EP0230834B1 - Signalling lamps with coloured lighting for a motor vehicle - Google Patents

Description

The present invention relates generally to signaling lights of motor vehicles, and more particularly relates to a signaling light intended to emit colored light radiation.

In most of the existing colored radiation signaling lights, the coloring of the light is given by the glass or the globe for closing the light, which is appropriately tinted.

however, from a purely aesthetic point of view, it has been found that some of these colors given to the glass for closing the lights were not very harmonious with certain other colors given to the body of the vehicle. In particular, the yellow-orange, or amber, color used for the indicators of motor vehicles (this specific color being imposed in certain countries by regulations) goes very poorly with a certain number of other colors. The overall aesthetics of the vehicle is thus degraded.

Furthermore, there is today a tendency to give all the exterior surfaces of the lighting devices of a motor vehicle, whether at the front or at the rear of the vehicle, a color and an appearance. relatively uniform.

In particular, the fact of having side by side a transparent closing glass projector and therefore of generally white appearance, with a flashing light of generally amber appearance is less and less desirable from the aesthetic point of view.

Already known in the art, in particular by patent FR-A-2 476 798 in the name of the Applicant, vehicle traffic lights cules to which we have tried to give, when they are extinct, a colorless external appearance. An example of such a light is shown diagrammatically in FIG. 1, in horizontal section passing through the optical axis. It includes a lamp 10, emitting white light, a reflector 12 and a closing glass 14. In this signaling light of the prior art, a balloon 16 (or even a plate, or any other suitable element), forming a filter colored, for example amber for a flashing light, is interposed between the lamp and the reflector. The balloon is partially masked on its outer surface by a cover 18 which is substantially impermeable to light from the outside to the inside, and substantially permeable in the opposite direction. The cover 18, which can also be reflective towards the outside, contributes to attenuating the amber aspect of the fire when the lamp is off and when it is observed from the outside.

However, such a fire has several drawbacks. On the one hand, the filtering balloon must leave a space around the lamp large enough to avoid excessive heating inside it. Its size is therefore relatively large. In addition, the cover should not cover an excessive proportion of the surface of the ball, as it influences the light output of the light, which cannot be excessively reduced. For these reasons, the amber color of the extinguished fire as observed from the outside is certainly attenuated, but it remains however clearly perceptible.

Finally, patent FR-A-2 501 333 discloses a signaling light in accordance with the preamble of claim 1 in the name of the Applicant.

However, in this known fire, the white light radiation is either divergent or parallel, which requires in all cases the use of a colored filter and a deflection mirror both of large dimensions, as well as d '' a specially designed reflector.

The first drawback of this known light is linked to the large size of the deflection mirror, which is the source of a black hole of substantially corresponding dimensions in the beam formed. This large black hole is undesirable not only from an aesthetic point of view, but also from a photometric point of view, making the regulations in this area difficult to comply with.

Another disadvantage of the known light lies in the large dimension of the color filter, which makes it clearly visible from the outside when the light is extinguished and that it is observed at an angle relative to the optical axis. The colorless aspect of the extinguished fire is therefore not perfect.

Finally, the use of a specially designed reflector may prove undesirable from the point of view of the cost price of the light.

The present invention aims to overcome these drawbacks of the prior art and for this purpose proposes a signaling light having the characteristics set out in claim 1.

Preferred arrangements of the invention are presented in the dependent claims.

• la figure 1 est une vue en coupe horizon­tale schématique d'un feu de signalisation à éclai­rement coloré et d'aspect incolore selon la technique antérieure; et
• la figure 2 est une vue en coupe horizontale partielle, passant par l'axe optique, d'un feu de signalisation selon la présente invention.

The invention will be better understood on reading the following detailed description of a preferred embodiment thereof, given by way of example and made with reference to the accompanying drawings, in which:

• Figure 1 is a schematic horizontal sectional view of a traffic light with colored illumination and colorless appearance according to the prior art; and
• Figure 2 is a partial horizontal sectional view, passing through the optical axis, of a signaling light according to the present invention.

The fire shown in Figure 1 has been described above during the discussion of the prior art.

Referring to Figure 2, the signaling light according to the present invention comprises a light source 20, such as a tungsten filament lamp, capable of emitting white light. The lamp base is mounted in a socket 22 secured to an auxiliary reflector 24 of optical axis X-X. The reflector 24 is in this example elliptical, and therefore has two focal points. Its first focus F1 is substantially coincident with the filament of the lamp, and its second focus F2 is located further forward (to the right in FIG. 2) on the optical axis X-X.

