EP1039215B1 - Improved signal light for motor vehicle comprising a plurality of light sources - Google Patents

Description

The present invention relates generally to multi-source signal lights for motor vehicles, and in particular to lights having as a light source a distributed set of light-emitting diodes.

In a known manner, such a light-emitting diode (LED) signaling light has, in association with each LED, an optics capable of distributing the light emitted by the LED in a given illumination field. An advantage of this type of fire is that its off aspect can be completely colorless, the LEDs emitting directly radiation (red, amber or color white regulatory).

The documents FR 2 707 223 A and FR 2 711 215 A describe signaling lamps of this type, each LED being associated with an individual miniature reflector for recovering the radiation emitted by the LED with a steep inclination with respect to its main direction. 'program. Optical arrangements such as Fresnel lenses are also provided at the right of each LED to collimate its radiation in the main direction of emission, generally parallel to the longitudinal axis of the vehicle.

The spatial distribution of the light at the output of these Fresnel lenses, intended to fill the regulatory photometric grid, is ensured for example by an external screen having a spherical or toric shot, or by other optical elements provided on the optical part. carrying the Fresnel lenses.

A difficulty with this type of known fire is that, if we consider an elementary subset consisting of an LED, its recuperator and its optical, this subset illuminates a certain area of the photometric grid, but not optimally. In particular, the homogeneous and complete filling of the regulatory lighting field of the fire requires the use of a large number of LEDs.

But while this requirement is not particularly restrictive with LEDs of low power, it becomes troublesome when one wishes to use more powerful LEDs, that the technological evolution makes it possible to realize today, by decreasing the number of those -this.

In this respect, a filling of the illumination field with subassemblies which each illuminate a specific field of this field leads to an aesthetic disadvantage when the light is on and we are moving in front of it. this means that depending on the position of the observer, some LEDs will appear lit and others off, and this distribution between LEDs "on" and LEDs "off" will vary.

Thus the illuminating surface observable at the outer surface of the fire indicator will be relatively indefinite and variable, which is undesirable.

The present invention proposes to overcome these limitations of the state of the art, and aims to provide a multiple LED signaling light which on the one hand can have a relatively small number of LEDs, and on the other hand offers the observer, in any position thereof at least in the regulatory illumination field of the light function considered, the vision of the light generated by each of these LEDs, this in order to obtain in all circumstances the impression of a homogeneous matrix fire of well-defined contours.

Another object of the invention is to obtain, together with such optical properties, a signaling light which has, both on and off, a new aspect particularly interesting for stylists.

Thus, the present invention proposes a signaling light for a motor vehicle, comprising a plurality of light sources such as light-emitting diodes and means for optically processing the light from the sources to generate a signaling beam in an illuminating range of given range. , said processing means comprising an optical processing element at the right of each of said sources, and an optical indicator substantially optically inactive, characterized in that each optical processing element is constituted by an individual balloon able to perform a distribution. light received throughout the illuminating range, said individual balloons being mounted to the right of openings formed in a support.

• les ballons sont de forme générale hémisphérique creuse, leur face concave étant tournée vers la source respective.
• les ballons sont tous de même taille.
• les ballons sont tous identiques.
• chaque ballon possède une face intérieure pourvue d'une multiplicité de facettes de répartition de la lumière.
• chaque ballon possède une face extérieure lisse.
• chaque ballon possède une face extérieure partiellement lisse et partiellement striée.
• ledit support est formé par une plaque commune d'ossature et de style possédant une pluralité de logements pour les sources lumineuses et une pluralité de surfaces de montage pour les ballons.
• ladite plaque commune est opaque.
• la plaque commune définit entre lesdits logements et lesdites surfaces de montage des récupérateurs de flux généralement coniques.
• lesdites surfaces de montage sont des surfaces annulaires prévues au fond d'une pluralité d'évidements s'étendant à partir d'une paroi de style appartenant à ladite plaque commune.
• le voyant est galbé, et ladite paroi de style est également galbée pour sensiblement épouser ledit voyant.
• lesdites surfaces de montage annulaires s'étendent dans des plans parallèles entre eux.
• lesdites surfaces de montage annulaires sont positionnées par rapport à la paroi de style de telle sorte que les sommets de ballons affleurent sur des prolongements imaginaires de ladite paroi de style au niveau des évidements.
• lesdits ballons et ledit voyant sont incolores.
• les sources lumineuses émettent un rayonnement coloré.
• en vue de face, les ballons occupent une surface inférieure à environ la moitié de la surface du feu.

