EP2809985B1 - Device for making the appearance of a motor vehicle signal light uniform - Google Patents

Description

The present invention relates to the field of lighting and signaling of vehicles, in particular motor vehicles. It relates more particularly to a device for vehicle signaling light comprising a guide arranged to be able to guide and diffuse the light emitted by at least one LED, and in front of this an element made of transparent material intended, in combination with said guide, to homogenize and / or adapt the light emitted by the device.

The regulations in force impose, depending on the type of vehicle, different lighting or signaling lights. However, in addition to the volume of all the lights, the performance and uniformity of lighting of the individual lights thus grouped are major concerns.

Transparent auxiliary screens are already known in the prior art in which the light emitted by an auxiliary light source can be propagated, these screens being intended to equip a light, in particular a rear light, for a motor vehicle. Local discontinuities provided in the screen material constitute centers of light scattering outside these screens (see French patent publication No. 2,868,506 ).

In the German patent application DE 101 01 795 flashing lights are described, in particular front turn signals for motor vehicles, in which an auxiliary light source for position light illuminates an element arranged transversely in the space between the main light and the front window, and provides through it lighting in the same direction as that of the main light.

In the French patent application 01 00048 , published under number 2,819,040 , is described an optical or stylistic component for lighting or signaling motor vehicles. This component is made of transparent material, inside which sources of light scattering are located only at predetermined locations for diffusing the light emitted by a source associated with the lighting or signaling device concerned. This component can constitute the lens of a motor vehicle headlamp, or an insert placed in such a headlamp.

In the German patent application DE 103 11 317 is described a lighting device for a vehicle comprising a light guide comprising diffusion structures located essentially at the focus of reflective surfaces which thus allow a uniform illumination to diffuse.

• une plaque d'un matériau optique transparent formant rideau,
• ladite plaque comportant au moins un renflement allongé bilatéral, de section droite globale substantiellement circulaire, ayant son axe longitudinal moyen dans le plan moyen de ladite plaque et apte à former un guide de lumière, et
• au moins une LED placée à au moins l'une des extrémités dudit guide de lumière, avec son axe principal orthogonal à l'axe longitudinal dudit guide de lumière.

The Applicant also designed, and described in the document FR 2 953 781 A1 , a new device for a motor vehicle light, comprising a transparent optical material and at least one LED-type light source arranged to emit light rays propagating within the thickness of said transparent optical material, which essentially comprises:

• a plate of transparent optical material forming a curtain,
• said plate comprising at least one elongated bilateral bulge, of substantially circular overall cross section, having its mean longitudinal axis in the mean plane of said plate and capable of forming a light guide, and
• at least one LED placed at at least one of the ends of said light guide, with its main axis orthogonal to the longitudinal axis of said light guide.

Other devices for motor vehicle fire are described in the documents FR 2 953 276 A , FR 2934353 A and EP 0936403 A .

In these various applications and these various embodiments of luminous screens diffusing the light emitted by at least one LED, there may appear inhomogeneities in the diffused light, in particular at the level of the guides, including those with which the curtains can be fitted. or diffusing screens.

It therefore appeared useful to seek to standardize the luminous rendering of such lights comprising a light guide, or to mask possible inhomogeneities.

The subject of the present invention is a device for a motor vehicle lighting and / or signaling light as defined in claim 1 and a motor vehicle light as defined in claim 12.

The present invention thus relates to a device for the lighting and / or signaling light of a motor vehicle, incorporating a guide and in which one combines with the above-mentioned guide, and whatever the type of guide, a transparent element or screen or translucent, essentially made of an opaline type material, provided with an internal and / or external embossing and disposed between said guide and the visible face of the lamp or of the lamp assembly concerned, so as to provide a light function of homogeneous color.

The front piece forming a translucent screen provided with a graining thus provided is arranged downstream of the light guide associated with at least one LED, in the direction of diffusion of the light emitted by the LED or LEDs. It has the effect and / or the purpose of standardizing the light rendering of said curtain and thus eliminating the distribution irregularities, therefore the appearance that the lightings emanating from such light guides can have.

