a glass unit in a building or vehicle assembly, it is transparent at least in the visible wavelength range;

[0018] - Smooth surfaces / interfaces: The following surfaces / interfaces have irregularities smaller than the wavelength of the radiation incident on them, such that the radiation is not deflected by these irregularities. The incident radiation is then mirror-transmitted and reflected by the surface / interface.

[0019] -Textured surfaces / interfaces: These are surfaces / interfaces whose surface / interface irregularities vary on a scale greater than the wavelength of radiation incident on the surface / interface. In practice, textured surfaces / interfaces have multiple patterns of depressions or protrusions relative to the general plane of the surface / interface. Due to the presence of these irregularities, incident radiation is subsequently diffusely transmitted and diffusely reflected by the surface / interface.

[0020] Furthermore, throughout the description and regarding the composition of the central layer, a distinction is made between the metal layer, on the one hand, where the refractive index value is not important, and the dielectric layer, on the other hand, where the difference in refractive index relative to the outer layer must be considered.

[0021] Figure 1 An example of a prior art assembly glass unit 1 is illustrated, which includes the layered elements 4 as described above and is typically integrated into a projection screen.

[0022] like Figure 1 As shown, the assembled glass unit 1 includes two transparent substrates, a lower substrate 2 and an upper substrate 3. More specifically, in this example, each of the substrates 2 and 3 corresponds to a glass sheet.

[0023] The layered element 4 is formed specifically of a lower layer 5 made of PU (abbreviation for polyurethane) and an upper layer 6 made of PMMA (abbreviation for polymethyl methacrylate), wherein the lower layer 5 and the upper layer 6 have substantially equal refractive indices. Furthermore, the lower layer 5 contacts the lower substrate 2 through a smooth interface (more precisely, a planar interface).

[0024] The layered element also includes a central layer 7 that contacts each of the lower layer 5 and the upper layer 6 via a textured interface. In other words, each of the lower layer 5 and the upper layer 6 has a textured surface, and the central layer 7 contacts the textured surface (therefore, each of the lower layer 5 and the upper layer 6 corresponds to a textured layer).

[0025] In this example, and purely for illustrative purposes, the central layer 7 is composed of a dielectric layer made of titanium oxide (TiO2) with a refractive index different from that of the lower layer 5 and the upper layer 6.

[0026] In addition to the layered element 4, the assembly glass unit 1 also includes a layer 8 made of PU and in contact with the upper layer 6 and the upper substrate 3 via smooth interfaces (more precisely, planar interfaces). It should be noted that the refractive index of the layer 8 is not critical given the presence of these smooth interfaces. Ultimately, the assembly formed by the layered element 4 and the layer 8 corresponds to a stack of layers characteristic of the assembly glass unit 1.

[0027] Although information projection systems are currently widely deployed (e.g., display screens integrated into buildings, display screens integrated into street facilities, personal projection screens, etc.), it has been proven, as shown in the reference... Figure 1 The described configuration is problematic. In fact, a phenomenon known as "waviness" is quite common when observed through such assembled glass units, which often gives the visual impression of ripples in the layers placed between the transparent substrates of the assembled glass units.

[0028] This ripple phenomenon is explained by the fact that the assembly of glass units through conventional autoclave lamination procedures (e.g., at a temperature of 95°C and a pressure of 6 bar) results in relative movement between the lower layer 5 and the upper layer 6.

[0029] This ripple effect leads to several defects, including:

[0030] - The overall visual appearance of the assembled glass unit is flawed. This is especially true in the absence of projection, and when the assembled glass unit is placed in front of a black background: the ripples become perceptible.

[0031] - Defects in the quality of the projected image. This is especially true when the background of the projected image is light: ripples can make the image difficult to interpret. The visual perception of these ripples also increases with the viewing angle of the projected image, which further helps to limit access to the information that the image is intended to convey. Summary of the Invention

[0032] The object of this invention is to overcome all or some of the disadvantages of the prior art by proposing a solution, particularly those disclosed above, which can provide a glass assembly unit with diffuse reflection to which ripples will not be observed, thereby giving the glass assembly a quality that is significantly superior to those of prior art solutions in terms of visual appearance and projected image.

[0033] Therefore, and according to a first aspect, the present invention relates to an assembly glass unit comprising a stack of layers between two substrates (a lower substrate and a transparent upper substrate), each substrate comprising smooth surfaces opposite each other, the stack of layers comprising:

[0034] - Two dielectric layers (lower and upper), the lower layer comprising a first layer made of adhesive material, referred to as the "first adhesive layer," the lower and upper layers respectively contacting the lower and upper substrates through smooth interfaces.

[0035] - An intermediate layer, made of polymer material, contacts the first adhesive layer through a smooth interface, and has a refractive index that is substantially the same, preferably the same, as that of the upper layer.

[0036] - A central layer, which contacts each of the intermediate and upper layers via a textured interface, the central layer being formed of a single layer, which is a metal layer or a dielectric layer having a refractive index different from that of the intermediate and upper layers; or formed of a stack of layers comprising a metal layer or at least one dielectric layer having a refractive index different from that of the intermediate and upper layers.

[0037] In a particular embodiment, the adhesive material of the first adhesive layer is a transparent adhesive material, and the first adhesive layer is referred to as the "first OCA layer".

[0038] In a particular embodiment, the upper layer is made of a transparent adhesive material or polyurethane.

[0039] In a particular embodiment, the intermediate layer is made of polymethyl methacrylate or polycarbonate.

[0040] In a particular embodiment, the substrate is absorbent and / or transparent glass.