Preferred, but not limiting, aspects of this traffic light are the following:

• the balloons are generally hollow hemispherical in shape, their concave face being turned towards the respective source.
• the balloons are all the same size.
• the balloons are all identical.
• each balloon has an inner face provided with a multiplicity of facets of light distribution.
• each balloon has a smooth outer face.
• each balloon has a partially smooth outer face and partially striated.
• said support is formed by a common framework and style plate having a plurality of housing for the light sources and a plurality of mounting surfaces for the balloons.
• said common plate is opaque.
• the common plate defines between said housings and said mounting surfaces generally tapered flow recuperators.
• said mounting surfaces are annular surfaces provided at the bottom of a plurality of recesses extending from a wall of a style belonging to said common plate.
• the indicator is curved, and said style wall is also curved to substantially match said indicator.
• said annular mounting surfaces extend in planes parallel to each other.
• said annular mounting surfaces are positioned relative to the styling wall such that the ball peaks are flush with imaginary extensions of said styling wall at the recesses.
• said balloons and said sight are colorless.
• the light sources emit a colored radiation.
• in front view, the balloons occupy an area less than about half the surface of the fire.

• la figure 1 est une vue schématique et partielle en perspective d'une cellule optique d'un feu de signalisation selon l'invention,
• la figure 2 est une vue schématique et partielle en coupe axiale de la cellule optique de la figure 1,
• la figure 3 est une vue schématique en coupe horizontale d'un feu de signalisation selon l'invention, incorporant une pluralité de cellules optiques selon les figures 1 et 2,
• la figure 4 est une vue partielle de face du feu de signalisation de la figure 3, et
• la figure 5 est une vue schématique et partielle en coupe axiale d'une variante de réalisation d'une cellule optique selon l'invention.

Other aspects, objects, and advantages of the present invention will become more apparent upon reading the following detailed description of preferred embodiments thereof, given as a non-exemplary example. and with reference to the accompanying drawings, in which:

• FIG. 1 is a schematic and partial perspective view of an optical cell of a signaling light according to the invention,
• FIG. 2 is a schematic and partial view in axial section of the optical cell of FIG. 1,
• FIG. 3 is a schematic view in horizontal section of a signaling light according to the invention, incorporating a plurality of optical cells according to FIGS. 1 and 2,
• FIG. 4 is a partial front view of the traffic light of FIG. 3, and
• FIG. 5 is a schematic and partial view in axial section of an alternative embodiment of an optical cell according to the invention.

Referring firstly to FIGS. 1 and 2, there is shown partially an optical cell of a signaling light according to the invention, this cell comprising a light-emitting diode (LED) whose substantially parallelepipedal housing 10 has on one side the source proper 11, of main transmission axis xx and a substantially hemispherical hollow balloon 20 for optical processing of the light from the LED.

This balloon 20, preferably made of colorless transparent molded plastic, is intended to perform a spatial distribution of this light so as to fill in a controlled manner the photometric grid imposed by the specifications and regulations, depending on the type of fire (position, stop, recoil, flashing, fog, ...).

In the present example, the outer face of this balloon is smooth, and its inner face has a plurality of individual facets 21 for performing the aforementioned distribution.

The orientation of these different facets is preferably carried out with computer-aided design means, which does not pose any particular difficulties for a person skilled in the art.

