WO2024223496A1

WO2024223496A1 - Anti-collision glazing unit

Info

Publication number: WO2024223496A1
Application number: PCT/EP2024/060959
Authority: WO
Inventors: Théo CHEVALLIER; Anne PENILLARD
Original assignee: Saint-Gobain Glass France
Priority date: 2023-04-25
Filing date: 2024-04-22
Publication date: 2024-10-31

Abstract

The present invention relates to the field of multiple glazing units suitable for being installed in a building, on a facade and/or on a roof. More precisely, the invention relates to "anti-collision" glazing units which make it possible to prevent, or at least reduce, the risk of birds colliding with the glazing unit. The invention also relates to the manufacture of such multiple glazing units and to the installation thereof in a building.

Description

Title of the invention: ANTI-COLLISION GLAZING

[0001] The present invention relates to the field of multiple glazings suitable for being mounted in a building, on a facade and/or roof. More specifically, the invention relates to so-called “anti-collision” glazings which make it possible to avoid or at least limit the risks of a bird colliding with said glazing. The invention also relates to the manufacture of such multiple glazing, as well as to its mounting in a building.

[0002] The present invention relates in particular to the integration of a transparent layered element with diffuse reflection within such a multi-glazing unit. The layered element may be rigid or flexible. It may in particular be a glazing unit, for example made from glass or polymer material. It may also be a flexible film based on polymer material, in particular capable of being applied to a surface in order to give it diffuse reflection properties while preserving its transmission properties.

[0003] Known glazings include standard transparent glazings, which give rise to specular transmission and reflection of radiation incident on the glazing, and translucent glazings, which give rise to diffuse transmission and reflection of radiation incident on the glazing.

[0004] Usually, the reflection by a glazing is said to be diffuse when radiation incident on the glazing with a given angle of incidence is reflected by the glazing in a plurality of directions. The reflection by a glazing is said to be specular when radiation incident on the glazing with a given angle of incidence is reflected by the glazing with a reflection angle equal to the angle of incidence. Similarly, the transmission through a glazing is said to be specular when radiation incident on the glazing with a given angle of incidence is transmitted by the glazing with a transmission angle equal to the angle of incidence.

[0005] A disadvantage of standard transparent glazing is that it gives off sharp, mirror-like reflections, which is undesirable in some applications. Thus, when glazing is used for a building window, it is

SUBSTITUTE SHEET (RULE 26) It is preferable to limit the presence of reflections, which reduce visibility through the glazing. Sharp reflections on glazing can also generate glare risks, with consequences in terms of safety, for example when vehicle headlights are reflected on glass facades of buildings. This problem is particularly relevant for airport glass facades. It is indeed essential to limit as much as possible the risk of glare for pilots approaching the terminals.

[0006] Furthermore, translucent glazing, although it has the advantage of not generating sharp reflections, does not allow a clear view through the glazing.

[0007] In order to overcome these drawbacks, it is known from the state of the art, including document WO2012104547A1, to implement a transparent layered element with diffuse reflection which comprises two smooth external main surfaces, as well as:

- two outer layers, a lower outer layer and an upper outer layer, each forming one of the two main outer surfaces of the layered element and consisting of dielectric materials having substantially the same refractive index, and

- a central layer interposed between the outer layers, this central layer being formed either by a single layer which is a dielectric layer with a refractive index different from that of the outer layers or a metallic layer, or by a stack of layers which comprises at least one dielectric layer with a refractive index different from that of the outer layers or a metallic layer, where each contact surface between two adjacent layers of the layered element which are one dielectric and the other metallic, or which are two dielectric layers with different refractive indices, is textured and parallel to the other textured contact surfaces between two adjacent layers which are one dielectric and the other metallic or which are two dielectric layers with different refractive indices.

[0008] The transparent substrate may be made, in particular, of transparent polymer, transparent glass, transparent ceramic. When the substrate

SUBSTITUTE SHEET (RULE 26) transparent is made of polymer, it can be rigid or flexible. In the form of a flexible film, such a transparent substrate is advantageously provided, on one of its main external surfaces, with a layer of adhesive covered with a protective strip intended to be removed for bonding the film. The layered element in the form of a flexible film is then capable of being bonded to an existing surface, for example a surface of a glazing, in order to give this surface diffuse reflection properties, while maintaining specular transmission properties.

[0009] Each outer layer of the layered element may be formed by a stack of layers, provided that the different constituent layers of the outer layer are made of dielectric materials all having substantially the same refractive index.

[0010] For the purposes of the invention, the term “dielectric material or layer” means a material or layer with low electrical conductivity, less than 100 S/m.

[0011] The term "index" refers to the optical index of refraction, measured at the wavelength of 550 nm.