[0041] In a particular embodiment, the substrate is opaque glass.

[0042] In a particular embodiment, at least one surface of the substrate is at least partially covered with a dark enamel or dark coating, such as black enamel or black coating.

[0043] In a particular embodiment, the surface of the first adhesive layer at the interface with the intermediate layer is at least partially covered with a dark enamel or dark paint, such as black enamel or black paint.

[0044] In a particular embodiment, the lower layer consists of the first adhesive layer.

[0045] In a particular embodiment, the adhesive material of the first adhesive layer is a transparent adhesive material, and the first adhesive layer is referred to as the "first OCA layer," the underlying layer comprising:

[0046] - A second layer, made of a transparent adhesive material, called the "second OCA layer," contacts the underlying substrate through a smooth interface.

[0047] - The so-called "intermediate" glass sheet contacts each of the first (41_OCA1) and second OCA layers through a smooth interface. The intermediate sheet is an active film, such as an active electrochromic film.

[0048] According to a second aspect, the present invention relates to an assembly glass unit comprising a stack of layers between two substrates (a lower substrate and a transparent upper substrate), each substrate comprising smooth surfaces opposite each other. The stack of layers comprises:

[0049] - Two dielectric layers (lower and upper), the lower layer comprising a first layer made of a transparent adhesive material, referred to as the "first OCA layer," the lower and upper layers being in contact with the lower and upper substrates respectively through smooth interfaces.

[0050] - An intermediate layer, made of polymer material, contacts the first OCA layer through a smooth interface, and has a refractive index that is substantially the same, preferably the same, as that of the upper layer.

[0051] - A central layer, which contacts each of the intermediate and upper layers via a textured interface, the central layer being formed of a single layer, which is a metal layer or a dielectric layer having a refractive index different from that of the intermediate and upper layers; or formed of a stack of layers comprising a metal layer or at least one dielectric layer having a refractive index different from that of the intermediate and upper layers.

[0052] The glass assembly unit according to the invention is particularly advantageous because the lower layer includes the first OCA layer. In fact, it is precisely because of this first OCA layer that the glass assembly unit according to the invention can eliminate the ripple phenomenon observed in prior art glass assembly units.

[0053] This is because the first OCA layer has specific characteristics: it maintains a constant thickness during the lamination process via thermoforming, as described in detail below, when assembling the glass unit. Therefore, these properties also keep the intermediate layer flat during manufacturing (at the interface between the intermediate layer and the first OCA layer), ultimately eliminating any possibility of relative movement of the intermediate layer relative to the upper layer. This generally avoids any potential problems arising from deformation of these layers in the short or long term.

[0054] This results in a significant performance quality advantage in terms of visual appearance and projected image compared to the solutions that can be proposed to date.

[0055] In a particular embodiment, the assembly glass unit may further include several of the following features, individually or in any technically feasible combination.

[0056] In a particular embodiment, the upper layer is made of a transparent adhesive material (OCA) or polyurethane.

[0057] The specification (according to which the upper layer is made of transparent adhesive material (OCA)) can ultimately yield an assembled glass unit comprising two OCA layers (the first OCA layer and the upper layer). The manufacture of such an assembled glass unit has proven advantageous because it requires reduced pressurization cycle time, but also limits the number of pressurization cycles in terms of energy consumption, as it can be carried out at temperatures lower than those used when there is only one OCA layer.

[0058] In a particular embodiment, the intermediate layer is made of polymethyl methacrylate or polycarbonate.

[0059] In a particular embodiment, the substrate is absorbent and / or transparent glass.

[0060] In a particular embodiment, the substrate is opaque glass.

[0061] In a particular embodiment, at least one surface of the substrate is at least partially covered with a dark enamel or dark coating, such as enamel or black coating.

[0062] By convention, color can be evaluated using color coordinates L*, a*, and b* calculated by the observer based on the light source D65 and CIE-1931. The component L* defines luminance, ranging from a value of 0 for black to a value of 100 for white. Therefore, "dark" refers to any element with a luminance such that the L* value measured in reflection is less than 50.

[0063] In a particular embodiment, the surface of the first OCA layer at the interface with the intermediate layer is at least partially covered with a dark enamel or dark coating, such as black enamel or black coating.

[0064] In a particular implementation, the lower layer consists of the first OCA layer.

[0065] In a particular implementation, the lower layer includes:

[0066] - A second layer, made of a transparent adhesive material, called the "second OCA layer," contacts the underlying substrate through a smooth interface.

[0067] - The so-called "intermediate" glass sheet contacts each of the first and second OCA layers through a smooth interface. The intermediate sheet is an active film, such as an electrochromic film.

[0068] According to a third aspect, the present invention relates to a projection screen comprising an assembly glass unit according to the invention.

[0069] According to a fourth aspect, the present invention relates to a projection system comprising a projection screen and a projector according to the invention, wherein an upper substrate is intended to be arranged facing the projector.

[0070] According to a fifth aspect, the present invention relates to a projection method.

[0071] According to a sixth aspect, the present invention relates to uses implemented by a projection system according to the invention.

[0072] According to a seventh aspect, the present invention relates to the use of the assembly glass unit according to the invention as all or part of the assembly glass unit for vehicles, buildings, street facilities, interior decoration, display screens, head-up display systems.

[0073] According to an eighth aspect, the present invention relates to a method for manufacturing an assembled glass unit, the method comprising the following steps:

[0074] - Obtain two substrates (lower substrate and transparent upper substrate), each substrate comprising smooth surfaces opposite each other.

