FR2779508A1 - Curved lighting assembly for automobile signalling - Google Patents

Abstract

The assembly comprises a housing (10a) curved to match the vehicle contour requirements, with light emitting diodes (LED) (21) mounted in linear array form on a circuit board held in curved form by supports (11). Optical plates (30) formed with fresnel lens elements capture light from the diodes and transmit through diffusing elements (12) to the curved glass cover (10b) to provide the signal output.

Description

The present invention relates generally to

  signaling for motor vehicles, and more particularly a light comprising one or more rows of light sources such as light emitting diodes (LEDs) cooperating with elements

respective optics.

  A well-known application of this type of light is the additional stop light, placed for example in the vicinity of the rear window of the vehicle (typically along the upper edge or the lower edge of this window) or integrated in the bodywork or in a spoiler. . Also conventionally, the light-emitting diodes are soldered onto a flat epoxy or similar printed circuit, so that they are aligned in a straight line, and the optical elements typically consist of a set of Fresnel lenses respectively focused in the vicinity of each LEDs and carried by a generally flat optical plate

  extending parallel to the printed circuit.

  These known lights also include a glass or sight glass which has on its inner surface beads or tori of light diffusion, so that the signaling beam fills the solid angle

regulatory.

  This glass can be slightly curved to match either the curve of the bodywork (in the case where the additional brake light opens directly outside the vehicle), or the curve of the rear window (in particular in the case of lights mounted on the beach

aft or on the roof).

  It is clear that this curve given to the glass of the light leads to a congestion of the light along the axis of the vehicle which may be excessive, in particular for large curves of curvature or for lights of large width and / or of great height. So it can be tricky, with the known multisource light structures, to house the fire in the increasingly reduced space that manufacturers tend to leave to this type of organ (case of fire

integrated).

  In the case of lights mounted against the rear window, the axial size is also significant, and in addition the visor ensuring the light tightness between the sources and their optical plate on the one hand, and the rear window on the other on the other hand, has an inconsistent shape. Finally, still in the case where the curve of the ice is pronounced, these known lights can have an illuminating surface which lacks homogeneity when the function

light is in use.

  The present invention aims to overcome these drawbacks of the state of the art and to allow multisource lights to be produced which integrate more easily into the space dedicated to them, and which moreover have, in the case of a interior fire,

an improved aesthetic appearance.

  Another object of the present invention is to provide a multi-source light with an illuminating surface

more homogeneous.

  Finally, an object of the invention is to propose such a signaling light, in which the spreading of the beam in width can be carried out easily and of

homogeneously.

  Thus the present invention provides a signaling light for a motor vehicle, comprising a housing, a plurality of essentially aligned light sources carried by a generally flat insulating support mounted in the housing, an optical plate having optical arrangements for processing the light coming from sources, as well as a closing glass, said closing glass having a curve, characterized in that said insulating support and said optical plate each have a curve similar to

that of said ice.

  Preferred, but not limiting, aspects of the signaling light according to the invention are the following: - the insulating support is essentially plane at rest and mounted in the housing in a constrained state.

giving its curved shape.

  - the insulating support has its shape at rest

curved.

  - the insulating support has at rest an intermediate form between a planar shape and its curved shape, and is mounted in the housing in a constrained state

giving said curved shape.

  - the optical plate is essentially flat at rest and mounted in the fire in a constrained state

giving its curved shape.

  - the optical plate has its curved shape at rest. - the optical arrangements comprise lenses focused in the vicinity of the respective sources, and the optical axes of the lenses are, from the center towards the edges of the plate, angularly offset

gradually.

  - the optical axes are angularly offset outwards to generate diverging beam parts. - spreading the signaling beam in a horizontal or vertical direction is achieved by the combination of said axis lenses progressively

  offset and optical arrangements provided on the ice.

  - the spreading of the signaling beam in a horizontal or vertical direction is carried out only

  by said lenses of axes progressively offset.

  the optical plate has a plurality of generally flat zones which are stepped relative to one another so as to give said optical plate its

curved shape.

  said generally flat zones each consist of optical arrangements associated respectively with each of the light sources, the width of said zones being substantially equal to the

  distance between two neighboring light sources.

  - said optical arrangements consist of

Fresnel lenses.

  - the insulating support for the sources, the optical plate, the closing glass as well as a housing wall located behind the insulating support

all substantially the same curve.

  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 appended drawing, in which: FIG. 1 is a schematic view in horizontal section of a multisource signaling light according to the invention, FIG. 2 FIG. 1 is a cross-sectional view along line II-II of the light from FIG. 1, FIG. 3 is a detail view on an enlarged scale of a first embodiment of an optical plate of the light from FIGS. 1 and 2, and Figure 4 is an enlarged detail view of a second embodiment of a plate

fire optics of Figures 1 and 2.

