FR3008770A1 - MODULAR LIGHTING SYSTEM, IN PARTICULAR FOR A MOTOR VEHICLE LIGHTING ARRANGEMENT - Google Patents

Abstract

The invention relates to a lighting system (10) comprising at least one elementary lighting module (10A, 10B) comprising: at least one light-emitting diode (12A, 12B), an elongated optical module (16A, 16B) a material shaped to propagate and guide a light beam, said optical module (16A, 16B) comprising a first portion (18A, 18B) and a second portion (20A, 20B) assembled together by respective ends: - a first part rectilinear (18A, 18B) extending parallel to said illumination direction (L), - a second portion (20A, 20B) extending in a plane transverse to said first portion, - a reflective element (22A, 22B) positioned in a junction area of the first and second parts, said reflector element being positioned and shaped to reflect the light beams from the first portion to the second portion.

Description

The invention relates to a modular lighting system, in particular for a motor vehicle lighting element. Some lighting systems include a printed circuit board equipped with light-emitting diodes, commonly called LED (light emitting diode), electrically connected to the printed circuit. A printed circuit board, often designated by the acronym PCB (Printed Circuit Board), is a support, generally a plate, for electrically connecting a set of electronic components to each other, with the aim of producing a complex electronic circuit. . This plate is flat and consists of an assembly of one or more thin layers of copper separated by an insulating material. Such a plate can be rigid or flexible. In a lighting device, a printed circuit board or plate equipped with LEDs is generally arranged perpendicular to the desired illumination direction for good light rendering, the majority of the light beam being emitted by the diodes in one direction. perpendicular to the printed circuit board. There are also lighting systems involving a light optical module associated with LEDs to provide a light guide function. The LEDs are then arranged at a small distance from the optical module so that the optical module receives the light emitted by the LEDs. The optical module is often integrated with another element of the lighting system, for example a mask or a deflector. Such masks often extend perpendicular to the direction of illumination of the LEDs, at a distance from them. Such lighting systems thus consist of many elements to be arranged with respect to each other which can make their assembly complex. In addition, such lighting systems may have a large volume which may limit their arrangement and shape, which is undesirable, particularly in the automotive field. Moreover, in this type of lighting system, each LED is differentiated and visible. For aesthetic reasons, it may be wise to improve the stylistic aspect of the lighting system while maintaining its lighting functions.

There is therefore a need for a lighting system to overcome at least some of these disadvantages and vary the design. For this purpose, the subject of the invention relates to a lighting system, in particular for a motor vehicle headlamp, characterized in that it comprises at least one elementary lighting module comprising: at least one light emitting diode capable of emitting a light beam in a direction of illumination, supported and fed by a printed circuit board, an elongated optical module of a material shaped to propagate and guide a light beam, said optical module comprising a first part and a second part assembled between them by respective ends: a first rectilinear part extending parallel to said illumination direction, comprising a free end situated facing said at least one light-emitting diode, a second part extending in a transverse plane to said first part, a reflector element positioned in a junction zone of the first and second parts, said reflective element being positioned and shaped to reflect the light beams from the first part to the second part.

A light-emitting diode generally emits a plurality of light rays in several directions: the light beam consisting of these rays thus generally has a conical shape. In the present application, the direction of illumination of an LED is considered as the direction of the axis of symmetry of the cone delimiting the light beam emitted by the LED. In the context of the present invention, light beam or light have an identical meaning. The arrangement according to the invention has the advantage of allowing an offset of a portion of the lighting module relative to the light source. Indeed, the second part of the optical module is offset from the length of the first rectilinear part of the optical module, so that the second part is more visible and can be used as the main illumination part of the lighting system. This second part being supported by one of its ends only, it may have various shapes and / or complex. It is thus possible to improve the aesthetics of the lighting system with a reduced number of elements and a small footprint. In addition, because of the remote position of the second part with respect to the light source of the lighting system formed of the LED or LEDs, the latter can be more easily hidden from the vision of a human being, further improving the 'aesthetic. The number of LEDs is preferably limited in order to reduce the size of the elementary lighting module, for example 1 to 10 LEDs may suffice, preferably 1 to 6 or 1 to 3. However, advantageously and in a nonlimiting manner, each elementary lighting module may comprise a single LED, for a smaller footprint and simplification of the realization of the lighting system without impairing the light rendering of the lighting system. The LED or LEDs are located opposite a free end of a first optical module portion. In particular, this free end can be positioned to capture 70 to 100% of the light radiation emitted by the LED or LEDs, preferably from 80 to 100% of the radiation, or even from 90 to 100% of the radiation. For example, the free end of the optical module can thus be located at a distance of about 0.5 to 5 cm from the LED or LEDs. Optionally a collimation device located between this free end of the first part of the optical module and the LED or may allow to focus all of the light radiation emitted by the LED or on the free end. In general, the collimation device of the light rays can involve one or more elements of conventional optics Fresnel lens type, diopters, facets or prisms. This free end may comprise, or be formed of, a receiving surface, for example substantially perpendicular to the lighting direction of the LED or LEDs. Advantageously and in a nonlimiting manner, the second part of the optical module of an elementary lighting module may extend in a plane perpendicular to the first part of said module. This may in particular make it possible to facilitate the realization of the module and to improve its aesthetics, the particular arrangement making it easier to camouflage the LED or LEDs, in particular in a direction parallel to the first part of the optical module. Advantageously and in a nonlimiting manner, each optical module may be formed of a polymeric or glass material, preferably translucent or transparent, capable of propagating and guiding at least one light beam flowing inside its volume, in particular a light beam. emitted by one or more electroluminescent diodes. The material used may be any material adapted to guide a light radiation, such as a glass or polymer material, colored or not, for example polycarbonate or poly (methylmethacrylate) (PMMA). Each optical module can thus be produced in a simple manner and its shape can be adapted to the member intended to receive the lighting system.