The light comprises a main reflector constituted by two concentric parts 24ʺ and 26, which together form a reflector, for example a parabolic hearth Fʹ and having the same optical axis XX as the reflector 24. The parts 24ʺ and 26 are arranged so that their common focus Fʹ is located in the vicinity of the second focus F2 of the reflector 24. In the present example, the focus Fʹ is located slightly in front of hearth F2.

As can be seen in Figure 2, the elliptical reflector 24 and the outer part 24ʺ of the parabolic reflector are integral and formed in one piece, the inner end edge of the part 24ʺ here being connected by a cylindrical section 24ʹ to the elliptical reflector 24. The second part 26 of the parabolic reflector, arranged centrally, is attached to the first 24ʺ by any suitable fixing means, for example by gluing the outer peripheral edge of the central part 26 to the adjacent inner edge of the part 24ʺ device.

Of course, the reflector 24ʺ, 26 can also be made in a single part, which will be attached by any suitable means to the free end of the intermediate cylindrical part 24ʹ.

A cup or cup-shaped element 28, forming a mirror on its outer surface, is placed in the region of the two foci F2 and Fʹ. It consists in the present example of a hemispherical mirror centered on the optical axis XX of the light and arranged so as to pass approximately through the focal point Fʹ of the parabolic reflector 24ʺ-26. The element 28 can be held in this position using one or more arms (not shown), preferably in one transparent plastic, extending for example from the region of the outer edge of the 24ʺ part of the parabolic reflector.

In the present embodiment, the signaling light further comprises a coloring filter 30 which is received in a window (not referenced) formed in the wall of the central part 26 of the parabolic reflector in the region of the bottom thereof. The filter 30 is produced in the present example from a tinted plastic material of amber color or the like, and extends between the mirror 28 and the lamp 20. Its center is located on the optical axis X-X. We can also observe that the diameter of the filter 30 is substantially equal to that of the mirror 28. We have shown in the figure a filter 30 whose shape matches that of the parabola 26. It is understood that a flat filter can also give satisfaction.

Furthermore, in a particularly advantageous variant embodiment, the central part 26 of the parabolic reflector and the filter 30 can be produced in the following manner: the body of this central part 26 is made of transparent colored plastic (amber in the present example) ), and the entire surface of said body, with the exception of its circular central region, which will thus define the filter 30, will be made reflective, for example by a vacuum metallization step or the like.

Finally, the signaling light comprises a closing globe or glass 32 comprising, for example on its inner surface, streaks or balls 34 for scattering and / or dispersing light. Although we have shown here a closure element for fire in return wing, it is clear that this is only one possible form of execution among others.

The closing glass 32 is colorless, and made for example of plastic.

The above traffic light behaves as follows. When the lamp 20 is on, it creates in combination with the elliptical reflector 24 a concentrated beam of white light which converges towards the second focus F2 of said reflector. However, this beam is intercepted by the colored filter 30, and therefore arrives in the interior space of the parabolic reflector 24ʺ-26 having taken on an amber, or yellow-orange color, as required by certain regulations for the fire function. turn signal.

The arrangement of the mirror 28 is such that it also intercepts the converging beam slightly downstream from its point of convergence F2, as indicated by the straight lines 36 which schematize various ray paths of the beam. These rays are reflected by the mirror while being distributed over the entire extent of the parabolic reflector 26. However, the mutual arrangement of the focal points F2 and Fʹ and of the mirror 28, as well as the diameter of the latter, are chosen so that all the rays reflected by the mirror seem to emanate approximately from the focal point Fʹ of the parabola 24ʺ-26. Thus, it is understood that the lamp 20, the elliptical reflector 24, the patch or filtering area 30 and the mirror 28 contribute in combination to create, in the region of the focus Fʹ of the parabolic reflector 24ʺ-26, a virtual source of light colorful. The fire therefore behaves in a manner completely analogous to a fire comprising a colored light source and a parabolic reflector, the focus of which is located in the vicinity of the source, to create a colored beam suitable in the present example for direction flashing or distress signaling light function.

