Luminous laminated glazing with diffusing material

Abstract

The invention relates to a laminated luminous glazing with a diffusing material, the material comprising a transparent and diffusing layer having two main faces which comprises a glass sheet and / or a lamination interlayer.

Description

Title of the invention: luminous laminated glazing with diffusing material Technical field

[0001] The present invention relates to the technical field of light-extracting diffusing materials for luminous glazing, in particular with light-emitting diodes.

[0002] In the field of luminous glazing, it is known to manufacture optical waveguides, for example optical fibers, comprising microcavities included in the waveguide, so as to diffuse light transversely to the axis of the waveguide. The microcavities are manufactured by trapping gas bubbles during the manufacture of the waveguide. These microcavities have a spherical shape and a random distribution in the material.

[0003] There are also luminous glazings comprising light-emitting diodes and glazing, the diodes being arranged facing an edge of the glazing to couple radiation emitted by the diodes inside the glazing. To extract the radiation from the glazing, surface diffusing microstructures are known. However, these diffusing microstructures exhibit residual diffusion when the diodes are switched off, which impairs vision in transmission.

[0004] There is a need for luminous glazing with a material capable of extracting and diffusing radiation and which has excellent transparency along the normal to its surface. Statement of the invention

[0005] The invention relates to a luminous laminated glazing comprising a first glass sheet, a lamination interlayer comprising (at least) one lamination interlayer (in particular based on PVB), a second transparent sheet of mineral or polymer glass, and a second glass sheet, the glazing comprising a diffusing material, in particular a diffuse light extractor, which comprises a diffusing layer having two main faces, the layer having an (optical) refractive index n2, the layer being transparent (in a visible spectral range) and having two main faces.

[0006] According to the invention, said diffusing layer comprises, or is, the second glass sheet and / or said diffusing layer comprises, or is, the interlayer of lamination and the glazing then comprises an optical isolating element (in particular optical isolating coating on a substrate, in particular a polymer) with a refractive index n3 less than n2 between the first sheet and the interlayer of lamination.

[0007] According to the invention, the (diffusing) layer comprises at least one zone comprising microcavities included between the two main faces of the layer, the microcavities having an elongated shape having a larger dimension in a longitudinal direction and a smaller dimension transverse to the larger dimension, the larger dimension being greater than 50 micrometers, the smaller dimension being between 0.5 micrometers and 130 micrometers, the longitudinal direction of the microcavities being parallel or inclined relative to a normal (Z) to a main face of the layer at an angle of at most 15° and better still at most 10° or 5°, the microcavities having in a plane of incidence, including the normal, on said zone a spatial distribution determined by a separation distance between microcavities, in which a first ratio (R1) equal to the ratio between the larger dimension and the first separation distance (Sx) being defined,the first ratio is above a determined lower threshold, the material being capable of extracting and diffusing a determined percentage of XM diffusion of an internal light beam propagating between the two main faces in said plane of incidence, in particular at an angle of incidence, internal greater than or equal to a total internal reflection angle 0 TIR , to form at least one external diffused beam coming from at least one of the two main faces. The lower threshold is preferably equal to: .

[0008] Advantageously, a light source, preferably a set of light-emitting diodes, is arranged to generate and inject the internal light beam into the diffusing layer (10), in particular via collimation optics.

[0009] The angle of the collimated beam is for example 22±4° -relative to the plane of the glazing-.

[0010] The optical isolating element with a refractive index n3 lower than n2 is, for example, a fluoropolymer or a film of crosslinked material (based on acrylate, for example) or preferably a coating, porous (silica sol-gel, for example) or based on hollow nanoparticles (in particular silica), for example in an organic matrix (acrylate, etc.) or mineral, on a thermoplastic film, in particular PET, preferably thick at most 300 pm and better still at most 150 pm.

[0011] Advantageously, the XM diffusion percentage is greater than or equal to 0.01, preferably greater than or equal to 0.1.

[0012] Preferably in the case of a layer with free main faces, the lower threshold can be equal to: x M J(ÿ - l where m is the (optical) refractive index of air.

[0013] According to a particular aspect, the layer has an external cut-off angle (in air) 0c determined in said plane of incidence, and in which the first ratio is below an upper threshold which is equal to: where Xm represents a percentage of diffusion by transmission, where m is the refractive index air, the layer being able to diffuse a percentage less than x m of an external light beam incident on one of the two main faces with a first angle of incidence less than the determined external cut-off angle and the layer being capable of diffusing a percentage greater than x m of an external light beam incident on one of the two main faces with a second angle of incidence greater than the determined external cut-off angle.

[0014] The lower threshold is preferably greater than or equal to 0.1, 0.2, 0.3, 0.4, 0.5, 0.8, 0.9, 1.0, 1.1, 1.2.

[0015] Advantageously, the upper threshold is less than or equal to 100.

[0016] Advantageously, the microcavities have an angular distribution (distribution of angles relative to the normal) with an angle standard deviation of less than 10 degrees, and even at most 5 degrees or 2 degrees and / or with an angle value at the peak of the angular distribution of at most 15° and even at most 10° or 5°.

[0017] The microcavities are empty or filled with a gas, with a refractive index close to 1 lower than the refractive index n2 of the layer (in the core in the case of an index cladding).

[0018] In this text the expression “between” two values ​​includes these two values ​​or limits.

[0019] The spatial distribution of microcavities can be regular and even periodic or pseudo-periodic.

[0020] In a particular aspect, the spatial distribution of the microcavities is arranged in a one-dimensional or two-dimensional microcavity array.

[0021] In an exemplary embodiment, the one-dimensional microcavity network comprises lines parallel to the main face of the layer and for example parallel to a lateral or longitudinal edge of the layer or even oblique to these edges.

[0022] In an exemplary embodiment, the two-dimensional microcavity array comprises lines of microcavities and columns of microcavities parallel to the main face, the columns being perpendicular to the lines, the columns of microcavities being arranged with a second separation distance Sy between adjacent columns of microcavities (in another direction parallel to one of the two main faces), and a second ratio R2 is defined equal to the ratio between the largest dimension and the second separation distance between Sy between columns: R2 = L / Sy, the second ratio is above the determined lower threshold.

[0023] Advantageously, the microcavities have a separation distance (Sx, Sy) of between 20 micrometers and 1 millimeter along at least one direction parallel to the main face of the layer and possibly a second separation distance (Sy) is between 20 micrometers and 1 millimeter along another direction parallel to the main face of the layer, in particular normal to said first direction.

[0024] According to another particular aspect, the microcavities have an aspect ratio between the largest dimension and the smallest dimension greater than 1.5 or 5 and even at least 20, 50 or 100.

[0025] Advantageously, the microcavities are closed or alternatively form openings on the surface of at least one of the main faces (in particular face F3 of a glass sheet forming the layer in the case of laminated glazing or main face of an interlayer sheet oriented towards face F3, interlayer sheet forming the layer).

[0026] According to another particular and advantageous aspect, the transparent (diffusing) layer comprises or is a sheet, a mineral glass, in particular clear or extra-clear, based on (silico)soda-lime glass, aluminosilicate or borosilicate, or comprises or is a sheet of transparent polymer in particular based on polymethyl methacrylate, polycarbonate, polyurethane, polyesters, in particular a lamination interlayer sheet (thermoplastic or crosslinked), the interlayer sheet preferably being based on polyvinyl butyral, a vinyl acetate-ethylene copolymer or thermoplastic polyurethane.

[0027] According to another particular and advantageous aspect, the (diffusing) layer has a high visual transparency. The layer (sheet) may have a blur value H of less than or equal to 30%, 25%, or 20%, preferably less than 18%, 16%, 14%, 12% or 10% and / or a clarity value of greater than or equal to 85%, 90% or even 95%.

[0028] Advantageously, one or more of the following characteristics can be provided: - the microcavities comprise a sheath (of index), in particular with a thickness of between 5 and 50 pm, for example approximately 10 pm - the thickness of the layer is uniform or varies - the first ratio (R1 = L / Sx) is included in a range determined by a lower threshold and an upper threshold. For example, the first ratio is equal to 0.1; 0.2; 0.3; 0.4; 0.5; 0.8; 0.9; 1.0 or 1.1; 1.2, and preferably between 0.1 and 0.7 or even between 0.1 and 0.3 - the first ratio (R1 = L / Sx) is included in a first determined range and the second ratio (R2 = L / Sy) is included in a second determined range; The first threshold and the second threshold can be equal (when the steps P and Q are identical, or different. - the first ratio, respectively the second ratio, is for example equal to 0.1; 0.2; 0.3; 0.4; 0.5; 0.8; 0.9; 1.0; 1.1 or 1.2, and preferably between 0.1 and 0.7, or between 0.1 and 0.3. - the first separation distance Sx, respectively the second separation distance Sy, is between 20 pm and 1 mm, preferably between 50 pm and 500 pm, for example 100 pm, 150 pm or 200 pm, -the layer (sheet) is planar, that is to say that the two main faces are flat and parallel or the two main faces are flat and form an angle or the two main faces extend along non-flat but parallel surfaces.

[0029] Preferably, the glazing, especially road glazing, is curved.

[0030] For example, in a vehicle application, one of the principal faces is concave and the other principal face is convex, with the two principal faces being locally parallel to each other.

[0031] Alternatively, the two main faces extend along non-planar and non-parallel surfaces.

[0032] Preferably, the material of the layer (glass sheet or lamination interlayer) is clear and better extra-clear to limit absorption. By clear material for the glass sheet, respectively extra-clear, is meant a material which has a light transmission TL, under normal incidence for visible radiation between 400 nm and 700 nm, of 90.0%, respectively 90.9% for a thickness of 6 mm and / or a light transmission TL of 88.8%, respectively 90.4% for a thickness of 10 mm. In this document, the light transmission is calculated from the transmission spectrum between 380 nm and 780 nm taking into account illuminant A and the CIE 1964 reference observer (10°).

[0033] The diffusing layer (second glass sheet in particular) can be between 0.1 mm and 19 millimeters thick, and preferably between 0.5 mm and 6 mm. In vehicle (road) diffusing material applications, the thickness of the layer (glass sheet in particular) is generally between 1.6 mm and 2.1 mm. In building diffusing material applications, the thickness of the layer can be between 2 mm and 10 or 12 mm for facades or 2 mm and 6 mm for windows and partitions.

[0034] The diffusing layer (interlayer in particular) can be between 0.1 mm and 3 millimeters thick, and preferably between 0.3 mm and 1 mm.

[0035] The interlayer may comprise several layers (for example different shades and / or thicknesses) of which at least one is the diffusing layer.

[0036] Preferably, the microcavities have an elongated shape along a longitudinal direction. The microcavities have in particular a symmetrical shape of revolution around their longitudinal direction, for example ellipsoidal or cylindrical with a circular section. L denotes the largest dimension of a microcavity along its longitudinal direction and T the small dimension along a direction transverse to the longitudinal direction. The small dimension T is also called the diameter of the microcavity. The small dimension T is measured along a section of the microcavity, for example at mid-height of the largest dimension L. In other words, the largest dimension L is the length taken in a longitudinal section and the small dimension T is the width taken in a transverse section or the diameter of a circular section.