The optical module of the lighting system according to the invention has an elongated shape, in other words its cross section is smaller in dimension than its length. The optical module may in particular have a circular cross section, elliptical or the like, a circular section being preferred for a simpler embodiment. Alternatively, the cross section of the optical module may also have a polygonal shape, for example frustoconical. This embodiment is however not preferred. The first part of the optical module is rectilinear. The second portion of the optical module may also be straight, although this embodiment is not preferred. Advantageously and without limitation, the second part has a curved shape, for example in an arc or an elliptical arc. For example, when its cross section is circular, the second part may be a torus portion, generally an open torus portion, other forms of crown type are however possible. Advantageously and in a nonlimiting manner, the lighting system according to the invention may comprise several identical elementary lighting modules juxtaposed so that the second parts of the optical modules are located in the same plane and extend in the extension of one another. others, especially to form a closed geometric form. It is thus possible to achieve a closed geometric shape simply by juxtaposing several identical elementary modules, which can thus reduce the manufacturing cost and improve the aesthetics of the lighting system, while obtaining a uniform illumination of the geometric shape obtained. It is thus possible to produce luminous closed shapes of very varied shapes: for example a polygonal shape, each side of the polygon being formed by a second optical module portion of a rectilinear lighting system, or a circular or elliptical shape by juxtaposing second parts of the optical modules each in the shape of an arc or an ellipse. The reflective element of an elementary module may be formed by a surface or a metallized element for reflecting the light beams in the desired direction. This embodiment is however not preferred because the luminous flux can not be continuous between two elementary lighting modules juxtaposed, especially when the ends of the second adjacent portions are tangent. Advantageously and in a nonlimiting manner, the reflector element of an elementary lighting module is formed by an outer plane surface forming a diopter of the optical module, said external flat surface being situated between the first and second parts and arranged so as to reflect a light beam from the first part to the second part. In the present application, an outer plane surface forming a diopter means an outer surface which is not covered by another material than that forming the optical module and which is not in contact with any other material. In other words, this outer surface is in contact with the ambient air only. Such an arrangement has the advantage of not requiring the addition or integration of a baffle element to the optical module: the reflector element is formed in the optical module, which reduces the manufacturing cost of the optical module and to facilitate its manufacture. The reflection of the light beam is then obtained by virtue of the difference in value between the refractive index of the material constituting the optical module, within which the light rays to be reflected, and the refractive index of the adjacent air. on the flat outer surface. The position of the outer planar surface with respect to the first and second parts, and in particular its orientation, can then be determined by the laws of Snell and Descartes as a function of these refractive indices, preferably so as to completely reflect the incident radiation.

