EP2647750A1 - Illuminating fabric and illuminating registration plate - Google Patents

Abstract

The illuminating fabric has a flexible frame (206) including a reflecting thread (404), and an assembly of regular fibers or intersected threads, where some of the fibers are optical fibers (406) intended to be traversed by light rays, so as to diffuse the light rays laterally. The frame includes translucent chain threads (402) and weft threads, where the optical fibers and the reflecting thread are weft threads. The reflecting thread includes a main thread coated with transparent particles such as microballs and micro-prisms. The reflecting thread is Scotchlite (RTM: reflective material). An independent claim is also included for an illuminating registration plate.

Description

Technical area

The present invention relates to an illuminating fabric and an illuminating license plate.

The invention may in particular apply in the field of equipment and vehicle signaling.

State of the art

Several companies market, for example under the names Lightex® and Luminex®, side-illuminated fiber optic weaves connected to light-emitting diodes and allowing to realize flexible or rigid luminous surfaces with very small dimensions, low consumption and long service life. .

This type of weaving offers visibility that can be used for aesthetic or safety reasons.

However, it may be desired to have a weave offering another type of visibility.

Presentation of the invention

For this purpose, it is proposed an illuminating fabric comprising a frame which is flexible and comprises a regular assembly of fibers or intertwined son, part of which are optical fibers to be traversed by light rays and to diffuse laterally, characterized in that the weft further comprises retro-reflective threads.

Thanks to the proposed lighting fabric, it is obtained very simply, without adding an additional layer, a retro-reflective effect. The double illuminating and retro-reflective effect is useful in many applications, such as for example road signs and vehicle-mounted lighting and information elements such as license plates, or even interior elements. vehicle, or even safety clothing, or any other application that uses fabrics, especially those requiring optical properties.

Optionally, the weft includes warp and weft yarns, and the optical fibers and retro-reflective yarns are weft yarns.

Optionally also, the weft son comprise an alternation of optical fibers and retro-reflective son.

Optionally also, the weft son comprise alternating optical fibers, retro-reflective son and optically neutral son.

Optionally also, the warp son are translucent.

Also optionally, each optical fiber has a treatment over all or part of its length to let the light escape laterally.

Also optionally, each retro-reflective yarn comprises a main yarn coated with transparent particles on all or part of its surface.

Also optionally, the particles are microbeads.

Also optionally, the particles are micro-prisms.

It is also proposed an illuminating license plate, comprising: a housing open towards the front of a front-rear direction; a transparent plate extending into the housing; an illuminating fabric as defined above, extending into the housing behind the transparent plate; and a light source for providing the light rays to the illuminating fabric.

Brief description of the drawings

• The figure 1 is a front view of an illuminating number plate embodying the invention.
• The figure 2 is a sectional view along line II-II of the figure 1 .
• The figure 3 is a sectional view along line III-III of the figure 2 .
• The figure 4 is an enlarged view of a frame of a fabric illuminating the license plate of the preceding figures.
• The figure 5 is a sectional view along line VV of the figure 4 , a reflective thread from the frame of the figure 4 .
• The figure 6 is a block diagram illustrating steps of a method of manufacturing the illuminating number plate of the preceding figures.
• The figure 7 is a block diagram illustrating steps of a method of operation of the illuminating license plate of the preceding figures.

Examples of implementation of the invention

Examples of implementation of the invention will now be described with reference to the figures.

In the following description, the elements will be located relative to each other according to an arbitrary reference defined by directions: left - right, denoted GD, high - low, denoted HB, and front - back, denoted Av - Ar.

With reference to the figure 1 an illuminating number plate 100 is shown from the front.

The illuminating number plate 100 firstly comprises a housing 102 of generally rectangular shape having a long side in the direction G-D and a short side in the direction H-B. The housing 102 is open towards the front of the Av-Ar direction and closed on the other sides.

The illuminating number plate 100 further comprises a transparent plate 104. The term "transparent" indicates a light transmission rate of greater than 80%. The transparent plate 104 is of generally rectangular shape like the housing 102 and extends in the latter except for a chamber 106 defined in the housing 102. In the example described, this chamber 106 extends on the left side of the housing 102. A registration number 108 (which may include all types of symbols, in particular letters and numbers) is further printed in an opaque material on a transparent film (not shown) adhered to the transparent plate 104, on the back side of the latter. Alternatively, the registration number 108 could be directly printed on the transparent plate 104.