[0012] For the purposes of the invention, two dielectric materials have substantially the same refractive index, or have their refractive indices substantially equal, when the absolute value of the difference between their refractive indices at 550 nm is less than or equal to 0.15. Preferably, the absolute value of the difference in refractive index at 550 nm between the materials constituting the two external layers of the layered element is less than 0.05, more preferably less than 0.015.

[0013] In contrast, two dielectric layers have different refractive indices when the absolute value of the difference between their refractive indices at 550 nm is strictly greater than 0.15.

[0014] Throughout the description and with regard to the composition of the central layer, a distinction is made between metallic layers, on the one hand, for which the value of the refractive index is indifferent, and dielectric layers, on the other hand, for which the difference in refractive index relative to that of the external layers is to be considered.

SUBSTITUTE SHEET (RULE 26) [0015] For the purposes of the invention, the contact surface between two adjacent layers is the interface between the two adjacent layers.

[0016] In the context of the invention, the following definitions are used:

- A transparent element is an element through which there is a specular transmission of radiation at least in the wavelength ranges useful for the intended application of the element. For example, when the element is used as glazing for a building or vehicle, it is transparent at least in the visible wavelength range.

- A smooth surface is one in which the surface irregularities are smaller than the wavelength of the radiation incident on the surface, so that the radiation is not deflected by these surface irregularities. The incident radiation is then transmitted and reflected specularly by the surface.

- A textured surface is a surface for which the surface irregularities vary on a scale larger than the wavelength of the radiation incident on the surface. The incident radiation is then transmitted and diffusely reflected by the surface.

[0017] The parallelism of the textured contact surfaces implies that the or each layer constituting the central layer which is dielectric with a refractive index different from that of the external layers, or which is metallic, has a uniform thickness perpendicular to the contact surfaces of the central layer with the external layers. This uniformity of thickness can be global over the entire extent of the texture, or local over sections of the texture. In particular, when the texture has variations in slope, the thickness between two consecutive textured contact surfaces can change, by section, depending on the slope of the texture, the textured contact surfaces however always remaining parallel to each other. This case occurs in particular for a layer deposited by cathode sputtering, where the thickness of the layer is all the less as the slope of the texture increases. Thus, locally, on each texture section having a given slope, the thickness of the layer remains constant, but the thickness of the layer is different between a first texture section having a first slope and a

SUBSTITUTE SHEET (RULE 26) second texture section having a second slope different from the first slope.

[0018] Figures 1 to 3 show such a transparent layered element known from the state of the art. For the clarity of the drawing, the relative thicknesses of the different layers have not been strictly respected. In addition, the possible variation in thickness of each layer constituting the central layer as a function of the slope of the texture has not been shown in the figures, it being understood that this possible variation in thickness does not impact the parallelism of the textured contact surfaces. Indeed, for each given slope of the texture, the textured contact surfaces are parallel to each other.

[0019] Throughout the description the transparent layered element is considered to be laid horizontally, with its first face oriented downwards defining a lower outer main surface and its second face, opposite the first face, oriented upwards defining an upper outer main surface; the meanings of the expressions "above" and "below" are thus to be considered in relation to this orientation. In the absence of a specific stipulation, the expressions "above" and "below" do not necessarily mean that the two layers are arranged in contact with each other. The terms "lower" and "upper" are used herein with reference to this positioning.

[0020] Note that the expression “between ... and ..." includes the limits in the interval.

[0021] The layered element 1 shown in Figure 1 comprises two outer layers 2 and 4, which are made of transparent dielectric materials having substantially the same refractive index n2, n4. Each outer layer 2 or 4 has a smooth main surface, respectively 2A or 4A, directed towards the outside of the layered element, and a textured main surface, respectively 2B or 4B, directed towards the inside of the layered element.

[0022] The smooth external surfaces 2A and 4A of the layered element 1 allow specular transmission of radiation at each surface 2A and 4A, i.e. the entry of radiation into an external layer or the exit of a

SUBSTITUTE SHEET (RULE 26) radiation from an outer layer without changing the direction of radiation.

[0023] The textures of the internal surfaces 2B and 4B are complementary to each other. As clearly visible in Figure 1, the textured surfaces 2B and 4B are positioned opposite each other, in a configuration where their textures are strictly parallel to each other. The layered element 1 also comprises a central layer 3, intercalated in contact between the textured surfaces 2B and 4B.

