Method for manufacturing a raised pattern and raised pattern manufactured by this method

Abstract

One aspect of the invention relates to a method (200) for manufacturing a raised pattern in a transparent film which is suitable for guiding light, the transparent film comprising a first layer of a first transparent material, the method comprising the following steps: - etching (201), in the first layer of transparent material, a pattern which is suitable for extracting the light guided inside the transparent film; - insolating and / or polymerising (202) the transparent film by ultraviolet radiation; and - forming (204) the raised pattern in a region of the transparent film.

Description

Method of manufacturing a relief pattern and relief pattern manufactured by this method TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of signaling and lighting.

[0002] The present invention relates to a method for manufacturing a relief pattern in a transparent film adapted to guide light. Another object of the invention is a relief pattern made in a transparent film adapted to guide light. The present invention further relates to a decorative structure comprising a relief pattern and a transparent film adapted to guide light. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Transparent films suitable for guiding light are used in the field of signage and lighting.

[0004] The illustrates an example of a transparent film used as a display screen according to the state of the art. Such a device comprises a transparent film having a thickness of a few tens of micrometers, a light source coupled to one of the side faces of the transparent film and one or more microstructured patterns etched in the upper face of the transparent film. The light emitted by the source propagates by total internal reflection inside the transparent film. The microstructured patterns allow the light to be extracted, which makes them visible from the outside. The illustrates one of the advantages of these devices, namely their flexibility and small size.

[0005] Other known advantages of transparent film-based lighting and signaling devices are their brightness and low energy consumption. These devices allow for high contrast even during the day.

[0006] There is a desire to create relief patterns in a transparent film suitable for guiding light.

[0007] The invention provides a solution to the problems mentioned above by describing a method for manufacturing a relief pattern in a transparent film suitable for guiding light.

[0008] One aspect of the invention relates to a method for manufacturing a relief pattern with a transparent film adapted to guide light, said transparent film comprising a first layer of a first transparent material, the method comprising the following steps:- etching in the first layer of transparent material a pattern adapted to extract the light guided inside the transparent film,- insolation and / or polymerization of the transparent film by ultraviolet radiation,- formation of the relief pattern in an area of ​​the transparent film.

[0009] Thanks to the invention, it is possible to combine engraved patterns, namely patterns illuminated by the light guided in the transparent film, and relief patterns. In other words, the invention makes it possible to obtain patterns that are both relief and illuminated.

[0010] Thanks to the invention, it is possible in particular to obtain logos or decorative structures or luminous signatures which are both three-dimensional or in relief and illuminated.

[0011] A transparent film suitable for guiding light is a film that can confine light by total internal reflection.

[0012] Etching a pattern in the first layer of the transparent material suitable for extracting the light guided inside the transparent film means forming a structured pattern on the upper side of the transparent film. Etching can be carried out, for example, by optical lithography.

[0013] Insolation of the transparent film by ultraviolet radiation means illuminating the film in order to fix the pattern to be engraved in order to print the pattern.

[0014] Relief pattern formation is understood to mean deformation of the transparent film adapted to guide light in order to obtain the desired relief pattern. This is possible thanks to the high flexibility of the transparent film used to guide light, which allows the film to adhere to a mold, for example when forming the relief pattern by thermoforming.

[0015] Thanks to the invention, it is possible to obtain illuminated three-dimensional structures with high contrast and brightness even during the day, while maintaining low energy consumption.

[0016] Thanks to the invention, it is possible to obtain structures that are both flexible and lightweight.

[0017] Advantageously, the step of forming the relief pattern is a step of three-dimensional forming of the transparent film.

[0018] Advantageously, the step of forming the relief pattern is a step of thermoforming the transparent film; the thermoforming step makes it possible to produce a three-dimensional pattern in a simple and reproducible manner.

[0019] the step of forming the relief pattern is carried out by pressure on the transparent film; Advantageously, shaping under pressure allows for better precision in the molding of details;

[0020] Advantageously, the relief pattern is a logo or a luminous signature or a decorative pattern;

[0021] Advantageously, the step of exposing the transparent film to ultraviolet radiation comprises a step of polymerizing the transparent film; the polymerization of the transparent film makes it possible to freeze the pattern suitable for extracting the light;

[0022] Advantageously, the method according to the invention further comprises a step of producing marks in the transparent film, the marks being adapted to position the pattern adapted to extract the light relative to the relief pattern; the marks make it possible to precisely position the illuminated pattern relative to the three-dimensional pattern, so as to obtain the desired effect;

[0023] Advantageously, the transparent film comprises an integer number N greater than or equal to 1 of layers of transparent materials superimposed with the first layer of the first transparent material, the method comprising, before the step of exposing the transparent film, a step of etching in at least one of the N layers of transparent materials, at least one pattern other than the first layer; this step makes it possible to obtain a plurality of patterns illuminated by the light.