[0075] - A stack of layers is formed between a lower substrate and an upper substrate, the stack of layers being suitable for manufacturing an assembled glass unit according to the invention.

[0076] - A hot-pressed lamination is an assembly formed by a lower substrate, an upper substrate, and a stack of layers.

[0077] In a particular embodiment, the method for manufacturing the assembled glass unit is the method for manufacturing assembled glass according to the present invention.

[0078] In a particular embodiment, the forming step includes:

[0079] - Deposit the lower layer on the lower substrate.

[0080] - Deposit an intermediate layer on the first adhesive layer.

[0081] -Texturize the intermediate layer at the surface opposite the smooth interface of the first adhesive layer.

[0082] -Conformally deposit the central layer on the textured surface of the intermediate layer.

[0083] - Deposit the upper layer on the upper substrate.

[0084] -Texturize the upper layer on the surface opposite the smooth interface of the upper substrate.

[0085] - Assemble the assembly consisting of a lower substrate, a lower layer, an intermediate layer, and a central layer with the assembly consisting of an upper substrate and an upper layer, such that the central layer also contacts the textured surface of the upper layer.

[0086] In a particular embodiment, the step of forming a stack of layers is carried out to manufacture the assembled glass unit according to the invention, wherein the upper layer is made of a transparent adhesive material.

[0087] In a particular embodiment, the step of forming a stack of layers to manufacture an assembled glass unit according to the invention includes:

[0088] - Deposit the lower layer on the lower substrate.

[0089] - Deposit an intermediate layer on the first OCA layer

[0090] -Texturize the intermediate layer at the surface opposite the smooth interface of the first OCA layer.

[0091] -Conformally deposit the central layer on the textured surface of the intermediate layer.

[0092] - Deposit the upper layer on the upper substrate.

[0093] -Texturize the upper layer on the surface opposite the smooth interface of the upper substrate.

[0094] - Assemble the assembly consisting of a lower substrate, a lower layer, an intermediate layer, and a central layer with the assembly consisting of an upper substrate and an upper layer, such that the central layer also contacts the textured surface of the upper layer.

[0095] In a particular embodiment, the steps of forming a stack of layers include:

[0096] - Adhere the lower layer to the lower substrate.

[0097] -To obtain an intermediate layer that includes a smooth surface and a relatively textured surface.

[0098] - A central layer is conformally deposited on the textured surface of the intermediate layer, the deposited central layer comprising a first textured surface in contact with the textured surface of the intermediate layer and a second textured surface opposite to it.

[0099] - Place the upper layer on the upper substrate.

[0100] - Assemble an assembly consisting of a lower layer and a lower substrate, and an assembly consisting of an intermediate layer and a central layer, such that the lower layer extends between the smooth surface of the intermediate layer and the lower substrate.

[0101] - Assemble an assembly consisting of a lower substrate, a lower layer, an intermediate layer, and a central layer, and an assembly consisting of an upper substrate and an upper layer, such that the central layer also contacts the upper layer.

[0102] In a particular implementation, the upper layer is made of a transparent adhesive material.

[0103] According to a ninth aspect, the present invention relates to a method for producing a projection screen, comprising the steps of manufacturing an assembly glass unit according to the present invention.

[0104] According to a tenth aspect, the present invention relates to a method for producing a projection system, comprising the steps of producing a projection screen according to the method of obtaining a projection screen, providing a projector, and arranging an upper substrate facing the projector.

[0105] Attached Figure Description

[0106] Other features and advantages of the invention will become apparent from the following non-limiting description, with reference to the accompanying drawings illustrating exemplary embodiments thereof. In the drawings:

[0107] Figure 1 An example of a prior art assembled glass unit including layered elements is illustrated schematically;

[0108] Figure 2 A particular embodiment of the assembled glass unit according to the present invention is illustrated schematically;

[0109] Figure 3 Another particular embodiment of the assembly glass unit according to the invention is illustrated schematically;

[0110] Figure 4 Another particular embodiment of the assembly glass unit according to the invention is illustrated schematically;

[0111] Figure 5 Another particular embodiment of the assembly glass unit according to the invention is illustrated schematically;

[0112] Figure 6 Another particular embodiment of the assembly glass unit according to the invention is illustrated schematically;

[0113] Figure 7 A particular embodiment of the projection system according to the present invention is illustrated schematically;

[0114] Figure 8 The main steps of the method for manufacturing and assembling glass units according to the present invention are illustrated in the form of a flowchart;

[0115] Figure 9 It shows Figure 8 A specific implementation scheme for the method;

[0116] Figure 10 It shows Figure 9The method or even more specific implementation scheme. Detailed Implementation Plan

[0117] The following describes several specific embodiments of the present invention. More specifically, a specific embodiment of assembling a glass unit according to the present invention is first described, followed by a specific embodiment of a method for manufacturing such an assembled glass unit.

[0118] For the remainder of the specification, it is not intended to be limiting that the assembled glass unit discussed is flat. However, it should be noted that such a designation does not limit the invention; considering similar techniques that can be implemented by those skilled in the art, the invention can also be applied to curved assembled glass units.

[0119] Furthermore, throughout the description, the assembled glass unit according to the invention is considered to be horizontally positioned, wherein a downwardly oriented first surface defines a lower outer surface, and an upwardly oriented second surface opposite the first surface defines an upper outer surface. Therefore, the expressions "above" and "below" are understood to refer to this orientation. The terms "below" and "above" are also used herein with respect to this arrangement.