When the optical modules comprise a diopter formed by an external planar surface for returning the light beams coming from their first part to their second part, adjacent elementary lighting modules can be advantageously arranged so that a free end of the second part an optical module is located facing the reflector element of another adjacent elementary lighting module, at a predetermined distance therefrom. This predetermined distance is preferably sufficient to maintain a layer of air between said outer planar surface of the optical module and the end of an adjacent module, and thus avoid any contact between these two parts during operation and / or the use of the lighting system. Such a distance can be of the order of 5 / 10th of a mm to 1 mm. In addition, this distance may advantageously be small enough to allow most of a light radiation flowing inside the volume of a second part of an optical module to be refracted inside the volume of the light. second portion of another adjacent optical module, through said outer planar surface forming a diopter. This makes it possible to improve the homogeneity and the continuity of illumination of the geometrical shape formed by the second parts end to end, over the entire periphery of the latter. In other words, there is no interruption in the illumination of the closed form consisting of juxtaposed elementary lighting modules, thus also improving the aesthetic appearance of the lighting system. This continuity of illumination is even greater when the ends of the second adjacent parts are tangent, for example when the second parts are in an arc or an elliptical arc. This distance may in particular be sufficiently small to allow the refraction of 70 to 100% of the light radiation, preferably 80 to 100%, or even 90 to 100%.

In order to improve the transmission of the light radiation from one elementary lighting module to another, the free end of the second part of an optical module located opposite the reflector element of another elementary module of adjacent lighting has a flat surface parallel to the outer flat surface forming said receiving member. Advantageously and in a nonlimiting manner, the second optical module portion of an elementary lighting module may comprise at least one shaped surface portion for reflecting the light rays inwardly of the volume of the second portion. This can be achieved by choosing a shape and / or material suitable for producing this surface portion. By way of example, this surface portion may have an adapted orientation allowing reflection of an incident ray in a preferred direction. Such an orientation can be determined by the laws of optics as a function of the characteristics of the light beam and the shape of the optical module. It is also possible to deposit a metal layer on this surface portion to form a mirror. Such a surface portion may for example be a portion located on the side of the first part of the module and the LED or LEDs.

Advantageously and in a nonlimiting manner, the lighting system according to the invention may comprise a housing inside which the at least one light emitting diode is fixed and its printed circuit board of an elementary lighting module, the optical module of said elementary lighting module being supported by at least one support element connecting said housing to the first part of the optical module. No support element thus disturbs the light emission of the second optical module portion, thus improving the aesthetics of the lighting system.

Such a support member may also be positioned so that the second portion of the optical module is located outside the housing for a better appearance. A support member may advantageously comprise an opaque sleeve surrounding said first optical module portion, which may be able to conceal the light emitted by this first part, increasing the suspended effect of the light emitted by the second part. The sleeve can for example hide 50% to 100% of the length of this first part. The support member may be for example of polymeric material, especially opaque, for example polypropylene. The lighting system may further comprise at least one optical module fixing element on the housing, in particular arranged between the second optical module portions of two adjacent elementary lighting modules, which may make it possible to avoid any misalignment between the second portions of optical modules of these adjacent elementary lighting modules.

The fasteners may be rods or strips of different shapes and sizes, such as rectangular. Preferably, the fixing elements are made of materials identical to those of the optical module, namely a material able to propagate and transmit light beams, which can make it possible to increase the "suspended" effect of the optical module, such elements disturbing little or little the propagation of light. The fasteners may be attached to an outer surface of the second optical module portions by an end region of said elements, the opposite end regions being attachable to the housing. The invention also relates to a lighting member of a motor vehicle equipped with a lighting system according to the invention. This lighting member may in particular be chosen from a projector for signaling the vehicle and a mood light intended to be located inside the passenger compartment. Preferably, the member is a projector. A lighting member usually comprises a housing whose one face is translucent or transparent for the output of the light beam. The rigid printed circuit board equipped with one or more diodes is then disposed inside the housing and fixed thereto, the direction of the lighting system being such that the light beams emerge from the translucent or transparent face of the housing. . The housing of the lighting system according to the invention can be integrated into the housing of the lighting member or form this housing.

Another object of the invention relates to a motor vehicle equipped with at least one lighting system according to the invention.

In particular, said lighting system can equip at least one of the following organs: - an ambient light located inside the passenger compartment of the vehicle, - a signaling light of the vehicle. This traffic light, front or rear, can be chosen especially from a daytime running light (a light that comes on automatically when the vehicle starts moving, also known by the acronym "DRL"), a position light, a reversing light, a fog light, a blinker, a brake light or any other traffic light. The invention is now described with reference to the accompanying non-limiting drawings, in which: - Figure 1 is a perspective view of a vehicle headlight equipped with a lighting system according to the invention; - Figure 2 is a schematic perspective view of a lighting system according to the invention; - Figures 3 and 4 are enlargements of the lighting system of Figure 2, on which is also partially shown a housing of the lighting system. By substantially parallel means a direction forming an angle of at most ± 20 ° or at most ± 10 ° with a particular direction. FIG. 1 shows a headlamp 1 for the signaling of the vehicle, comprising a housing 3 of which one face 5 is translucent or transparent for the output of the light beams in a lighting direction L. This face 5 can adopt any flat shape or more complex as in the example shown. This headlamp 1 is equipped with a lighting system 10 comprising two elementary lighting modules 10A, 10B shown in greater detail in FIG. 2. These elementary lighting modules 10A, 10B are identical: their elements will therefore be designated by the same numerical reference followed by the letters A and B to show their membership in modules 10A and 10B respectively.

