EP2080948A2 - Rear optical block element of an automobile forming a retro-reflector with diffusion lenses and with backlighting - Google Patents

Abstract

The block (FA) has a case (B) for housing two LEDs (D), and a mask (M) provided with windows (F) placed before the LEDs. A lens (G) is placed before the mask, and a monoblock element (EL) is installed between the LEDs and the mask. The monoblock element comprises a reflex reflector forming part (C) that is prolonged at its periphery by diffusion lenses (L). The diffusion lenses are partially housed in the windows before the LEDs to diffuse light from the LEDs towards the lens (G). The element is made of colored or uncolored synthetic material such as polymethyl methacrylate.

Description

The invention relates to the rear light units of a motor vehicle, also called rear lights signaling.

• un boîtier, logeant au moins deux diodes électroluminescentes (ou DELs (ou encore LEDs en anglais)), un masque, généralement métallisé (par exemple chromé) et muni de fenêtres placées devant les diodes électroluminescentes, et des lentilles de diffusion logées dans les fenêtres devant les diodes électroluminescentes pour diffuser leur lumière vers l'avant (qui correspond à l'arrière véhicule),
• une glace placée devant le masque, et
• un catadioptre (ou cataphote) défini dans la glace ou solidarisé à la glace ou au boîtier.

As known to those skilled in the art, some rear optical units consist of an assembly of elements comprising:

• a housing, housing at least two light-emitting diodes (or LEDs), a mask, usually metallized (for example chromed) and provided with windows placed in front of the light-emitting diodes, and diffusion lenses housed in the windows in front of the light-emitting diodes to diffuse their light towards the front (which corresponds to the rear vehicle),
• an ice cream placed in front of the mask, and
• a reflex reflector (or cataphot) defined in the ice or secured to the ice or the case.

The high number of elements of these rear optical blocks makes their assembly and disassembly relatively long and increases the probability that they are incomplete or the probability of losing one of their elements.

On the other hand, the light-emitting diodes emitting light not only forwards (which corresponds to the rear of the vehicle) but also on the sides, part of the light emitted on the sides propagates inside the housing and constitutes thus a parasitic light which is all the more unsightly as the number of light-emitting diodes is high. It is certainly possible to prevent the spread of this stray light by means of dedicated screens, but these increase the weight and the costs of design and manufacture.

The invention therefore aims to improve the situation.

The invention also proposes a rear optical unit of a motor vehicle, comprising a housing housing at least two diodes electroluminescent, a mask with windows placed in front of the light emitting diodes, an ice placed in front of the mask, and an element of the type shown below.

To this end, the invention proposes a rear optical unit intended to form part of a motor vehicle and comprising a housing housing at least two light-emitting diodes, a mask provided with windows placed in front of the light-emitting diodes and an ice-cream placed in front of the mask.

This element is characterized in that it is adapted to be installed between the diodes and the mask and comprises a part which defines a reflex reflector and which is extended at its periphery by diffusion lenses adapted to be housed at least partially in the windows in front of the light-emitting diodes to diffuse their light towards the ice. This element cooperates with the mask, and in particular with the opaque parts of the mask, to prevent or reduce the propagation of the parasitic light coming from the diodes, in particular at the level of the frames surrounding the windows. Indeed, part of the light of the diodes is emitted forward thanks to the presence of the lenses. Another part of the light of the diodes is blocked by the mask instead of being transformed into parasitic light emitted on the sides and being reflected everywhere.

• ses lentilles de diffusion peuvent être solidarisées à sa partie formant un catadioptre par des ponts qui sont agencés de manière à guider une partie de la lumière émise par les diodes électroluminescentes jusqu'à l'intérieur de ladite partie pour l'illuminer par rétro-éclairage ; dans ce cas préférentiel, une partie de la lumière issue des diodes est récupérée pour être réfléchie au niveau du catadioptre : cette lumière parasite non seulement ne l'est plus mais devient même de la lumière utile ;
  • 
    les ponts peuvent être agencés de manière à faire pénétrer la lumière dans la partie formant un catadioptre sous un angle choisi qui est propre à permettre sa réflexion sur les faces internes de ladite partie ;
• sa partie formant un catadioptre peut comprendre une face arrière propre à être orientée vers le boîtier et munie de facettes de réflexion ;
• en présence d'un masque comportant une ouverture centrale entourée au moins partiellement par les fenêtres, sa partie formant un catadioptre peut être propre à être placée en regard de l'ouverture ;
• il peut être réalisé dans un matériau synthétique, comme par exemple le PMMA ;
  • 
    le matériau synthétique peut être coloré ou non coloré.