[0120] Figure 2 A particular embodiment of the assembled glass unit V1 according to the present invention is illustrated schematically.

[0121] exist Figure 2 In the embodiment, the assembled glass unit V1 includes a stack 40 of layers between two substrates:

[0122] - The lower substrate 20 includes a smooth lower surface 20_inf (which is the lower outer surface V1_inf of the assembled glass unit V1) and a smooth upper surface 20_sup (which is the surface opposite to the lower surface 20_inf).

[0123] - Transparent upper substrate 30 includes a smooth upper surface 30_sup (which is the upper outer surface V1_sup of the assembled glass unit V1) and a smooth lower surface 30_inf (which is the surface opposite to the upper surface 30_sup).

[0124] The lower surfaces 20_inf and 30_inf and the upper surfaces 20_sup and 30_sup are substantially parallel to each other, preferably parallel to each other.

[0125] More specifically, in the embodiments described herein, the upper substrate 30 is a transparent (mineral) glass. It should be noted that such glass may, for example, be completely transparent, or both transparent and absorbent.

[0126] Examples of glass substrates that can be directly used as the upper substrate 30 include Saint-Gobain Glass. or Glass substrates sold within the specified scope.

[0127] However, this does not preclude the consideration of an upper substrate 30 made of polymeric materials. Examples of transparent polymers suitable for the upper substrate 30 include, in particular, polycarbonate and PMMA (an abbreviation for "polymethyl methacrylate").

[0128] Similarly, in this embodiment, the lower substrate 20 is a transparent (mineral) glass. Furthermore, the alternatives mentioned above regarding the upper substrate 30 (fully transparent, absorbent, and transparent, made of polymeric materials) also apply to the lower substrate 20. Other embodiments in which an opaque lower substrate 20 is envisioned are described in more detail below.

[0129] An example of a glass substrate that can be directly used as the substrate 20 is the glass substrate sold by Saint-Gobain Glass in the PARSOLULTRA GREY VENUS (VG10, VG20, VG40) range.

[0130] It should be noted that there are no limitations on the dimensions of the lower substrate 20 and the upper substrate 30. Therefore, for example, the thickness of the lower substrate 20 and the upper substrate 30 (depending on the intended application) can be from 1.1 mm to 12 mm, more particularly from 1.6 mm to 6 mm, and even more particularly from 1.6 mm to 2.6 mm, or even, for example, substantially equal to or equal to 2 mm (thickness in...). Figure 1 (Measured perpendicularly in the plane).

[0131] The stack of layers 40 includes two dielectric layers, a lower layer 41 and an upper layer 42.

[0132] like Figure 2 As shown, the lower layer 41 consists of a first layer made of a transparent adhesive material, referred to as the "first OCA layer" (the term "OCA" is an abbreviation for "Optically Transparent Adhesive"). It should be noted that, according to a more particular embodiment, the transparent nature of the adhesive material does not preclude the assumption that the adhesive material is also absorbent.

[0133] Furthermore, the first OCA layer 41 contacts the lower substrate 20 through a smooth interface. In other words, the first OCA layer 41 includes a smooth lower surface 41_inf that contacts the upper surface 20_sup of the lower substrate 20. The first OCA layer 41 also includes a smooth upper surface 41_sup opposite to the lower surface 41_inf.

[0134] In a manner known per se, the term "OCA" refers to a group of polymeric materials, which, in the case of this invention, are therefore used as a transparent adhesive. Examples of polymeric materials suitable for use in the first OCA layer 41 particularly include polyurethane, preferably thermosetting polyurethane, polyepoxide, polysiloxane, polyacrylate, polyester, etc.

[0135] Furthermore, the thickness of the first OCA layer 41 is, for example, 200 μm to 250 μm. However, this thickness value does not limit the invention. More generally, there is no limitation on the size of the first OCA layer 41.

[0136] The upper layer 42 is made of polyurethane and contacts the upper substrate 30 through a smooth interface. In other words, the upper layer 42 includes a smooth upper surface 42_sup that contacts the lower surface 30_inf of the upper substrate 30. The thickness of the upper layer 42 is, for example, 0.2 mm to 0.8 mm.

[0137] It should be noted that the upper layer 42, made of polyurethane, constitutes only one variant embodiment of the invention. Therefore, other variants are not excluded, particularly an upper layer 42 made of a transparent adhesive OCA material, or an upper layer 42 made of PVB (an abbreviation for "polyvinyl butyral"), EVA (an abbreviation for "ethylene-vinyl acetate"), etc. More particularly, the PVB or EVA used for the upper layer 42 is especially suitable for cases where the assembled glass unit according to the invention comprises a dark enamel or dark coating, and is intended for use in the manufacture of opaque screens, as described in more detail later.

[0138] like Figure 2 As shown, the stack 40 of layers also includes an intermediate layer 43 made of a polymer material, which contacts the first OCA layer 41 through a smooth interface. In other words, the intermediate layer 43 includes a smooth lower surface 43_inf that contacts the smooth upper surface 41_sup of the first OCA layer. Furthermore, the refractive index of the intermediate layer 43 is substantially the same as, preferably the same as, the refractive index of the upper layer 42.

[0139] In the embodiments described herein, the interlayer 43 is made of PMMA and has a thickness of, for example, 50 μm to 250 μm. However, other materials, such as polycarbonate, are not excluded from consideration for the production of the interlayer 43. Other examples of suitable materials for the interlayer 43 include polyesters, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN); polyacrylates, such as polymethyl methacrylate (PMMA); polycarbonate; polyurethane; polyamide; polyimide; cellulose triacetate (TAC); and the like.