[0037] Advantageously, the small internal dimension T is less than 10 microns, and generally between 0.5 pm and 10 microns, generally greater than 1 pm, and preferably greater than 5 pm. largest dimension L is generally between 50 μm and 12 mm. The microcavities 5 have an aspect ratio RA = L / T, defined as the ratio between the largest dimension L and the small dimension T. According to one aspect of the present disclosure, the aspect ratio of a microcavity is above a lower threshold. According to one aspect of the invention, the aspect ratio of a microcavity (of the majority or even at least 80% or 90% or 100% of the microcavities) is preferably greater than 1.5, or 2, or 5, or 7 and in particular less than 20, or 15 or 10 (in particular by a Gaussian beam) and even at least 20, 50 or 100 (in particular by a Bessel beam which allows larger aspect ratios).

[0038] According to another aspect of the present disclosure, the aspect ratio of a microcavity is below an upper threshold. The aspect ratio of a microcavity may be within a range determined by the lower threshold and the upper threshold.

[0039] Advantageously, the microcavities are closed and have homogeneous dimensions, i.e. they preferably have the same largest dimension L ± 30% and the same small dimension T ± 30%.

[0040] In the case of microcavities comprising a cladding, the largest dimension of a microcavity is the largest external dimension of the cladding and the small dimension is the external dimension or diameter of the cladding perpendicular to the largest dimension. In this case, the small dimension may be between approximately 10 μm and 130 microns, preferably less than 50 microns, for example between 20 μm and 40 μm. And / or the largest dimension may be greater than or equal to 60 μm, and even between 60 μm and a few millimeters. The ranges of values ​​for the aspect ratio RA indicated above remain valid for microcavity structures 5 with an index cladding. An aspect ratio of, for example, 1.9; 2.2; 2.3; 2.7; 2.9 or even 3.0 is obtained. Alternatively, a thermal annealing process is applied after laser treatment, in order to homogenize the properties of the layer around the microcavities.In this case, no sheath with a refractive index different from that of the layer around the core of the microcavities is detected. The presence of a sheath around the core of the microcavities can be measured, for example by optical microscope or by phase contrast imaging.

[0041] The (laser-treated) area covers at least 50%, 60%, 70%, 80%, and even at least 90%, 95%, 99% of the surface of the (diffusing) layer, in particular extending over the entire surface. In one embodiment, the (laser-treated) area extends over a limited part (and in particular of predetermined shape) of the surface of the layer. For example, the surface of the area extends over a surface of geometric shape or in the form of a pictogram, number, letter, logo or drawing or any other shape (adapted to the desired application). The surface of the area can range from 1 mm 2 at 18 m 2 depending on the applications, generally around 1.5 m 2for a window or car glazing, and about 3-5 m 2 for a glass partition.

[0042] The spatial distribution of microcavities can have a variable density along a direction (parallel to one of the main faces) for example to allow homogeneous diffusion of light.

[0043] Laminated glazing, particularly vehicle or building glazing, may be part of multiple glazing (double or triple glazing).

[0044] Laminated glazing can be with a first sheet of clear glass, an interlayer of lamination (PVB or EVA), a second of clear or even extra-clear glass forming the diffusing layer.

[0045] Laminated glazing can be with a first sheet of clear glass, an interlayer of lamination (PVB or EVA) forming the diffusing layer, a second of clear and even extra-clear glass.

[0046] The invention relates to a luminous laminated glazing sold alone or with a light source. Also preferably a light source, in particular diodes (one or more diode strips), is arranged to generate and inject the internal light beam into the layer.

[0047] The light source can be removable, added, sold separately or in a kit. The light source is preferably a set of light-emitting diodes (on a printed circuit board support such as a PCB for "printed circuit board" in English for example flexible), in particular a straight or curved strip. Preferably the diodes are components mounted on the surface on the front face of a printed circuit board called a PCB board (with conductive tracks). The width (or length) of a diode with a single semiconductor chip, generally a square-shaped diode, is preferably at most 5mm. The width of the PCB board, in strip form, is preferably at most 5cm, better at most 2cm, and even at most 1cm.

[0048] One can have one or more light sources (peripheral, preferably offset by a window clear), several sets of diodes. The light source(s) can be mono- (emitting in blue, green, red, etc.) or polychromatic, or can be adapted or combined to produce for example white light, etc.; they can be continuous or discontinuous, etc. The light source can be extended linearly (rectangular strip like a bar of diodes) along one side of the glass or polymer sheet forming the layer (longitudinal edges) or split (with similar or distinct light e.g. different color intensity, driven independently or simultaneously) along both sides.

[0049] Luminous laminated vehicle glazing is particularly road (automobile, transport, truck, bus), rail (train, tram) or aerial, such as laminated side glazing (including quarter window), rear glazing (or rear window), a laminated roof, a laminated windscreen, or building glazing, particularly facade glazing, in particular window, partition, glass door.

[0050] In particular the second sheet facing the interior of a building or a (vehicle) passenger compartment, in particular the roof of a road vehicle.

[0051] The interlayer of lamination, in particular the layer forming the diffusing layer, is preferably in contact with the internal face F3 of the second glass sheet.

[0052] The luminous laminated glazing of a road vehicle comprises the first sheet of glass (in particular tinted or clear with a solar control layer, in particular silver-based), one or more interlayer lamination layers, the second transparent sheet of mineral or polymer glass, in particular clear or extra-clear, and the diffusing layer is in particular the second sheet facing the passenger compartment when the glazing is a roof, or even side glazing or a windshield.

[0053] In one embodiment, the laminated luminous glazing (in particular a road vehicle roof) comprises a light source, preferably a set of light-emitting diodes, for example which is optically coupled with the second sheet of preferably mineral glass, - thus forming an optical guide - and being said diffusing layer,: - by a light redirection element, -local-, reflective light redirection element and side third main face F3 or transparent light redirection element side fourth main face F4, in particular facing a peripheral internal masking layer on the first sheet (enamel, black etc.). - by all or part of the slice of the second sheet, - or by a wall of a hole (through in thickness, closed) of the second sheet (or several walls of several holes), in particular a hole offset by a clear window, facing a peripheral internal masking layer on the first sheet (enamel, black etc.).

[0054] In the case of light injection through the second edge, the light source is coupled to the edge of the second sheet, possibly in a peripheral opening notch. The light source can be housed in a polymer encapsulation as described in application WO2010049638, in particular in figure 15 or in figure 16, and even having a recess for removal or replacement of the source.

[0055] In the case of light injection via an internal wall of a hole, the second sheet, in particular made of mineral glass, comprises at least one peripheral hole (through or even blind in thickness, open on the fourth face F4 side at least) under an internal masking layer (outside the clear glass) and the light source is coupled to the wall of the second sheet delimiting the hole, preferably housed in the hole. The light source, in particular the diodes, may be in the hole. Examples of embodiments described in patents WO2018 / 178591 or WO2013 / 110885 may be cited in particular.

[0056] In the case of light injection by moving the light source to the passenger compartment side, preferably the peripheral light redirection element (prismatic) is: -reflector and third side F3 or transparent fourth main side F4. The light source is then opposite or offset from the fourth main face, in particular direct optical coupling or via an optic, in particular light source and light redirection element offset by a window clear, facing an internal masking layer.

[0057] Preferably, the luminous glazing comprises a light source, preferably a set of light-emitting diodes, in particular which is optically coupled with the second sheet of preferably mineral glass, which is said diffusing layer, with a main face called the third main face F3 oriented towards the lamination interlayer with a main face called the fourth main face F4 opposite, a light source facing the face F4 and coupled with a light redirection element, local, reflector light redirection element and on the third main face F3 side or transparent light redirection element on the fourth main face F4 side, in particular facing a peripheral internal masking layer on the first sheet.

[0058] The light redirection element (in one or more preferably connected portions) may be elongated (preferably perpendicular to the direction of propagation) thus having a length and having a width (preferably parallel to the direction of propagation). The light redirection element, for example, is rectangular in shape in the plane of the glazing. The prismatic element thus has an internal (longitudinal) edge and an external (longitudinal) edge, the most peripheral of the two edges.

[0059] In the reflective light redirection element is on the third main face F3 side, in particular on the periphery of the laminated glazing, the light redirection element being a reflective prismatic element comprising reflective prisms (oriented towards the third main face F3 or towards the second main face F2), capable of redirecting light from a light source (elongated, collimated, of low divergence), preferably a set of light-emitting diodes, positioned (facing the laminated glazing) on ​​the fourth main face F4 side (coupled with the light redirection element, positioned for injecting the light).

[0060] For example, the light redirection element may be a reflective prismatic element (film) comprising reflective prisms oriented towards the third main face F3 or towards the second main face F2 and even with an opposite so-called smooth (planar) face, preferably a smooth face and / or reflective prisms in adhesive contact with the lamination interlayer. The light redirection element may be a reflective prismatic film comprising a carrier film (in particular PET) and a layer, in particular a textured organic layer, forming the prisms topped with a reflective layer (conformal deposition). The prismatic film may be flexible to adapt to the curvature of the glazing. The refractive index of the prismatic film is, for example, 1.52 to 1.58. The refractive index of the carrier film (for example PET) and / or of the textured layer (for example acrylate) is, for example, 1.52 to 1.58.In particular, the reflective prisms are oriented towards the third main face F3 and in adhesive contact with a local (transparent) glue, in particular the light redirection element can be a reflective prismatic film comprising a possibly tinted carrier film (in particular opaque PET) and a layer in particular textured organic forming the prisms topped with a reflective layer (conformal deposition).

[0061] In embodiments, the reflecting prisms have an inclined face (redirecting, therefore receiving the light and redirecting it) forming an angle ranging from 30° to 50° with the smooth face of the reflecting prismatic element (with the plane of the reflecting prismatic element). The inclined surfaces of the prisms are in particular formed in the micrometric range. The length of the inclined faces (in section view) of the prisms is for example preferably from 10 pm to 250 pm, in particular preferably from 20 pm to 100 pm, for example approximately 30 pm. And / or the prisms may have a height of at least 1 pm and preferably at most 100 or 50 pm or 30 pm.

[0062] In a preferred embodiment of the invention, the prismatic element is a flexible polymer (or metallic) film. The film, in particular the prismatic polymer or substrate of the prisms (prismatic layer, organic for example) may have a thickness of less than 200 pm, 100 pm, 80 pm or 50 pm and even at least 30 pm. If the reflecting prisms are oriented towards the third face F3, the substrate film may be tinted and even opaque or opacified. For example, it is a tinted and even opaque (black) PET carrying the reflecting prisms. Preferably, the reflecting prismatic element has a total thickness of at most 500 pm or even 400 pm or 200 pm or 100 pm and even at least 30 pm.

[0063] In one embodiment of the invention, the prismatic element is a rigid (micro)textured plate, in particular made of glass, metal or plastic, for example it is a (micro)textured aluminum plate or a transparent (micro)textured plate with a reflective layer.

[0064] The luminous laminated glazing may include an optical module carrying the light source. For example, the optical module may be fixed to a peripheral seal, a profiled seal of the glazing (polymer encapsulation, etc.) and / or to the F4 face (outside the light injection zone). The optical module may include a face oriented towards the F4 face that is substantially horizontal.

[0065] In one or more embodiments, the light redirection element extends (laterally) between an external edge (longitudinal) and an internal edge (longitudinal, the internal edge being located downstream of the external edge in the main direction of light propagation, the luminous laminated glazing further comprising an absorbent element (black, with a molecular coloring agent, etc.), opposite the light redirection element and on the fourth main face F4 side (outside the injection zone) in particular elongated (perpendicular to the direction of propagation), and even which is a linear strip.

