FR3035183A1 - DEVICE FOR LIGHTING OR LIGHT SIGNALING WITH DEPTH EFFECT - Google Patents

Abstract

Lighting device comprising a reflector (4) having orifices (12), a semi - reflecting screen (6) and defining with said reflector a cavity (14) at least one light source (8) arranged outside the cavity (14) and adapted to emit light rays intended to penetrate into said cavity (14), a part of the light rays entering the cavity being successively reflected by the semi-reflecting screen (6) and the reflector (4). The device comprises at least one light guide (22) whose first end (24) is connected to said light source and a second end (26) is arranged in the vicinity of an orifice (12) of the reflector (4) and opposite said orifice (12) or is engaged in an orifice (12) of the reflector (4), the or each light guide (22) conveying light rays from said source (18) into the cavity (14) through an orifice (12).

Description

The invention relates to lighting or light-signaling devices, in particular for a motor vehicle, and providing a visual effect of depth.

This type of device is for example used to give a luminous shape, such as for example a set of light spots, a visual effect in three dimensions. These devices then allow for example to simulate a starry sky. Such a device provided with a reflector and a semi-reflecting screen delimiting between them a cavity in which light rays penetrate is known in particular from EP 1 916 471 A1. Part of these rays undergo one or more reflections on the screen and then on the reflector, which produces a visual effect of depth for an observer looking at the device. In this device, the light rays are derived from light sources arranged opposite an orifice arranged in the reflector which then allows the passage of light rays in the cavity. Such a device has several disadvantages. Indeed, the relative arrangement of the light sources facing the orifices results in a relatively large size of the device and a very limited design flexibility, which may in particular cause difficulties concerning the integration of the device with another structure, such as for example a front or rear light of a motor vehicle, or a ceiling light cockpit. Also, the invention aims to improve the situation. For this purpose, the invention relates to a lighting or light-signaling device, in particular for a motor vehicle, said device comprising: a reflector comprising a reflective surface provided with orifices; a semi-reflecting screen arranged facing the reflector; and defining with said reflector a cavity located between said screen and said reflector, and - a light source arranged outside the cavity and adapted to emit light rays intended to penetrate into said cavity, a part of the light rays entering the cavity. cavity being successively reflected by the semi-reflective screen and the reflector so as to form a visual effect of depth.

In particular, the device further comprises at least one light guide whose first end is connected to said light source and a second end is arranged in the vicinity of an orifice of the reflector and facing said orifice or is engaged in an orifice of the reflector, so that the or each light guide conveys light rays from said light source into the cavity through at least one orifice. This allows in particular to soften the relative arrangement of the light source or sources of the device. Indeed, because of the presence of the light guide or guides, the source is no longer disposed opposite an orifice. This results in a relaxation of the relative positions of light sources and orifices, resulting in increased compactness for the device. In fact, the integration of the device is facilitated, in particular in a motor vehicle. Also, in a particular embodiment, at least one light source is arranged facing an area of the reflector which is devoid of orifice or is offset relative to the reflector. The device according to the invention thus allows provisions relative sources 15 and the reflector more varied, which reduces the size of the device. According to a particular embodiment, the device comprises a plurality of light guides whose first ends are connected to the same light source and whose second respective ends are arranged in the vicinity of an orifice of the reflector and facing said orifice or are engaged. in said orifice. This configuration has the particular effect of limiting the number of light sources required to form a given light effect such as a starry sky. According to one embodiment, the device comprises a plurality of light sources adapted to emit light rays in said cavity, the device comprising, for at least one light source, a single light guide whose first end is connected to said source and a second end of which is arranged in the vicinity of an orifice of the reflector facing said orifice or is engaged in said orifice. This configuration makes it possible in particular to obtain a visual effect whose variety is improved. In a particular embodiment, each orifice being oriented in a given direction of orientation, and the second end of at least one light guide extending in a direction angularly offset from the direction of orientation of the orifice corresponding. This makes it possible to vary the directions of emission of the light rays coming out of the device, which results in a greater variability of the visual effect obtained with respect to the angle at which the device is observed. According to another aspect of the invention, the first end and / or the second end of at least one light guide has a shaping portion configured to change the distribution of the emitted light beam. This makes it possible, in particular, to introduce a heterogeneity between the respective appearances of the light spots formed by the light source (s), and to optimize the photometric distribution of the system. In a particular embodiment, at least one light guide comprises a shaping portion. arranged at the first or second end, said forming portion being constituted by a region having a diameter different from the diameter of the opposite end of said light guide. This allows in particular to change the opening of the light beam from the corresponding light guide. According to another aspect of the invention, at least one light guide comprises a shaping portion formed by a circumferential bevel arranged at the second end of said light guide. In a particular embodiment, the bevel has a wall having one or more facets and / or having at least one slot arranged in said wall. According to another aspect of the invention, the device further comprises a control module configured to control the or each of the light sources in transmitted light power. In one embodiment, the reflector has a concave or convex portion. According to one aspect of the invention, the device is integrated with an element of the group formed by: a vehicle front lamp, a rear vehicle signaling light, a vehicle interior lighting device, such as for example a dome lighting intended to be fixed to a vehicle interior ceiling, a portion of the cabin ceiling (roof liner) or a module integrated into a vehicle door. The invention will be better understood on reading the detailed description which follows, given solely by way of example and with reference to the appended figures, in which: FIG. 1 is an illustration of a first embodiment a lighting or light-signaling device according to the invention; Figure 2 illustrates a light guide of the device of Figure 1; Figure 3 illustrates an example of visual rendering provided by a device according to the invention; and Figure 4 illustrates a second embodiment of the device according to the invention. Figure 1 illustrates a lighting device or light signaling according to the invention, hereinafter device 2. The device 2 is particularly adapted to be an integral part of a motor vehicle.