[0140] like Figure 2As shown, the stack 40 of layers also includes a central layer 44 that contacts each of the intermediate layer 43 and the upper layer 42 via a textured interface. In other words, the intermediate layer 43 (corresponding to the upper layer 42) includes a textured surface 43_tx opposite to the lower surface 43_inf (correspondingly including a textured surface 42_tx opposite to the upper surface 42_sup), which the central layer 44 contacts.

[0141] The central layer 44 is configured such that the assembled glass unit V1 has diffuse reflection properties. For this purpose, the central layer 44 is formed as a single layer that is a metal layer or a dielectric layer having a refractive index different from that of the intermediate layer 43 and the upper layer 42, or is formed as a stack of layers including a metal layer or at least one dielectric layer having a refractive index different from that of the intermediate layer 43 and the upper layer 42.

[0142] Examples of a central layer that can be inserted between the intermediate layer 43 and the upper layer 42 include a thin dielectric layer selected from oxides, nitrides, or halides of several transition metals, nonmetals, or alkaline earth metals, particularly Si3N4, SnO2, ZnO, ZrO2, and SnZnO. x Layers of AlN, NbO, NbN, TiO2, SiO2, Al2O3, MgF2, AlIF3, or thin metal layers, especially layers of silver, gold, copper, titanium, niobium, silicon, aluminum, nickel-chromium (NiCr) alloys, stainless steel, or alloys of these metals.

[0143] The texturing patterns of each of the textured surfaces 42_tx and 43_tx (and the texturing patterns of the contact surfaces between the layers when the central layer 44 is formed by a stack of layers) can be randomly distributed on the surface in question. As a variation, the texturing patterns can be periodically distributed on the surface. These patterns may in particular be cones, pyramids, grooves, ribs, or wavelets.

[0144] It should also be noted that the central layer 44 may be deposited only on a portion of the textured surface 43_tx of the intermediate layer 43.

[0145] The configuration details of the central layer 44 will not be described further here, as they have been disclosed in many existing technical documents. For this purpose, see, for example, the previously mentioned document WO2012104547A1.

[0146] Other particular embodiments of the assembled glass unit according to the invention will now be described with reference to other accompanying drawings. The reference numerals used in these other figures are the same as those previously used. Figure 2 The same reference numerals are used in the accompanying drawings to indicate similar or identical elements.

[0147] Figure 3Another particular embodiment of the assembled glass unit V2 according to the invention is illustrated schematically, wherein the lower layer 41 is also composed of an OCA layer and the lower substrate 20 is opaque glass.

[0148] More specifically, in Figure 3 In one embodiment, the lower substrate 20 is glass, and its upper surface 20_sup is covered with dark black enamel or dark coating (e.g., paint) 50, such as black or dark gray.

[0149] It should be noted that, in Figure 4 In this example, the dark enamel or dark paint 50 completely covers the upper surface 20_sup. However, other instances in which the dark enamel or dark paint 50 only partially covers the upper surface 20_sup are not excluded, a provision that is generally advantageous in the automotive or transport assembly glass industry.

[0150] Figure 4 schematically illustrates another particular embodiment of the assembled glass unit V3 according to the present invention.

[0151] exist Figure 4 In the embodiment, the lower layer 41 is also composed of an OCA layer, and the lower substrate 20 is opaque glass. However, the assembly glass unit V3 and Figure 3 The difference with the assembled glass unit V2 is that, in this case, a dark enamel or dark coating 50 covers the lower surface 20_inf of the lower substrate 20.

[0152] Figure 5 schematically illustrates another particular embodiment of the assembled glass unit V4 according to the present invention.

[0153] exist Figure 5 In the implementation scheme, the lower layer 41 is also composed of an OCA layer. However, the assembly glass unit V4 and Figure 3 The assembly glass unit V2 and Figure 4 The difference in the assembled glass unit V3 is that the upper surface 41_sup of the first OCA layer 41 is covered with dark enamel or dark paint 50 (in this case, dark enamel or black paint 50 is contained in the stack of layers 40).

[0154] Figure 6 Another particular embodiment of the assembled glass unit V5 according to the invention is illustrated schematically.

[0155] exist Figure 6 In the implementation scheme, the assembly glass unit V5 and Figure 2 The difference in the assembled glass unit V1 is that the lower layer 41 no longer consists only of the OCA layer, but includes:

[0156] - The first OCA layer 41_OCA1 contacts the intermediate layer 43 through a smooth interface. In other words, the first OCA layer 41_OCA1 includes a smooth upper surface 41_OCA1_sup that contacts the smooth lower surface 43_inf of the intermediate layer.

[0157] - A second layer, made of a transparent adhesive material, referred to as the "second OCA layer" 41_OCA2, is in contact with the lower substrate 20 through a smooth interface. In other words, the second OCA layer 41_OCA2 includes a smooth lower surface 41_OCA2_inf that is in contact with the upper surface 20_sup of the lower substrate 20.

[0158] In addition, Figure 6 In one embodiment, the lower layer 41 of the assembled glass unit V6 further includes a so-called "intermediate" glass sheet 41_GL, which contacts each of the first and second OCA layers 41_OCA1 and 41_OCA2 via a smooth interface. In other words, the intermediate sheet 41_GL includes a smooth lower surface 41_GL_inf (and a corresponding smooth upper surface 41_GL_sup), which contacts the upper surface 41_OCA2_sup of the second OCA2 layer (and correspondingly contacts the lower surface 41_OCA1_inf of the first OCA1 layer).