The illuminating license plate 100 further comprises a material 110 filling the chamber 106 of the housing 102, next to the transparent plate 104. In the example described, the material 110 is a solid molding. Alternatively, the chamber 106 could be filled with liquid material, such as a monomeric fluid, for example silicone oil.

With reference to the figure 2 , the illuminating number plate 100 further comprises a light guide 204 extending behind the transparent plate 104 and intended to diffuse light rays towards the front, that is to say towards the transparent plate 104. light guide 204 is an illuminating fabric. The illuminating fabric 204 firstly comprises a frame 206 which is flexible and comprises a regular assembly of fibers or intertwined threads, at least a portion of which are optical fibers. The optical fibers of the illuminating fabric 204 are intended to be traversed by light rays and to diffuse them laterally. The optical fibers are for example made of polymethyl methacrylate (abbreviated as PMMA, of "Polymethyl Methacrylate ").

The optical fibers of the frame 206 have protruding ends 208 relative to the frame 206 on one side thereof in the chamber 106 of the housing 102. In the example described, the projecting ends 208 of the illuminating fabric 204 protrude from the left side of the weft 206. The projecting ends 208 are substantially aligned along the HB direction. Preferably, there are between 5 and 15 protruding ends 208 per centimeter along the HB direction. In addition, the projecting ends 208 extend substantially parallel to each other along the direction GD. For example, they are parallel to each other within 10 °, preferably to 5 °. As the projecting ends 208 are not grouped together as in the state of the art, they are all spaced from each other and therefore do not touch.

Each projecting end 208 is terminated by a light input section 210 for receiving the light rays. As the light entry sections 210 are not polished as in the state of the art, they are rough, that is to say that their surface state is rough cut: during the manufacture of the illuminating fabric 204, no polishing step of the light entry sections 210 is provided after cutting the optical fibers.

The illuminating number plate 100 further comprises a light source 212 extending into the space 106 of the housing 102. The light source 212 has a lighting surface 214 for sending the light rays towards the light entry sections 210. The illuminating surface 214 extends substantially opposite the light entry sections 210, at a distance from the latter, so that the projecting ends 208 of the optical fibers are substantially perpendicular to it, for example to 5 ° near. The illuminating surface 214 has a refractive index between 1.4 and 1.6, for example between 1.49 and 1.53, and preferably equal to 1% close to the refractive index of the material 110 filling the gap. room 106.

The protruding ends 208 of the illuminating fabric 204 and the light source 212, at least its illuminating surface 214, are embedded in the material 110. Thus, each projecting end 208 is separated from the illuminating surface 214 only by the material 110. This material 110 has a refractive index greater than that of air. This refractive index is for example between 1.3 and 1.7, for example between 1.4 and 1.6, and preferably equal to the refractive index of the optical fibers of the illuminating fabric 204 (and therefore in particular projecting ends 208 optical fibers) to 1%. In the case where the optical fibers are of PMMA having a refractive index of 1.51, the material 110 therefore has a refractive index close to 1.51, for example a refractive index of 1.52. For example, in the example described, the molding 110 is formed of the same material as the optical fibers, such as PMMA, to ensure the proximity of the refractive indices.

In this way, there is no interface on the path of the light rays with a medium (such as an air cavity) having a refractive index very different from that of the illuminating surface 214 and the optical fibers of the light. 204. The light rays are thus deviated a little way in this path and a large number of them can reach a light input section 210 with an angle of incidence allowing them to enter the corresponding optical fiber.

The housing 102 has walls delimiting the chamber 106 and which are in contact with the material 110. To further improve the light coupling between the light source 212 and the optical fibers, these walls are provided with a reflective coating 216, so that the light rays that would not have reached a light input section 210 are reflected in the chamber 106 and may eventually return to a light input section 210 with an angle of incidence allowing them to enter the optical fiber corresponding.