  Referring firstly to FIGS. 1 and 2, a signaling light of the complementary stop or even raised stop type, comprises a housing 10 of which an opaque rear part 10a forms a part of the light structure, and therefore a front part 10b forms on one side

  front a fire closing glass.

  It will be observed here that the terms "front", "rear", and the like are understood here in relation to the

  general direction of emission x'-x of fire.

  The two parts 10a and lo0b are assembled by any suitable means such as latching, welding, gluing, screwing, etc. It is observed here that the lens lo0b of the light has a relatively pronounced curve, with its convex face facing outwards, so as to conform as closely as possible to the curve of a part C of bodywork (or

  rear spoiler, spoiler, etc.) of the vehicle.

  Part 10a has a corresponding curve, so that the depth of the housing according to the

  direction x'-x is essentially constant.

  The housing part 10a carries, integrally, a set of uprights 11 intended for fixing, by screwing, clipping or the like, of a printed circuit 20 on which are welded a plurality of light-emitting diodes 21, in this case diodes called "Piranha", arranged in a row essentially

horizontal.

  According to an essential aspect of the invention, the printed circuit 20 has a curve close to that of the housing parts 0la and lOb, so as to be able to be accommodated in the interior space of said housing without

have to increase its depth.

  This curve of the printed circuit can be obtained from

different ways.

  In the case where it does not have to be very pronounced, it is possible to use an ordinary flat printed circuit, for example made of epoxy, on which a deformation stress is exerted during its mounting on the uprights 11. The precautions necessary for the implementation of this solution essentially consists in not deforming the

  printed circuit and the connection tabs of the diodes

  beyond their elastic bending limits and the limit of deterioration of the conductive tracks or of the solder points, and to provide a fixing on the uprights 11 which is sufficiently resistant to

  oppose the recall effort thus generated.

  A second solution, applicable in particular when the curve to be given is more pronounced, may consist in using for the substrate of the printed circuit a special insulating material of suitable flexibility to allow, in the same way as before, obtaining the desired curve. Bakelite can thus be used for example. One can naturally, in the two cases above, play on the thickness of the printed circuit to give it

  the elastic deformability required.

  A third approach, which can be implemented in particular in the event of difficulty with the two preceding ones (very pronounced curve and great robustness desired) consists in using a special printed circuit pre-curved during manufacture, either by presenting the curve required at rest. , or again by requiring only a reasonable constraint to pass from its curve at rest to its curve

after mounting in the fire.

  It will be noted here that if the printed circuit is mounted in spaced slots or notches, the elastic return force created during the positioning of the printed circuit in these slots or notches is capable of inducing sufficient friction forces to ensure maintenance

  perfectly stable circuit board in its position.

  The light also includes an optical plate 30 having optical arrangements able to cooperate

  respectively with each of the LEDs 21.

  This plate 30 advantageously has the same curve as the parts 10a, 10b and that the printed circuit 20. It is mounted in one or the other of said parts (in this case in part 10b defining the glass) by any means suitable (clipping, screwing,

  bonding, ultrasonic welding, ...).

  The optical arrangements of the plate 30 advantageously consist of Fresnel lenses molded on this optical plate, as indicated

  in Ln, Ln + l, ... in Figures 3 and 4.

  Here again, the curve of the plate 30 can be

obtained in different ways.

  The first approach, illustrated in FIG. 3, consists in making a flat optical plate with Fresnel lenses Ln, Ln + l, ... having axes An, An + l, ... parallel to each other and arranged substantially

  in the same pitch as the diodes 21.

  This plate 30 is subjected during assembly to a deformation stress intended to give it - in the same way as for the printed circuit as described above - the curved shape illustrated in solid lines in FIG. 3, while its resting form is

  illustrated in dashed lines and designated in 30 '.

  It is understood that, in this case, the axes of the Fresnel lenses will gradually move outward relative to the axis An of a Fresnel lens Ln (typically the central lens), and we observe in particular that the axis An + l of the Fresnel lens Ln + l is shifted outward by an angle a by

relative to the axis An.

  We understand that, in this way, the average direction of light after treatment at each Fresnel lens will deviate from the general emission axis x'-x gradually as we

  moves away from the center of the plate 30.

  In this way, the lenses together carry out a pre-spreading of the light towards the outside, favorable to the

  filling the regulatory solid angle.

  According to a second embodiment, the optical plate 30 can be produced by molding in order to present, at rest, the curved shape of FIG. 3. Here again, the axes An of the Fresnel lenses Ln progressively move away from the center towards the edges

  with respect to the general direction of emission x'-x.

