FR2791121A1 - IMPROVED MULTI-SOURCE SIGNAL LIGHT FOR MOTOR VEHICLE - Google Patents

Abstract

A signaling light comprises a plurality of light sources (10) and means (20) for optically processing the light coming from the sources to generate a signaling beam in an illuminating range of given extent, and an essentially inactive external indicator of the optical point of view; the processing means comprise an optical processing element (20) in line with each of said sources. According to the invention, each optical processing element (20) consists of an individual balloon capable of distributing the light received to any the extent of the illuminating surface, said individual balloons being mounted in line with openings formed in a support. Application in particular to matrix lights with light-emitting diodes for motor vehicles.

Description

The present invention relates generally to

  multi-source signaling for motor vehicles, and in particular lights having as light source a distributed set of light-emitting diodes. In known manner, such a light-emitting diode (LED) signaling light has, in association with each LED, an optic capable of distributing the light emitted by the LED in a given illumination field. An advantage of this type of light is that its extinct appearance may be completely colorless, the LEDs directly emitting radiation (red, amber or

regulatory color white).

  The document FR 2 707 223 A and FR 2 711 215 A describe signaling lights of this type, each LED being associated with an individual miniature reflector for recovering the radiation emitted by the LED with a strong inclination relative to its main direction d 'program. Optical arrangements such as Fresnel lenses are also provided at the level 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 outlet of these Fresnel lenses, intended to fill the regulatory photometric grid, is ensured for example by an external screen having a spherical or toric billing, or by other optical elements provided

  on the optical part carrying the Fresnel lenses.

  A difficulty with this type of known fire lies in that, if we consider an elementary sub-assembly consisting of an LED, its recuperator and its optics, this sub-assembly illuminates a certain area of the photometric grid, but not optimally. In particular, the homogeneous and complete filling of the regulatory field of illumination of the fire requires the use of a large number of LEDs. But while this requirement is not particularly restrictive with low-power LEDs, it becomes troublesome when it is desired to use more powerful LEDs, which technological development makes it possible to achieve today, in

decreasing the number of these.

  In this respect, filling the illumination field with sub-assemblies which each will illuminate a specific area of this field leads to an aesthetic drawback when the fire is lit and when one moves in front of it, in this sense that depending on the position of the observer, certain LEDs will appear on and others off, and this distribution between LEDs

  "on" and "off" LEDs will vary.

  Thus the illuminating surface observable on the external surface of the fire indicator will be relatively undefined

  and variable, which is undesirable.

  The present invention proposes to overcome these limitations of the state of the art, and aims to propose a signaling light with multiple LEDs which on the one hand can comprise a relatively small number of LEDs, and which on the other hand offers to the observer, in any position thereof at least in the regulatory field of illumination of the light function considered, the vision of the light generated by each of these LEDs, this in order to obtain the impression in all circumstances

  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 in the on and off state, a new aspect which is particularly interesting for stylists. Thus, the present invention provides a signaling light for a motor vehicle, comprising a plurality of light sources such as light-emitting diodes and means for optical processing of the light coming from the sources to generate a signaling beam in an illuminating range of given extent. , these processing means comprising an optical processing element in line with each of said sources, and an external indicator light that is essentially inactive from the optical point of view, characterized in that each optical processing element consists of an individual balloon capable of carrying out a distribution of the received light towards the whole extent of the illuminating surface, said individual balloons being mounted at right

  openings formed in a support.

  Preferred, but not limiting, aspects of this signaling light are as follows: - the balloons are of generally hollow hemispherical shape, their concave face being turned towards the source

respective.

  - the balloons are all the same size.

- the balloons are all identical.

  - each balloon has an inner face provided with a multiplicity of facets for distributing the

light.

  - each balloon has a smooth outer face.

  - each balloon has an outer face

  partially smooth and partially striated.

  - Said support is formed by a common frame and style plate having a plurality of housings for the light sources and a plurality of

  mounting surfaces for balloons.

- Said common plate is opaque.

  - the common plate defines between said housings and said mounting surfaces of the flow recuperators

generally conical.