[0159] The intermediate sheet 41_GL is an active film, such as an active electrochromic film (e.g., an active electrochromic film based on anisotropic particles or liquid crystal with added dichroic dyes).

[0160] To date, the present invention has been referenced Figures 2 to 6 Individual embodiments have been described. However, it is important to note that these embodiments do not limit the invention, and other embodiments are not excluded from contemplation. In particular, within the sense of the invention, it is conceivable that… Figures 2 to 6 Any technically effective combination of implementation schemes.

[0161] Furthermore, the present invention is not limited to the assembled glass unit as described above. Therefore, according to other aspects, the present invention also relates to a projection screen including such an assembled glass unit.

[0162] Therefore, it can be noted that this screen implementation is most particularly suitable (but not limited to) implementations where the lower substrate 20 is absorbent glass, and also relates to implementations where the lower substrate 20 is opaque glass and / or the screen is a black screen due to the use of dark paint or dark enamel (the achieved technical effect is to enhance the contrast of the projected image).

[0163] The present invention also relates to a projection system 100. A particular embodiment of this projection system 100 is provided by... Figure 7 It is shown schematically and entirely without limitation.

[0164] like Figure 7 As shown, the projection system 100 includes a projection screen 110 according to the invention. More specifically, in the embodiment described herein, the projection screen 110 includes a mounting glass unit V2, for example, referring to... Figure 3 The described assembly glass unit.

[0165] The projection system 100 also includes a projector 120 of a known design. The relative positions of the projector 120 and the projection screen 110 are such that the upper substrate 30 of the mounting glass unit incorporated in the projection screen 110 is arranged to face the projector 120 (therefore the image is projected onto the upper substrate 30).

[0166] It should be noted that, within the meaning of this invention, a projection system refers not only to an assembly in which a screen and a projector are arranged relative to each other to project an image, but also to an assembly in the form of a kit, the components of which are a screen and a projector arranged with the aim of performing image projection.

[0167] Of course, by implementing the projection method according to the invention (not shown in the figure), the projection system 100 described above can be used to project images.

[0168] However, the applications of the assembly glass unit according to the present invention are not limited to projection screens. Therefore, the assembly glass unit according to the present invention can be used in all known applications of assembly glass units, such as for vehicles, buildings, street facilities, interior furnishings, lighting, display screens, etc.

[0169] The assembly glass unit according to the present invention can also be used in a head-up display (HUD) system.

[0170] "HUD" here refers to a system that can display information projected onto a glass unit, typically the windshield of a vehicle, reflecting the information toward the driver or observer. Such HUD systems are particularly suitable for aircraft cockpits and trains, but are now also applicable to privately owned motor vehicles (cars, trucks, etc.). These systems can provide information to the driver without requiring them to look away from the vehicle, significantly improving safety.

[0171] An embodiment of the method for manufacturing an assembled glass unit according to the present invention will now be described.

[0172] Figure 8 The main steps of the manufacturing method are shown in the form of a flowchart.

[0173] like Figure 8As shown, the manufacturing method includes step E10 of obtaining a lower substrate 20 and an upper substrate 30.

[0174] The manufacturing method also includes step E20 of forming a stack 40 of layers between the lower substrate 20 and the upper substrate 30.

[0175] Once an assembly is obtained, consisting of a lower substrate 20, an upper substrate 30, and a stack of layers 40, the manufacturing method includes step E30 of hot-pressing the assembly.

[0176] As a non-limiting example, when the upper layer 42 is made of polyurethane, the pressurization cycle is carried out at a temperature of 80°C to 100°C, preferably 85°C to 95°C, and at a pressure of 6 to 10 bar, particularly substantially equal to or equal to 6 bar.

[0177] According to another example, when the upper layer 42 is made of a transparent adhesive OCA material, the pressurization cycle is carried out at a temperature of 30°C to 50°C and a pressure of approximately 5 bar.

[0178] Figure 9 It is shown in the form of a flowchart Figure 8 A specific implementation scheme of the method.

[0179] More specifically, in Figure 9 In one embodiment, the manufactured assembly glass unit is an assembly glass unit in which the upper layer 42 is made of transparent adhesive OCA material.

[0180] like Figure 9 As shown, in the particular embodiment described herein, forming step E20 includes:

[0181] - An E20_1 lower layer 41 is deposited on the lower substrate 20 to contact the lower substrate 20 through a smooth interface.

[0182] - An E20_2 intermediate layer 43 is deposited on the first layer 41_OCA1 to allow contact with the first layer 41_OCA1 through a smooth interface.

[0183] -Texturing E20_3 is performed on the intermediate layer 43 at the surface opposite the smooth interface of the first OCA layer 41_OCA1 to form a textured surface 43_tx.

[0184] -Conformally deposit the E20_4 central layer 44 on the textured surface 43_tx of the intermediate layer 43.

[0185] - An E20_5 upper layer 42 is deposited on the upper substrate 30 to allow contact with the upper substrate 30 through a smooth interface.

[0186] - The upper layer 42 is textured E20_6 at the surface opposite to the smooth interface of the upper substrate 30 to form a textured surface 42_tx (of course, the textured surface 42_tx is complementary to the textured surface of the central layer 44 so that they can be superimposed).

[0187] -Assemble E20_7, which is an assembly formed by a lower substrate 20, a lower layer 41, an intermediate layer 43 and a central layer 44, and an assembly formed by an upper substrate 30 and an upper layer 42, such that the central layer 44 also contacts the textured surface 42_tx of the upper layer 42.