With reference to the figure 3 , the light source 210 comprises several elementary light sources 302 aligned along the direction HB. On the figure 3 the references are applied for only one of the elementary light sources 302. In the example described, the elementary light sources 302 are light-emitting diodes. Each light-emitting diode 302 comprises a semiconductor 304 and an outer envelope 306 directly in contact with the semiconductor 304. The illuminating surface 214 thus corresponds to the face of the outer envelope 306 directed towards the projecting ends 208. This outer envelope 306 is for example made of polyepoxide having a refractive index of between 1.55 and 1.65.

With reference to the figure 4 , the weft 206 of the illuminating fabric 204 comprises warp yarns 402 and weft yarns 404, 406.

The weft yarns 404, 406 comprise an alternation of optical fibers 406 forming illuminating fibers and retro-reflecting yarns 404. In the example described, the optical fibers 406 and the retroreflective yarns 404 alternate one by one. In other embodiments, other alternations could be used, for example two by two or one by two. Each optical fiber 406 has a treatment over all or part of its length in order to let the light escape laterally, as is done, for example, in the fabrics sold under the name Lightex® or Luminex®.

The warp yarns 402 are transverse to the weft yarns 404, 406, and preferably translucent, that is to say having a light transmission rate of between 30% and 80%, so as not to mask the effects of the yarns. illuminating wires 406 and / or retroreflective wires 404.

The density, the alternation and, more generally, the relative position of the retroreflective yarns 404 and the optical fibers 406 are adapted to the desired effects.

Thus, to obtain important illuminating properties or lower retro-reflective properties, the illuminating fabric 204 will be designed so that the optical fibers 406 have a density greater than or equal to 12 fibers per centimeter along the H-B direction. Conversely, to obtain strong retro-reflection properties, as is often desired in road sign applications, the fabric 204 will be designed such that the retro-reflective yarns 404 have a density greater than or equal to 15 threads. per centimeter along the HB direction.

Furthermore, in a variant not shown, the illuminating fabric comprises, alternately with the optical fibers and retro-reflective son, optically neutral son, that is to say, non-illuminating and non-retro-reflective and preferably translucent . The insertion of these neutral son also allows to modulate the illuminating and reflective properties of the fabric.

Also in a variant not shown, the warp son include, in addition to translucent son, retro-reflective son.

Thus, by playing on the various parameters presented above, it is possible to easily design a fabric having the illuminating and retroreflective properties sought.

On the other hand, the illuminating number plate 100 includes a current regulator 408 and a power supply connector 410 to which the light source 212 is connected via the current regulator 408. In an improvement, a switch (no shown) is also provided, for example between the power supply connector 410 and the current regulator 408.

With reference to the figure 5 each retroreflective thread 404 comprises a main wire 502 of circular cross-section, for example of aluminum, coated on all or part of its surface with transparent microbeads 504.

As a variant not shown, the transparent microbeads 504 may be replaced by transparent micro-prisms.

In a variant not shown, the retro-reflective yarns are flat yarns such as those sold under the name 3M Scotchlite® by the company 3M.

With reference to the figure 6 a method 600 for manufacturing the illuminating number plate 100 first comprises (step 602) the insertion of the light source 212 into the chamber 106 of the housing 102, so that the illuminating surface 214 faces the chamber 106 of the housing 102.

The manufacturing method 600 further comprises (step 604) inserting the illuminating fabric 204 into the housing 102, as shown in FIG. figure 2 . In particular, the projecting ends 208 of the optical fibers 404 extend into the chamber 106 of the housing 102 opposite the illuminating face 214.

The manufacturing method 600 further comprises (step 606), while the projecting ends 208 are kept substantially parallel to each other and perpendicular to the illuminating surface 214, the casting of liquid material in the chamber 106 of the housing 102, so as to drown the projecting ends 208 and the illuminating face 214.

The manufacturing method 600 further comprises (step 608) the solidification of the cast material so that it becomes solid and forms the molding 110. Of course, in the case where the material 110 is intended to remain liquid, the step of solidification is omitted.

The manufacturing method 600 further comprises (step 610) the printing of the registration number on the transparent film.

The manufacturing method 600 further comprises (step 612) the bonding of the transparent film printed on one side of the transparent plate 104.

The manufacturing method 600 further comprises (step 614), on the one hand, the insertion of the transparent plate 104 in the housing 102, so that the face on which the transparent printed film is glued forms the rear face of the transparent plate 104, and, secondly, the fixing of the transparent plate 104 to the housing 102, for example in a non-removable manner.