When the lamp 20 is extinguished and the fire is observed from the outside, the only colored part of the latter, namely the pellet or filtering zone 30, is largely masked by the mirror 28, of colorless appearance. Thus, among the light rays entering the enclosure of the fire (for example in daylight), a very small proportion of these meet said patch or zone 30. The fire therefore has a generally colorless appearance. It can be noted in this regard that the dispersion elements 34 provided on the inner surface of the closing glass 32 have the effect of "diluting" the very small proportion of amber light reflected by the fire in the predominant white light which comes out after reflection. It can be noted here that the quality of the result obtained is due to the fact that, in contrast to the solutions of the prior art, the filtering element giving the coloring is carried outside the volume defined by the parabola 24ʺ-26 and the glass closing 32.

Furthermore, to avoid the presence of the mirror 28 causing the appearance of a dark spot when the fire is out, its interior surface, facing the closing glass, can also be made to be reflective.

Of course, the fire described above with reference to FIG. 2 is only an example of a reaction. reading among others. In particular, the means for creating the concentrated beam of white light directed towards the filter 30 may alternatively be constituted by a light source in combination with a reflector and / or a lens of any shape.

In addition, it is understood that the filter 30, in most circular cases, will be given the smallest possible diameter, and preferably equal to the diameter of the beam at this location.

In addition, the mirror 28 may more generally consist of any part of revolution, such as a cone, a paraboloid, etc., made reflective and capable of distributing the colored beam which it receives towards the parabolic reflector.

Furthermore, it is understood that the geometric arrangement of the various elements, and in particular the relationship between the mirror 28, its center, and the foci Fʹ and F2 may be entirely arbitrary, provided that, by empirical tests or by calculation , we obtain both a colored beam of correct intensity and distribution at the exit of the fire, and a reasonably little colored appearance, when the fire is extinguished, in external observation. In particular; the point of convergence F2 of the converging beam may be situated both in front of and behind the adjacent surface of the mirror 28.

If excessive heating is likely to occur in the relatively small space reserved for the lamp 20, it will be possible to provide, for example in the cylindrical junction portion 24ʹ, windows which will allow the air to circulate.

In addition, a traffic light has been described above, the amber coloration of the beam of which corresponds to the flashing light function. It is understood that the beam can be given, by means of the filter 30, any suitable coloring, for example red to fulfill the functions of stop light and / or position light.

Claims (11)

1. An indicator lamp for a vehicle such as an automotive vehicle, adapted to emit an indicating beam of coloured light through an uncoloured closure glass (32), and being of the type comprising a reflector (24ʺ, 26) in the region of the base of which a window is formed, a coloured filter (30) disposed in the window, means (20, 24) provided at the back of the filter for emitting a beam of white light through the said filter, and a mirror (28) disposed in front of the filter for redirecting the said beam towards the reflector once it has been coloured by the filter, characterised in that the beam of white light converges towards the vicinity of the mirror, in that the reflector (24ʺ, 26) is of the parabolic kind, and in that the deflecting mirror (28) is arranged in the vicinity of the focus (Fʹ) of the reflector.

2. An indicator lamp according to claim 1, characterised in that the general direction of the convergent beam is aligned with the optical axis (xx) of the reflector (24ʺ, 26).

3. An indicator lamp according to one of Claims 1 and 2, characterised in that the means for emitting a convergent beam comprise a filament lamp (20) and a second reflector (24).

4. An indicator lamp according to claim 3, characterised in that the second reflector (24) is of the elliptical type, with its primary focus (F1) being situated in the vicinity of the filament of the lamp.

5. An indicator lamp according to Claim 4, characterised in that the second focus (F2) of the second reflector (24) is situated slightly rearwards of the mirror.

6. An indicator lamp according to one of Claims 3 to 5, characterised in that the first reflector (24ʺ, 26) is formed in two concentric parts, namely an outer part and an inner part respectively, and in that the outer part (24ʺ) and the second reflector (24) are formed in a single piece.

7. An indicator lamp according to Claim 6, characterised in that the inner part (26) of the first reflector is formed of a coloured plastics material and includes a reflective coating over its whole surface with the exception of a central region, whereby to define the filter (30).

8. An indicator lamp according to one of Claims 1 to 7, characterised in that the size of the filter (30) is close to that of the cross section of the convergent beam at that point.

9. An indicator lamp according to one of Claims 1 to 8, characterised in that the deflecting mirror (28) is hemispherical in form.

10. An indicator lamp according to Claim 9, characterised in that the focus (Fʹ) of the first reflector (24ʺ, 26) is situated in close proximity to the surface of the mirror (28).

11. An indicator lamp according to one of the preceding Claims, characterised in that the uncoloured closure glass (32) includes light-dispersing elements (34).

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