It is of course possible, alternatively, to provide that the light distribution dioptres are formed on the outside of the balloon 20, or both on the inside and on the outside of the balloon.

It can also be provided that these diopters are formed by projection of cylindrical type patterns, parabolic, possibly combined with a prismatic function, in a manner well known to those skilled in the art.

As will also be seen later, it is possible for one of the faces of the balloon to deal with the distribution of light in a given first direction, for example a vertical direction, and for the other face of the balloon to deal with the distribution of light in the orthogonal direction, in this case horizontal.

Figure 2 illustrates in more detail the case where the balloon 20 is, as indicated above, smooth on its outer face 22 and provided with facets 21 on its inner face. It is interesting to observe here that the facets 21 are joined to each other by flanking surfaces 211 which have the property of being also, at least for some, optically active (see radius R1).

The number of such cells in a traffic light is chosen mainly according to the light power available at each LED, knowing that advances in technology now allow LEDs to be more and more powerful. Thus, for a fire made today with 25-watt filament lamps (including stop and flashing lights), regulatory minimums can be reached with a fire with 10 to 15 LEDs.

Figure 3 schematically illustrates a fire according to the invention, comprising three rows of four cells, and illustrates one of these rows.

This fire has a housing or pedestal 30 closed at the front by a transparent 40, advantageously smooth and colorless to give the fire a "showcase" aspect particularly sought after today by stylists.

The LEDs 10 are electrically powered from a common support 12 (or by independent supports), and are received in an optical mounting and recovery plate 50, fixed inside the fire by means not shown. More specifically, this plate has a set of conical cavities 51 having at their bottom a respective opening 55 of dimension adapted to the LED, in which it is mounted from the rear. This plate 50 is advantageously designed so as to be reflective (for example by a method of vacuum metallization), so that the conical surfaces of the cavities 51 recover the light emitted by the respective LEDs with an inclination greater than half the angle at top of the cone, to straighten this light towards the main direction of emission xx.

It is also observed that each conical cavity is surmounted by an annular shoulder 52 on which is supported and is fixed (for example by gluing or ultrasonic welding the associated balloon 20.

The plate 50 also has, between the different optical cells each consisting of an LED, the conical cavity 51 and the associated balloon 20, a curved style wall 53, which follows the curve of the transparent 40, at a small distance determined. inside of it. Finally, the plate 50 has other conical recesses 54 extending between the shoulders 52 and the wall 53, to give said plate its structural continuity. The half-angle at the apex of the conical portions 54 is chosen so as not to obscure the light at the outlet of the respective balloons 20, so as not to alter the photometry. In addition, and as shown in FIG. 3, the shape and the depth of the conical recesses 54 are chosen here on the one hand so that the optical cells have optical axes xx which are all parallel to each other; that is, the shoulders 52 extend in planes parallel to each other, and on the other hand so that the tops of the balloons 20 are substantially flush with the imaginary extensions of the outer face of the wall of the wall. style 53 at their level.

In this way, a multi-source signaling light is produced in which, contrary to what has been practiced in the past in LED lights, the aim is no longer a continuity of the illuminating surface, but a marked matrix aspect, in which each source, or more precisely each balloon, illuminates in the entirety of the illuminating range sought, with a controlled intensity. This new aspect will be well understood by observing Figure 4, where we have also drawn sections of the different surfaces shown, in order to materialize the relief. It is also observed in this figure that the surface occupied by the balloons is very substantially less than the total surface of the fire. Typically, the area occupied by the balloons will be less than about half of the total area of the fire.

At the same time, it is understood that a signaling light according to the invention can easily be adapted, by playing in particular on the curve of the wall 53 and on the distribution of the light cells in the extent of this wall, in all imposed configurations. in terms of dimensions, contours, curvature, ... traffic light.

It will also be observed that, since the color of the signaling beam is given directly by the LEDs, such a light may, when extinguished, have a perfectly colorless appearance, with an interesting "showcase" appearance.