[0024] In the variant shown in Figure 2, the central layer 3 is single-layer and made of a transparent material which is either metallic or dielectric with a refractive index n3 different from that of the external layers 2 and 4. In the variant shown in Figure 3, the central layer 3 is formed by a transparent stack of several layers 31, 32,..., 3k, where at least one of the layers 31 to 3k is either a metallic layer or a dielectric layer with a refractive index different from that of the external layers 2 and 4. Preferably, at least each of the two layers 31 and 3k located at the ends of the stack is a metallic layer or a dielectric layer with a refractive index n31 or n3k different from that of the external layers 2 and 4.

[0025] In Figures 1 to 3, S0 denotes the contact surface between the external layer 2 and the central layer 3, and S1 denotes the contact surface between the central layer 3 and the external layer 4. Furthermore, in Figure 3, S2 to Sk denotes successively the internal contact surfaces of the central layer 3, starting from the contact surface closest to the surface S0.

[0026] In the variant of Figure 2, due to the arrangement of the central layer 3 in contact between the textured surfaces 2B and 4B which are parallel to each other, the contact surface S0 between the external layer 2 and the central layer 3 is textured and parallel to the contact surface S1 between the central layer 3 and the external layer 4. In other words, the central layer 3 is a textured layer having, at least locally, a uniform thickness e3, taken perpendicular to the contact surfaces S0 and S1.

[0027] In the variant of Figure 3, each contact surface S2,...,Sk between two adjacent layers of the stack constituting the central layer 3 is

SUBSTITUTE SHEET (RULE 26) textured and strictly parallel to the contact surfaces SO and S1 between the outer layers 2, 4 and the central layer 3. Thus, all the contact surfaces S0,S1, ...,Sk between adjacent layers of the element 1 which are either of different natures, dielectric or metallic, or dielectrics of different refractive indices, are textured and parallel to each other. In particular, each layer 31,32,...,3k of the stack constituting the central layer 3 has, at least locally, a uniform thickness e31,e32,...,e3k, taken perpendicular to the contact surfaces S0,S1,...,Sk.

[0028] As shown in Figure 1, the texture of each contact surface S0,S1 or S0,S1,...,Sk of the layered element 1 is formed by a plurality of textures recessed or projecting relative to a general plane TT of the contact surface.

[0029] Figure 1 illustrates the path of a radiation, which is incident on the layered element 1 on the side of the outer layer 2. The incident rays Ri arrive perpendicular to the outer layer 2. As shown in Figure 1, the incident rays Ri, when they reach the contact surface S0 between the outer layer 2 and the central layer 3, with a given angle of incidence θ, are reflected either by the metal surface, or due to the difference in refractive index at this contact surface respectively between the outer layer 2 and the central layer 3 in the variant of Figure 2 and between the outer layer 2 and the layer 31 in the variant of Figure 3. Since the contact surface S0 is textured, the reflection takes place in a plurality of directions Rr. The reflection of the radiation by the layered element 1 is therefore diffuse.

[0030] A portion of the incident radiation is also refracted in the central layer 3. In the variant of Figure 2, the contact surfaces S0 and S1 are parallel to each other, which implies according to the Snell-Descartes law that n2.sin(6) = n4.sin(6’), where 6 is the angle of incidence of the radiation on the central layer 3 from the outer layer 2 and 6’ is the angle of refraction of the radiation in the outer layer 4 from the central layer 3. In the variant of Figure 3, since the contact surfaces S0, S1, ..., Sk are all parallel to each other, the relationship n2.sin(6) = n4.sin(6’) from the Snell-Descartes law remains verified. Therefore, in both variants, since the refractive indices n2 and n4 of the two outer layers are substantially equal to each other,

SUBSTITUTE SHEET (RULE 26) the other, the rays Rt transmitted by the layered element are transmitted with a transmission angle 0' equal to their angle of incidence 0 on the layered element. The transmission of radiation by the layered element 1 is therefore specular.

[0031] Similarly, in both variants, radiation incident on the layered element 1 on the side of the external layer 4 is reflected diffusely and transmitted specularly by the layered element, for the same reasons as previously.

[0032] Examples of polymers suitable for the transparent substrate include, but are not limited to, polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN); polyacrylates such as polymethyl methacrylate (PMMA); polycarbonate; polyurethane; polyamides; polyimides; fluorinated polymers such as ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), ethylene chlorotrifluoroethylene (ECTFE), fluorinated ethylene-propylene copolymers (FEP); photocrosslinkable and/or photopolymerizable resins, such as thiolene, polyurethane, urethane-acrylate, polyester-acrylate resins.

[0033] Examples of glass substrates directly usable as the outer layer of the layered element include:

- glass substrates marketed by the Saint-Gobain Glass company in the SATINOVO® range, which are already textured and have on one of their main surfaces a texture obtained by sandblasting or acid etching;

- glass substrates marketed by the Saint-Gobain Glass company in the ALBARINO® S, P or G range or in the MASTERGLASS® range, which have a texture obtained by rolling on one of their main surfaces,

- high index glass substrates textured by sandblasting such as flint glass, for example, marketed by the Schott company under the references SF6 (n=1.81), 7SF57 (n=1.85), N-SF66 (n=1.92), P-SF68 (n=2.00).

