Assembly comprising a mask and a thin, flexible and luminous electroluminescent film
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-05-08
- Publication Date
- 2026-03-18
AI Technical Summary
Current LED-based decorative and signaling elements for vehicles are expensive, inefficient, and lack flexibility to conform to complex shapes, consuming excessive electricity and requiring cooling systems, making them unsuitable for thin, flexible, and energy-efficient lighting solutions.
A thin, flexible electroluminescent film assembly with a mask featuring opaque and transparent parts, comprising a flexible support layer, conductive electrode layers, a phosphor layer, and a protective layer, which allows for the creation of various light patterns and reduces power consumption by over three times compared to LEDs.
The solution provides a thin, flexible, and energy-efficient lighting system capable of producing vibrant light patterns across diverse shapes and dimensions, offering improved aesthetic appeal and reduced power consumption while maintaining mechanical resistance and flexibility.
Smart Images
Figure EP2024062831_14112024_PF_FP_ABST
Abstract
Description
DESCRIPTION TITLE: Assembly comprising a mask and a thin, flexible, luminous electroluminescent film TECHNICAL FIELD OF THE INVENTION
[0001] The technical field of the invention is that of decorative or signaling assemblies comprising one or more luminous motifs.
[0002] The present invention relates to such decorative or signaling assemblies suitable for use for interior or exterior decoration or signaling of vehicles, in particular automobiles. TECHNOLOGICAL BACKGROUND OF THE INVENTION
[0003] Particularly in the automotive sector, the current trend is to decorate the interior and / or exterior of vehicles and integrate numerous signaling elements. Among these decorations and signaling elements, the most popular are those that are illuminated, especially because they remain visible even at night.
[0004] These decorations and signaling elements are sometimes based on light-emitting diodes (LEDs) or microLED arrays, and are generally in the form of light strips or wires, whose flexibility allows them to cover very diverse interior and body parts with concave and / or convex, sometimes complex, shapes.
[0005] However, these LED-based elements have many disadvantages.
[0006] Firstly, LEDs are expensive, so they are more commonly used for lighting than for decoration or signage.
[0007] Furthermore, LEDs tend to generate heat. Their use in large numbers therefore necessitates a cooling system, which adds bulk and thickness to the LED surfaces. Consequently, surfaces with a high LED density are neither thin nor flexible enough to conform to complex concave and / or convex shapes.
[0008] Finally, LEDs are not very energy efficient, with an efficiency of around 1%, and therefore consume a lot of electricity.
[0009] As a result, LED-based decorations are not a financially advantageous solution, either for their manufacture or for their use, and are unlikely to be flexible enough to cover concave and / or convex shapes.
[0010] There is therefore a need for decorative and illuminated signage that is thin, flexible, and adaptable enough to cover concave and / or convex interior and body panels. This decorative and illuminated signage must also allow for a wide range of designs and sizes. Furthermore, it must be very bright and capable of providing all colors of light across the visible spectrum without consuming excessive electricity. SUMMARY OF THE INVENTION
[0011] The invention offers a solution to the problems mentioned above, by providing an assembly comprising a thin, flexible and luminous electroluminescent film covered with a mask having opaque parts and transparent parts allowing the film to show through to generate luminous patterns whose shape and surface are determined by those of said transparent parts.
[0012] The thin, flexible and luminous electroluminescent film used in the invention is described in particular in detail in patent application FR2304675 in the name of the same applicant as the present application.
[0013] One aspect of the invention relates to a flexible assembly comprising a mask and a flexible electroluminescent film, the film comprising successively: a flexible support layer; a first flexible electrode layer made of conductive material; a flexible electrically insulating layer made of dielectric material; a flexible electroluminescent layer, comprising a phosphor layer having a refractive index rn U m; a second flexible and transparent electrode layer made of conductive material having a refractive index Hélec J; a flexible and transparent protective layer; and in that the mask is positioned above the top surface of the film and includes at least one opaque part and at least one transparent part through which the electroluminescent layer is visible.
[0014] Thanks to this invention, a decorative element is provided that is advantageously thin, lightweight, flexible, and highly luminous. It can be supplied in sheet form in any size, is easy to cut, and can produce luminous patterns with a great deal of freedom in terms of shape and size. These luminous patterns are defined by transparent areas that are not opaque, allowing the electroluminescent film to be seen through them. Furthermore, the power consumption of electroluminescent films is more than three times lower than that of LEDs.