[0066] In an embodiment with the light source, the angle of the main emission direction of the light source (of the diodes) with the normal to the plane of the glazing (therefore the angle of incidence) is preferably at most 30° and even 25°, preferably with a divergence of at most 8°. In particular, the main emission direction relative to a normal to the fourth main face F4 emits a cone of light with an angle in the range 22° ± 4°, or even in the range 22° ± 2°. Preferably, a collimator can be inserted between the light source and the face F4. The light source can be oblique to the plane of the glazing, to the face F4. The prisms can have an inclined (redirecting) face with an angle of 35° to 50°, in particular 40° to 50° with the smooth face.

[0067] In another embodiment with the light source, the angle of the main emission direction of the light source with the normal to the plane (therefore the angle of incidence) is preferably 0° ± 5°, preferably with a divergence of at most 8°. In particular, the main emission direction with respect to a normal to the fourth main face F4 emits a cone of light with angles in the interval [0° ± 4°], or even in [0° ± 2°]. Preferably, a collimator can be inserted between the light source and the face F4. The light source can be (substantially) parallel to the plane of the glazing. The prisms can have an inclined (redirecting) face with an angle of 30° to 40°, in particular 35° to 40°, with the smooth face.

[0068] Preferably, a collimator is placed between the light source and the F4 face. In the simplest case, the collimator is a kind of converging lens, with the light source preferably being arranged in its focal point. The collimator can be made of glass or transparent plastic, in particular polycarbonate (PC) or polymethyl methacrylate (PMMA). The collimator is preferably attached to an optical module carrying the light source. If the light source is designed as a (linear) arrangement of light-emitting diodes, a separate collimator can be provided for each light-emitting diode. However, it is preferable to use a common collimator for all the LEDs. For example, in the case of a linear LED array, a strip-shaped collimator can be used whose length is at least equal to the length of the LED array. The output face of the collimator can be substantially horizontal.

[0069] The laminated luminous glazing may incorporate one or more functional elements (non-adhesive) above the second sheet of glass forming the diffusing layer or the interlayer forming the diffusing layer in particular: electronic device (more or less extensive) chosen from at least one of the following devices: sensors; electrically controllable device with variable tint (electrochromic based) and / or variable diffusion (liquid crystal based), a photovoltaic device, in particular with one or more connected photovoltaic cells (in one or more lines), - functional polymer film, for example infrared reflective film (solar control, silver stacking, replacing a layer on the F2 face), and / or heating for example polymer substrate with an electroconductive (transparent) coating, in particular with a thickness of at most 0.4 or 0.2 mm, in particular local or preferably extending over almost the entire glazing (and over the entire clear glass), with the electroconductive coating on the F2 face or F3 face

[0070] Examples of electrically controllable devices are PDLC functional elements (PDLC = Polymer Dispersed Liquid Crystal), known for example from DE102008026339A1 or the elements SPD functional elements (SPD = Suspended Particle Device), known for example from EP0876608B1 and WO2011033313A1. There are also electrochromic functional elements, known for example from EP3702572A1 or EP2917159A1.

[0071] According to one characteristic, an electrically controllable device is a liquid crystal cell, in particular incorporating dichroic dyes, in particular the liquid crystal cell is a host-guest cell called "GH" (for "Guest-Host in English) or a polymer-based cell such as a PDLC cell (for "Polymer-Dispersed Liquid Crystal" in English), or a PNLC cell (for "Polymer Network Liquid Crystal" in English) or a PSLC cell (for "Polymer stabilized liquid crystal" or a DDPDLC cell (for "Dye-Doped Polymer-Dispersed Liquid Crystal" in English).

[0072] A DDPDLC cell has a "discontinuous" phase of microscopic liquid crystal (LC) droplets in the "continuous" phase of the polymer matrix. The shapes, dimensions and distribution of the microscopic droplets depend on many physicochemical parameters (and the phase separation process used). When switched off, the DDPDLC scatters light in the OFF mode due to the presence of microdroplets with a different refractive index than the polymer matrix. And the DDPDLC absorbs light due to the presence of dichroic dyes in the LC phase. The combination of both properties leads to a dark and hazy (opaque) appearance.When lit, the dyes and LC are oriented perpendicular to the plane of the film and therefore the light is not (or slightly) scattered, the refractive index corresponds to that of the polymer matrix, the absorption cross section is low, which leads to a transparent and clear appearance. Examples of DDPDLC cells are described in patent application CN117567875.

[0073] A liquid crystal cell called a host-guest cell (or GH), with variable tint (light to dark state and vice versa), comprises an electroactive layer comprising a liquid volume of liquid crystals mixed with dichroic dyes (dissolved), electroactive layer between a support, in particular dielectric and transparent, upper (electrode) comprising an upper electrode, in particular transparent, surmounted by an upper alignment layer and a lower support (electrode) in particular dielectric and transparent comprising a lower electrode, in particular transparent, surmounted by a lower alignment layer, the electroactive layer being between the lower and upper alignment layers, the lower support being closer to the F3 face than the upper support, in particular the host-guest cell being surrounded by an intercalary lamination frame layer (based on PVB).A guest host cell is advantageous because it has very fast switching times, high contrast between light and dark states, low blur, and a hue that can be neutral.

[0074] The invention also relates to a method for manufacturing a diffusing material, in particular a diffuse light extractor, comprising a diffusing layer, comprising at least one following laser treatment step - applying a laser beam to a transparent layer having two main faces, in particular a glass or polymer sheet, the laser beam being incident on one of the two main faces, the laser beam being focused in the layer between the two main faces, the laser beam scanning at least one area of ​​the layer with a determined scanning speed, the laser beam comprising laser pulses of duration less than or equal to 100 picoseconds, the laser beam having an energy per pulse, a repetition frequency and a scanning speed adapted to generate an arrangement of microcavities between the two main faces of the layer in said at least one zone, in particular the microcavities (5) being closed or forming openings on the surface of one of the main faces, the microcavities having an elongated shape having a larger dimension in a longitudinal direction and a smaller dimension transverse to the larger dimension, the larger dimension being greater than 50 micrometers, the smaller dimension being between 0.5 micrometers and 130 micrometers, the longitudinal direction of the microcavities being parallel to a first alignment axis parallel or inclined relative to a normal to one of the two main faces in particular at an angle of at most 15° or even 10° or 5°, the arrangement of microcavities being arranged with a first separation distance between adjacent microcavities in at least one direction transverse to the longitudinal direction of the microcavities,in which a first ratio R1 is defined equal to the ratio between the largest dimension and the first separation distance between microcavities, the first ratio is above a determined lower threshold. The lower threshold is preferably equal to, , where 0 TIR is the angle of total internal reflection and XM a determined percentage of scattering.

[0075] Advantageously, the energy per pulse is between 1 microjoule and 100 microjoules and the repetition frequency is less than or equal to 2 megahertz.

[0076] Advantageously, the laser beam operates in a laser-material interaction domain between a refractive index modification domain of the transparent material and an ablation domain of the transparent material.

[0077] The method may include a step of spatially shaping the beam to adjust the shape of the laser beam, generally Gaussian, for example to form a Bessel beam (focused on a focal line) or to focus the beam (on a focal point), for example using a standard lens or an f-theta lens generally used in scanner systems.

[0078] According to a particular embodiment, the method comprises a heat treatment step following the laser treatment step, in particular of at least 500°C for a layer which is a glass sheet, in particular monolithic glazing. The heat treatment may be thermal tempering of the glass.

[0079] According to a particular embodiment, the layer is an interlayer of lamination, the application of the laser beam is in said layer forming part of a laminated glazing.

[0080] In this document, the term femtosecond pulse is understood to mean a pulse with a duration less than or equal to 100 picoseconds, preferably less than or equal to 1 picosecond, generally between 1 fs and 800 fs, for example approximately 300 fs. The laser pulses are emitted at an inter-pulse repetition frequency or repetition frequency, noted Frep. The repetition frequency Frep is generally between 1 kHz and several MHz, for example 1.5 MHz or 2 MHz. According to a variant, the femtosecond pulses are emitted in bursts, with a repetition frequency between pulse packets lower than the inter-pulse repetition frequency. Each pulse packet may comprise from 1 to 20 pulses, preferably between 1 and 5 pulses.

[0081] Adjusting the number of pulses, the repetition frequency Frep, the packet repetition frequency, the scanning speed and the focusing plane allows the regularity of the microcavities to be controlled. It is thus possible to generate microcavities having in a plane parallel to one of the main faces of the layer a random spatial distribution, or in lines, circles (to not favor any direction) or points on a two-dimensional network, following a rectangular mesh grid for example.

[0082] Of course, the various features, variants and embodiments of the invention may be combined with each other in various combinations to the extent that they are not incompatible or mutually exclusive. Brief description of the drawings

[0083] In addition, various other characteristics of the invention emerge from the appended description given with reference to the drawings which illustrate non-limiting embodiments of the invention and where:

[0084] [Fig. 1] is a schematic sectional view of a material according to the invention;

[0085] [Fig. 2] is a schematic view of the manufacturing method according to the invention;

[0086] [Fig. 3] is a diagram illustrating different laser-matter interaction domains between a femtosecond pulsed laser and a layer as a function of the energy per pulse (on the abscissa) and the repetition frequency (on the ordinate);

[0087] [Fig. 4] includes microscope images of examples of material comprising an arrangement of microcavities in top view (left) and in section (right);

[0088] [Fig. 5] is a microscope image of a second example of a material comprising an arrangement of microcavities in top view;

[0089] [Fig. 6] is a schematic cross-sectional representation of a material comprising an arrangement of microcavities modeled as cylinders, and illustrating the cut-off angle;

[0090] [Fig. 7] is an example of a light-emitting diode module showing the extraction and diffusion of the radiation emitted by the diodes, in lighting mode;

[0091] [Fig. 8] is a view illustrating transmission through the same LED module as in Fig. 7 with the LEDs off.

[0092] [Fig. 9] is a sectional view of luminous laminated glazing in a first embodiment incorporating the diffusing material in particular as described in Figures 1 to 8

[0093] [Fig. 10] is a detail view of the light injection used in this first embodiment

[0094] Fig. 11] is a front view of the glazing of Figure 9

[0095] [Fig. 12] is a sectional view of luminous laminated glazing in a second embodiment incorporating the diffusing material in particular as described in Figures 1 to 8

[0096] [Fig. 13] is a front view of the glazing of Figure 12

[0097] [Fig. 14] is a sectional view of luminous laminated glazing in a third embodiment incorporating the diffusing material in particular as described in Figures 1 to 8

[0098] [Fig. 15] is a sectional view of luminous laminated glazing in a fourth embodiment incorporating the diffusing material in particular as described in Figures 1 to 8.

[0099] [Fig. 16] is a sectional view of luminous laminated glazing in a fifth embodiment incorporating the diffusing material in particular as described in Figures 1 to 8.

[0100] [Fig. 17] is a sectional view of a device used in the fifth embodiment.

[0101] [Fig. 18] is a sectional view of a device usable in the fifth embodiment.

[0102] It should be noted that in these figures the structural and / or functional elements common to the different variants may have the same references. Detailed description

[0103] In this document, the term "transparent or essentially transparent layer or material" means a layer or material capable of transmitting a light beam in a visible spectral range with little scattering. Such a transparent layer or material may nevertheless exhibit absorption in this visible spectral range or in another visible spectral range.

[0104] A diffusing material is understood to mean a material capable of diffusing at least part of a light beam in the visible spectral range.