SUBSTITUTE SHEET (RULE 26) [0034] Examples of core layers that may be intercalated between the outer layers include thin dielectric layers, selected from oxides, nitrides or halides of one or more transition metals, non-metals or alkaline earth metals, including layers of Si3N4, SnO2, ZnO, ZrO2, SnZnOx, AIN, NbO, NbN, TiO2, SiO2, AI2O3, MgF2, AIF3, or thin metal layers, including layers of silver, gold, copper, titanium, niobium, silicon, aluminum, nickel-chromium alloy (NiCr), stainless steel, or alloys of these metals.

[0035] The texturing of one of the main surfaces of the external layers can be obtained by any known texturing method, for example by embossing the surface of the substrate previously heated to a temperature at which it is possible to deform it, in particular by rolling by means of a roller having on its surface a texturing complementary to the texturing to be formed on the substrate; by abrasion by means of abrasive particles or surfaces, in particular by sandblasting; by chemical treatment, in particular acid treatment in the case of a glass substrate; by molding, in particular injection molding in the case of a thermoplastic polymer substrate; by etching.

[0036] The texturing of each contact surface between two adjacent layers of the layered element which are one dielectric and the other metallic, or which are two dielectric layers of different refractive indices, is of a random nature on the contact surface. Alternatively, the texturing of each contact surface between two adjacent layers of the layered element which are one dielectric and the other metallic, or which are two dielectric layers of different refractive indices, is of a periodic nature on the contact surface. Such texturing may be in the form, in particular, of cones, pyramids, grooves, ribs, wavelets.

[0037] In a known manner, a layered element as described above can be obtained via a manufacturing method comprising the following steps: a) providing (S1), as a lower external layer 2, a transparent substrate of which one of the main surfaces 2B is textured and the other main surface 2A is smooth; b) depositing S2 a central layer 3 on the textured main surface 2B of the lower external layer 2 either when the central layer 3 is formed by

SUBSTITUTE SHEET (RULE 26) a single layer, which is a dielectric layer with a refractive index different from that of the outer layer 2 or a metal layer, by depositing the central layer 3 conformally on said textured main surface 2B, or, when the central layer 3 is formed by a stack of layers (31, 32, ..., 3k) comprising at least one dielectric layer with a refractive index different from that of the first outer layer 2 or a metal layer, by depositing the layers (31, 32, ..., 3k) of the central layer 3 successively conformally on said textured main surface 2B; c) forming (S3) the upper outer layer 4 on the textured main surface 3B of the central layer 3 opposite the lower outer layer 2, where the lower 2 and upper 4 outer layers are made of dielectric materials having substantially the same refractive index.

[0038] The conformal deposition of the central layer 3, whether it is a single layer or formed by a stack of several layers, must preferably be carried out under vacuum, by magnetic field-assisted cathode sputtering (so-called "magnetron cathode sputtering"). This technique makes it possible in particular to deposit, on the textured surface 2B of the substrate 2, either the single layer in a conformal manner, or the different layers of the stack successively in a manner conforming to the texture. In other words, the implementation of this technique guarantees that the surfaces delimiting the different layers are parallel to each other.

[0039] Alternatively or in combination, the deposition of the central layer 3 can be carried out by screen printing and comprises: b1) The positioning of a screen printing screen opposite the textured main surface of the lower external layer, b2) The deposition on the screen printing screen, preferably using a squeegee, of a dielectric layer with a refractive index different from that of the external layers or of a metallic layer.

[0040] There is a need to make building glazing clearly visible to birds so that they do not accidentally hit it. A known solution to meet this need is to texture the outer face of the glazing to reveal a pattern visible to birds.

SUBSTITUTE SHEET (RULE 26) [0041] One identified drawback is that a blur is generated at the pattern level for an observer positioned inside the building, due to the diffuse transmission of light at this location. At least from an aesthetic point of view, this is not desirable.

[0042] There is therefore a need to provide multiple anti-collision glazing with an anti-collision pattern which, on the one hand, presents satisfactory visibility for a bird and which, on the other hand, limits or eliminates the blur which may be perceived by an observer positioned inside the building.