For example, the device 2 is integrated with an element of the group formed by a vehicle headlight, a rear vehicle signaling light, a car interior lighting device, such as for example a lighting dome to be fixed to a vehicle cabin ceiling, a part of the cabin ceiling or a module integrated in a vehicle door.

Device 2 is adapted to generate light images having an optical depth effect. In particular, the device 2 is configured to generate a plurality of light points adapted to undergo multiple reflections within the device so as to form a depth effect simulating a starry sky. With reference to FIG. 1, the device 2 comprises a reflector 4, a semi-reflecting screen 6 and light sources 8. The reflector 4 has a reflecting surface 10 oriented towards a principal direction of X-radiation of the device 2. In the example of Figure 1, the reflecting face 10 has a generally convex shape. Alternatively, the reflecting face 10 has a generally concave or flat shape. More generally, the reflecting face 10 may be flat, or have at least one convex or concave portion. The reflector 4 has a plurality of orifices 12 passing through and opening through the reflecting face 10 in a cavity 14 defined by the reflector 4 and the screen 6. The cavity 14 is more precisely located between the reflector 4 and the screen 6 .

As will be seen later, the orifices 12 are provided for the transport of light rays from the light sources 8 to the cavity 14, a light source 8 then being associated with one or more orifices 12. 12 has a generally cylindrical shape of circular section. In addition, each orifice 12 extends in a direction of orientation Di given corresponding to the axis of the cylinder of the corresponding orifice 12. In Figure 1 are illustrated four orifices, three of which extend in directions D1, D2 and D3 parallel to each other and parallel to the direction X, and one of which extends in a direction D4 angularly offset from the direction X.

The orifices have a radius of between 1 and 10 mm. At least two orifices 12 have different dimensions, in particular different radii. More specifically, preferably, the dimensions of the orifices 12 and in particular their respective radii are chosen as a function of the maximum power of the associated light source 8. For example, the device 2 comprises at least one orifice 12 whose radius is less than 3 mm, and at least one orifice 12 whose radius is greater than 3 mm. The semi-reflecting screen 6 is adapted to pass part of the incident light rays moving in the cavity 14 in the general direction X and to reflect another part towards the reflector 4. For this purpose, the screen 6 comprises a face, for example the inner face 16 facing the reflector 6, which has a surface metallization of small thickness. This metallization is for example made from aluminum or stainless steel. The semi-reflecting screen 6 has a transmission percentage of between 25% and 50%. This has the consequence that a light beam penetrating into the cavity results in a number of reflections resulting in visualizable repetitions of the light beam of up to about 10.