The subject of the invention is therefore a motor vehicle light, of the type comprising a guide for diffusing the light emitted by at least one LED capable of illuminating perpendicularly to at least one of the lateral faces of said guide, while the latter is supplemented by an element of translucent material, disposed frontally between the face of the guide facing the front face of the projector concerned and the outside, substantially perpendicular to the main direction of the light beam. This element is thus intended to cover at least partially the face determining the lighting of said light guides for LED lighting of motor vehicles.

In a preferred embodiment, the above-mentioned translucent material element is an opaline or at least predominantly opaline part, or even a part having substantially the optical characteristics of opaline or of an equivalent translucent material.

This part can constitute an additional element of a signaling device for vehicles. As a variant, it may constitute the window of the optical unit comprising the other functional elements of such a signaling light for vehicles.

In all cases, said graining can be provided on the external face and / or on the internal face of such an element, or even inside the latter. It is preferred to impart said embossing to the internal face of the aforementioned element when it is integrated in a suitable housing.

It will be shown later that said element thus grained is disposed at the front of the above-mentioned guide, with a space between them.

• sans adjonction ni retrait de matière, par traitement approprié de tout ou partie de la paroi intérieure du moule de confection de l'élément à grainer, et/ou
• par addition de matière réactive apte à générer des inclusions dans la matière servant à élaborer l'écran opalin grainé, dans les conditions de préparation de celui-ci, dans les deux cas selon des techniques connues de l'homme du métier, qui sait adapter aux besoins la rugosité conférée à l'élément ajouté au guide.

In the present description, by graining is meant the formation of discontinuities in and / or on the material concerned. Conventionally, the grained material can then be produced:

• without adding or removing material, by appropriate treatment of all or part of the interior wall of the mold for making the element to be grained, and / or
• by addition of reactive material capable of generating inclusions in the material used to prepare the grained opal screen, under the conditions of preparation thereof, in both cases according to techniques known to those skilled in the art, who can adapt as needed, the roughness given to the element added to the guide.

The material made opaline is in practice PMMA or poly (methyl methacrylate) to which are added, for example by injection, materials chosen from microbeads of material with an opalescent effect and a dispersible material, in particular for the injection and distribution of 'a gas, in particular CO ₂ , to give a random character to the opalescence produced.

The opaline material can be left whitish or be colored, in particular to appear amber or super-light blue in color, by techniques known to those skilled in the art. It can thus make it possible to provide another effect in the on state in which the color of the light emitted by the LEDs can thus be different from the color in the off state.

The piece of opaline material has dimensions allowing it to conform to the dimensions of the aforementioned light guides.

In practice, the light guides used can have a length (straight or curvilinear) of approximately 200-300 mm when they are lit by an LED at one of their ends, and even up to approximately 600 mm s' they have an LED at each of their two ends.

It might have seemed simpler to attach said translucent element to the light guide. However, it has been found that, on the contrary, it is appropriate for a good distribution and a correct preservation of the intensity of the transmitted light that a certain distance between the light guide and said translucent element be respected.

In practice, the aforementioned piece of opaline material is fixed at a distance from the light guide as described above. It is placed, in front of this guide in the direction of the path of the scattered light, at a distance which is in practice between 5 and 10 mm approximately, more preferably between 6 and 9 mm, and more advantageously between 7 and 8 mm about. The attachment of this element near the ends of the above guide or to any other support that may be available nearby is carried out without difficulty by conventional means, within the reach of the skilled person.

In the implementation of the present invention, there is also great freedom of form to satisfy the desired design function.

It should also be noted that, in such a configuration, the guide of the lighting device according to the invention becomes comparable to a filament of a virtual light source.