[0188] It should be noted that, in a manner known per se, surface texturing can be achieved by any known texturing method, for example, by embossing the surface of a layer preheated to a temperature at which it can deform, particularly by lamination using rollers whose surfaces have a texture complementary to the texture to be formed on the layer; by abrasion of a granular or frosted surface, particularly by sandblasting; by chemical treatment, particularly acid treatment in the case of glass substrates; by molding, particularly injection molding in the case of substrates made of thermoplastic polymers; or by etching.

[0189] The conformal deposition of the central layer 44, whether it is a single layer or a stack of several layers, is carried out, for example, by magnetron sputtering under vacuum.

[0190] Of course, more specific implementation schemes of the manufacturing method can be envisioned, depending on the composition of the assembled glass unit in terms of its layers.

[0191] Therefore, if the manufactured assembly glass unit is Figure 6 If the type is specified, then step E20 of forming the stack 40 of layers may also include (before the deposition E20_1 of the lower layer 41 and as shown in the figure). Figure 10 The lower layer 41 is formed as shown in a completely non-limiting manner (as illustrated in the diagram), the formation of E20_0 comprising:

[0192] - A second OCA layer 41_OCA2 of E20_0_1 is deposited on the lower substrate 20 to contact the lower substrate 20 through a smooth interface.

[0193] - An E20_0_2 intermediate glass sheet 41_GL is deposited on the second OCA layer 41_OCA2 to allow for contact with the second OCA layer 41_OCA2 through a smooth interface.

[0194] - Deposit an E20_0_3 first OCA layer 41_OCA1 on the intermediate glass sheet 41_GL to contact the intermediate glass sheet 41_GL through a smooth interface.

[0195] Furthermore, if a dark enamel or dark coating is used according to one of the above embodiments, the manufacturing method includes the step of applying the dark enamel or dark coating.

[0196] The first adhesive layer of the first lower layer 41 is the adhesive layer prior to the hot lamination step.

[0197] According to one exemplary embodiment, the first adhesive layer is an adhesive film.

[0198] The second adhesive layer of the first lower layer 41 is an adhesive applied before the hot lamination step.

[0199] According to one exemplary embodiment, the second adhesive layer is an adhesive film.

[0200] The lower surface 41_inf of the lower layer 41 is the adhesive surface, and the upper surface 41_sup of the lower layer 41 is the adhesive surface.

[0201] The lower surface 41_inf and the upper surface 41_sup of the lower layer 41 are adhesives prior to the hot lamination step.

[0202] As a variant, the steps for forming the stack of forming layers include:

[0203] - Adhere the lower layer 41 to the lower substrate 20.

[0204] -To obtain an intermediate layer 43 comprising a smooth surface and a relatively textured surface.

[0205] - A central layer 44 is conformally deposited on the textured surface of the intermediate layer 43, the deposited central layer 44 comprising a first textured surface in contact with the textured surface of the intermediate layer 43 and a second textured surface opposite to it.

[0206] - The upper layer 42 is arranged on the upper substrate 30.

[0207] - Assemble the assembly formed by the lower layer 41 and the lower substrate 20 with the assembly formed by the intermediate layer 43 and the central layer 44, such that the lower layer 41 extends between the smooth surface of the intermediate layer 43 and the lower substrate 20.

[0208] - Assemble the assembly formed by the lower substrate 20, the lower layer 41, the intermediate layer 43 and the central layer 44 with the assembly formed by the upper substrate 30 and the upper layer 42, such that the central layer 44 also contacts the upper layer 42.

[0209] For example, the lower layer 41 is bonded to the smooth surface of the intermediate layer 43 and the lower substrate 20 by pressing the lower layer 41 to the intermediate layer 43 and the lower substrate 20.

[0210] During the hot lamination step, the upper layer 42 is textured on the surface opposite the smooth interface of the upper substrate 30 to form a textured surface 42_tx.

[0211] Specifically, during the hot lamination step, the lower layer 41 remains flat.

Claims

1. An assembly of glass units (V1, V2, V3, V4, V5) comprising a stack (40) of layers between two substrates, a lower substrate (20) and a transparent upper substrate (30), each substrate comprising smooth surfaces opposite each other, the stack of layers comprising: - Two dielectric layers, a lower layer (41) and an upper layer (42), wherein the lower layer includes a first layer made of an adhesive material, referred to as the "first adhesive layer", wherein the lower layer and the upper layer are in contact with the lower substrate and the transparent upper substrate respectively through a smooth interface, wherein the adhesive material of the first adhesive layer is a transparent adhesive material, the first adhesive layer is referred to as the "first OCA layer (41_OCA1)", and the first OCA layer maintains a constant thickness during the hot lamination step in its manufacturing process. - An intermediate layer (43), made of a polymer material, contacts the first adhesive layer through a smooth interface and has the same refractive index as the upper layer. - A central layer (44) that contacts each of the intermediate and upper layers through a textured interface, the central layer being formed by a single layer or by a stack of layers, the single layer being a metal layer or a dielectric layer with a refractive index different from the intermediate and upper layers, the stack of layers including a metal layer or at least one dielectric layer with a refractive index different from the intermediate and upper layers.

2. The assembled glass unit (V1, V2, V3, V4, V5) according to claim 1, wherein the upper layer (42) is made of a transparent adhesive material or polyurethane.

3. The assembled glass unit (V1, V2, V3, V4, V5) according to claim 1, wherein the intermediate layer (43) is made of polymethyl methacrylate or polycarbonate.