Each of the elementary lighting modules 10A, 10B comprises: an LED 12A, 12B capable of emitting a light beam in a lighting direction L, supported and fed by a printed circuit board 14A, 14B, an optical module 16A, 16B of elongated form of a shaped material for propagating and guiding a light beam, this optical module 16A, 16B comprises a first portion 18A, 18B and a second portion 20A, 20B joined together by respective ends. The optical modules 16A, 16B are for example in PMMA.

As seen in FIG. 2 and shown in more detail in FIGS. 3 and 4 for one of the modules 10A, each of the elementary lighting modules 10A, 10B also comprises a reflector element 22A, 22B positioned in a junction zone. first and second portions, respectively 18A, 18B and 20A, 20B, said reflective element 22A, 22B being positioned and shaped to reflect light beams from the first portion 18A, 18B to the second portion 20A, 20B. In FIGS. 2 and 3, the light radiation emitted by the diode 12A is symbolized by the solid black arrows and the light radiation emitted by the diode 12B is symbolized by the black arrows in broken lines. The first portions 18A, 18B are rectilinear and extend parallel to the lighting direction of the associated LED 12A, 12B. The first portions 18A, 18B have a circular cross section in the example shown. Each first portion 18A, 18B comprises a free end 19A, 19B, located opposite the associated LED, 12A, 12B respectively. The second portions 20A, 20B, also of circular cross section in the example, extend in a plane transverse to the first portions 18A, 18B, perpendicular to the latter in the example shown. In this example, each second portion 20A, 20B forms a half torus. These second parts 20A, 20B are also in the same plane and extend in the extension of one another so as to form a complete torus, as visible in Figures 1 and 2.

In the example shown, each of the reflector elements 22A, 22B is an outer planar surface of the optical module 16A, 16B respectively. In the arrangement shown, the free ends 21A, 21B of the second portions 20A, 20B, respectively, each form a planar surface which extends parallel to the outer planar surface of the receiving member 22B, 22A, respectively, at a distance from the latter so as to leave these external flat surfaces in contact with the air, thus ensuring the reflection of incident radiation from a first portion towards the second portion. In addition, the radiation flowing inside the second portion 20B of the module 16B can thus be refracted inside the second portion 20A of the module 16A, after passing through the air layer separating 21B and 22A, and similarly, the radiation flowing through the second portion 20A of the module 16a can thus be refracted inside the second portion 20B of the module 16B, so that the two second portions 20A, 20B are illuminated continuously and homogeneously. This can make it possible to produce illuminations giving the impression of going through the torus formed by the two second parts by making each LED 12A, 12B emit with a phase shift. In the example shown in the figures, the lighting directions of the LEDs 12A and 12B are parallel and correspond to the lighting direction L of the lighting system 10 and the projector 1.

In order to improve the luminous rendering of the second portions 20A, 20B, a surface portion of these second portions may be shaped to reflect the light rays inwardly of the volume of the second portion. It is preferably portions 24A, 24B located on the side of the first portions 18A, 18B, as shown in FIG. 4. These portions may extend over 1/3 of the cross-section of a second portion, or even on half of this cross section. The lighting system 10 further comprises a housing 26 visible in Figures 1, 3 and 4. The housing 26 of the example has a substantially cylindrical shape. On this housing 26 are fixed the printed circuit boards 14A, 14B supporting the LEDs 12A, 12B (these fasteners are not shown in the figures). Each first portion 18A, 18B is further supported by a support member 28, shown only in Figure 3. This support member 28 forms a sleeve enclosing the first portion over a large portion of its length. Since this support element 28 is opaque, the light propagating inside the first part does not pass through it. This support member 28 is part of the housing 26, in the example shown and is arranged so that the second portion 20A is located outside the housing 26. In addition, two fastening elements 30 (see Figures 1 and 4) are provided for fixing the optical modules 16A, 16B to the housing 26. Each fixing element 30 is disposed between the optical modules 16A, 16B, more precisely between two second portions 20A, 20B. They are diametrically opposed in the example shown. Each fastening element 30 is formed of a rectangular strip of the same material as the optical module 16A, 16B (in this case PMMA) one end of which is integral with the optical modules 16A, 16B (see FIG. 1) and of which the Another end 30b is attached to the housing 26. For clarity, Figure 4 does not show the end 30a. These fastening elements 30 hold the optical modules 16A, 16B in alignment with one another. Thus, in the example shown, the second parts 20A, 20B are located outside the casing 26 while the first parts 18A and 18B are arranged partly inside the casing and the LEDs 12A, 12B entirely at the housing. 26. The illumination function is therefore essentially provided by the second parts. The housing 26 of the lighting system shown, for example of polymer material, can be fixed or integrated into the housing 3 of the projector 1. The torus formed by the second parts 20A, 20B thus appears as suspended, bringing a better aesthetic appearance to the system lighting. In this example, only two basic lighting modules are provided. However, it is possible to envisage the use of a single elementary module or of more than two, depending on the desired shape of the visible illuminated part of the lighting system, formed by each second part of a lighting system. The lighting member described with reference to Figure 1 is a motor vehicle headlight.