Finally, FIG. 5 shows a variant embodiment of the balloon 20, according to which its internal face is always provided with facets 21 for distributing the light, and its external face 22 also comprises, in the vicinity of the base of the balloon, a plurality of grooves 221 extending along circular paths in planes perpendicular to xx.

Such streaks can contribute to the homogeneity of the light distribution, especially in the extreme zones of the illuminating surface. They can also be adopted for style reasons.

Of course, the present invention is not limited to the embodiments described and shown, but the skilled person will be able to make any variant or modification consistent with his spirit.

In particular, it is possible to provide the plate 50, or at least its style wall 53, not with a neutral reflective appearance, but with a chosen color, for example that of the vehicle body. This can be achieved either by making the plate with a plastic material dyed in the mass, or by painting.

On the other hand, it is also possible for the color of the radiation at the exit of the light to be given by any combination of the color as emitted by the LEDs, of any hue of the balloons 20 and of any hue of the transparency 40.

Finally each balloon 20 may optionally be made in two parts juxtaposed and each having its own light distribution dioptres, especially if the demoulding constraints impose.

Claims (17)

1. Indicator light for a motor vehicle, comprising a plurality of light sources (10) such as light emitting diodes and means (20) for the optical treatment of the light issuing from the sources in order to generate a signalling beam in an illuminating range of given extent, these treatment means comprising an optical treatment element (20) in line with each of the said sources, and an external window (40) essentially inactive from the optical point of view, characterised in that each optical treatment element (20) consists of an individual dome able to effect a distribution of the light received to the entire extent of the illuminating range, the said individual domes being mounted in line with openings (55) formed in a support (50).
2. Indicator light according to claim 1, characterised in that the domes (20) are roughly hollow and hemispherical in shape, their concave face being turned towards the respective source.
3. Indicator light according to claim 2, characterised in that the domes (20) are all the same size.
4. Indicator light according to one of claims 1 to 3, characterised in that the domes (20) are all identical.
5. Indicator light according to one of claims 1 to 4, characterised in that each dome (20) has an internal face provided with a multiplicity of facets (21, 211) for distributing the light.
6. Indicator light according to claim 5, characterised in that each dome (20) has a smooth external face (22).
7. Indicator light according to claim 5, characterised in that each dome (20) has a partially smooth (22) and partially serrated (221) external face.
8. Indicator light according to one of claims 1 to 7, characterised in that the said support is formed by a common framework and style plate (50) having a plurality of housings (55) for the light sources and a plurality of mounting surfaces (52) for the domes (20).
9. Indicator light according to claim 8, characterised in that the said common plate is opaque.
10. Indicator light according to one of claims 8 and 9, characterised in that the common plate (50) defines, between the said housings (55) and the said mounting surfaces (52), roughly conical flux recuperators (51).
11. Indicator light according to one of claims 8 to 10, characterised in that the said mounting surfaces (52) are annular surfaces provided at the bottom of a plurality of recesses (54) extending from a style wall (53) belonging to the said common plate (50).
12. Indicator light according to claim 11, characterised in that the window (40) is curved, and in that the said style wall (53) is also curved in order to substantially follow the shape of the said window.
13. Indicator light according to one of claims 10 and 11, characterised in that the said annular mounting surfaces (52) extend in planes parallel to one another.
14. Indicator light according to one of claims 10 to 13, characterised in that the said annular mounting surfaces (52) are positioned with respect to the style wall (53) so that the tops of the domes (20) are flush with imaginary extensions of the said style wall level with the recesses.
15. Indicator light according to one of claims 1 to 14, characterised in that the said domes (20) and the said window (40) are colourless.
16. Indicator light according to claim 15, characterised in that the light sources (10) emit a coloured radiation.
17. Indicator light according to one of claims 1 to 15, characterised in that, in front view, the domes (20) occupy a surface area less than approximately half the surface area of the light.

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