[0001] According to one aspect of the invention, the electroluminescent layer also comprises at least one refractive index matching element having a refractive index n ng such that nium > n ng > neiec. Thus, since light preferentially travels through the nearest material with a lower refractive index, the light emitted by the phosphor layer first passes through the material of the refractive index matching element, then through the second electrode layer to be emitted upwards through the film. As the refractive index of the matching element is intermediate between that of the adjacent layers with which it acts as an interface, its presence advantageously reduces any refraction and / or reflection of light from the phosphor layer towards the second electrode layer.
[0015] According to another aspect of the invention, the phosphor layer comprises zinc sulfide doped with at least one metal, including copper. This type of phosphor is advantageously very luminous and can, in particular, provide all the colors of illumination in the visible spectrum.
[0016] According to a further aspect of the invention, the mask is glued to the upper surface of the film. Thus, the mask can be made of any flexible material, and the transparent parts can, for example, be formed by cutting or die-cutting, and then the mask can be glued to the film to form a flexible assembly usable on any element for decoration.
[0017] According to one aspect of the invention, the mask is printed on the upper surface of the film. This provides an alternative method of attaching the mask to the film, which notably allows for the generation of transparent sections of all shapes and sizes, for example, from a print file, by directly printing the opaque sections of the mask to generate transparent areas where the opaque sections are not printed.
[0018] According to another aspect of the invention, at least one transparent part is a through-hole made in an opaque part of the mask. This advantageously allows the transparent parts to be created by cutting out only a layer of the opaque surface or the entire thickness of the mask if it is made of an opaque material, which is a simple and easy way to generate the transparent parts of the mask.
[0019] According to a further aspect of the invention, the transparent parts occupy between 5 and 50% of the total surface area of the mask. This is merely a preferred surface area ratio, as the transparent parts can advantageously occupy any surface area of the mask without altering the overall properties of suppleness, flexibility, brightness, or mechanical strength.
[0020] According to one aspect of the invention, the transparent parts are in the form of dots, circles, ovals, chevrons, oblongs, squares, rectangles, triangles, stars, crosses, rhombuses, polygons, honeycombs, alphanumeric characters, or a combination of at least two of these shapes. In fact, the transparent parts can advantageously be of any shape and not necessarily all identical within the same set.
[0021] According to another aspect of the invention, the transparent parts are arranged in lines, and according to a further aspect of the invention, the transparent parts are distributed uniformly over the surface of the mask. This makes it possible, in particular, to provide an overall impression where the light patterns are ordered and organized so as to give a cohesive look, with an enhanced aesthetic effect.
[0022] According to one aspect of the invention, at least one opaque part of the mask has an upper surface made of natural or synthetic leather. Indeed, it is a This variant is particularly suitable for interior vehicle decorations, where the leather look for surfaces is highly valued.
[0023] According to another aspect of the invention, at least one opaque part of the mask is made of opaque polymer material. Indeed, to be opaque, the mask can be entirely opaque or only have a layer of opaque polymer material, which may, for example, be less expensive than the rest of the mask or play a protective role for it.
[0024] According to a further aspect of the invention, the mask also includes a logo, text, geometric pattern, or design on its upper surface. This advantageously allows for the combination of illuminated patterns with other non-illuminated decorative or informational elements within the same design.
[0025] According to one aspect of the invention, the protective layer comprises a transparent UV-blocking material, a UV-blocking additive, or a transparent UV-blocking coating. Thus, in addition to its role in protecting the environment, the protective layer also protects the film against the effects of ultraviolet radiation.
[0026] According to another aspect of the invention, the protective layer comprises a layer of transparent UV-resistant material selected from an acrylic resin, a mixture of high-density polyethylene and zinc oxide, polycarbonate, polyamide-imide, and poly(vinylidene fluoride). These materials exhibit highly effective UV protection and can therefore be supplied in a very thin layer, contributing to the film's flexibility and transparency.
[0027] Another aspect of the invention relates to a vehicle component, which is at least partially covered by an assembly as described above. Such a component can thus be decorated with luminous motifs exhibiting all the freedom of form and dimension offered by the invention.
[0028] According to one aspect of the invention, the vehicle component is a body part, a dashboard, a decorative element, a grille, a logo, or a headlight. Thanks to the invention, it is advantageously possible to incorporate lighting patterns on these components, which car manufacturers typically seek to make visually appealing.