With reference to the figure 7 , a method 700 of operation of the illuminating number plate 100 comprises first (step 702) the generation of light rays by the light source 212.

The operating method 700 further comprises (step 704) traversing the material 110 by the light rays, until reaching the input sections of light 210 with an angle allowing entry into the corresponding optical fiber 404.

The operating method 700 further comprises (step 706) the lateral scattering of the light rays along the optical fibers 404.

The operating method 700 further comprises (step 708) the reception of light rays from the front of the illuminating number plate 100, and the crossing, by these light rays, of the transparent plate 104 until reaching the fabric illuminating 204, where they are reflected.

The operating method 700 further comprises (step 710) the passage of the light rays from the light source 212 and the reflected light rays, through the transparent plate 104 to exit through the front of the illuminating number plate 100.

The invention is not limited to the embodiment described above, but instead defined by the following claims.

It will be apparent to those skilled in the art that, in the light of the teaching that has just been given to them, various modifications can be made to the previous embodiment.

For example, optical fibers may be polycarbonate instead of PMMA. In this case, the refractive index intervals indicated above will be adjusted.

Moreover, in the following claims, the terms used should not be interpreted as limiting the claims to the elements of the implementation examples described above, but must be interpreted to include all equivalents whose forecasts are within the scope of the person skilled in the art by applying his general knowledge. <u> List of references: </ u> 100 First illuminating license plate 102 Housing 104 Transparent plate 106 Bedroom 108 Registration number 110 Material / Molding 204 Light guide / Illuminating fabric 206 weft 208 Protruding ends 210 Light input sections 212 Light source 214 Illuminating face 216 Reflective coating 302 Elementary light sources 304 Semiconductor 306 External envelope 402 Chain yarn 404 Retro-reflective yarns 406 Optical fiber 408 Current regulator 410 Power supply connector 502 Main wire 504 microbeads 600 Manufacturing process 602 Insertion of the illuminating fabric 204 in the housing 102 604 Inserting the light source 216 into the space 106 of the housing 102 606 Pouring liquid material into the space 106 of the housing 102 608 Drying of the casting material 610 Transparent film printing 612 Collage of the transparent film printed on the transparent plate 104 614 Inserting into the housing 102 and fixing the transparent plate 104 700 Operating method 702 Generation of light rays by the light source 212 704 Crossing the molding 106 by the light rays 706 Lateral diffusion of light rays along optical fibers 404 708 Reception of light rays from the front of the number plate 100 710 Passage of the light rays through the transparent plate 104 to exit from the front of the number plate 100

Claims (10)

An illuminating fabric having a weft (206) which is flexible and comprises a regular assembly of intertwined fibers or threads, a portion of which are optical fibers (406) to be traversed by light rays and to diffuse them laterally, characterized in that that the frame (206) further comprises retroreflective son (404). An illuminating fabric according to claim 1, wherein the weft (206) comprises warp yarns (402) and weft yarns (404, 406), and wherein the optical fibers (406) and retroreflective yarns (404) ) are weft threads. An illuminating fabric according to claim 2, wherein the weft yarns comprise an alternation of optical fibers (406) and retro-reflective yarns (404). An illuminating fabric according to claim 3, wherein the weft yarns comprise an alternation of optical fibers (406), retro-reflective yarns (404) and optically neutral yarns. An illuminating fabric according to one of claims 1 to 4, wherein the warp threads (402) are translucent. An illuminating fabric according to one of claims 1 to 5, wherein each optical fiber (406) has a treatment over all or part of its length to let the light escape laterally. An illuminating fabric according to one of claims 1 to 6, wherein each retroreflective yarn has a main yarn (502) coated with transparent particles (504) over all or part of its surface. The illuminating fabric of claim 7 wherein the particles are microbeads. An illuminating fabric according to claim 7, wherein the particles are micro-prisms. Illuminating license plate, comprising: a housing (102) open towards the front of a front-rear direction (Av-Ar), a transparent plate (104) extending in the housing (102), - an illuminating fabric according to one of claims 1 to 9, extending in the housing (102) behind the transparent plate (104), a light source (212) for supplying the light rays to the illuminating fabric (204).

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