  Finally, according to a third embodiment, and now with reference to FIG. 4, the optical plate can be produced by providing individual Fresnel lenses which are each generally plane and parallel to each other, so as to present respective optical axes An , An + l, ... which are all

substantially parallel to each other.

  In order for the plate 30 to adopt the generally curved shape as it is required, the different lenses are progressively offset with respect to each other in steps, with staggerings (in particular the offset tel as indicated between the lenses Ln and Ln + l) chosen so that overall, the plate has the desired neighboring curve

  those of the printed circuit 20 and parts 10a and 0lb.

  This embodiment is advantageous when, for reasons in particular of photometry, it is desired that a substantial part of the radiation downstream of the optical plate 30 and upstream of the lens 0lb is

  substantially parallel to the x'-x axis.

  Finally, the 0lb glass preferably has on its internal face arrangements 12 for diffusing the light at the outlet of the Fresnel lenses, these arrangements being chosen so as to fill

  suitably the regulatory photometric grid.

  These arrangements are, for example, spherical or toric balls of suitable pitch and radii of curvature. It will be observed here that, when the angular offset of the different lenses Ln,... Of the plate 20 is sufficient to ensure by itself the required horizontal spreading of the beam, then the arrangements 12 of the glass can consist of simple streaks horizontal suitable for spreading the beam vertically. Of course, the present invention is in no way limited to the embodiments described above and shown in the drawings, but a person skilled in the art will know how to make any variant or modification in accordance with his spirit. In particular, although we have described above the case where the curve of the printed circuit 20 and the optical plate 30 are curved in a horizontal plane, it is understood that the invention applies equally well to a curve in a vertical plane (in the case of vertically elongated lights), or even in an oblique plane, or with more complex curves. It also applies, when the case requires, to curves giving the

  external face of the fire a concave shape.

  Furthermore, the invention also applies to lights comprising several rows of light sources, which can then be mounted on the same

  printed circuit or on different printed circuits.

Claims (14)

  1. Signaling light for a motor vehicle, comprising a housing (0la), a plurality of light sources (21) essentially aligned and carried by a generally flat insulating support (20) mounted in the housing, an optical plate (30) having optical arrangements (Ln) for processing the light from the sources, as well as a closing glass (10b), said closing glass having a curve, characterized in that said insulating support (20) and said optical plate (30) each have a curve similar to that of said ice.   2. Signaling light according to claim 1, characterized in that the insulating support (20) is essentially plane at rest and mounted in the housing   (10a) in a constrained state giving it its curved shape.   3. Signaling light according to claim 1, characterized in that the insulating support (20) has at rest its curved shape.   4. Signaling light according to claim 1, characterized in that the insulating support (20) has at rest an intermediate shape between a planar shape and its curved shape, and is mounted in the housing (10a) in   a constrained state giving it said curved shape.   5. Signaling light according to one of   claims 1 to 4, characterized in that the plate   optics (30) is essentially flat at rest and mounted in the fire in a constrained state giving it its curved shape. 6. Signaling light according to one of   claims 1 to 4, characterized in that the plate   optical (30) at rest has its curved shape.   7. Signaling light according to one of   claims 5 and 6, characterized in that the   optical arrangements comprise lenses (Ln) focused in the vicinity of the respective sources (21), and in that the optical axes (An) of the lenses are, from the center towards the edges of the plate, angularly offset gradually.   8. Signaling light according to claim 7, characterized in that the optical axes (An) are angularly offset towards the outside to generate diverging beam parts.   9. Signaling light according to claim 8, characterized in that the spreading of the signaling beam in a horizontal or vertical direction is achieved by the combination of said lenses (Ln) of axes (An) progressively offset and arrangements   optics (12) provided on the glass (0lb).   10. Signaling light according to claim 8, characterized in that the spreading of the signaling beam in a horizontal or vertical direction is achieved only by said lenses (Ln) of axes (An) gradually shifted.   11. Signaling light according to one of   claims 1 to 4, characterized in that the plate   optical (30) has a plurality of generally planar areas and stepped relative to each other so as to give said optical plate its curved shape. 12. Signaling light according to claim 11, characterized in that said generally flat areas each consist of optical arrangements (Ln) associated respectively with each of the light sources (21), the width of said areas being substantially equal to the distance between two sources bright neighbors.   13. Signaling light according to claim 12, characterized in that said optical arrangements   consist of Fresnel lenses (Ln).   14. Signaling light according to one of   Claims 1 to 13, characterized in that the support   insulator (20) from the sources (21), the optical plate (30), the closing glass (0lb) as well as a housing wall (10a) situated behind the insulating support have all substantially the same curve.