The element according to the invention may comprise other characteristics that can be taken separately or in combination, and in particular:

• its diffusion lenses can be secured to its retro-reflector portion by bridges which are arranged to guide a portion of the light emitted by the light-emitting diodes to the interior of said portion to illuminate it by backlighting ; in this preferential case, part of the light coming from the diodes is recovered to be reflected at the level of the reflector: this parasitic light not only is no longer but becomes useful light;
  • 
    the bridges may be arranged to penetrate the light in the part forming a reflex reflector at a chosen angle which is suitable for allowing its reflection on the internal faces of said part;
• its part forming a retro-reflector may comprise a rear face which is be oriented towards the case and provided with reflection facets;
• in the presence of a mask having a central opening surrounded at least partially by the windows, its part forming a retro-reflector may be able to be placed opposite the opening;
• it can be made of a synthetic material, such as PMMA;
  • 
    the synthetic material can be colored or uncolored.

• la figure 1 illustre schématiquement, dans une vue en perspective, un exemple de bloc optique arrière de véhicule automobile, avant assemblage et comprenant un exemple de réalisation d'élément selon l'invention,
• la figure 2 détaille l'exemple d'élément de la figure 1,
• la figure 3 illustre l'exemple d'élément de la figure 2 une fois assemblé au masque du bloc optique arrière de la figure 1,
• la figure 4 illustre schématiquement, dans une vue en coupe transversale, le bloc optique arrière de la figure 1 une fois assemblé, et
• la figure 5 détaille schématiquement, dans une vue en coupe transversale, une partie de l'élément des figures 1 à 4 et le trajet (TL) de la lumière entre l'une de ses lentilles de diffusion et sa partie formant catadioptre.

Other features and advantages of the invention will appear on examining the detailed description below, and the attached drawings, in which:

• the figure 1 illustrates schematically, in a perspective view, an example of a rear optical unit of a motor vehicle, before assembly and comprising an embodiment of element according to the invention,
• the figure 2 details the example element of the figure 1 ,
• the figure 3 illustrates the example element of the figure 2 once assembled to the rear optical block mask of the figure 1 ,
• the figure 4 schematically illustrates, in a cross-sectional view, the rear optical block of the figure 1 once assembled, and
• the figure 5 schematically details, in a cross-sectional view, a part of the element of Figures 1 to 4 and the path (TL) of the light between one of its diffusion lenses and its reflector part.

The attached drawings may not only serve to complete the invention, but also contribute to its definition, if any.

We have schematically represented on the figure 1 an embodiment of a rear optical unit (or taillight signaling) FA according to the invention, before assembly, intended to equip a motor vehicle.

Such a rear optical unit FA comprises a housing B secured to the front side with a mirror (front) G and possibly the rear side to the person skilled in the art called a "lamp holder" PL.

The housing B houses (on the front side) at least two light-emitting diodes (or LEDs (or LEDs in English)), an EL element according to the invention and a mask M.

In the nonlimiting exemplary embodiment illustrated on the figure 1 , the housing B is intended to house fifteen light-emitting diodes D constituting as many light sources. However, the invention is not limited to this number of light-emitting diodes D. It applies in fact to the housings B housing at least two light-emitting diodes D.

Moreover, in the nonlimiting exemplary embodiment illustrated on the figure 1 , the light emitting diodes D are mounted on three bars BD (two of them having six while the third has three). But this is not obligatory.

The mask M comprises windows F in number equal to the number of light-emitting diodes D and intended to be placed opposite them, respectively. This mask M is preferably metallized (for example chromed), at least partially, especially on its front face which is intended to be observed from outside the vehicle and on reflective portions at least partially defining the windows F (and generally grained to absorb parasitic light rays). It will be understood that the shape of the mask M depends on the way in which the light-emitting diodes D are arranged relative to one another in the housing B. In the non-limiting exemplary embodiment illustrated in FIG. figure 1 , the light-emitting diodes D are arranged substantially in a U.

The EL element according to the invention is intended to be installed between the electroluminescent diodes D and the mask M. As is better illustrated on the figure 2 it comprises a part C which defines a retro-reflector (or cataphot) and which is extended over at least part of its periphery by diffusion lenses L whose number is equal to the number of light-emitting diodes D. As is better illustrated on the figures 4 and 5 , each diffusion lens L is intended to be housed at least partially in one of the windows F of the mask M in front of the corresponding light-emitting diode D so as to diffuse the light that the latter emits towards the ice-cream G (that is forward (which is the rear of the vehicle)).

An EL element according to the invention is therefore a monobloc element which provides at least two functions: the reflection of the light which comes from a light source located behind the vehicle (catadiopter C) and the scattering of the light emitted by the light-emitting diodes D (diffusion lenses L).

The rear face F1 of the reflector portion C, which is opposite its front face F2 facing the ice G (see figure 5 ), is provided with facets (or patterns) for reflecting the light forward (which corresponds to the rear vehicle).