[0105] Preferably, the diaper material is clear and better extra-clear to limit absorption.

[0106] In Figure 1, a cross-sectional view of a material 110 is schematically shown. The material 110 is formed from a transparent layer which is a sheet 10 having two main faces 1, 2 and side faces 3, 4. As described below, an arrangement of microcavities 5 is formed inside the transparent layer 10 between the two main faces 1, 2. The main faces extend over a surface adapted according to the application, for example to form the roof of a road vehicle (automobile). The side faces 3, 4 extend along the thickness of the material. The side faces 3, 4 are also called slices of the material. In other words, the thickness of the material corresponds to the distance between the two main faces 1, 2. The thickness of the material can be uniform. Layer 10 is planar, that is to say that the two main faces 1, 2 are flat and parallel.Alternatively, the two main faces 1, 2 are planar and form an angle. Alternatively, the two main faces 1, 2 extend along non-planar but parallel surfaces. For example, in an application to a motor vehicle roof, one of the main faces 1, 2 is concave and the other main face is convex, the two main faces 1, 2 being locally parallel to each other. Alternatively, the two main faces 1, 2 extend along non-planar and non-parallel surfaces.

[0107] The layer 10 which is used in the manufacture of the material 110 may be a sheet of mineral glass or transparent polymer. The sheet is preferably made of mineral glass, soda-lime (silico)glass, aluminosilicate or borosilicate. The sheet may be thermally toughened glass. The sheet may be made of transparent polymer, in particular polymethyl methacrylate (PMMA), polycarbonate (PC), polyester or polyurethane (PU).

[0108] The material 110 comprises a sheet-like layer 10 and microcavities 5 (described below) formed within the layer 10. More specifically, the microcavities 5 are formed and arranged in the layer 10 during the manufacture of the material 110.

[0109] Alternatively, the material comprises several layers and even several sheets assembled to form a stack, one of the layers or sheets comprising microcavities. For example, the microcavities are formed in a layer such as a sheet usable in a laminated glazing comprising a polymer lamination interlayer sheet, (for example polyvinyl butyral (PVB), EVA or PU), fixed between a glass sheet and a glass or polymer sheet. The microcavities are preferably formed in one of the glass sheets in a laminated glazing. Alternatively, the microcavities are formed in a polymer lamination interlayer sheet fixed between two glass sheets.

[0110] The material may comprise several layers attached to each other, with the microcavities being arranged in one of the layers of the material.

[0111] The present disclosure also relates to a glazing comprising the material. The glazing may be single glazing, laminated glazing or multiple glazing, such as double glazing or triple glazing.

[0112] In Figure 1, an orthonormal XYZ reference frame is shown. For clarity of the description, without being in any way limiting, the two main faces 1, 2 of the layer 10 extend for example parallel to an XY plane.

[0113] Main face 1 has a normal of 11 to its surface and, respectively, main face 2 has a normal of 12 to its surface.

[0114] The material 110 comprises microcavities 5 included in the transparent and diffusing layer 10 between the two main faces 1, 2, microcavities 5 being filled with a gas or vacuum, with a refractive index close to 1, less than n2. Advantageously, the microcavities 5 are entirely included in the layer 10 of the material 110. The microcavities 5 are located in the layer of the material 110 (or even over a fraction of the thickness, more or less equidistant from the main faces). For example, the microcavities 5 are at a distance of between 200 micrometers and several millimeters from each of the main faces 1, 2 of the layer 10. Advantageously, the microcavities 5 are closed. The method of manufacturing the microcavities 5 does not modify the surface of the main faces 1, 2 which remain flat. Alternatively, the microcavities 5 form openings on the surface of one of the main faces 1, 2.

[0115] The microcavities 5 have an elongated shape along a longitudinal direction. The microcavities 5 generally have a symmetrical shape of revolution around their longitudinal direction, for example ellipsoidal or cylindrical with a circular section. We denote L the largest dimension of a microcavity structure 5 along its longitudinal direction and T the small dimension along a direction transverse to the longitudinal direction.

[0116] In some embodiments, each microcavity 5 comprises a solid cladding surrounding the empty core. The cladding has a refractive index different from the refractive index of the layer. The cladding has a thickness of between 5 and 50 μm, for example 10 μm. The presence of a cladding around the core of the microcavities can be measured, for example by optical microscope or by phase contrast imaging. The outer diameter or diameter of the cladding is, for example, of the order of 25 to 30 μm. In the case of microcavities comprising a cladding, the largest dimension of a microcavity structure is the largest dimension of the cladding and the small dimension is the dimension or diameter of the cladding perpendicular to the largest dimension.

[0117] In addition, the microcavities 5 are arranged in the layer in a particular arrangement. The longitudinal direction of the microcavities 5 included in the layer 10 is parallel to a first alignment axis 6. The first alignment axis 6 is parallel or inclined relative to a normal 11, 12 to one of the two main faces 1, 2. According to one embodiment, illustrated in FIG. 4, the microcavities 5 are arranged in parallel lines separated by an average separation distance Sx. In other words, the lines of microcavities 5 are arranged with a periodic pitch noted P along an X axis. The pitch P from one line to the other along the X axis is equal to the sum of the separation distance Sx and the small dimension T of the microcavities 5. In a given incidence plane, we note a first ratio R1 = L / (PT) = L / Sx, defined as being the ratio between the largest dimension and the separation distance Sx between lines of microcavities.According to the present disclosure, the first ratio (R1 = L / Sx) is within a range determined by a. lower threshold and an upper threshold. For example, the first ratio is equal to 0.1; 0.2; 0.3; 0.4; 0.5; 0.8; 0.9; 1.0 or 1.1; 1.2, and preferably between 0.1 and 0.7 or even between 0.1 and 0.3.

[0118] According to another embodiment, illustrated in Figure 5, the microcavities 5 are arranged in parallel lines separated by a separation distance Sx and in parallel columns separated by a separation distance Sy. In other words, the lines of microcavities 5 are arranged with a periodic pitch denoted P along an X axis and the columns of microcavities 5 are arranged with a periodic pitch denoted Q along a Y axis. The pitch P from one line to the other along the X axis is equal to the sum of the separation distance Sx and the small dimension T of the microcavities 5 and the pitch Q from one column to the other along the Y axis is equal to the sum of the separation distance Sy and the small dimension T of the microcavities 5. A second ratio R2 = L / Sy is noted, defined as being the ratio between the largest dimension and the separation distance Sy between columns of microcavities.According to the present disclosure, the first ratio (R1 = L / Sx) is included in a first determined range and the second ratio (R2 = L / Sy) is included in a second determined range. The first threshold and the second threshold may be equal (when the steps P and Q are identical, or different. The first ratio, respectively the second ratio, is for example equal to 0.1; 0.2; 0.3; 0.4; 0.5; 0.8; 0.9; 1.0; 1.1 or 1.2, and preferably between 0.1 and 0.7, or between 0.1 and 0.3. The separation distance Sx, respectively Sy, is between 20 pm and 1 mm, preferably between 50 pm and 500 pm, for example 100 pm, 150 pm or 200 pm.

[0119] According to the present disclosure, the material makes it possible to extract diffuse light from guided light propagating by total internal reflection and which is scattered on the microcavities. In addition, the material is transparent to an incident external beam at normal incidence, weakly scattering up to an angle of incidence equal to a cut-off angle and more scattering above this cut-off angle 0c.

[0120] Without being bound by a theory, the first ratio R1, respectively the second ratio R2, is above a lower threshold equal to: — tan — e T — IRwhere XM represents a percentage of light scattering propagating inside the layer perpendicular to the rows and, respectively, to the columns of microcavities, with an internal angle of incidence greater than or equal to the angle of total internal reflection and which is scattered on the microcavities. For example, the first ratio (R1 = L / Sx) is greater than or equal to 1.145 XM for a glass sheet having a refractive index of 1.5 arranged in air. In an exemplary embodiment, it is desired to obtain a percentage XM of at least 10% or 30% of light guided at the angle of total internal reflection scattered towards the outside for rows of microcavities having a pitch P between 100 pm and 200 pm, a largest dimension L of approximately 55-60 pm, a small dimension D of approximately 7 pm and a cladding with a diameter of approximately 26 pm.

[0121] Particularly advantageously, the first ratio R1, respectively the second ratio R2, is below an equal upper threshold where x m represents a maximum percentage of light scattered on the microcavities from external light refracted inside the layer in a plane of incidence perpendicular to the rows, respectively to the columns, of microcavities up to the cut-off angle 0c of the material, n2 represents the refractive index of the layer, m the refractive index of air. For a given cut-off angle 0c, we want the percentage of scattered light to be less than x m when the angle of incidence of the external light beam is less than the cut-off angle 0c and the percentage of scattered light greater than x m when the angle of incidence of the external light beam is greater than the cut-off angle 0c.

[0122] The microcavities 5 are generated in a layer 10, as described above, by a laser process. The laser process operates in a relatively narrow operating parameter range as illustrated in connection with Figures 2 and 3. For example, a solid-state laser, fiber laser or laser diode type laser is used. In one example, a Yb:YAG / Nd:YAG solid-state laser or a Yb:YVO4 laser is used.

[0123] In a first step 60, a femtosecond pulse laser beam is generated.

[0124] For example, a Yb:YAG solid-state laser emitting at a wavelength of approximately 1030 nm is used. The wavelength of the laser is chosen in the transparency range of the layer. In one example, the duration of a laser pulse is approximately 300 fs at a wavelength of 1030 nm. The repetition frequency Frep of the pulse packets is, for example, 2 MHz or a sub-multiple of 2 MHz. The inter-pulse frequency is, for example, 40 MHz. Each pulse packet may comprise from 1 to 20 pulses, preferably a number less than or equal to 5 pulses, for example 2 pulses.

[0125] The laser beam has an energy per pulse E. More particularly, as illustrated in Figure 3, we place ourselves in a particular and narrow laser-matter interaction domain so as to generate microcavities 5 inside a material.

[0126] The method includes an optional spatial beam shaping step 61 to adjust the shape of the laser beam, for example to form a Bessel beam. The advantage of a Bessel beam is that it has a small diameter over a large distance, which allows the focus to be maintained over several tens, hundreds of microns, or even on the order of a millimeter along the propagation direction. A Bessel beam makes it possible to create microcavities with a larger aspect ratio RA or to better control the aspect ratio RA. In contrast, for a Gaussian beam, there is a compromise between the waist diameter and the propagation distance over which this diameter is maintained.

[0127] In a step 62, the femtosecond pulsed laser beam is applied to a transparent layer to be treated. The laser beam is focused inside the layer 10, between the two main faces. The size of the focused laser beam is between 55 and 60 μm in diameter (defined by the “waist” or neck of a Gaussian beam). The laser beam is generally applied to a solid layer, for example through the face 1 of the layer 10. The laser beam is generally applied at an angle of incidence of less than 10 degrees and preferably at an incidence normal to the face 1 of the layer 10.

[0128] In a step 63, a scanning of the laser beam is carried out relative to an area of ​​the layer to be treated. Alternatively, in step 63, the layer is moved relative to the laser beam which is fixed to produce the scanning of the laser beam over the area to be treated. The scanning can be carried out step by step, so as to apply the laser beam at determined points of the layer, the points being regularly spaced from one another, for example along lines or following a matrix of lines and columns. Alternatively, the scanning is carried out during the laser shots, for example to generate microcavities along lines regularly spaced from one another. Steps 60, (if applicable 61), 62 and 63 are iterated until the entire area of ​​the layer to be treated is covered. A material 110 is thus obtained comprising microcavities 5 arranged inside the layer 10.