  - Said mounting surfaces are annular surfaces provided at the bottom of a plurality of recesses extending from a style wall belonging to

said common plate.

  - the sight glass is curved, and said style wall is

  also curved to substantially match said sight.

  - said annular mounting surfaces

  extend in planes parallel to each other.

  - said annular mounting surfaces are positioned with respect to the style wall so that the tops of balloons are flush with imaginary extensions of said style wall at

level of the recesses.

  - said balloons and said sight glass are colorless.

  - the light sources emit colored radiation. - in front view, the balloons occupy an area

  less than about half the surface of the fire.

  Other aspects, aims and advantages of the present invention will appear better on reading the

  following detailed description of embodiments

  preferred thereof, given by way of nonlimiting example and made 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 Figures 1 and 2, Figure 4 is a partial front view of the signaling light of Figure 3, and Figure 5 is a schematic and partial view in axial section of an alternative embodiment of a cell

optics according to the invention.

  Referring firstly to Figures 1 and 2, there is partially shown an optical cell of a signal light according to the invention, this cell comprising a light emitting diode (LED) including a housing 10 substantially parallelepipedic has on one side the actual source 11, with main emission axis xx and a substantially hemispherical and hollow balloon 20 of

  optical treatment of light from the LED.

  This balloon 20, preferably made of transparent colorless molded plastic, is intended to effect 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, reversing, flashing, fog, ...) In the present example, the external face of this balloon is smooth, and its internal face has a multiplicity of individual facets 21 intended for

  carry out 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 the skilled person.

  It is of course, as a variant, provide that the light distribution diopters are formed on the outside of the balloon 20, or even on both

  inside and outside of the ball.

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

the skilled person.

  As will also be seen below, it can be provided that one of the faces of the balloon treats the distribution of light in a given first direction, for example vertical, and that the other face of the balloon treats the distribution of light in the

  orthogonal direction, in this case horizontal.

  FIG. 2 illustrates in more detail the case where the balloon 20 is, as indicated above, smooth on its external face 22 and provided with facets 21 on its internal face. It is interesting to observe here that the facets 21 are joined to each other by draft surfaces 211 which have the property of also being, at least for

  some, optically active (see radius Rl).

  The number of such cells in a traffic light is chosen mainly according to the light power available at the level of each LED, knowing that the progress of technology makes it possible today to produce increasingly powerful LEDs. Thus, for a light produced today with 25 watt filament lamps (in particular the case of brake and flashing lights), we can reach the minimum

  regulatory with a light comprising from 10 to 15 LEDs.

  FIG. 3 schematically illustrates a light according to the invention, comprising three rows of four cells,

and illustrates one of these rows.

  This light has a housing or base 30 closed at the front by a transparent 40, advantageously smooth and colorless to give the fire a "showcase" appearance.

  particularly sought after today by stylists.

  The LEDs 10 are supplied electrically from a common support 12 (or by independent supports), and are received in an optical mounting and recovery plate 50, fixed inside the light 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 the latter is mounted from the rear. This plate 50 is advantageously designed so as to be reflective (for example by a vacuum metallization process), 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

emission x-x.

  It is also observed that each conical cavity is surmounted by an annular shoulder 52 on which rests and is fixed (for example by gluing or welding

  ultrasound 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 transparency 40, at a small determined distance. inside of it. Finally, the plate 50 has other conical recesses 54 extending between the shoulders 52 and the style wall 53, to give said plate its structural continuity. The half-angle at the top of the conical parts 54 is chosen so as not to substantially obscure the light leaving the respective balloons 20, so as not to alter the photometry. In addition, and as clearly 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, c ' that is to say that 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 external face of the wall

style 53 at their level.

  This produces a multi-source signaling light in which, unlike what was practiced in the past in LED lights, we are no longer aiming for continuity of the illuminating surface, but a marked matrix aspect, in which each source, or more precisely each balloon, lights up the entire lighting area sought, with controlled intensity. This new aspect will be clearly understood by observing FIG. 4, where sections of the various surfaces illustrated have also been drawn, in order to materialize the relief. It can also be seen in this figure that the surface occupied by the balloons is very significantly less than the total surface of the light. 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 be easily adapted, in particular by playing on the curve of the wall 53 and on the distribution of the light cells in the extent of this wall, to any configuration imposed. in terms of dimensions, contours,

  curvature, ... of the traffic light.