The semi-reflecting screen 6 is in the exemplary embodiment shown disposed substantially orthogonal to the general direction X. It may advantageously be inclined with respect to the general direction X and also have a curve, in order to adapt or integrating optimally with the surrounding surface in which the device 2 is integrated (curvature of the roof horn or a vehicle headlamp in particular). The screen 6 is for example substantially plane, as illustrated. Alternatively, the screen 6 has a concave portion and / or a convex portion.

The light sources 8 are preferably semiconductor light emitting elements adapted to generate light rays by electroluminescence. For example, the light sources 8 are light emitting diodes such as organic light emitting diodes or others. Other types of light sources 8 are nevertheless possible, such as for example an incandescent lamp, in particular a halogen lamp, or a discharge lamp. Preferably, at least two light sources 8 have different respective maximum powers. In particular, the device 2 comprises one or more light sources 8 adapted to generate alone or in combination a predetermined power illumination 10 greater than a predefined value, by a standard or a specification. In other words, the device 2 preferably comprises at least one light source 8 at a time intended to generate a visual effect and intended to generate a functional lighting, which is then subject to standards or prerequisites including minimum light output. For example, in the case of an interior lighting device, part of the light sources 8 will advantageously make it possible to carry out a reading function and another part, or, if the two functions are not performed simultaneously, the same sources. with a reduced intensity, to achieve ambient lighting. In addition, preferably, at least two light sources 8 are configured to generate light rays whose respective colors are different.

This advantageously makes it possible to confer a more plausible rendering of the desired aesthetic visual effect "starry sky", the stars visible in the night sky having varying intensities and colors. Preferably, one of said sources has a warm white color (> 5000K) and the other has a cold white color (<4500K). The device 2 further comprises a control module 18 configured to control the light power emitted by each of the light sources 8. The device 2 is connected to each light source 8 and comprises a memory 20 containing one or more files whose execution by the control module 18 results in a temporal sequence of light variations of each of the sources. This allows the implementation of visual scenarios by the device 2, each scenario being for example triggered in response to the detection of an event, such as for example a door opening of the vehicle which is integrated the device 2, the starting the vehicle, etc.

For this purpose, the control module 8 comprises for example a microcontroller such as an FPGA, for Field Programmable Gate Array which means programmable gate network, or a PIC microcontroller, etc. According to the invention, the device 2 further comprises at least one light guide 22 adapted to convey light rays from a light source 8 to the cavity 14. In the example of Figure 1, the device 2 comprises a plurality of light guides 22 each coupled to a given light source 8. Each light guide extends between a light source 8 and an orifice 12. Each light guide 22 comprises a first end 24 connected to the associated light source 8, so that at least a portion of the light rays generated by the source 8 penetrate into the light guide 22. The first end 24 is further adapted to collect the light rays entering it with the best possible efficiency. In addition, each light guide 22 comprises a second end 26 oriented towards the reflector 6. More specifically, each second end 22 is arranged in the vicinity of an orifice 12 of the reflector 4 and opposite this orifice 12, or is engaged in the orifice 12 and is oriented towards the cavity 14. In the example of Figure 1, the device 2 comprises four light guides 22, three of which engage in the associated orifice 12 and one of which is arranged in the vicinity of the rear mouth of an orifice 12, that is to say the mouth di stale of the orifice 12 relative to the screen 6, and faces the reflector 6 through the orifice 12. Is meant 20 here by "neighborhood" a small distance from the length of the light guide. The presence of the light guides enables the light generated by the sources 8 to be conveyed towards the cavity 14 independently of the relative position of the sources 8 with respect to the reflector 4. In fact, the sources 8 have not then been arranged in look at the corresponding source.