[0043] The present invention meets this need. More particularly, in at least one embodiment, the proposed technique relates to a multi-glazing unit suitable for being mounted in a building, on the facade and/or on the roof, comprising at least one exterior laminated glazing unit and one interior glazing unit separated by a gas gap and intended respectively to be arranged towards the outside and the inside of the building, said laminated glazing unit integrating a transparent layered element comprising two smooth external main surfaces, as well as:

- two outer layers, a lower outer layer and an upper outer layer, at least one of which is a lamination interlayer, each of which forms one of the two outer main surfaces of the layered element and which are made of dielectric materials having substantially the same refractive index, and

- a central layer interposed between the outer layers, this central layer being formed either by a single layer which is a dielectric layer with a refractive index different from that of the outer layers or a metallic layer, or by a stack of layers which comprises at least one dielectric layer with a refractive index different from that of the outer layers or a metallic layer, where a first part of each contact surface between two adjacent layers of the layered element which are one dielectric and the other metallic, or which are two dielectric layers with different refractive indices, is textured and parallel to the other textured contact surfaces between two adjacent layers, and where a second part of each contact surface between two layers

SUBSTITUTE SHEET (RULE 26) adjacent layers of the layered element are smooth, characterized in that said first part forms a textured pattern which contrasts with a background formed by the second part, said pattern being such that:

- each subset of said pattern is separated from an adjacent subset by a distance of less than 10.16 cm, preferably less than 5.08 cm,

- said pattern has a visibility score “SCORE” greater than or equal to 0 in relation to the background, and which satisfies the equation:

SCORE = 0.85*AS + 0.15*AL

Where AS is the chromatic contrast and satisfies the equation:

Where “wi” is the Weber fraction representing the sensitivity of a cone “i” in a bird’s retina,

Where “Afi” is the actual perceptual difference between said pattern (14) and the background (15), Where “fi” satisfies the equation: fi = In (Qi/Qi_ref) where Qi is the sensory response of a cone “i” of a bird’s retina and satisfies the equation:

Where “A” is the wavelength, “S” is the spectrum considered, “I” is the illuminant D65 according to the EN410 standard which describes the average solar spectrum and “Ri” is the sensitivity spectrum of said cone “i”,

Where “Qi_ref” corresponds to “Qi” with S equal to 1,

Where “AL” is the achromatic contrast and satisfies the equation:

AL = Af_achromatic/w_achromatic

Where "w_achromatic" equals 0.1 is the Weber fraction representing the achromatic sensitivity of a bird's retina,

Where “Af_achromatic” is the actual achromatic perceptual difference between said pattern (X) and the background (X),

SUBSTITUTE SHEET (RULE 26) Where "f_achromatic" satisfies the equation: f_achromatic = In (Q/Q_ref)

Where Q is the achromatic sensory response of a bird's retina and satisfies the equation:

Where “R” is the achromatic sensitivity spectrum, Where “Q_ref” corresponds to “Q” with “S” equal to 1.

[0044] For the purposes of the invention, multi-glazing means a plurality of glazings - laminated or not - spaced and separated by one or two gas or vacuum layers, depending on whether the multi-glazing is double or triple glazing. Clearly, the implementation of anti-collision multi-glazing is particularly useful in the construction sector.

[0045] According to the invention, the textured and reflective pattern formed within the layered element contrasts with the background in the sense that it is visually distinguished from it, at least from a bird's eye view. This background therefore corresponds to a surface defined in opposition to the reflective textured pattern, such as a negative of the latter.

[0046] The present invention resides firstly in the selection of an anti-collision pattern on the basis of a geometric criterion but also of a contrast criterion: the visibility score. This “SCORE” has excellent reliability, since it takes into account the optical perception of a bird in all its complexity, and in particular with regard to the sensitivity both chromatic and achromatic of its retina. A multi-glazing having a score greater than or equal to 0 thus makes it possible to satisfactorily limit the risk of a bird colliding with a glazing.

[0047] As detailed in the description, the implementation of a reflective central layer allows diffuse reflection at the level of the textured pattern, thus making it visible from a bird's eye view.

[0048] Finally, the integration of such an anti-collision pattern within a transparent element with diffuse reflection makes it possible to eliminate, or at least limit, the blurring that can

SUBSTITUTE SHEET (RULE 26) be perceived by an observer positioned inside the building, at the level of the pattern.

[0049] According to a particular embodiment, said laminated glazing incorporates an electrochromic stack.

[0050] For the purposes of the invention, an electrochromic stack, also called an electrochemical functional system with electrically controllable optical and/or energy properties, comprises at least one electrochemically active layer arranged between a first electrode coating and a second electrode coating, the at least one electrochemically active layer being adapted to switch, under the effect of an appropriate electrical supply and reversibly, between a clear state and a tinted state, the optical and/or energy properties of which vary. Such properties relate in particular to transmission, absorption, reflection, or even light diffusion. The induced variation generally occurs in the optical domain (infrared, visible, ultraviolet) and/or in other domains of electromagnetic radiation, hence the name device with variable optical and/or energy properties, the optical domain not necessarily being the only domain concerned.