[0129] In certain exemplary embodiments, each microcavity structure 5 is surrounded by an envelope or sheath. For example, in FIG. 4, in a top view under an optical microscope, a microcavity structure appears as a black dot surrounded by a circle that corresponds to the boundary of the envelope. The solid envelope has a structure and / or an optical index of refraction that is different from the structure and / or the refractive index of the transparent layer, respectively. This envelope is supposedly induced by compressive stresses in the layer during the laser process. These compressive stresses can be relaxed via a thermal annealing step that makes the envelope disappear. Optionally, after finishing processing the material, the process includes a heat treatment step 65 or thermal annealing. For example, the heat treatment is carried out at a temperature of 650°C for 3 minutes. This heat treatment increases the transmission of the material at an angle of incidence normal to the main faces 1,2.

[0130] Generally speaking, the application of a femtosecond pulsed laser beam to a transparent layer is likely to result in different laser-material interaction processes depending on the layer and the laser operating parameters. Laser operating parameters are understood here to mean all the laser parameters including in particular the energy per pulse, the duration of the laser pulses, the number of pulses, the inter-pulse and / or inter-pulse burst repetition frequency, the wavelength of the laser beam, its spatial shape, the fixed-frequency or packet pulse regime, the scanning speed of the laser beam on the layer, and the orientation of the laser beam.

[0131] In particular, the application of a femtosecond laser to a transparent layer is likely to produce different effects on the layer, as illustrated in Figure 3. Figure 3 represents different laser-matter interaction domains between a femtosecond laser beam focused inside a sheet of clear soda-lime glass (here for example an SGG Planiclear glass from the company Saint-Gobain) as a function of two selected laser parameters: the energy E per pulse (on the abscissa) and the repetition frequency Frep (on the ordinate). In this example, the other laser parameters are assumed to be constant. In this example, a Yb:YAG type laser is used, for example a Satsuma HP Laser 2from the company Amplitude Systèmes, which generates pulses with a duration of approximately 300 fs, at a wavelength of 1030 nm, the fixed frequency pulse regime with a scanning speed of 5 mm / s. In Figure 3, no effect is observed in the sheet in a domain 50 located below a first energy threshold per pulse, here approximately 2 pJ / pulse, this first threshold being approximately independent of the repetition frequency Frep. Beyond the first energy threshold per pulse and below a second energy threshold per pulse, the creation of colored centers in the sheet in a domain 51 is observed, under the microscope or visually. For example, at Frep = 500 kHz, the second energy threshold per pulse is approximately 4.5 pJ / pulse.The second pulse energy threshold decreases progressively as a function of increasing repetition frequency Frep up to 2 MHz, where the second pulse energy threshold is very close to the first pulse energy threshold. In a domain 52, located above the second pulse energy threshold and below a third pulse energy threshold, in a domain 52, an evolution of the sheet is observed under the microscope, without modification of its color. According to the scientific literature, this evolution corresponds to a modification of the refractive index in the sheet. The third pulse energy threshold decreases sharply as a function of increasing repetition frequency Frep up to 2 MHz, where the third pulse energy threshold is very close to the second pulse energy threshold.This refractive index modification range 52 covers a wide range of operating parameters, with the energy per pulse ranging from about 5 pJ / pulse to 20 pJ / pulse at the repetition frequency Frep. of 250 kHz, or between about 3 pJ / pulse and 9 pJ / pulse at the Frep repetition frequency of 666 kHz, or between about 2 pJ / pulse and 6 pJ / pulse at the Frep repetition frequency of 1 MHz and about 2.5 pJ / pulse at the Frep repetition frequency of 2 MHz. There is also a high energy per pulse and high Frep repetition frequency domain 54, in which ablation of the sheet, i.e. removal of material, is observed. However, the present disclosure highlights a narrow domain 53 of parameters, located between the domain 52 of modification of the refractive index of the layer and the domain 54 of ablation of the sheet, in which the creation of microcavities inside the sheet is observed, without removal of material. This microcavity generation domain 53 is located between the third pulse energy threshold and a fourth pulse energy threshold.The ablation range 54 of the sheet lies beyond the fourth pulse energy threshold. The fourth pulse energy threshold decreases sharply with increasing Frep repetition frequency up to 2 MHz, where the fourth pulse energy threshold is about 4 pJ / pulse. This range 53 thus covers a narrow range of operating parameters, the energy per pulse being about 22 pJ / pulse at the Frep repetition frequency of 250 kHz, or between about 13.5 pJ / pulse and 14.5 pJ / pulse at the Frep repetition frequency of 500 kHz, or between about 6 pJ / pulse and 7.5 pJ / pulse at the Frep repetition frequency of 1 MHz and between about 2.5 pJ / pulse and 4 pJ / pulse at the Frep repetition frequency of 2 MHz.Nevertheless, it is observed that this domain 53 widens when the repetition frequency Frep increases, which makes it possible to define a domain sufficiently wide to ensure the stability of the process, for example for a repetition frequency Frep greater than or equal to 1 MHz.

[0132] Figure 4 illustrates a top view (left) and a sectional view (right) of materials obtained following a femtosecond laser treatment according to the present disclosure. The material 10 is here formed from a sheet of soda-lime glass with main faces 1, 2 that are planar and parallel. The thickness of the sheet 10 between the main faces 1, 2 is approximately 4 mm. In this example, a Yb:YAG laser is used which generates pulses having a duration of approximately 300 fs, at a wavelength of 1030 nm, the pulse regime at a burst repetition frequency of 2 MHz, with an energy per pulse burst of 21% of 10 pJ distributed between the different pulses of the burst. A scanner device allows scanning along lines parallel to the Y axis spaced at a pitch P of approximately 50 pm to 300 pm with a scanning speed of, for example, 5 mm / s.Advantageously, the lines are arranged regularly, that is to say that the pitch P from one line to the next along the X axis is constant on the treated surface. This produces a material 110 comprising lines forming a one-dimensional periodic structure. The scanner device comprises an f-theta lens which focuses the laser beam through the main face 1 at mid-distance between the main faces of the sheet. In the top view, microcavities 5 are observed aligned along the scanning lines of the laser beam. In the sectional view, it is observed that the microcavities 5 are elongated parallel to a first alignment axis 6. The microcavities 5 with their sheath 15 have here, on average, a large dimension L of between approximately 300 pm and 600 pm and a small dimension D of approximately 25 pm to 50 pm. Sx denotes the average separation distance, here along the X axis, between two adjacent lines of microcavities 5.The step P from one line to another along the X axis is equal to the sum of the average separation distance Sx and the small dimension D of the microcavities 5.

[0133] The longitudinal end of the microcavities 5 is at a distance of about 200 pm to 300 pm from the main surface 1. The other longitudinal end of the microcavities 5 is at a distance of about 1 mm from the main surface 2. The microcavities 5 here form neither hollows nor bumps on the main faces 1 and 2 of the material 1 10 which are flat.

[0134] The scanner device parameters are adjusted so that the distance Sx between two adjacent lines of microcavities is less than or equal to the product of the major dimension L and a factor depending on the refractive index of the sheet and the target scattering level. The ratio L / Sx determines a cut-off angle in a plane of incidence parallel to the XZ plane, as detailed below.

[0135] In Figure 4, we observe a very high regularity of the microcavities 5 concerning not only their dimensions L and D, but also their position in the material between the two main faces 1, 2 and also the orientation of their longitudinal axis. This high regularity is allowed by the laser process. The adjustment of the laser scanning parameters makes it possible to adjust the spatial distribution of the microcavities 5. The adjustment of the number of pulses, the repetition frequency Frep, the repetition frequency of the packets, the scanning speed and the focusing plane make it possible to control the regularity of the microcavities 5. It is thus possible to generate microcavities 5 having in an XY plane a random spatial distribution, or in lines, in circles (to not favor any direction) or in points on a two-dimensional network, following a rectangular mesh grid for example.

[0136] As indicated previously, the scanning direction and speed also make it possible to adjust the orientation and inclination of the first alignment axis 6 of the microcavities 5. It is thus possible to adjust a determined inclination angle of the first alignment axis 6 of the microcavities 5 relative to the normal 11, 12 to the main face 1, 2 of the material 110.

[0137] Figure 5 illustrates another example of spatial distribution of microcavities 5 in a material 110 following a two-dimensional network. In this example, layer 10 is a 4 mm thick soda-lime glass sheet (SGG Planiclear), the femtosecond laser applies pulses having a duration of approximately 300 fs, at a wavelength of 1030 nm. The laser beam is focused in the middle of the layer in the thickness direction.

[0138] In Figure 5, the laser beam is scanned point by point in rows and columns, with the laser beam interrupted between each point. The laser beam is static here during each irradiation. The laser operates here with a burst energy of 21% of 10 pJ, two pulses per burst, with a burst repetition frequency of 2 MHz. The microcavities 5 appear spontaneously at the points arranged in a regular mesh pattern in rows and columns, here with a pitch P of 100 pm and a pitch Q of 100 pm. This produces a distribution of the microcavities 5 following a periodic lattice of a square mesh with a side of 100 pm. In this example, the rows are spaced by a distance Si of approximately 90 pm and the columns are spaced by a distance S2 of approximately 90 pm. In addition, we observe a very high regularity of the transverse dimensions of the microcavities 5 over the entire laser-treated area.In this example, the laser beam being static during the irradiation of each point, the microcavities 5 are aligned in a direction perpendicular to the surface of the main faces 1, 2. Alternatively, the lines are arranged periodically with a pitch P greater than or equal to 30 pm, for example 50 pm or 200 pm, and the columns are arranged periodically with a pitch Q greater than or equal to 30 pm, for example 50 pm or 200 pm. Preferably, the pitch P is equal to the pitch Q, so as to allow homogeneous diffusion of the light in both directions X and Y. However, in certain applications, the pitch P is different from the pitch Q.

[0139] We note S y the average separation distance between two adjacent microcavities in the same column. The pitch Q between microcavities in a column along the Y axis is equal to the sum of the average distance S yand the small dimension T of the microcavities 5. Advantageously, the average distance S y , here along the Y axis, between two adjacent microcavities of the same column is less than or equal to the product of the large dimension L and a factor depending on the refractive index of the layer and the targeted diffusion level. This second ratio L / S y determines the cut-off angle in another plane of incidence parallel to the YZ plane, as detailed below. By choosing a pitch Q different from the pitch P, a different cut-off angle can be obtained depending on the plane of incidence.

[0140] The laser-treated area advantageously extends over the entire surface of the material. In other embodiments, the treated area extends over a limited part of the surface of the material. For example, the surface of the treated area extends over a surface of geometric shape or in the form of a number, letter, logo or drawing or any other shape suitable for the desired application. The surface of the treated area can range from 1 mm 2 at 18 m 2 depending on the applications, generally around 1.5 m 2 for a window or automotive glass.

[0141] We will now describe the optical properties and operation of the material 110 in connection with figures 1, 6 and the different examples of spatial distribution of the microcavities 5. The material 110 has both angularly selective diffusion and transmission properties, and allows extraction of diffused light.

[0142] In the example of figures 1 and 6, the first alignment axis 6 of the microcavities 5 is parallel to the normal 11 to the main face 1. The microcavities 5 are arranged in lines parallel to a second alignment direction oriented along the Y axis. The XZ incidence plane of figure 1 comprises the first main axis 6 and the X axis transverse to the second alignment direction.