The aforementioned translucent element cooperates with the other elements of the lighting device and provides an overall effect which can be adapted to suit in particular by the choice of the geometry, the distance with the guide and / or the translucency characteristics of said element.

The device according to the invention is mainly intended to equip lighting systems forming lanterns, brake lights, raised brake lights, flashing lights and / or possibly daytime running lights for motor vehicles.

Depending on the case, the translucent element thus designed is in practice of crystal color or red or other color. It can comprise two parts, in total or preferably partial overlap with one another, and one of which is maintained in crystal color, while the other is in red or other color.

The invention will be better understood, and other objectives, advantages and characteristics thereof will appear more clearly, in the light of the detailed description below of embodiments of the invention.

• La figure 1 représente schématiquement une vue de dessus d'un feu arrière 1 de véhicule automobile non équipé de l'élément opalin grainé selon l'invention.
• La figure 2 représente une vue schématique de face du dispositif selon la Fig. 1, mais muni de l'élément 5 avec grainage 6 selon l'invention.
• La figure 3 représente schématiquement une vue en coupe longitudinale selon C-C du dispositif selon l'invention, intégré dans un ensemble comme schématisé dans la Fig. 2.
• La figure 4 représente (Figs. 4A, 4B, 4C) une coupe transversale schématique partielle selon A-A d'un dispositif d'éclairage, comportant une pièce de matière translucide 5 munie d'un grainage 6 selon la Fig. 2.

These embodiments are provided for purely illustrative and non-limiting purposes, while annexed to said description are the drawing boards in which:

• The figure 1 shows schematically a top view of a rear light 1 of a motor vehicle not equipped with the grained opaline element according to the invention.
• The figure 2 represents a schematic front view of the device according to the Fig. 1 , but provided with the element 5 with graining 6 according to the invention.
• The figure 3 schematically represents a view in longitudinal section along CC of the device according to the invention, integrated into an assembly as shown schematically in the Fig. 2 .
• The figure 4 represented ( Figs. 4A, 4B, 4C ) a partial schematic cross section along AA of a lighting device, comprising a piece of translucent material 5 provided with a graining 6 according to the Fig. 2 .

In the embodiment shown in the appended figures, the motor vehicle rear light device 1 according to the invention thus combines with a guide 3, advantageously incorporated in a structure or a housing 4 and capable of being lit by a light source 2, a translucent screen 5 provided with a graining 6.

An external, transparent screen can also be provided by the cover of the box containing the lighting fire device.

The invention thus preferably relates to a motor vehicle light, of the type comprising a guide 3 for the diffusion of the light emitted by at least one LED 2 illuminating perpendicularly to at least one of the side faces of said guide 3, further comprising a screen 5 made of translucent material provided with a graining 6, disposed frontally between the face of the guide 3 turned towards the front face of the projector concerned and the outside, substantially perpendicular to the main direction of the light beam.

The device advantageously has one or more LEDs 2 for a light source, the light beam of which is channeled by a guide 3 of the type mentioned above, and dispersed by this guide (provided with appropriate cavities / asperities, conventionally constituted by prismatic entities, designed or integrated by means and according to arrangements known to those skilled in the art) in a curtain 4. The device 1 according to the invention has been found to provide as main positive effect the homogenization of the lighting provided by these elements, also well to the right of this set of elements only under an offset viewing angle.

The intensity of the light thus better diffused and better distributed was maintained at a satisfactory level taking into account the standards in force.

The profile of an average cross section of said piece forming a translucent curtain can be arbitrary; it is preferably similar or equivalent to one of those illustrated by way of examples in the Fig. 4 (see 4A, 4B and 4C). It can thus, for example, and without this being limiting, be a profile in a bowl with rounded internal bottom facing the bead forming light guide 3, or a U-shaped profile whose width can vary between 10 and 25 mm approximately, or a profile in a bowl, the rounded bottom of which is surmounted by a cover plate 7 carrying the graining elements 6 capable of giving it opalescence. As for the guide 3, it has on its rear part conventional prisms 8.