[0024] A second aspect of the invention relates to a relief pattern obtained according to the method having at least one of the preceding characteristics.

[0025] A third aspect of the invention relates to a decorative structure capable of being illuminated, comprising:a relief pattern obtained using the method having at least one of the preceding characteristics,a light guide comprising a first layer of a transparent material,a light source for illuminating the light guide,

[0026] the light guide being positioned so as to guide rays from the light source into the first layer of transparent material and to illuminate the engraved pattern.

[0027] According to one embodiment, the decorative structure further comprises:N other light guides,N other light sources for illuminating each of the N light guides, the N light sources emitting in different spectral regions,

[0028] the N other light guides being positioned so as to guide rays from one of the N other illumination light sources into a corresponding layer of N layers of transparent materials and to illuminate at least one other pattern.

[0029] These features allow for a plurality of patterns to be illuminated by light, each pattern having a different color.

[0030] 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

[0031] The figures are presented for information purposes only and in no way limit the invention. Figures 1a and 1b illustrate an example of a display screen according to the state of the art; illustrate the method for manufacturing a relief pattern according to the invention; illustrate an example of a relief pattern according to the invention; illustrate an example of a transparent film suitable for guiding light comprising a plurality of layers of a transparent material. DETAILED DESCRIPTION

[0032] The figures are presented for information purposes only and in no way limit the invention.

[0033] andillustrate a display screen comprising a transparent film adapted to guide light according to the state of the art.and have been described in relation to the state of the art.

[0034] illustrates the method 200 of manufacturing a relief pattern in a transparent film adapted to guide light according to the invention. The transparent film comprises a first layer of a first transparent material.

[0035] The method 200 according to the invention comprises a step 201 of etching in the first layer of transparent material a pattern suitable for extracting the light guided inside the transparent film. This step makes it possible to define the shape of the patterns illuminated by the light propagating inside the transparent film. According to one embodiment, the etching step 201 is a microetching step.

[0036] The method 200 according to the invention further comprises a step 202 of exposing the transparent film by ultraviolet radiation. This step makes it possible to freeze the patterns engraved during step 201. According to one embodiment, the exposure step 201 further comprises a step of polymerizing the transparent film.

[0037] According to one embodiment, the method 200 according to the invention further comprises a step of producing marks 203 in the transparent film, the marks being configured to position the pattern adapted to extract the light relative to the relief pattern. This step makes it possible to precisely align the relief pattern and the illuminated pattern so as to be able to obtain the desired effect.

[0038] The method 200 according to the invention further comprises a step 204 of forming the relief pattern in an area of ​​the transparent film.

[0039] According to one embodiment, step 204 of forming the relief pattern is a step of thermoforming the transparent film. Thanks to its flexibility, the transparent film can adhere to a mold during the thermoforming step.

[0040] According to another embodiment, step 204 of forming the relief pattern is carried out by pressing on the transparent film.

[0041] According to an embodiment of the method 200 according to the invention, the transparent film comprises an integer N greater than or equal to 1 of layers of transparent materials superimposed with the first layer of the first transparent material. In this case, the method 200 comprises, before the step of exposing the transparent film, a step of etching 201N in at least one of the N layers of transparent materials, at least one other pattern.

[0042] According to this embodiment, it is possible to obtain a relief pattern comprising several independent illuminated patterns.

[0043] illustrates an example of a decorative structure 300 comprising a relief pattern 301. The decorative structure 300 further comprises a transparent film or light guide 302.

[0044] The device 300 according to the invention further comprises a light source 303 adapted to inject light into the waveguide 302.

[0045] The light guide 302 comprises a first layer of a transparent material in which one or more patterns 304 are etched. The patterns 304 are adapted to extract the light propagating inside the guide 302. For this reason, the patterns 304 appear illuminated when the device 300 is illuminated.

[0046] In the example illustrated in , the relief pattern 301 is surrounded by the engraved patterns 304.

[0047] According to another embodiment of the decorative structure 300, the decorative structure further comprises N other light guides and N other light sources. This illustrates the case with N = 3.

[0048] Thus, with reference to the, which represents another example of embodiment of decorative structure 300, the latter here comprises a first light source S1, a second light source S2, and a third light source S3. The structure 300 further comprises a first light guide G1, a second light guide G2 and a third light guide G3. For example, the first light guide G1, the second light guide G2 and the third light guide G3 are parallelepipedal in shape.

[0049] The transparent film 302 is a multi-layer structure, having a front face and a back face, and comprising a first layer C1, a second layer C2 and a third layer C3. The first layer C1, the second layer C2 and the third layer C3 are superimposed. The front face and the back face are substantially parallel. The transparent film 302 is flexible. Typically, the thickness of the first layer C1, the second layer C2 and the third layer C3 is of the order of 50 microns.