[0143] The material 110 is adapted to receive an internal light beam 30 propagating between the two main faces 1, 2. The light beam 30 is emitted by a light source, for example a light-emitting diode 7 arranged opposite a lateral face 3 of the material. The light beam 30 forms an angle, denoted ALPHA, with the normal 11 to the main face 1. The angle ALPHA is greater than or equal to an angle of total internal reflection determined by the refractive index n2 of the material of the layer and the refractive index m of air. For example, for a glass in air and a light beam 30 in the visible, the angle of total internal reflection is approximately 41 degrees. In the absence of microcavities 5, the internal light beam 30 propagates for example by multiple internal reflection between the two main faces 1, 2. The internal light beam 30 then propagates in the layer 10 without absorption and without diffusion in the direction of the X axis.Alternatively or complementary, another light source is arranged to inject another light beam propagating between the two main faces 1, 2 in the Y direction.

[0144] As illustrated in Figure 1, the microcavities 5 are configured and arranged to receive a portion of the internal light beam 30 propagating in the layer 10 between the two main faces 1, 2 in the propagation direction X. The light beam incident on the microcavities 5 is diffused in different directions and forms a diffused internal beam 35. A portion of the diffused internal beam which forms an angle less than the total internal reflection angle with the normal to the main face 1 is extracted from the material 110 and forms an external diffused beam 41 coming from the main face 1. Similarly, another portion of the diffused internal beam which forms an angle less than the total internal reflection angle with the normal to the main face 2 is extracted from the material 110 and forms a diffused external beam 42 coming from the main face 2. On the other hand, the parts of the diffused internal beam which form an angle greater than the total internal reflection angle with the normal to the main face 1, respectively 2, remain trapped and can again be diffused on other microcavities 5. We thus obtain a diffused external beam 41, respectively 42, extracted from the material 110 through the main face 1, respectively the main face 2.The properties of the scattered external beam 41, respectively 42, in particular the intensity distribution in the XZ incidence plane are a function of the material of the layer, of the spatial distribution (in particular the average separation distance Sx between lines of microcavities along the X axis) of the microcavities 5, of the first ratio R1 = L / (PT) = L / Sx, between the largest dimension and the average separation distance Sx between lines of microcavities. It follows that the external beam 41, respectively 42 scattered outside the material 110 forms an angle less than an angle corresponding to the angle of total internal reflection with the normal 11, respectively 12 to the main face 1, respectively the main face 2. The external beam 41, respectively 42 scattered is therefore scattered essentially around the axis Z, that is to say transversely to the direction of propagation, along the axis X, of the internal light beam 30 injected into the layer 10.

[0145] In a plane transverse YZ to the plane of figure 1, the response of the material for the extraction and diffusion of light depends on the spatial distribution of the microcavities 5. Let us first consider a first example where the microcavities 5 are arranged in lines parallel to the Y axis, the distribution of the microcavities 5 along the Y axis not being ordered.

[0146] In another example, the microcavities 5 are arranged in columns parallel to the X axis and Sy denotes the average separation distance between two columns. In this case, in a manner analogous to the description of diffusion in the XZ plane of incidence, the internal light beam propagating by total internal reflection undergoes diffusion under certain conditions. The external beam diffused in the transverse plane YZ to the plane of FIG. 1 is extracted from the material 110 through the main face 1, respectively 2. Similarly, in the YZ plane of incidence, the properties of the diffused external beam 41, respectively 42, are a function of the material of the layer, of the spatial distribution (in particular the average separation distance Sy between points or between columns of microcavities along the Y axis), and in particular of the second ratio R2 = L / (Q- T) = L / Sy, between the largest dimension and the average separation distance Sy between microcavities along the Y axis.

[0147] The material 110 comprising elongated and ordered microcavities has advantages for the extraction and diffusion of light compared to a material comprising randomly dispersed bubbles. It makes it possible to extract and diffuse a portion of the light propagating inside the layer by total internal reflection, and thus obtain a diffusion of light in a direction transverse to the main faces of the material 110, which thus makes it possible to obtain more efficient lighting.

[0148] The material also has special transmission properties. Generally, transmission depends on the density of the microcavities and their small dimension T. Advantageously, the material has low scattering by transmission, through the material, of an external beam incident on one of the main faces at an angle of incidence lower than a given external cut-off angle.

[0149] Consider an external light beam 20 incident on the main face 1 in the plane of incidence XZ of figure 1. The external light beam 20 transmitted through the main face 1 forms a light beam 21 refracted in the material 10, then exits through the opposite main face 2, in the form of a beam transmitted light beam 22. When the external light beam 20 is parallel to the normal 11 to the main face 1, the refracted light beam 21 is also parallel to the normal 11. In the example of FIG. 1, the refracted light beam 21 is then parallel to the first alignment axis 6 of the microcavities 5. If the first alignment axis 6 is inclined, the direction in which the glazing is transparent corresponds to the direction aligned with the first alignment axis 6, taking into account the refraction. The transverse dimension T of the microcavities 5 is between 0.5 micrometers and 130 micrometers and preferably greater than or equal to 10 pm. It follows that the transmitted light beam 22 through the material 110 parallel to the first alignment axis 6 undergoes practically no diffusion on the microcavities 5.More generally, as long as the angle between the refracted light beam 21 and the first alignment axis 6 of the microcavities remains less than an internal cut-off angle 0r, the transmitted light beam 22 is not or is only slightly diffused by the microcavities 5. This remains valid when the first alignment axis 6 is inclined relative to the normal 11 to the main face 1. On the other hand, when the angle between the refracted light beam 21 and the first alignment axis 6 is greater than or equal to the internal cut-off angle, the refracted light beam 21 is likely to be diffused by the microcavities 5. The internal cut-off angle 0r corresponds to an external cut-off angle 0c (see figure 6).

[0150] The presence of the microcavities of small transverse dimension aligned in a direction normal to the surface has the effect that the material 1 10 has a high visual transparency under normal incidence or when the angle of incidence of an external light beam incident on one of the main faces of the layer is less than a cut-off angle 0c determined in the plane of incidence. The visual transparency can be evaluated by means of a haze meter, which measures the intensity in transmission TL, the haze value, noted H (or "haze" in English) and the clarity value, noted C (or "clarity" in English) of the material. For example, a HazeGard Plus haze meter from the company BYK-Gardner is used to carry out measurements according to the ASTM D1003 standard.The haze meter measurements in the table below were performed at normal incidence for different samples, in which microcavity lines are formed, at a scanning speed of 5 mm / s and with a separation distance between microcavity lines of 10Oprn, 150 pm and 200 pm respectively. The microcavities have a largest dimension L of about 60 pm ± 5 pm, a small dimension T of about 7 pm ± 5 pm and an index cladding diameter of about 27 ± 1 pm. The microcavities are here fabricated in a layer having an optical index of refraction of about 1.5. [Table 1]

[0151] As the separation distance between microcavity lines increases, blur decreases and clarity increases.

[0152] In addition, the presence of microcavities elongated in a direction normal to the surface has the effect of observing an external cut-off angle 0 C, beyond which the material 110 has a lower visual transparency. By modeling the microcavities in the form of cylinders of circular section, having a height equal to the largest dimension L and a diameter equal to the transverse dimension T, the separation distance between microcavities being noted Sx = P - T, where P is the pitch between lines of microcavities, and x m the percentage of light scattered on the microcavities, we calculate the cut-off angle 0 C external according to the following formula: The percentage x of scattered light considered here is understood in relation to the external light incident on one of the main incident faces, transmitted directly through the material without scattering.

[0153] For a given L and an xm of 30%, we choose the cut-off angle to be 34 degrees for a P pitch of 100 pm, respectively 49 degrees for a pitch of 150 pm, or 75 degrees for a pitch of 200 pm.

[0154] To have the highest transparency at all observation angles, we seek to have the highest possible cut-off angle for a given xm (the lowest possible acceptable).

[0155] The material has a high visual transparency for an external light beam 20 incident on one of the main faces 1, 2 with an angle of incidence less than the external cut-off angle in the plane of incidence and the material 110 has a strong diffusion towards the outside of the material for an internal light beam 30 forming an angle ALPHA greater than an internal cut-off angle with the longitudinal direction 6 of the microcavities in the plane of incidence.

[0156] The internal cut-off angle is determined by the ratio between the large dimension L and the distance Sx between lines along the X direction. The internal cut-off angle corresponds to an external cut-off angle of the external light beam 20 incident on the main face 1. The relationship between the internal cut-off angle and the external cut-off angle is determined by the Snell-Descartes laws as a function of the refractive index of the material of the layer. Consequently, the external light beam 20 is transmitted without diffusion when it forms an angle smaller than this external cut-off angle in a plane determined by the first alignment axis 6 and a direction X transverse to the microcavity lines 5.

[0157] The higher the average separation distance Sx, respectively Sy, between microcavities, the higher the transmission, especially in off mode for a lighting module.

[0158] The material 110 of the present disclosure finds applications in particular in the manufacture of a lighting device such as luminous glazing (of a building, of a vehicle) in particular monolithic or laminated or multiple, for example comprising a light-emitting diode (or LED) module, as illustrated in transmission in the lit state in Figure 7 and in the unlit state in Figure 8.

[0159] The lighting device 100 here comprises a material 110 which is a glazing combined with a plurality of light-emitting diodes 7, 17 here arranged on a side face or edge of the material. An area of ​​the material comprises microcavities 5 arranged in lines as described above. This area of ​​the material appears lighter when the LEDs 7 are lit due to the extraction and diffusion of light through one of the faces of the material. The diffused light beam 41 is thus observed. Another area 8 of the material is devoid of microcavities. This other area 8 appears dark due to the absence of diffusion of light although the LED 17 illuminates the interior of this area 8 between the main faces 1, 2 of the material. analogously to the LEDs 7 illuminating the microcavity area 5. However, the light from the LED 17 remains inside this area 8 and is not extracted or diffused outside the material 110 in this area without microcavities.

[0160] In Figure 8, all LEDs 7, 17 are off. In this case, no scattered beam is observed. On the contrary, a background image 9 can be clearly observed by transmission through the material. The transmission transversely to the main faces is excellent and free of scattering, in other words with little blurring and high transmission and clarity.

[0161] A lighting device such as luminous glazing (of a building, vehicle) may be based on a distribution of microcavities 5 along lines or in lines and columns. Alternatively, the distribution of microcavities has a variable density along a direction, for example, to allow homogeneous diffusion of light.

[0162] Of course, various other modifications may be made to the invention within the scope of the appended claims.

[0163] [Fig. 9] is a sectional view here side of luminous laminated glazing 1000 in a first embodiment incorporating the diffusing material in particular as described in figures 1 to 8. [Fig. 10] is a detail view of the light injection used in this first embodiment. [Fig. 11] is a front view of the glazing of figure 9.