The invention is however in no way limited by the type and shape of the lighting member, which may also be an interior or exterior lighting member, for a vehicle or a building. The lighting system according to the invention has the advantage of being able to be used in many organs which we seek in particular to reduce the size and weight.

Claims (10)

REVENDICATIONS1. Lighting system (10), in particular for a motor vehicle headlamp (1), characterized in that it comprises at least one elementary lighting module (10A, 10B) comprising: at least one light-emitting diode (12A, 12B) capable of emitting a light beam in a lighting direction (L), supported and fed by a circuit board (14A, 14B), an elongate optical module (16A, 16B) of a shaped material for propagating and guiding a light beam, said optical module (16A, 16B) comprising a first portion (18A, 18B) and a second portion (20A, 20B) assembled together by respective ends: - a first straight portion (18A, 18B) s' extending parallel to said illumination direction (L), comprising a free end (19A, 19B) facing said at least one light-emitting diode, - a second portion (20A, 20B) extending in a plane transverse to said first part, a reflector element (22A, 22B) positioned in a junction area of the first and second portions, said reflector element being positioned and shaped to reflect the light beams from the first portion to the second portion. 2. Lighting system (10) according to claim 1, characterized in that the second portion (20A, 20B) extends in a plane perpendicular to the first portion (18A, 18B). 3. Lighting system (10) according to one of claims 1 or 2, characterized in that the second portion (20A, 20B) has a curved shape, for example in an arc or an elliptical arc, or a rectilinear form. 4. Lighting system (10) according to one of claims 1 to 3, characterized in that it comprises a plurality of identical elementary lighting modules (10A, 10B) juxtaposed so that the second parts (20A, 20B) optical modules are located in the same plane and extend in the extension of each other, in particular so as to form a closed geometric shape. 5. Lighting system (10) according to one of claims 1 to 4, characterized in that the reflector element (22A, 22B) of an elementary lighting module is formed by an outer plane surface forming diopter of optical module, said outer planar surface being located between the first and second portions and arranged to reflect a light beam from the first portion to the second portion. 6 Lighting system (10) according to claims 4 and 5, characterized in that adjacent elementary lighting modules (10A, 10B) are arranged so that a free end (21A, 21B) of the second part d an optical module is located facing the reflector element (22A, 22B) of another adjacent elementary lighting module, at a predetermined distance therefrom. 7. Lighting system (10) according to one of claims 1 to 6, characterized in that the second portion (20A, 20B) optical module of an elementary lighting module comprises at least one surface portion ( 24A, 24B) shaped to reflect the light radiation towards the interior of the volume of the second part. 8. lighting system (10) according to one of claims 1 to 7, characterized in that it comprises a housing (26) inside which are fixed at least one light emitting diode and circuit board printed on a basic lighting module and comprising: at least one support element (28) of the optical module on the housing, said support element (28) connecting said housing (26) to the first part (18A, 18B) of the optical module, said support member (28) comprising for example an opaque sleeve surrounding said first part, and / or at least one fixing element (30) of the optical module on the case, in particular arranged between the second portions (20A, 20B) of optical modules of two adjacent lighting element modules (10A, 10B). Motor vehicle lighting unit (1) equipped with a lighting system (10) according to one of claims 1 to 8. 10. Motor vehicle equipped with at least one lighting system (10) according to one of claims 1 to 8, said at leastsystem (10) equipping including at least one of the following organs: - a light of atmosphere inside the cockpit, - a vehicle signaling light.5