[0051] As detailed in the description, the combination, within the multi-glazing, of an anti-collision pattern and an electrochromic stack has the advantage of increasing the contrast between the pattern and the background, as perceived by a bird. In other words, the anti-collision pattern appears more visible to a bird.

[0052] According to a particular embodiment, said electrochromic stack is in contact with said gas blade.

[0053] According to a particular embodiment, said electrochromic stack at least partly forms said central layer.

[0054] According to a particular embodiment, one of said external layers of the layered element is formed from an external substrate of said laminated glazing intended to be arranged towards the exterior of the building.

SUBSTITUTE SHEET (RULE 26) [0055] According to a particular embodiment, one of said external layers of the layered element is formed from an internal substrate of said laminated glazing intended to be arranged towards the interior of the building.

[0056] According to a particular embodiment, the Weber fraction “wi” representing the sensitivity of a cone “i” of the retina of a bird is selected according to the following specific values: W1 = 0.2; W2 = 0.14142; W3 = 0.14142; W4 = 0.1.

[0057] Such a set of Weber fractions corresponds to the typical sensitivity of a bird. The selection of such a set of Weber fractions therefore makes it possible to provide an anti-collision pattern whose visibility is excellent for the vast majority of avian species.

[0058] According to a particular embodiment, said pattern comprises wavy or rectilinear bands.

[0059] According to a particular embodiment, said pattern comprises points.

[0060] According to a particular embodiment, the invention also relates to a method comprising a step of manufacturing such multi-glazing.

[0061] According to a particular embodiment, the invention also relates to a method comprising a step of mounting in a building, on a facade and/or on a roof, at least one such multi-glazing unit.

[0062] Other characteristics and advantages of the invention will appear on reading the following description of particular embodiments, given as simple illustrative and non-limiting examples, and the appended figures, for which:

- Figure 1 is a schematic cross-section of a layered element known from the state of the art;

- Figure 2 is a larger scale view of detail I of Figure 1 for a first variant of the layered element known from the state of the art;

- Figure 3 is an enlarged view of detail I of Figure 1 for a second variant of the layered element known from the state of the art; and

- figure 4 is a schematic sectional view of multiple glazing according to a first particular embodiment of the invention,

SUBSTITUTE SHEET (RULE 26) - figure 5 is a schematic sectional view of multiple glazing according to a second particular embodiment of the invention,

- figure 6 is a schematic sectional view of multiple glazing according to a third particular embodiment of the invention.

[0063] The various elements illustrated by the figures are not shown to actual scale, the emphasis being on representing the general operation of the invention. In particular, the exact path of the incident solar rays within the multiple glazing is not detailed - in particular the angular deviations that can be generated at each interface - the diagram focusing more on the illustration of the diffuse reflection generated at the pattern 14, as opposed to the specular reflection generated at the background 15.

[0064] According to a first particular embodiment and as illustrated by Figure 4, the invention relates to a multiple glazing unit 7 suitable for being mounted in a building, on the facade and/or on the roof, comprising at least one exterior laminated glazing unit 8 and one interior glazing unit 9 separated by a gas blade 10 and intended respectively to be arranged towards the outside and the inside of the building. In Figure 1, a sun and a bird are positioned outside the building, while an observer is positioned inside. The exterior laminated glazing unit 8 incorporates a transparent layered element 1, which constitutes a lamination interlayer 16 and is interposed between an interior transparent substrate 11 coated with an electrochromic stack 12 in contact with said gas blade 10, and an exterior transparent substrate 14.

[0065] The transparent layered element 1 comprises, between a lower external layer 2 and an upper external layer 4, a reflective central layer 3.

[0066] According to the invention, a first part 14 of the interface between the lower external layer 2 and the upper external layer 4 is textured and forms, with the assistance of the reflective central layer 3, a textured pattern 14 which contrasts with a background 15 formed by a smooth part of this same interface.

[0067] In order to highlight the diffusing effect generated at the level of the pattern 14, two incident solar light rays R1 and R2 are illustrated in FIG. 4. The first ray R1 passes through the layered element 1 at the level of the bottom 15. The

SUBSTITUTE SHEET (RULE 26) central layer 3 being smooth at this location, as opposed to the textured interface of the pattern 14, the ray R1 is reflected there and transmitted specularly. The bird therefore does not see this background area 15. In contrast, the second ray R2 passes through the layered element 1 at the reflective textured pattern 14. The second ray R2 is then transmitted specularly - due to the structure of the layered element - and reflected diffusely, i.e. in a plurality of directions. The risk of generating blur in transmission is therefore limited, or even eliminated. A portion of the diffusely reflected rays can then be perceived by the bird, which distinguishes a pattern 14, by contrast with the background 15.