[0029] An additional aspect of the invention relates to a method for manufacturing an assembly according to the invention, which comprises the following successive steps: provision of a flexible support layer; deposition of a first flexible electrode layer of conductive material on the flexible support layer; deposition of a flexible electrically insulating layer of dielectric material on the first electrode layer; deposition of a flexible electroluminescent layer, including a phosphor layer; deposition of a second flexible and transparent electrode layer of conductive material on the electroluminescent layer; deposition of a flexible and transparent protective layer on the second electrode layer; and positioning of a mask on the upper face of the film, said mask comprising at least one opaque part and at least one transparent part through which the electroluminescent layer is visible.
[0030] This manufacturing process is advantageous because it can be implemented both simply and inexpensively. For example, it allows for the production of a large assembly that can then be cut to the desired dimensions, for instance, to decorate a vehicle component.
[0031] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES
[0032] The figures are presented for illustrative purposes only and are in no way limiting to the invention.
[0033] [Fig. 1] is a schematic representation of a flexible assembly according to an example of the invention comprising a mask and an electroluminescent film, which has transparent rectangular parts.
[0034] [Fig. 2] is a detailed view of the substantially circled part on [Fig. 1] in the case where the electroluminescent layer comprises a phosphor layer located on the electrically insulating layer, and a refractive index matching element layer located on the phosphor layer.
[0035] [Fig. 3] is a detailed view of the substantially circled part on [Fig. 1] in the case where the electroluminescent layer includes a heterogeneous layer comprising refractive index matching elements located on the electrically insulating layer and embedded in a phosphor layer.
[0036] [Fig. 4] is a schematic perspective view of a flexible assembly according to an example of the invention having transparent star-shaped parts.
[0037] [Fig. 5] is a schematic cross-sectional view of a flexible assembly according to an embodiment of the invention in which the transparent parts are obtained by cutting through holes through a mask made of opaque material.
[0038] [Fig. 6] is a schematic cross-sectional view of a flexible assembly according to an embodiment of the invention in which opaque parts are deposited on a transparent layer.
[0039] [Fig. 7] is a schematic cross-sectional view of a flexible assembly according to an embodiment of the invention in which a transparent layer is deposited on opaque parts.
[0040] The thicknesses of the different layers shown in the figures are for illustrative purposes only and do not reflect reality in any way. DETAILED DESCRIPTION
[0041] Unless otherwise specified, the same element appearing on different figures has a unique reference.
[0042] By convention, in this application, the terms "lower" and "upper", and "inner" and "outer" are defined with respect to the position of the electroluminescent film as shown in [Fig. 1]. Thus, an outer layer such as the protective layer is shown in the upper part of the film in [Fig. 1] while an inner layer, such as the support layer, is shown in the lower part of the film, even if the film can be used in a different orientation.
[0043] Within the scope of the invention, a material or layer of material is said to be flexible if the mechanical and electrical properties of the film remain unchanged even under a significant stress of 2.5% with a concave and convex radius of curvature of 0.5 mm. In other words, a layer can be considered, in particular, as The electrode on the support layer is flexible if, after a 2.5% deformation, this deformation does not affect the change in electrical resistance of the electrode film deposited on the support layer. The deformation (flexibility) can be evaluated using the following equation:
[0044] Deformation = ( ts - tp - tf ) / 2 x rc, where: ts is the thickness of the support layer; tp is the total thickness of the working layers (luminescent layer + electrically insulating layers) tf is the total thickness of the electrode layers rc is the radius of curvature.
[0045] Finally, the term "transparent" refers to a material that is optically transparent, that is, one with a transmittance greater than 75% in the visible spectrum.
[0046] The flexible assembly 11 according to the invention comprises a mask 10 and an electroluminescent film 1.
[0047] The film 1 according to the invention is a flexible electroluminescent film 1 comprising at least six flexible and superimposed layers, where each layer is in contact with the adjacent layer(s), namely a support layer 2, a first electrode layer 3, an electrically insulating layer 4, an electroluminescent layer 5, a second electrode layer 8 and a protective layer 9.
[0048] The film 1 according to the invention comprises a first layer, preferably lower, which is a flexible support layer 2, onto which the other layers are deposited. This support layer 2 is preferably supplied in the form of a film roll. It has, for example, a thickness of between 0.5 and 2.0 mm, preferably between 0.8 and 1.5 mm, and more preferably equal to 1.1 mm.