  It will also be observed that, the color of the signaling beam being given directly by the LEDs, such a light can present when it is extinguished a perfectly colorless appearance, with in addition a

interesting "showcase" aspect.

  Finally, FIG. 5 shows an alternative 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 further comprises, in the vicinity of the base of the balloon, a plurality of streaks 221 extending along trajectories

  circular in planes perpendicular to x-x.

  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 reasons of style.

  Of course, the present invention is not limited to the embodiments described and shown, but the skilled person will be able to bring it

  any variant or modification in accordance with its spirit.

  In particular, provision may be made to produce the plate 50, or at least its style wall 53, no longer with a reflective neutral appearance, but with a chosen color, for example that of the vehicle body. This can be achieved either by making the plate with a mass-dyed plastic,

either by painting.

  Furthermore, it can also be provided that the color of the radiation leaving the fire is given by any combination of the color as emitted by the LEDs, of a possible shade of the balloons 20 and of a

  possible shade of transparency 40.

  Finally each balloon 20 can if necessary be made in two juxtaposed parts and each having its own light distribution dioptres, in particular

  if the constraints in terms of release require it.

Claims (17)

  1. Signaling light for a motor vehicle, comprising a plurality of light sources (10) such as light-emitting diodes and means (20) of optical treatment of the light coming from the sources to generate a signaling beam in an illuminating range of given scope, these processing means comprising an optical processing element (20) in line with each of said sources, and an external indicator (40) essentially inactive from the optical point of view, characterized in that each optical processing element (20) consists of an individual balloon capable of distributing the light received over the entire extent of the illuminating surface, said individual balloons being mounted in line with openings (55) formed in a support (50).   2. Signaling light according to claim 1, characterized in that the balloons (20) are of generally hollow hemispherical shape, their concave face being facing the respective source.   3. Signaling light according to claim 2, characterized in that the balloons (20) are all of same size.   4. Signaling light according to one of   Claims 1 to 3, characterized in that the balloons (20) are all identical.   5. Signaling light according to one of   Claims 1 to 4, characterized in that each balloon   (20) has an inner face provided with a multiplicity of light distribution facets (21, 211). 6. Signaling light according to claim, characterized in that each balloon (20) has a smooth outer face (22).   7. Signaling light according to claim, characterized in that each balloon (20) has a partially smooth outer face (22) and partially striated (221).   8. Signaling light according to one of   claims 1 to 7, characterized in that said support   is formed by a common frame and style plate (50) having a plurality of housings (55) for the light sources and a plurality of surfaces mounting (52) for the balloons (20).   9. Signaling light according to claim 8, characterized in that said common plate is opaque.   10. Signaling light according to one of   claims 8 and 9, characterized in that the plate   common (50) defines between said housings (55) and said mounting surfaces (52) of recuperators generally conical flows (51).   11. Signaling light according to one of   claims 8 to 10, characterized in that 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 said common plate (50).   12. Signaling light according to claim 11, characterized in that the indicator (40) is curved, and in that said style wall (53) is also curved   to substantially marry said light.   13. Signaling light according to one of   claims 10 and 11, characterized in that said   annular mounting surfaces (52) extend into planes parallel to each other.   14. Signaling light according to one of   claims 10 to 13, characterized in that said   annular mounting surfaces (52) are positioned relative to the style wall (53) such that the balloon tops (20) are flush with imaginary extensions of said style wall at the recesses. 15. Signaling light according to one of   claims 1 to 14, characterized in that said   balloons (20) and said sight glass (40) are colorless.   16. Signaling light according to claim, characterized in that the light sources (10) emit colored radiation.   17. Signaling light according to one of   Claims 1 to 15, characterized in that for the purpose of   face, the balloons (20) occupy an area less than about half the surface of the light.