It will be understood that the shape of the element EL depends at least on the manner in which the light-emitting diodes D are arranged relative to one another in the housing B. It can also depend, as in the non-limiting embodiment illustrated on FIG. the Figures 1 to 3 of the form of the mask M. In fact, in the nonlimiting exemplary embodiment illustrated on the Figures 1 to 3 , the mask M comprises a central opening O which is surrounded at least partially by the windows F and opposite which is placed the reflector portion C of the EL element.

It will be noted that the reflector portion C may possibly be extended by an extension EX beyond the zone in which the diffusion lenses L are located. This is particularly the case in the nonlimiting exemplary embodiment which is illustrated in FIGS. Figures 1 to 3 . In this case, the central opening O of the mask M may have substantially the shape of the retro-reflector portion C and its extension EX. It will be noted that this extension EX does not necessarily constitute a retro-reflector, and that it may have a different orientation from that of the retro-reflector portion C (as in the non-limiting embodiment example which is illustrated in FIGS. Figures 1 to 3 ).

As illustrated on the figures 2 , 4 and 5 , each diffusion lens L may be secured to the reflector portion C by a bridge P. The latter does not necessarily provide a binding function. It is indeed particularly advantageous, as illustrated on the figure 5 it also provides a light guide function. Indeed, a bridge P can be arranged to guide part of the light, which is emitted by a light-emitting diode D and which penetrates into the diffusion lens L associated therewith, to the inside (path TL) of the reflector portion C so as to illuminate it by backlighting.

The light which is guided towards the reflector portion C is that which is emitted at relatively large angles, typically between about 30 ° and about 60 ° when the light-emitting diode D emits light forward (which corresponds to the vehicle) at angles between 0 ° and approximately 60 ° (as shown in figure 5 ). It will therefore be understood that the invention advantageously proposes to recover at least a portion of the light emitted by the light-emitting diodes D, which has hitherto been regarded as parasitic (and therefore not diffused towards the front) in order to retract illuminate the reflector portion C.

In order for the light picked up in a diffusion lens L to be effectively reflected by the internal faces of the reflector portion C (path TL), the associated bridge P may be shaped so as to penetrate the light in this part C in a direction. chosen angle of incidence (see figure 5 ), for example between about 20 ° and about 60 °. This forms a kind of curtain of light that gives an impression of backlighting.

This backlight function is a third function of the EL element. It will of course be understood that it is active only when the light-emitting diodes D are in continuous operation (that is to say when they provide a lantern function which corresponds to a continuous ignition).

The EL element is made of a material having optical properties similar to those of glass, such as a synthetic material. For this purpose, PMMA can be used.

It will be noted that the synthetic material used may be colored or not colored as required, and in particular depending on whether the area of the ice G which is located opposite the reflex reflector portion C (as well as its possible extension EX) is uncoloured or colored.

The invention is not limited to the embodiments of element and rear optical block described above, only by way of example, but it encompasses all the variants that can be considered by those skilled in the art in the context of the invention. of the claims below.

Claims (10)

Rear optical unit (FA) for a motor vehicle, comprising a housing (B) housing at least two light-emitting diodes (D), a mask (M) provided with windows (F) placed in front of said light-emitting diodes (D) and an ice-cream (G) ) placed in front of said mask (M), characterized in that it comprises an element (EL) which is installed between said diodes (D) and said mask (M) and which comprises a part (C) defining a reflex reflector and extended to its periphery by diffusion lenses (L) housed at least partially in said windows (F) in front of said light emitting diodes (D) so as to diffuse their light towards said ice (G). An optical unit according to claim 1, characterized in that said diffusion lenses (L) are secured to said portion (C) by bridges (P) arranged to guide part of the light emitted by said light-emitting diodes (D) to the interior of said portion (C) to illuminate it by backlighting. Optical block according to claim 2, characterized in that said bridges (P) are arranged to penetrate the light in said portion (C) at a selected angle suitable for allowing reflection on the internal faces of said portion (C) . Optical block according to one of claims 1 to 3, characterized in that said portion (C) comprises a rear face (F1) facing said housing (B) and provided with reflection facets. Optical block Element according to one of claims 1 to 4, characterized in that the mask (M) has a central opening (O) at least partially surrounded by said windows (F), said portion (C) is placed opposite said opening (O). Optical block according to one of claims 1 to 5, characterized in that said element (EL) is made of a synthetic material. An optical unit according to claim 6, characterized in that said synthetic material is PMMA. Optical block according to one of claims 6 and 7, characterized in that said synthetic material is uncolored. Optical block according to one of claims 6 and 7, characterized in that said synthetic material is colored. An optical unit according to any one of the preceding claims, characterized in that the associated bridge (P) may be shaped to penetrate the light in that portion defining a retro-reflector (C) at an angle of incidence of between approximately 20 ° and about 60 °.

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