Also, in certain modes such as that of FIG. 1, at least one light source 8 is not arranged opposite an orifice 12. Here, the term "opposite" means that the preferred transmission direction of the source 8 does not correspond to the direction in which the orifice extends. In the example of FIG. 1, the second source 8 (starting from the left) is not arranged opposite an orifice of the reflector 4. More generally, the positioning of the light sources 8 can be arbitrary relative to the reflector 4. In particular, a light source 8 may be offset relative to the reflector 4, such as for example located outside a housing enclosing the other members of the device 2, as shown in dotted line on the In addition, the second end of the light guides 22, in particular those engaged in an orifice 12, extends in an orientation direction E 1. Advantageously, the orientation direction Ei of at least one light guide 22 is chosen so as to optimize the light distribution with respect to the standard or the specifications so as to be offset angularly from the direction Di of the orifice 12 correspondent. This allows, on the one hand, to obtain a greater variability of the visual effect provided by the device 2 with respect to the angle at which the device is observed and, on the other hand, to optimize the light distribution in relation to the required lighting values. For example, this offset is chosen greater than a threshold, for example 5 °. In the example of FIG. 1, the third light guide (starting from the left) has a second end of direction E3 angularly offset from the direction D4 of the orifice 12 which receives it. In practice, this orientation shift is achieved by slightly projecting the second end of the associated orifice 12 and / or shaping this end into the desired position. In addition, preferably, the orientation direction Ei of at least one light guide 22 is chosen to be offset angularly both from the direction Di of the corresponding orifice 12 but also from the general direction X. This allows to retain the above effect while avoiding the formation of dot lines in the overall rendering, which does not correspond to the desired effect of starry sky simulation. Preferably, for such a guide 22, the minimum of these two angular offsets is chosen greater than the threshold value above. With reference to FIG. 2, the light guides 22 are in the general form of rigid or flexible solid rods. In addition, they have a generally cylindrical shape, for example of circular or square section, whose dimensions are chosen according to the power of the associated light source 8 and the dimensions of the orifice 12. The light guides 22 are made in a material having good light-guiding properties, such as polymethyl methacrylate, acronym PMMA. According to one variant, the light guides may be made of optical fibers. Each light guide 22 provides, at its second end 26, a light beam Fi obtained from the light rays from the light source 8 to which the first end 24 of this guide is connected. The emitted light beams have a punctual appearance for an observer. Advantageously, at least one light guide 22 has, at its first or second end, a shaping portion configured to modify the photometry of the light beam emitted by this guide 22, that is to say of the light distribution of the light beam. In the example of FIG. 2, the light guide 22 comprises a first shaping portion 28A formed by a zone having a diameter different from that of the opposite end of the light guide 22. For example, the portion of Shaping 28A is formed by the first end itself, which has a diameter greater than that of the second end. This differential between the diameters of the two ends has the effect of modifying the opening of the light beam Fi, in this case to enlarge the opening of the light beam Fi. In practice, in the example of Figure 2, the shaping portion is obtained by continuously varying the cross section of the light guide 22 between its two ends. In addition, the light guide of Figure 2 also comprises a second shaping portion arranged at its second end and formed by a circumferential bevel 28B at the end of the guide 22. The bevel is in the form of a wall disposed circumferentially and inclined relative to the corresponding direction Ei. The presence of this bevel has the effect of generating a diffraction phenomenon of the light beam Fi. The bevel 28B comprises for example one or more facets 30. Parallel or alternatively, the bevel 28B comprises one or more slots 32. For example, the bevel is provided with several slots evenly distributed around the bevel, for example four slots. These facets and these slots have the respective effect of generating a flickering effect of the light spots from the light beam Fi as a function of the viewing angle of the device 2, and of forming Hi points with radial halos (FIG. 5). relative to the light spots from the light guide 22. The operation of the device 2 will now be described with reference to Figure 1.