According to one embodiment, the device according to the invention comprises a part as described above, having an elongated shape having a length of approximately 210-310 or 610 mm, and a width of approximately 10-20 mm , preferably about 15 mm.

Such a U-shaped piece of approximately 15-25 mm in width constitutes an appropriate means for imparting style or signature effects to the lighting device.

In the cases thus presented as illustrative examples, as well as in others, the opalescent part covering the light guides is preferably made opalescent on its external faces, in such a way that the incident rays are deflected by the elements. conferring opalescence and are thus diffused according to a wider and more homogeneous spatial distribution.

Claims (12)

1. A device for a motor vehicle lighting and/or signal lamp incorporating a light guide (3) and, between the light guide and a translucent screen (5), the screen being translucent and provided with graining (6) on one or the other or both of its main faces suitable for being passed through by the light emitted by the light guide, characterized in that the screen (5) is placed, in front of said guide (3) in the direction of the scattered light path, at a distance of about 5 mm to 10 mm, in order to om said guide to provide a light function of uniform color.
2. The device as claimed in claim 1, in which the translucent screen (5) is provided with graining (6) on one or the other or both of its main faces suitable for being passed through by the light emitted by one or multiple LEDs (2).
3. The device as claimed in claim 1 or 2, in which said screen of translucent material (5) is a part made from opaline or primarily opaline or indeed a part having optical characteristics substantially like those of opaline or an equivalent translucent material.
4. The device as claimed in any one of claims 1 to 3, in which the graining (6) of the translucent screen (5) is internal and/or external to the material of said translucent screen.
5. The device as claimed in any one of claims 1 to 4, characterized in that the translucent screen (5) is composed of polymethyl methacrylate to which is added, for example by injection, materials chosen amongst the material microbeads that have an opalescent effect and a dispersive material, notably for the injection and distribution of a gas, notably CO₂, to give the opalescence produced a random character.
6. The device as claimed in any one of claims 1 to 5, characterized in that the opaline-type translucent material (5) is left off-white.
7. The device as claimed in any one of claims 1 to 5, characterized in that the translucent material (5) is colored, notably to appear amber colored or super-light blue, and allows another effect to be provided in the illuminated state in which the color of the light emitted by the LEDs can thus be different from the color in an extinguished state.
8. The device as claimed in any one of claims 1 to 7, characterized in that the translucent material part (5) is placed at a distance of about 7 mm to 8 mm from the light guide (3).
9. The device as claimed in any one of claims 1 to 7, characterized in that the translucent material part (5) is placed at a distance of about 6 mm to 9 mm from the light guide (3).
10. The device as claimed in any one of claims 1 to 9, characterized in that the translucent screen (5) has a recessed profile with a rounded internal bottom turned towards the bead forming the light guide (3), or a recessed profile of which the rounded bottom is overlaid by a covering plate (7) having graining elements (6) suitable for providing it with an opalescence, or indeed a U-section of a width than can vary between approximately 10 mm and 25 mm.
11. The device as claimed in any one of claims 1 to 10, characterized in that it is used to equip lighting systems forming side marker lamp, stop lamp, high-mounted stop lamp, indicator and/or possibly a front daytime running lamp of motor vehicles.
12. A lamp for a motor vehicle, of the type having a light guide (3) for diffusion of the light emitted by at least one LED (2) illuminating perpendicularly to at least one of the lateral faces of said guide (3), the lamp comprising a screen (5) of translucent material provided with graining (6), on one or the other or both of its main faces suitable for being passed through by the light emitted by the light guide, the screen being arranged frontally between the face of the light guide (3) turned towards the front face of the projector concerned and the exterior, effectively perpendicularly to the main direction of the light beam, characterized in that the screen (5) is placed, in front of said guide (3) in the direction of the scattered light path, at a distance of about 5 mm to 10 mm, in order to om said guide to provide a light function of uniform color.

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