[0164] The luminous laminated glazing 1000 can be illuminated by injecting and redirecting light. It can be, for example, a laminated glass roof of a car, but the invention is not limited to this example. It is noted that the elements shown in Figure 9, as in all the Figures, are not shown to scale, to facilitate the visibility of these elements and the understanding of the invention. The curved laminated glazing 1000 includes: - a first sheet of glass T, for example rectangular (of dimensions 1600x1100 mm for example), with a tinted composition (VENUS VG10 or TSA 4+ glass marketed by the company Saint-Gobain Glass with a light transmission or TL of approximately 28%), for example with a thickness equal to 2.1 mm, with a first main face 11' corresponding to face F1, a second main face 12' called face F2 and an edge (longitudinal slices 101 and 101'), of which face F2 is optionally coated with a transparent functional coating (for example heating), or even face F1; or alternatively a clear glass with an infrared-reflecting coating (silver stack) forming solar control - a second transparent sheet 2', preferably mineral glass, here of the same shape and dimensions as the first sheet 1', forming internal glazing, on the passenger compartment side, having a third main face 13 or face F3 and a fourth main face 14 or face F4, and an edge (longitudinal slices 20' and 20”), for example a sheet of sodium-calcium silico glass, extra-clear such as Diamant glass marketed by the company Saint-Gobain Glass with a TL of at least 91%, with a thickness equal to, for example, 2.9 mm, glass with a refractive index of the order of 1.52 to 600 nm or Optiwhite glass of 1.95 mm, or Sunmax glass of 2.05 mm; and - between face F2 and face F3, a transparent 3' lamination interlayer, with a 30' edge here longitudinal aligned or possibly offset from the longitudinal edges 101, 10T towards the center of the glass (therefore set back).

[0165] The lamination interlayer 3 comprises at least one interlayer, called the lower interlayer 3', of PVB (with plasticizers, at least 10% by weight and at most 30%, or even 20%), clear (as transparent as possible and with as few optical defects as possible), of 0.38 mm or 0.76 mm (in one or two sheets) in adhesive contact with the F3 face, with a refractive index of approximately 1.48 at 600 nm, for example PVB with a TL equal to 99.9%. Alternatively, the lower interlayer is based on PVB with little or no plasticizers (in particular less than 5% by weight), in particular Kuraray SkyViera film or Optical grade Thin Film, for example with a thickness of at most 100 pm or 25 pm. Alternatively, the lower interlayer is based on crosslinked polymer adhesive material, in particular adhesive polyacrylate film or adhesive silicone film, in particular at least 30 pm, or it is an adhesive coating (polyacrylate, etc.) obtained by deposition on the third F3 face.

[0166] The glazing 1000 further comprises an internal masking layer 5' (optional) forming a masking frame delimiting a window clear 50' (daylight), for example rectangular with straight edges (see Figure 13). For example, the internal masking layer 5 is: - black enamel on the F2 face; or - a black ink, on one of the faces of the upper interlayer, preferably the face facing face F2, ink preferably based on PVB with black pigments if upper interlayer is PVB.

[0167] In certain embodiments, the luminous laminated glazing may comprise another masking layer (not shown in Figure 13), called the inner, peripheral, opaque masking layer, on the fourth main face F4. In particular, the inner masking layer may be congruent or of a width less than the width of the inner masking layer 5' and absent in the injection zone and even opposite the light redirection element.

[0168] For the light function, the luminous laminated glazing 1000 further comprises, preferably masked from the outside by the internal masking layer 5', an optical module 7 comprising a light source 7', for example light-emitting diodes (here with front emission) mounted on a support for example a printed circuit board (PCB), arranged opposite (or offset) the fourth main face F4 14.

[0169] The module 7 may also carry a collimator 72' (notably common to diodes) and comprising a preferably opaque housing 71' (black etc.) which may for example be fixed to the glazing, by a mechanical fastener. The module may be in optical contact with the glazing by means of a foam. The collimator may also be fixed to the face F4. In particular, the light source 7' may be lateral emitting. Alternatively, the light source T may be one or more primary sources (diodes, etc.) coupled directly to a guide. Diodes emitting white or colored light may be chosen for ambient lighting, reading lighting, etc. Several series of diodes (one edge, two edges, three edges, over the entire periphery) may be provided, controlled independently and even in different colors.

[0170] In addition, the luminous laminated glazing 1000 comprises, on the third main face side F3 13, a local, peripheral light redirection element 8', which is a prismatic reflective film 8', for example of rectangular shape in the plane of the glazing.

[0171] The prismatic film of Figure 10 extends between an external longitudinal edge 80' and an internal longitudinal edge 80”, the external edge 80' being located upstream of the internal edge 80” in the direction of propagation of the light rays (noted P), with: - a flat part 81' (substrate for example PET preferably at most 100 μm) glued or fixed by suction to the third face F3 13; and - a textured layer (by embossing, etc.), partially or even entirely textured, forming prisms 82' which have become reflective by a reflective layer 83', for example metallic (by conformal deposition on the prismatic textured surface).

[0172] Here the 8' prismatic reflective film is glued with a 60' glue on the third main face F3. It can also be held by suction.

[0173] The (micro)prisms are schematically in section in the form of inclined faces forming right triangles but the angle of the inclined faces can be adjusted to better redirect the second glass sheet 2' towards the extraction means 5, here internal.

[0174] For example, the 8' reflective prismatic film comprises a transparent thermoplastic film, for example based on polyethylene terephthalate (PET), on which transparent prisms are formed from a polyacrylate (resin crosslinked for example by UV), and a metallic layer (conformal deposition, for example aluminum) makes it possible to form the reflective prisms.

[0175] The reflective prismatic film 8' is in adhesive contact, here with the lower interlayer 3'. Alternatively, the reflective prismatic film 8' is a monolithic polymer film, for example preformed, on which the reflective layer 83' or a textured metallic film is applied.

[0176] The light from the light source 7 is refracted in the second glass 2', in the prismatic reflector film 8' and then redirected at a given angle towards the light extraction means 56. The light rays propagate by total internal reflection at the level of the face F4 14, and: - for some, by total internal reflection at the interface between the lower interlayer of the lamination and the second sheet 2 up to the light extraction means 5, - and even for others at the interface of the lower lamination interlayer and an optical insulation layer 17, and reach the light extraction means 5 (case of figures 14, 15, 16).

[0177] The glazed roof 1000 comprises an internal masking layer 5' forming a masking frame delimiting a window clear 50' (daylight) here rectangular with straight edges. Any local modification of the edges 50' is possible (gradient of points, wider zone, etc.), and other shapes for the window clear 50' are possible. The glazed roof 1000 has a length L1 in the longitudinal direction X and a width L2 in the transverse direction Y (orthogonal to the longitudinal direction X). The transverse direction Y corresponds to the main direction P of propagation of the light in the light guide. The glazed roof 1000 also comprises a module carrying a light source 7 forming a longitudinal strip along a longitudinal edge 101, 20' of the glazed roof 100 (parallel to the edges or at an angle, in particular with inclined edges, trapezoid-shaped glazing, etc.). The prismatic film 8' also forms a longitudinal strip (bar), in particular rectangular.The glass roof 1000 further includes three light extraction “lines” 5 arranged side by side.

[0178] In this example, the laminated car roof 1000 is rectangular and curved (in one or more directions). In particular, for a fixed roof (canopy) the width L2 is 85 cm to 1.4 m and the length L1 is 75 cm to 1.65 m. The dimensions of the internal masking layer 5' may be such that: - the masking width at the front (side edge towards the driver's seat) is for example 10 to 40 cm; - the masking width at the rear (rear side edge towards the rear passenger seats) is for example 5 to 25 cm; and Tl - the masking width on the long sides (longitudinal edges) is for example 5 to 20 cm, identical or different width for the two long sides.

[0179] [Fig. 12] is a sectional view of luminous laminated glazing 2000 in a second embodiment incorporating the diffusing material in particular as described in Figures 1 to 8. [Fig. 13] is a front view of the glazing of Figure 12.

[0180] This second embodiment differs from the first embodiment 1000 in that a second module 7” carrying a second light source and a second light redirection element 8” are placed on the side of the second longitudinal edge 101 ', 20”. This may be a vehicle roof, for example a car. Compared to the vehicle roof of Figure 13, the glazed roof 2000 of Figure 13 comprises the second optical module carrying a second light source 7' forming a second longitudinal strip on the edge side 101 ', 20”. The glazed roof 2000 of Figure 13 further comprises a second prismatic film 8' also forming a longitudinal strip on the edge side 101 ', 20”.

[0181] It is noted that, in all embodiments, the light redirection element 8 may be a single element, or a plurality of abutting elements (i.e. placed end to end, without discontinuity).

[0182] [Fig. 14] is a sectional view of luminous laminated glazing 3000 in a third embodiment incorporating the diffusing material in particular as described in Figures 1 to 8.

[0183] The luminous laminated glazing 3000 differs in that it further comprises a substrate 16 coated with a low-index layer 17 forming an optical isolator, positioned at the interface between the lower interlayer 3' and the upper interlayer 3”. The layer 17, in particular, makes it possible to increase the quantity of guided light. Typically, the layer 17 has a refractive index lower than the refractive index of the interlayer 3'. The coated substrate therefore comprises an optical isolator coating 17 on one of the main front faces (facing face F2), or alternatively or rear Fb (facing face F3) as here, then called the coated (or deposited) face of a transparent film 16, preferably polymer and preferably distinct from a fluoropolymer. The coated substrate 16, 17 is sandwiched between the upper interlayer 3” and the lower interlayer 3', extends throughout the clear of glass and beyond, its edge being under the 5' masking layer.

[0184] The optical isolating coating 7 is made of material, preferably polymer, comprising a matrix of submillimeter thickness Ei, of at least 400 nm and better 500 nm or 800 nm, and with an edge possibly set back from the edge of the film 16 without harming the optical isolation function. The optical isolating coating can be directly or on a functional sub-layer (barrier, etc.), transparent on the film 16.

[0185] The film 16 is transparent but can be tinted. The optical isolating coating 17 is transparent and even as transparent as possible and can be tinted.

[0186] In one configuration, the optical isolating coating comprises a crosslinked polymer matrix with said index n2, preferably at most 1.42 and even at least 1.35, matrix preferably among polymers based on polyacrylate with fluorinated function, in particular urethane acrylate or fluorourethane acrylate or fluorosilicone acrylate. The thickness is preferably at most 10 pm or 5 pm or 2 pm and at least 800 nm.

[0187] In one configuration, the optical isolating coating 17 comprises a matrix with a refractive index n2m greater than n2 and less than m, and with preferably n2m of at most 1.48 (and n2 preferably of at most 1.42 and even at least 1.35), and comprising (na no) porosities and / or (nano)particles of low index and / or porous, hollow, with a refractive index of less than m, in particular hollow, with a size of at most 300 nm or even 100 nm, for example hollow silica nanoparticles. The thickness is preferably at most 10 pm or 5 pm and at least 800 nm.

[0188] The matrix is ​​crosslinked or thermoplastic, in particular chosen from polymer based on polyacrylate, polyepoxides, polyvinyl acetate, polyester, polyurethane, PVB or mineral, in particular silica. The polymer matrix based on polyacrylate, polyurethane or even polyepoxides, polyvinyl acetate, polyester is preferred. Alternatively, the film 7' is an ultra-thin glass and / or the coating 17 is porous silica.

[0189] In order to avoid creases, undulations, preferably the coated substrate 16, 17 may be in an area of ​​the roof having a curvature, a sphericity limited in particular by a radius of curvature of at least 1.5 μm. For example, the edge of the film 16 may be sufficiently distant from the edge of the sheets 1', 2'. The masking width on the sides and / or front and rear may be adjusted (increased) for this purpose. For example, the transparent film 16 is a clear PET of less than 200 μm, in particular 100 μm or 75 μm, with a TL of approximately 90% or more.

[0190] The light redirection element 8' is on the periphery of the rear face of the film 16 (layer 7 can be removed) for example glued on it, and for example positioned upside down (reflecting prisms oriented towards the face F3 13).