[0049] The support layer 2 can be transparent, particularly when the entire film 1 is to be transparent. It can also be opaque, for example when film 1 is intended to be applied to an opaque surface.
[0050] In particular, where this layer is transparent, the support layer 2 is preferably made of PET (polyethylene terephthalate), Plasil (polymerized silicon monoxide-based siloxane), PMMA (polymethyl methacrylate), PCL (polycaprolactone), PC (polycarbonate), COP (cycloolefin polymer) or a mixture of at least two of these products.
[0051] The film 1 according to the invention comprises a second layer, deposited on the support layer 2, namely a first flexible electrode layer 3 made of conductive material.
[0052] This first electrode layer 3 is preferably supplied in the form of a nanonet (or nanomesh in English), a metal mesh (or electrode mesh in English) or a homogeneous flat layer.
[0053] A nanonet is a net-like nanostructure formed by nanowires in mutual contact, creating a mesh, whether these wires are interwoven, overlapping, welded, or a single piece. A nanowire is a thread-like nanostructure with a diameter on the nanoscale, for example, less than 100 nm, and a significantly greater length.
[0054] By wire mesh, we mean a net-like structure, made of interlaced, superimposed, welded or single-piece wires, these wires having a diameter on the order of a micron.
[0055] The unit patterns of the mesh of such a nanonet or metal lattice can, for example, be squares, rectangles, triangles, rhombuses, hexagons or any other shapes and combinations thereof.
[0056] By homogeneous flat layer, we mean a layer of material substantially flat, without significant inequalities in level, whose composition and structure are substantially the same at every point, and which extends over a surface suitable for forming an electrode of the desired surface area, for example substantially equal to the surface of the support layer 2 where we wish to form a luminescent film.
[0057] The first electrode layer 3, when supplied in the form of a nanonet or a metal mesh, preferentially comprises silver nanowires (or AgNWs for Ag nanowires) or copper nanowires (or CuNWs for Cu nanowires).
[0058] It should be noted that wide bandgap nanowires composed of gallium nitride (GaN) or zinc oxide (ZnO) are materials that can also be used for nanowires.
[0059] When supplied as a flat layer, the first electrode layer 3 preferentially comprises carbon nanotubes, graphene, a metal oxide-based material, a PEDOT [poly(3,4-ethylenedioxythiophene)]-based material, a PEDOT:PSS [poly(3,4-ethylenedioxythiophene) mixed with sodium polystyrene sulfonate]-based material, or a PEDOT:TOS [poly(3,4-ethylenedioxythiophene) mixed with tosylate]-based material. Such a flat layer is as homogeneous as possible and usually unstructured.
[0060] Metal oxide-based materials for the first electrode layer 3 preferentially include ITO (indium tin oxide), ZnO (zinc oxide), ZnO:Al (aluminum-doped zinc oxide), TiO2 (titanium dioxide) and SnO2:F (fluorine-doped tin dioxide, or FTO for Fluorine-doped Tin Oxide).
[0061] The first electrode layer 3 can be transparent or opaque.
[0062] The film 1 according to the invention comprises a third layer, deposited on the first electrode layer 3, namely a first electrically insulating flexible layer 4 made of dielectric material.
[0063] This electrically insulating layer 4 has, for example, a thickness between 1 and 50 pm. It preferably has a thickness between 5 and 30 pm, more preferably between 8 and 15 pm, for example approximately equal to 10 pm.
[0064] The dielectric material of the electrically insulating layer 4 preferably comprises an epoxy resin matrix loaded with alkaline earth metal titanate particles, the alkaline earth metal being selected from calcium titanate (CaTiOa), barium titanate (BaTiOa), strontium titanate (SrTiOa), mixed perovskites of the barium and strontium titanate type (BaxSrp-xjTiOa, with 0 < x < 1) and a mixture of these products. Preferably x is such that 0 < x < 1.
[0065] The electrically insulating layer 4 can be transparent or opaque.
[0066] The film 1 according to the invention comprises a fourth layer, deposited on the electrically insulating layer 4, namely a flexible electroluminescent layer 5.
[0067] This electroluminescent layer 5 comprises both a luminophore material capable of generating light, and a refractive index matching material capable of directing the light emitted by the luminophore material towards the following upper layers, namely the second electrode layer 8 and the protective layer 9.