[0068] It should be noted that according to the invention, the laminated glazing “integrates” a layered element 1 in the sense that this layered element 1 can be intercalated between the inner 11 and outer 13 transparent substrates of the glazing, as illustrated in Figure 4, or alternatively that one of these two substrates (11, 13) constitutes one of the external layers (2, 4) of the layered element 1, as illustrated by Figures 5 and 6.

[0069] Thus, and according to a second particular embodiment illustrated by Figure 5, the external transparent substrate 13 plays the role of upper external layer 4 and comprises on a part of its internal face the textured pattern 14.

[0070] According to a third particular embodiment illustrated by Figure 6, it is the interior transparent substrate 11 which plays the role of lower external layer 2 and comprises on a part of its external face - that is to say intended to be oriented towards the exterior of the building - the textured pattern 14.

[0071] According to an alternative embodiment covered by the invention, the central layer 3 is made up of said electrochromic stack 12.

[0072] In order to better understand what is perceived by the bird, it is appropriate to detail the composition of the light spectrum perceived on the one hand at the level of the pattern 14, and on the other hand at the level of the background 15. Generally speaking, the spectrum observed by the bird can be considered as being the sum of the diffuse light leaving the building and the sunlight reflected diffusely by the multi-glazing.

SUBSTITUTE SHEET (RULE 26) [0073] At the bottom 15, which is a smooth interface, the reflection is specular and can therefore be neglected. As for the diffuse light leaving the building, it can be estimated that it corresponds to the sunlight transmitted into the building, diffusely reflected on the interior walls and retransmitted to the outside.

[0074] The “BKG” spectrum of background 15 as seen by the bird is therefore as follows: BKG = %T_window ^A 2 * %R_wall

Where %T_window is the overall transmission of the glazing,

Where %R_wall can be considered as a fixed value of 40%, assuming that the interior walls of the building reflect 40% of the solar radiation (albedo).

[0075] At pattern 14, which is a textured and reflective interface, the reflection is diffuse and must therefore be added. As for the diffuse light coming out of the building, it is transmitted diffusely by pattern 14.

[0076] The “PTRN” spectrum of pattern 14 as seen by the bird is therefore as follows: PTRN = %T_window * %R_wall + %R_pattern

Where %R_pattern is its diffuse reflection at said pattern 14.

[0077] According to the invention, the textured and reflective pattern 14 is characterized in that:

- each subset of said pattern 14 is separated from an adjacent subset by a distance of less than 10.16 cm, preferably less than 5.08 cm, and

- said pattern 14 has, in relation to the background 15, a visibility score “SCORE” greater than or equal to 0, and which satisfies the equation:

SCORE = 0.85*AS + 0.15*AL

[0078] According to this particular embodiment, the Weber fraction “wi” representing the sensitivity of a cone “i” of the retina of a bird is selected according to the following specific values: W1 = 0.2; W2 = 0.14142; W3 = 0.14142; W4 = 0.1

[0079] As previously indicated, the value of this SCORE depends directly on the sensory response (Q; Qi) of the bird's retina, one of the components of which "S" is the value of the observed spectrum.

SUBSTITUTE SHEET (RULE 26) [0080] This allows for a better understanding of the advantage provided by the implementation of an electrochromic stack 12, in combination with the anti-collision pattern 14. This electrochromic stack, by becoming tinted, will cause a significant reduction in the light transmission through the multi-glazing (%T_window). With reference to the previously given definitions of the spectra of pattern 14 (“PTRN”) and background 15 (“BKG”), it is understood that when the light transmission decreases, the first part of the spectrum calculation (%T_window ^A 2 * %R_wall) tends towards 0. The “BKG” spectrum of background 15 then tends towards 0, while the “PTRN” spectrum of pattern 14 tends towards the diffuse reflection value “%R_pattern” of pattern 14, hence an increase in the contrast perceived by the bird between pattern 14 and background 15. When the electrochromic stack switches to its tinted state, anti-collision pattern 14 is consequently more visible to the bird.

[0081] The visual functions Ri and R implemented for the present invention are detailed in the following Table 1 [Tables 1], as a function of the wavelength λ:

[0082] [Tables 1]

SUBSTITUTE SHEET (RULE 26)

SUBSTITUTE SHEET (RULE 26)

SUBSTITUTE SHEET (RULE 26)

SUBSTITUTE SHEET (RULE 26)

SUBSTITUTE SHEET (RULE 26)

SUBSTITUTE SHEET (RULE 26)

SUBSTITUTE SHEET (RULE 26)

SUBSTITUTE SHEET (RULE 26) Tl

[0083] Although particular embodiments of the present invention have been illustrated and described, it is obvious that various other changes and modifications may be made within the spirit and scope of the invention. The present text is therefore intended to cover in the appended claims all modifications falling within the scope of the present invention.