During operation of the device 2, the light sources 8 generate light rays which penetrate into the corresponding light guide 22 through the first end 24. The light rays are conveyed by the guide 22 to its second end 26, and forms a light beam Fi entering the cavity 14 in the direction of the screen 6. Part of the light of the light beam passes through the screen 6, another part being reflected towards the reflector 4. This transmission mechanism This reflection is repeated for all the light beams Fi, which results in a visual rendering of many luminous points having an effect of depth like a starry sky. The control module 18 then controls the light power supplied by each of the light sources 8, for example to successively extinguish and then radiate at maximum power some of the sources 8. When they are injected into the cavity, the light beams 10 Fi see their modified photometry by the shaping portion or portions of the associated guide 22, which results in a wide variety of visual rendering of the different points of the starry sky simulated by the device 2. An example of the visual rendering of the device 2 is illustrated in FIG. 3. Other embodiments are possible. In particular, with reference to the variant of FIG. 4, the device 2 comprises at least one light source 8 to which several light guides 22 are associated. These light guides 22 each have their first end 24 connected to the light source. 8, the configuration of the other members then being identical to that described with reference to Figure 1. In some embodiments of this variant, the first end 24 of the different guides 22 connected to the source is common. Alternatively, these first ends 24 are disjoint and are arranged facing the light source 8 being spatially offset from each other. This variant has the effect of reducing the number of light sources 8 that includes the device 2, which limits the consumption of electrical energy and reduces the cost generally.

Claims (12)

REVENDICATIONS1. Lighting or light-signaling device, in particular for a motor vehicle, said device comprising: a reflector (4) comprising a reflective surface provided with orifices (12), a semi-reflecting screen (6) arranged facing the reflector (4) ) and defining with said reflector a cavity (14) located between said screen and said reflector, at least one light source (8) arranged outside the cavity (14) and adapted to emit light rays intended to penetrate into said cavity (14), a part of the light rays penetrating into the cavity being successively reflected by the semi-reflecting screen (6) and the reflector (4) so as to form a visual effect of depth, characterized in that the device comprises in addition at least one light guide (22) having a first end (24) connected to said light source and a second end (26) arranged in the vicinity of a light source orifice (12) of the reflector (4) and facing said orifice (12) or is engaged in an orifice (12) of the reflector (4), so that the or each light guide (22) conveys light rays from said source (18) into the cavity (14) through at least one orifice (12). 2. Device according to claim 1, characterized in that at least one light source (8) is arranged facing an area of the reflector which is devoid of orifice, or is offset relative to the reflector. 3. Device according to claim 1 or claim 2, characterized in that it comprises a plurality of light guides (22) whose first ends are connected to the same light source or whose second respective ends are arranged in the vicinity an orifice (12) of the reflector (4) and facing said orifice (12) or are engaged in said orifice (12). 4. Device according to any one of the preceding claims, characterized in that it comprises a plurality of light sources (8) adapted to emit light rays in said cavity (14), the device comprising, for at least one light source (8), a single light guide (22) whose first end is connected to said light source and a second end (26) of which is arranged in the vicinity of an orifice (12) of the reflector facing said orifice (12) or is engaged in said orifice (12). 5. Device according to any one of the preceding claims, characterized in that each orifice (12) is oriented in a given orientation direction (Di), and in that the second end (26) of at least one light guide (22) extends in a direction (Ei) angularly offset from the orientation direction (Di) of the corresponding orifice. 10 6. Device according to any one of the preceding claims, characterized in that the second end (26) of each light guide (22) emits a light beam obtained from light rays from the corresponding light source (8), the first end (24) and / or the second end (26) of at least one light guide (22) having a shaping portion (28A, 28B) configured to change the light distribution of the emitted light beam by said light guide (22). 7. Device according to claim 6, characterized in that at least one light guide (22) comprises a shaping portion arranged on the first or the second end of said light guide (22), the setting portion wherein the form is formed of a region (28A) having a diameter different from the diameter of the opposite end of said light guide. 8. Device according to claim 6 or claim 7, characterized in that at least one light guide (22) comprises a shaping portion formed by a circumferential bevel (28B) arranged at the second end of said guide bar light. 9. Device according to claim 8, characterized in that the bevel has one or more facets (30) and / or at least one slot (32) arranged in said wall. 30 10. Device according to any one of the preceding claims, characterized in that it further comprises a control module (18) configured to control the or each of the light sources emitted light power. 3035183 13 11. Device according to any one of the preceding claims, characterized in that the reflector (4) has a concave or convex portion. 12. Device according to any one of the preceding claims, characterized in that it is integrated in an element of the group formed by: a vehicle front lamp, a rear vehicle signaling light, a lighting device of automotive interior, such as for example a lighting dome intended to be fixed to a vehicle cabin ceiling, a part of the cabin ceiling or a module integrated in a vehicle door.