[0068] Luminophore here refers to a material containing electroluminescent pigments that emit white or colored light after receiving energy supplied by an electric field.
[0069] Thus, the electroluminescent layer 5 comprises a phosphor layer 6 having a refractive index rn U m and at least one refractive index matching element 7 having a refractive index n ng so that nium > n ng > neiec where neiec is the refractive index of the second electrode layer 8.
[0070] Since the refractive index of the refractive index matching element 7 is intermediate between that of the adjacent layers for which it serves as an interface, its presence reduces the effects of refraction and / or reflection of light from the phosphor layer 6 towards the second electrode layer 8.
[0071] Laboratory tests have proven that adding the refractive index matching element 7 to a conventional electroluminescent film multiplies its luminance by a factor of between 1.8 and 2. Thus, for a film 1 according to the invention, for which the luminance is optimized, a luminance greater than 1600 cd / m² is obtained. 2 , which can even exceed 2000 cd / m 2 values that have never been achieved to date for an electroluminescent film.
[0072] According to a first variant of the invention shown in [Fig. 2], the electroluminescent layer 5 comprises two successive layers, namely a phosphor layer 6 located on the electrically insulating layer 4, and a refractive index matching element layer 7 located on the phosphor layer 6.
[0073] According to a second embodiment of the invention shown in [Fig. 3], the electroluminescent layer 5 comprises a heterogeneous layer including refractive index matching elements 7 located on the electrically insulating layer 4 and embedded in a phosphor layer 6. According to this second embodiment of the invention, a layer of refractive index matching element 7 may also be located on said heterogeneous layer.
[0074] The phosphor layer 6 has a refractive index rn Um whose value is for example approximately equal to 4. In the context of the invention, each refractive index is measured by method A of the standard NF EN ISO 489 of March 2022.
[0075] Luminophore layer 6 comprises zinc sulfide doped with at least one metal including copper.
[0076] By metallic composition doped with a material, we mean here a metallic composition incorporating small quantities (generally on the order of ppm) of a material which is introduced into its matrix in order to modify its properties.
[0077] For example, the luminophore layer 6 comprises zinc sulfide, a mixture of zinc sulfide and cadmium sulfide, or a mixture of zinc sulfide, cadmium sulfide, zinc selenide, and cadmium selenide. Preferably, these metallic compositions are either doped with copper alone or doped with copper and at least one compound selected from the group consisting of yttrium aluminum garnet, manganese, aluminum, europium, and inorganic dyes.
[0078] The deposition of the phosphor layer 6 is preferably carried out by screen printing, by atomic thin film deposition (or ALD, for the English Atomic Layer Deposition) or by a sol-gel process.
[0079] Screen printing or ALD deposition is preferred in the case of the first variant of the invention, where the electroluminescent layer 5 comprises two successive layers, while sol-gel deposition is preferred in the case of the second variant of the invention, where the electroluminescent layer 5 comprises refractive index matching elements 7 embedded in a phosphor layer 6.
[0080] Screen printing deposition generally allows for the provision of a phosphor layer 6 with a thickness, for example, between 25 and 30 pm because the particles of the luminophore layer 6 usually have a diameter less than or equal to 29 pm.
[0081] In the case where the deposit of the luminophore layer 6 is carried out by screen printing, the electroluminescent pigments are preferentially bound in an epoxy resin matrix.
[0082] The refractive index 7 matching element is transparent and, when in the form of a layer, it is flexible.
[0083] The refractive index matching element 7 has the role of directing the light emitted towards the phosphor layer 6 towards the second electrode layer 8 located above it, so that a greater part of the light emitted by the phosphor layer 6 passes through the second electrode layer 8, for greater brightness of the film 1.
[0084] Thus, the refractive index matching element 7 has a refractive index n ng whose value is chosen so as to be between that of the two adjacent layers, namely the phosphor layer 6 and the second electrode layer 8, so as to form an intermediate layer reducing the effects of refraction and / or reflection of light. The refractive index n ngthe adaptation element of the refractive index is for example between 2 and 3.5.
[0085] The refractive index matching element 7 preferentially comprises nano-antennas 17, also known as light nanosensors, or nano-antennas in English
[0086] These nano-antennas 17 preferentially comprise nano-objects, preferably metallic, which promote the movement of light from the phosphor layer 6 to the second electrode layer 8, at a scale smaller than the wavelength, so that the refractive index matching element 7 is also very thin and transparent.