SUBSTITUTE SHEET (RULE 26)

Claims

[Claim 1] 1. Multi-glazing (7) suitable for being mounted in a building, on the facade and/or on the roof, comprising at least one exterior laminated glazing (8) and one interior glazing (9) separated by a gas blade (10) and intended respectively to be arranged towards the outside and the inside of the building, said laminated glazing (8) integrating a transparent layered element (1) comprising two smooth external main surfaces (2A, 4A), as well as:

- two external layers, a lower external layer (2) and an upper external layer (4), at least one of which is a lamination interlayer (16), which each form one of the two external main surfaces (2A, 4A) of the layered element and which are made of dielectric materials having substantially the same refractive index (n2, n4), and

- a central layer (3) intercalated between the external layers (2, 4), this central layer (3) being formed either by a single layer which is a dielectric layer with a refractive index (n3) different from that of the external layers or a metallic layer, or by a stack of layers (31, 32, ..., 3k) which comprises at least one dielectric layer with a refractive index different from that of the external layers or a metallic layer, where a first part (14) of each contact surface (SO, S1, ..., Sk) between two adjacent layers of the layered element which are one dielectric and the other metallic, or which are two dielectric layers with different refractive indices, is textured and parallel to the other textured contact surfaces between two adjacent layers, and where a second part (15) of each contact surface (SO, S1, ..., Sk) between two adjacent layers of the layered element is smooth, characterized in that said first part forms a pattern (14) textured which contrasts with a background (15) formed by the second part, said pattern (14) being such that:

- each subset of said pattern (14) is separated from an adjacent subset by a distance of less than 10.16 cm, preferably less than 5.08 cm, - said pattern (14) has, relative to the background (15), a visibility score

“SCORE” greater than or equal to 0, and which satisfies the equation:

SCORE = 0.85*AS + 0.15*AL

Where AS is the chromatic contrast and satisfies the equation:

Where “Afi” is the actual perceptual difference between said pattern (14) and the background

(15),

Where “fi” satisfies the equation: fi = In (Qi/Qi_ref) where Qi is the sensory response of a cone “i” of a bird's retina and satisfies the equation:

Where “Qi_ref” corresponds to “Qi” with S equal to 1,

Where “AL” is the achromatic contrast and satisfies the equation:

AL = Af_achromatic/w_achromatic

Where "f_achromatic" satisfies the equation: f_achromatic = In (Q/Q_ref) Where Q is the achromatic sensory response of a bird's retina and satisfies the equation:

[Claim 2] 2. Multi-glazing (7) according to claim 1, characterized in that said laminated glazing (8) incorporates an electrochromic stack (12).

[Claim 3] 3. Multi-glazing (7) according to claim 2, characterized in that said electrochromic stack (12) is in contact with said gas blade (10).

[Claim 4] 4. Multi-glazing (7) according to claim 2, characterized in that said electrochromic stack (12) at least partly forms said central layer (3).

[Claim 5] 5. Multi-glazing (7) according to one of claims 1 to 4, characterized in that one of said external layers (2, 4) of the layered element (1) is formed from an external substrate (13) of said laminated glazing (8) intended to be arranged towards the exterior of the building.

[Claim 6] 6. Multi-glazing (7) according to one of claims 1 to 4, characterized in that one of said external layers (2, 4) of the layered element (1) is formed from an internal substrate (11) of said laminated glazing (8) intended to be arranged towards the interior of the building.

[Claim 7] 7. Multi-glazing (7) according to one of claims 1 to 6, characterized in that the Weber fraction “wi” representing the sensitivity of a cone “i” of the retina of a bird is selected according to the following specific values: W1 = 0.2; W2 = 0.14142; W3 = 0.14142; W4 = 0.1.

[Claim 8] 8. Multi-glazing (7) according to one of claims 1 to 7, characterized in that said pattern (14) comprises wavy or rectilinear bands.

[Claim 9] 9. Multi-glazing (7) according to one of claims 1 to 8, characterized in that said pattern (14) comprises dots.

[Claim 10] 10. Method comprising a step of manufacturing a multi-glazing unit (7) according to one of claims 1 to 9. [Claim 11] 11. Method comprising a step of mounting in a building, on a facade and/or on a roof, at least one multi-glazing unit (7) according to one of claims 1 to 9.