4. The assembled glass unit (V1, V2, V3, V4, V5) according to claim 1, wherein the lower substrate (20) is absorbent and / or transparent glass.

5. The assembled glass unit (V1, V2, V3, V4, V5) according to claim 1, wherein the lower substrate (20) is opaque glass.

6. The assembled glass unit (V2) according to claim 5, wherein at least one surface of the lower substrate (20) is at least partially covered with dark enamel or dark coating (50).

7. The assembled glass unit (V2) according to claim 6, wherein at least one surface of the lower substrate (20) is at least partially covered with black enamel or black coating.

8. The assembled glass unit (V4) according to claim 1, wherein the surface of the first adhesive layer at the interface with the intermediate layer (43) is at least partially covered with dark enamel or dark paint (50).

9. The assembled glass unit (V4) according to claim 1, wherein the surface of the first adhesive layer at the interface with the intermediate layer (43) is at least partially covered with black enamel or black paint.

10. The assembled glass unit (V1) according to claim 1, wherein the lower layer (41) is composed of the first adhesive layer.

11. The assembly glass unit (V5) according to claim 1, wherein the lower layer (41) comprises: - The second layer (41_OCA2), which is made of a transparent adhesive material and is called the "second OCA layer", contacts the lower substrate (20) through a smooth interface. - An "intermediate" glass sheet (41_GL) is in contact with each of the first and second OCA layers through a smooth interface. The "intermediate" glass sheet is an active film.

12. The assembly glass unit (V5) according to claim 11, wherein the "intermediate" glass sheet is an active electrochromic film.

13. A projection screen (110) comprising an assembly glass unit (V1, V2, V3, V4, V5) according to any one of claims 1 to 12.

14. A projection system (100) comprising a projection screen (110) according to claim 13 and a projector (120), wherein the transparent upper substrate (30) is intended to be arranged facing the projector.

15. A projection method implemented by the projection system (100) according to claim 14.

16. The use of the glass assembly unit (V1, V2, V3, V4, V5) according to any one of claims 1 to 12 as all or part of the glass assembly unit for vehicles, buildings, street facilities, interior decoration, display screens, head-up display systems.

17. A method for manufacturing an assembled glass unit (V1, V2, V3, V4, V5) according to any one of claims 1 to 12, the method comprising the following steps: - Obtain two substrates (E10), a lower substrate (20) and a transparent upper substrate (30), each substrate comprising smooth surfaces opposite each other. - A stack (40) of (E20) layers is formed between the lower substrate and the transparent upper substrate, the stack of layers being adapted for manufacturing the assembled glass unit. - A hot press lamination (E30) of an assembly formed by the stack of the lower substrate, the transparent upper substrate, and the layers, wherein the step of forming a stack (40) of layers (E20) between the lower substrate and the transparent upper substrate includes: -Deposit (E20_1) the lower layer (41) on the lower substrate (20), - Deposit (E20_2) the intermediate layer (43) on the first adhesive layer. -Texturize the intermediate layer at the surface opposite the smooth interface of the first adhesive layer (E20_3). -Conformal deposition (E20_4) of the central layer (44) on the textured surface of the intermediate layer, - A top layer (42) (E20_5) is deposited on the transparent substrate (30). -Texturize the upper layer (42) at the surface opposite the smooth interface of the transparent upper substrate (E20_6). - Assembly (E20_7) is an assembly formed by the lower substrate, lower layer, intermediate layer and central layer and an assembly formed by the transparent upper substrate and upper layer, such that the central layer is also in contact with the textured surface of the upper layer.

18. A method for manufacturing an assembled glass unit (V1, V2, V3, V4, V5) according to any one of claims 1 to 12, the method comprising the following steps: - Obtain two substrates (E10), a lower substrate (20) and a transparent upper substrate (30), each substrate comprising smooth surfaces opposite each other. - A stack (40) of (E20) layers is formed between the lower substrate and the transparent upper substrate, the stack of layers being adapted for manufacturing the assembled glass unit. - A hot press lamination (E30) of an assembly formed by the stack of the lower substrate, the transparent upper substrate, and the layers, wherein the step of forming a stack (40) of layers (E20) between the lower substrate and the transparent upper substrate includes: - The lower layer (41) is bonded to the lower substrate (20). -To obtain the intermediate layer (43) comprising a smooth surface and a relatively textured surface, - A central layer (44) is conformally deposited on the textured surface of the intermediate layer (43), the deposited central layer (44) comprising a first textured surface in contact with the textured surface of the intermediate layer (43) and an opposing second textured surface. - The upper layer (42) is arranged on the transparent upper substrate (30). - Assemble an assembly formed by the lower layer (41) and the lower substrate (20) and an assembly formed by the intermediate layer (43) and the central layer (44) such that the lower layer (41) extends between the smooth surfaces of the intermediate layer (43) and the lower substrate (20). Assemble the assembly formed by the lower substrate (20), lower layer (41), intermediate layer (43) and central layer (44) with the assembly formed by the transparent upper substrate (30) and upper layer (42) such that the central layer (44) also contacts the upper layer (42).

19. The method (200) according to claim 18, wherein the upper layer (42) is made of a transparent adhesive material.

20. A method for producing a projection screen (110), comprising the steps of the method for manufacturing an assembly glass unit according to claim 18 or 19.

21. A method for producing a projection system (100), comprising the steps of obtaining a projection screen, providing a projector (120), and arranging the transparent upper substrate (30) facing the projector, according to the method for producing a projection screen of claim 20.

Images