[0087] According to one embodiment of the invention, the nano-objects can be colloidal nanoparticles, preferably nano-cubes. They can also be three-dimensional elements with round, oval, triangular, square, rectangular, rhombic, polygonal, etc. cross-sections or other polygonal three-dimensional elements, such as tetrahedra, octahedra, dodecahedra, icosahedra, etc.
[0088] A nanoparticle is a nano-object whose three dimensions are on the nanometric scale, that is to say a particle whose nominal diameter is less than about 100 nm.
[0089] Colloidal nanoparticles are preferentially based on silver, gold, platinum or a mixture thereof.
[0090] In the case of the second variant of the invention, where the electroluminescent layer 5 comprises refractive index matching elements 7 embedded in a phosphor layer 6, the nanoparticles are preferentially deposited on the electrically insulating layer 4 by a drop-deposition process, for example randomly, but in such a way that the nanoparticles are well dispersed, without aggregates and with the most homogeneous density possible on the phosphor layer 6.
[0091] In the case of the first embodiment of the invention, where the electroluminescent layer 5 comprises two successive layers, the colloidal nanoparticles are preferably embedded in a matrix, for example, polyvinylpyrrolidone (PVP), or coated with a layer of PVP. This matrix or PVP layer has, for example, a thickness of approximately 1 to 10 nm, preferably approximately 3 nm.
[0092] According to another variant of the invention, the nano-objects can be nanofibers, nanotubes, nanofilaments, nanowires, nanorods, nanosticks or a mixture of these nano-objects.
[0093] Nanofibers, nanotubes, nanofilaments, nanorods and nanorods are nano-objects whose two similar external dimensions are on the nanometric scale, less than about 100 nm, and whose third dimension is significantly larger.
[0094] These nano-objects are preferably based on zinc oxide. They are grown for example by hydrothermal synthesis from a layer of ZnO seeds directly deposited on the phosphor layer 6 (first variant of the invention) or on the electrically insulating layer 4 (second variant of the invention).
[0095] These nano-objects are preferentially arranged in the form of a very dense network of nanowires (NWs), nanofibers, nanotubes, nanofilaments, nanorods and / or vertically aligned nanorods. They preferentially have a diameter between 30 and 50 nm and a length between 400 and 500 nm.
[0096] In the case of the second variant of the invention, where the electroluminescent layer 5 comprises refractive index matching elements 7 embedded in a phosphor layer 6, the nanoparticles and nano-objects can, for example, be deposited in the form of islands, i.e. in the form of small groups of nanoparticles and nano-objects isolated from each other, or in the form of lines, in particular parallel and / or intersecting to form a network.
[0097] The refractive index matching elements 7, whether embedded in the phosphor layer 6 or in the form of a separate layer, may have a very small height (or thickness in the case of a layer), in particular less than 1 pm.
[0098] Depending on its thickness, the luminophore layer 6 can be transparent, translucent or opaque.
[0099] The film 1 according to the invention comprises a fifth layer, deposited on the electroluminescent layer 5, namely a second flexible and transparent electrode layer 8 made of conductive material.
[0100] This second electrode layer 8 can have the same characteristics as the first electrode layer 3.
[0101] It has a refractive index neiec whose value is, for example, approximately equal to 1.5.
[0102] Within a single film 1 according to the invention, the first electrode layer 3 and the second electrode layer 8 may be identical, for example in their nature, composition, thickness, and / or deposition process, but they may also be different. However, it is more practical and less costly for the manufacture of the film 1 if the first and second electrode layers 3, 8 are identical.
[0103] The first and second electrode layers 3, 8 are intended to be connected to an alternating current source in order to form an electrostatic field between them, capable of exciting the phosphor layer 6 provided between these two layers 3, 8.
[0104] Finally, the film 1 according to the invention comprises a sixth layer, preferably upper, deposited on the second electrode layer 8, namely a flexible and transparent protective layer 9.
[0105] This protective layer 9 has, for example, a thickness between 0.5 and 2.0 mm, preferably between 0.8 and 1.5 mm and more preferably equal to 1.1 mm.
[0106] It is preferably deposited by printing.