[0191] Alternatively, the light redirection element 8' is on the periphery of the film 16 attached to the edge of the film 16 or all or part under the film 16.

[0192] A 5” opaque element (black ink etc.) to the right of the 8' prismatic film can be used to suppress stray light exiting towards the F2 side.

[0193] Unlike the previous embodiments, the diffusing layer for light extraction is the lower 3' lamination interlayer. Alternatively, it is only the second sheet (glass or plastic).

[0194] [Fig. 15] is a sectional view of luminous laminated glazing 4000 in a fourth embodiment incorporating the diffusing material in particular as described in Figures 1 to 8.

[0195] The 4000 laminated luminous glazing differs from the 3000 luminous glazing in that the diffusing layer for light extraction is both the lower 3' lamination interlayer and the second glass sheet. Alternatively, it is only the second sheet (glass or plastic).

[0196] The 8' light redirecting element is a prismatic reflective film turned over and bonded to the F3 13 face with a transparent optical adhesive with a predetermined refractive index.

[0197] [Fig. 16] is a sectional view of luminous laminated glazing 5000 in a fifth embodiment incorporating the diffusing material in particular as described in Figures 1 to 8.

[0198] The luminous laminated glazing 5000 of the previous 5000 in that it comprises, between the upper interlayer 3a and an additional interlayer 3c, an electrically controllable device 9, here with variable diffusion and even variable tint, additional interlayer 33c for example preferably tinted, gray, in particular tinted or clear PVB. The device 9 is for example a liquid crystal cell: GH, PDLC, PDLC with dichroic dye called DDPDLC.

[0199] The thickness of the device 9 being for example 0.4 mm, an interlayer frame 3b with a thickness of 0.38 mm, based on PVB, clear or tinted or even opaque, is added. The edges of the device 9 are under the internal masking layer 5'. For example, the blur in the diffusing state of the roof with the device 9 is at least 80%. The coated substrate 16, 17 is then in adhesive contact with the additional interlayer 3c and the lower interlayer 3'.

[0200] Outside the injection zone, the edge of device 9 is at least 10 mm or 15 mm from the edge of the glazing.

[0201] The outer glass 1 is clear, including a 2.1 mm Planiclear glass with an IR-reflecting 18 coating (silver stack) on the F2 12 side, the whole having a TL of 71.8% (91% without the 18 coating).

[0202] As shown in Figures 17 and 18, the device 9 may comprise:

[0203] - an upper support 91 (polymer, in particular PET or glass) with an upper electroconductive coating 92 (for example ITO) on the second side F2;

[0204] - a lower support 9T (polymer in particular PET or glass) with a lower electrically conductive coating 92' (for example ITO) on the third face F3; and

[0205] - an electroactive layer 93, which is preferably based on liquid crystals, for example in a polymer matrix (PDLC in English).

[0206] Preferably, if made of glass, one or both supports 91 and 91' are made of chemically toughened glass. Each of the supports 91 and 91' has a thickness of less than 1000 μm, in particular between 25 μm and 700 μm, preferably a thickness of less than 300 μm, or even less than 200 μm or 100 μm. The glass thickness of each support is sufficiently thin to provide the device 9 with film-like flexibility when it comes to associating the liquid crystal cell with the glass sheets 1 and 2, especially when the latter are curved. In particular, the glass thickness of each of the supports 91 and 91' is such that each glass support has a minimum radius of curvature which is at least of the order of 600 mm and can even reach 200 mm.

[0207] Preferably, the lower support and the lower electrode extend beyond the upper edge in a first protruding area and the upper support and the upper electrode extend beyond the lower edge in a second protruding area opposite the first protruding area.

[0208] In these first and second protruding zones, current supply strips 90 are added to the electrodes for the electrical supply.

[0209] The electrically conductive coatings 92, 92' at the periphery are not covered by the electroactive layer 93 and current supply strips 90 for the power supply are placed thereon. In particular, the supports 91, 9T protrude on two opposite sides.

[0210] The device 9 further comprises glass spacers 93' in contact with the first and second electrically conductive coatings 92 and 92' and the electroactive layer 93, respectively.

[0211] The glazed element 700 may further comprise a barrier element 94, at the periphery of the device 9, separating the electroactive layer from the lamination interlayer, here from 31, 32 and 33 barrier element, on the periphery of the electroactive layer. For example, the barrier element may comprise PET polymer strips glued or in contact.

[0212] Figures 17 and 18 represent different cases of barrier element 94. In Figure 17, the barrier element 94 here is external, comprising here a pair of coupled polymer barrier films, in particular without plasticizers, for example PET films: - covering all or part of the first protruding zone and even extending over the upper face Fs and / or extending to the rear face Fb; - covering all or part of the second protruding area and extending over the rear face and even extending to the upper face.

[0213] In particular, these are two polymer barrier films: a first film which is a polymer frame (PET), in particular of Z-section (three portions 941, 942, 943), coupled with a second film 944 which is a frame of rectangular section.

[0214] In Figure 18, it is a seal 94', 94 which covers the first and second protruding areas, for example polymer, in particular epoxy resin or silicone.

[0215] Alternatively, it is an internal peripheral seal that seals the liquid crystal cell, for example polymer, especially epoxy resin or silicone. The internal seal is for example 5 mm.

[0216] Alternatively, the peripheral sealing joint is external to both supports 91 and 91'.

[0217] Of course, one can use all the location and arrangement configurations for the reflective prismatic film already described in the previous figures, in particular one or more reversed reflective prismatic films (with or without coated substrate, under the coated substrate or adjacent).

Claims

Claims

1. Luminous laminated glazing (1000 to 5000) comprising a first glass sheet, a lamination interlayer comprising a lamination interlayer, a second transparent sheet, made of mineral or polymer glass, the glazing comprising diffusing material comprising a diffusing layer (2', 3') having two main faces (13, 14, 31', 32'), the layer being transparent, having a refractive index n2, characterized in that: - said diffusing layer comprises the second sheet -and / or said diffusing layer comprises the interlayer of lamination and the glazing then comprises an optical isolating element of refractive index n3 less than n2 between the first sheet and the interlayer of lamination, the diffusing layer comprises at least one zone comprising microcavities (5) included between the two main faces of the diffusing layer, the microcavities (5) having an elongated shape having a larger dimension in a longitudinal direction and a small dimension transverse to the larger dimension, the larger dimension being greater than 50 micrometers, the small dimension being between 0.5 micrometers and 130 micrometers, the longitudinal direction of the microcavities (5) being parallel or inclined relative to a normal to a main face of the layer at an angle of at most 15°, the microcavities (5) having in a plane of incidence, including the normal,on said area a spatial distribution determined by a first separation distance (Sx) between microcavities, in which a first ratio (R1) being defined equal to the ratio between the largest dimension and the first separation distance, the first ratio is above a determined lower threshold, the diffusing layer being capable of extracting and diffusing a determined percentage of XM diffusion of an internal light beam propagating between the two main faces in said plane of incidence, in particular under an internal angle of incidence greater than or equal to an angle of total internal reflection 0, TIR , to form at least one diffused external beam (41, 42) coming from at least one of the two main faces, the lower threshold preferably being equal to:

2. Luminous laminated glazing according to claim 1 which comprises a light source (7, 7'), preferably a set of light-emitting diodes, in particular which is optically coupled with the second sheet forming said diffusing layer, the second sheet having a main face called third main face F3 oriented towards the lamination interlayer, having a main face called fourth main face F4 opposite, light source opposite the face F4 and coupled with a local light redirection element, in particular facing a peripheral internal masking layer on the first sheet, which is - a reflector light redirection element and third main face F3 side - or a transparent light redirection element on the fourth main face side F4.

3. Luminous laminated glazing according to claim 2 in which a collimating optic is between the light source and said light redirection element, in particular the collimated beam is inclined relative to the normal of the second sheet, in particular the collimating light source and light redirection element assembly facing a peripheral internal masking layer on the first sheet.

4. Luminous laminated glazing according to one of claims 2 or 3 in which the light redirection element is reflective, preferably comprising reflective prisms, and is - between the F3 face and the interlayer of lamination, preferably the second sheet forms the diffusing layer - or is between the interlayer of lamination and the face F2, and even between the interlayer of lamination and the optical isolating element, and preferably the diffusing layer comprises the interlayer of lamination.

5. Luminous laminated glazing according to one of the preceding claims which incorporates one or more functional elements above the second sheet, functional elements chosen from at least one of the following devices: electrically controllable device with variable tint and / or variable diffusion based on liquid crystals, or a photovoltaic device.

6. Luminous laminated glazing according to one of the preceding claims in which the optical isolating element with refractive index n3 less than n2 is a porous coating (17) or with hollow nanoparticles, on a thermoplastic film (16), in particular PET.

7. Luminous laminated glazing according to one of the preceding claims in which the microcavities have an angular distribution with a standard angle deviation of less than 10 degrees, and even 5 degrees or 2 degrees and / or with an angle value at the peak of the distribution of at most 15° and even at most 10° or 5°.

8. Luminous laminated glazing according to one of the preceding claims in which the spatial distribution of the microcavities (5) is according to a one-dimensional or two-dimensional network of microcavities, in particular the one-dimensional network comprises lines of microcavities parallel to the main face of the diffusing layer.

9. Luminous laminated glazing according to claim 8 in which the two-dimensional network comprises lines of microcavities and columns of microcavities parallel to the main face, the columns being perpendicular to the lines, the columns of microcavities being arranged with a second separation distance Sy between adjacent columns of microcavities (5), in which a second ratio R2 is defined equal to the ratio between the largest dimension and the second separation distance between Sy between columns: R2 = L / Sy, the second ratio is above the determined lower threshold.

10. Luminous laminated glazing according to one of the preceding claims in which the first separation distance (Sx) is between 20 micrometers and 1 millimeter in a first direction parallel to the main face (1, 2) of the layer and optionally a second separation distance (Sy) is between 20 micrometers and 1 millimeter in another direction parallel to the main face (1, 2) of the diffusing layer, in particular normal to said first direction.

11. Luminous laminated glazing according to one of the preceding claims in which the microcavities (5) have an aspect ratio between the largest dimension and the smallest dimension of at least 1.5 or 5 and even at least 20, 50 or 100.

12. Luminous laminated glazing according to one of the preceding claims in which the microcavities (5) are closed.

13. Luminous laminated glazing according to one of claims 1 to 11 in which the microcavities form openings on the surface of at least one of the main faces (1, 2).

14. Luminous laminated glazing according to one of the preceding claims in which the diffusing layer, which comprises the second sheet, comprises a sheet of mineral glass, extra-clear or comprises a sheet of transparent polymer in particular based on polymethyl methacrylate, polycarbonate, polyurethane, polyesters and / or the diffusing layer which comprises the lamination interlayer, is based on polyvinyl butyral, an ethylene / vinyl acetate copolymer, thermoplastic polyurethane.

15. Luminous laminated glazing according to one of the preceding claims, forming luminous glazing for a vehicle, in particular road, rail or air, such as laminated side glazing, laminated rear glazing, a laminated roof, a laminated windshield.

16. Luminous laminated glazing according to one of claims 1 to 14 forming a building glazing, possibly multiple, in particular a facade glazing, in particular a window, a partition, a glass door.

17. Luminous laminated glazing according to one of claims 1 to 16, the second sheet is oriented towards the interior of a building or a passenger compartment.

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