[0050] The first layer C1 comprises first microengravings forming a first pattern M1. The second layer C2 comprises second microengravings forming a second pattern different from the first pattern M1. The third layer C3 comprises third microengravings forming a third pattern different from the first pattern M1 and the second pattern M2. The second and third patterns are not shown in the.

[0051] Typically, the first microengravings, the second microengravings and the third microengravings are etched respectively in the first layer C1, in the second layer C2 and in the third layer C3 by ultraviolet radiation printing.

[0052] According to one embodiment, each of the N light guides has a different engraved pattern. It is then possible to independently illuminate each engraved pattern with a different wavelength.

[0053] Each light source is adapted to inject light into one of the light guides. According to one embodiment, the N light sources can emit in different spectral regions,

[0054] When light enters the first layer C1, only the portion of the first layer C1 with the first micro-engravings scatters light, or in other words, is illuminated. When light enters the second layer C2, only the portion of the second layer C2 with the second micro-engravings scatters light, or in other words, is illuminated. When light enters the third layer C3, only the portion of the third layer C3 with the third micro-engravings scatters light, or in other words, is illuminated.

[0055] Each of the first layer C1, the second layer C2 and the third layer C3 may be polycarbonate, PMMA, PET (polyethylene terephthalate), or TPU (thermoplastic polyurethane). For example, the first layer C1, the second layer C2 and the third layer C3 may be components from Azumo™. These components have a transparency greater than 97%, a light extraction efficiency, when illuminated, of between 25 and 80%, and may have a luminance ranging from 100 to 1000 cd / m² when illuminated by a light source

[0056] The transparent film 302 comprises a light entry face 305. The light entry face 305 is substantially perpendicular to the front face and the back face. For example, the light entry face 305 consists of one of the two side edges of the transparent film 302.

[0057] With reference to the example of the, the first light guide G1, the second light guide G2 and the third light guide G3 are superimposed. The first light guide G1, the second light guide G2 and the third light guide G3 are furthermore attached to the light entry face 6 so as to ensure optical coupling with the light entry face 6. The first light guide G1 is juxtaposed with the first layer C1. The second light guide G2 is juxtaposed with the second layer C2. The third light guide G3 is juxtaposed with the third layer C3.

[0058] The first light source S1 is configured to emit a first light beam and is positioned such that the first beam illuminates the first light guide G1. For example, the first light source S1 is positioned opposite one end of the first light guide G1.

[0059] The second light source S2 is configured to emit a second light beam and is positioned such that the second beam illuminates the second light guide G2. For example, the second light source S2 is positioned opposite one end of the second light guide G2.

[0060] The third light source S3 is configured to emit a third light beam and is positioned such that the third light beam illuminates the third light guide G3. For example, the third light source S3 is positioned opposite one end of the third light guide G3.

Claims

Method (200) for manufacturing a relief pattern with a transparent film adapted to guide light, said transparent film comprising a first layer of a first transparent material, the method (200) comprising the following steps:- etching (201) in the first layer of transparent material a pattern adapted to extract the light guided inside the transparent film,- formation (204) of the relief pattern in an area of ​​the transparent film. Method (200) according to the preceding claim, characterized in that the relief pattern is a logo. Method (200) according to one of the preceding claims, characterized in that the step of forming (204) the relief pattern is a step of three-dimensional forming of the transparent film. Method (200) according to the preceding claim, characterized in that the step of three-dimensional forming of the transparent film is a thermoforming step. Method (200) according to claim 1, characterized in that the step of forming (204) the relief pattern is carried out by pressing on the transparent film. Method (200) according to one of the preceding claims, characterized in that it further comprises a step of producing marks (203) in the transparent film, the marks being configured to position the pattern suitable for extracting the light relative to the relief pattern. Method (200) according to one of the preceding claims, characterized in that the transparent film comprises an integer number N greater than or equal to 1 of layers of transparent materials superimposed with the first layer of the first transparent material, the method comprising, transparent, a step of etching in at least one of the N layers of transparent materials, at least one other pattern, as well as a step of insolation and / or polymerization of the film. Relief pattern produced by a method according to one of the preceding claims. Decorative structure (300) capable of being illuminated, comprising:a relief pattern (301) according to claim 8;a light guide (302) comprising a first layer of a transparent material;a light source (303) for illuminating the light guide,the light guide being positioned so as to guide rays from the light source into the first layer of transparent material and to illuminate an engraved pattern (304). Decorative structure according to claim 9, wherein the relief pattern is manufactured by the method according to claim 7, the decorative structure further comprising:- N other light guides,- N other light sources for illuminating each of the N light guides, the N light sources emitting in different spectral regions, the N other light guides being positioned so as to guide rays from one of the N other light sources into a corresponding layer of N layers of transparent materials and to illuminate at least one other pattern.

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