[0107] The protective layer 9 is preferably made of PET (polyethylene terephthalate), Plasil (polymerized silicon monoxide siloxane), PMMA (polymethyl methacrylate), PCL (polycaprolactone), PC (polycarbonate), COP (cycloolefin polymer) or a mixture of at least two of these products.
[0108] The protective layer 9 preferably comprises a transparent anti-UV material, an anti-UV additive or a transparent anti-UV coating in order to protect the film 1 from the harmful effects of ultraviolet radiation.
[0109] Indeed, UV protection can be embedded in the mass of the material constituting the protective layer 9, or be in the form of a coating deposited on the lower and / or upper layer of said protective layer 9.
[0110] Similarly, the constituent material of the protective layer 9 may naturally have an anti-UV effect, or be modified to exhibit such an effect without significantly negatively affecting its flexibility and transparency.
[0111] Thus, the protective layer 9 includes, for example, a layer of transparent anti-UV material chosen from an acrylic resin, a mixture of high-density polyethylene and zinc oxide, polycarbonate, polyamide-imide and poly(vinylidene fluoride).
[0112] The following materials are known to have anti-UV action: Plasil anti-UV, PC, PCL, PMMA, PET and COP.
[0113] The mask 10 comprises at least one opaque part 13, preferably several, and at least one transparent part 14, preferably several, through which the electroluminescent layer 5 is visible.
[0114] By opaque we mean here a material that does not allow light from the visible spectrum to pass through from the electroluminescent layer 5.
[0115] When the phosphor layer 6 is excited and becomes luminous, the transparent parts 13 allow light to pass through the mask 10 and form luminous patterns on the outside whose shape corresponds to those of the transparent parts 13.
[0116] The flexible assembly 11 according to the invention presents a very satisfactory aesthetic effect when the transparent parts 13 occupy between 5 and 50% of the total surface of the mask 10. The transparent parts 13 can however occupy more or less of this surface depending on the desired effect.
[0117] The transparent parts 13 can be any shape. For example, they can be in the form of dots, circles, ovals, chevrons, oblongs, squares, rectangles, triangles, stars, crosses, diamonds, polygons, honeycombs, alphanumeric characters, or be in the form of a combination of at least two of these patterns.
[0118] To create an organized aesthetic effect, the transparent parts 13 can be arranged in rows, with the patterns then either aligned in columns or staggered. The transparent parts 13 are preferably distributed uniformly across the surface of the mask 10. They can also be distributed progressively, with the mask surface gradually occupied by more and more transparent parts 13 or, conversely, by fewer and fewer transparent parts 13.
[0119] The mask 10 can be located at a distance from the upper face 12 of the film 1, but it is preferentially in contact with it, and more preferably attached to the film 1, for example by gluing or by being printed on it.
[0120] The opaque parts 12 can for example be made of an opaque polymer material.
[0121] According to a variant of the invention shown in [Fig. 5], at least part of the mask 10 can for example be formed of a layer of opaque material, forming the opaque parts 12, in which through holes are cut to form the transparent parts 13. It is also possible to consider filling these through holes with a transparent material.
[0122] According to another variant of the invention shown in [Fig. 6], at least part of the mask 10 can for example be formed of a layer of transparent material 16, on which are deposited one or more layers of opaque material forming opaque parts 12 delimiting between them the transparent parts 13.
[0123] According to a further embodiment of the invention shown in [Fig. 7], at least a portion of the mask 10 may, for example, be formed by one or more layers of opaque material forming one or more opaque parts 12 delimiting the transparent parts 13. These layers of opaque material may be covered with a layer of transparent material 16, for example, in order to be protected, this layer of transparent material 16 being an integral part of the mask 10. As shown in [Fig. 7], the layer of transparent material 16 may be flat, or may at least partially occupy the empty spaces located between the opaque parts 12 and forming the transparent parts 13.
[0124] The mask 10 can be decorated on its upper surface 15. Opaque parts 12 can, for example, be at least partially covered with natural or synthetic leather, while the mask 10 can be decorated with a logo, text, geometric pattern, design or any other decorative or informative element on its upper surface 15. Of course, the upper surface 15 of the mask 10, in its opaque parts 12, can have any appearance, color or texture.
[0125] The assembly 11 according to the invention is preferably intended for decorating the interior or exterior of a vehicle, but its applications are innumerable. It can, for example, be used indoors as well as outdoors, to decorate a building, furniture, accessories, architectural elements, clothing, etc.
[0126] Thus, the invention also relates to a vehicle component at least partially covered by an assembly 1 1 according to the invention, this component being for example a body part, a dashboard, a decorative part, a grille, a logo, a lens or any other part of a vehicle.
[0127] Finally, the invention also relates to a method of manufacturing an assembly 11 according to the invention comprising the following successive steps: supplying a flexible support layer 2; deposition of a first flexible electrode layer 3 made of conductive material on the flexible support layer 2; deposition of a flexible electrically insulating layer 4 made of dielectric material on the first electrode layer 3; - deposition of a flexible electroluminescent layer 5 comprising a phosphor layer 6 on the electrically insulating layer 4; deposition of a second flexible and transparent electrode layer 8 made of conductive material on the electroluminescent layer 5; deposition of a flexible and transparent protective layer 9 on the second electrode layer 8; and positioning of a mask 10 on the upper face 12 of the film 1, said mask 10 comprising at least one opaque part 13 and at least one transparent part 14 through which the electroluminescent layer 5 is visible.
Claims
CLAIMS
1. Flexible assembly (11) characterized in that it comprises a mask (10) and an electroluminescent film (1), the film (1) successively comprising: - a flexible support layer (2); - a first flexible electrode layer (3) made of conductive material; - a flexible electrically insulating layer (4) made of dielectric material; - a flexible electroluminescent layer (5), comprising a phosphor layer (6) having a refractive index rn U m ; - a second flexible and transparent electrode layer (8) made of conductive material having a refractive index Hélec J - a flexible and transparent protective layer (9); and in that - the mask (10) is positioned above the upper face (12) of the film (1) and comprises at least one opaque part (13) and at least one transparent part (14) through which the electroluminescent layer (5) is visible.
2. Assembly (1 1 ) according to claim 1 , characterized in that the electroluminescent layer (5) also comprises at least one refractive index matching element (7) having a refractive index n ng such as nium > Ung > Hélec-
3. Assembly (1 1 ) according to claim 1 or 2, characterized in that the phosphor layer (6) comprises zinc sulfide doped with at least one metal including copper.
4. Assembly (11) according to any one of the preceding claims, characterized in that the mask (10) is glued to the upper face (12) of the film (1).
5. Assembly (11) according to any one of claims 1 to 3, characterized in that the mask (10) is printed on the upper face (12) of the film [Claim s] Assembly (11) according to any one of the preceding claims, characterized in that at least one transparent part (14) is a through-orifice made in an opaque part (13) of the mask (10).
7. Assembly (11) according to any one of the preceding claims, characterized in that the transparent parts (12) occupy between 5 and 50% of the total surface area of the mask (10). [Claim s] An assembly (11) according to any preceding claim, characterized in that the transparent parts (12) are in the form of dots, circles, ovals, chevrons, oblongs, squares, rectangles, triangles, stars, crosses, diamonds, polygons, honeycombs, alphanumeric characters, or in the form of a combination of at least two of these patterns.
9. Assembly (11) according to any one of the preceding claims, characterized in that the transparent parts (12) are arranged in lines.
10. Assembly (11) according to any one of the preceding claims, characterized in that the transparent parts (12) are distributed uniformly over the surface of the mask (10). [Claim 1 1 ] Assembly (11 ) according to any one of the preceding claims, characterized in that at least one opaque part (13) of the mask (10) has an upper face (13) made of natural or synthetic leather.
12. Assembly (11) according to any one of the preceding claims, characterized in that at least one opaque part (13) of the mask (10) is made of opaque polymer material.
13. Assembly (11) according to any one of the preceding claims, characterized in that the mask (10) further comprises a logo, text, geometric pattern or design on its upper face (15).
14. Assembly (11) according to any one of the preceding claims, characterized in that the protective layer (9) comprises a transparent anti-UV material, an anti-UV additive or a transparent anti-UV coating.
15. Assembly (11) according to any one of the preceding claims, characterized in that the protective layer (9) comprises a layer of transparent anti-UV material chosen from an acrylic resin, a mixture of high density polyethylene and zinc oxide, polycarbonate, polyamide-imide and poly(vinylidene fluoride).
16. Element for a vehicle, characterized in that it is at least partially covered by an assembly (11) according to any one of the preceding claims.
17. Vehicle element according to the preceding claim, characterized in that said element is a bodywork part, a dashboard, a decorative part, a grille, a logo or an optical element.