FR3042258A1 - TRANSPARENT LIGHT ELEMENT WITH MULTIPLE LIGHT SOURCES AND A COMMON EXIT SIDE - Google Patents

Abstract

The invention relates to an optical element (6) of transparent or translucent material capable of producing a light beam and comprising a first input face (101) of light rays produced by a first light source (16), a first face reflector (103) light rays from the first input face (101), a second input face (121) of light rays produced by a second light source (18), a second reflection face (123) light rays from the second input face (121), and a common output face (81). The light rays coming from the first reflection face (103) and the second reflection face (123) propagate in the same direction towards one or more reflection faces (82) of said rays towards the exit face (81).

Description

The invention relates to the field of light signaling and lighting, in particular for a motor vehicle.

The published patent document FR 2 947 325 A1 discloses a lighting or light-signaling device for a motor vehicle. This device comprises two different light sources associated with different photometric functions and a main light guide arranged to guide the light from the light sources to an output face. The exit face thus forms an illuminating face common to both photometric functions. One of the light sources can thus produce a white light and the other an amber light, thus providing functions of daylighting and direction indication, respectively. The main light guide comprises a reflection zone of substantially conical shape so as to return a portion of the rays coming from one of the light sources directly to the exit face and the other part of the rays to a return face to be then returned to the exit face as well. A generally Y-shaped auxiliary light guide may be disposed between the light sources and the input face of the main guide. Each of the two light sources is disposed opposite one of the two upper branches of the Y, while the common branch of the Y is disposed in front of the input face of the main light guide. This device is interesting in that it allows to form a common illuminating face for two light signaling functions. However, the multiple reflections, especially on the rear facing face, are subject to light losses, in particular because part of the rays thus returned to the exit face are likely to meet the substantially conical reflection zone. In addition, making a Y-shaped auxiliary light guide can be expensive. In the absence of this auxiliary guide, it is necessary to strongly bring the light sources together which may cause problems of arrangement.

Patent document FR 3,003,928 A1 discloses a lighting or light-signaling device for a motor vehicle, similar to that of the previous document. However, it differs in that the light guide is generally U-shaped, each of the two light sources being disposed opposite one of the two branches of the U. The exit face, meanwhile, is located at middle of the junction between the two branches of the U. The rays undergo a reflection at each of the corners of the U and are then reflected towards the output face by two inclined faces forming a V-shaped profile. This device provides the same input principle light in the two branches of the U than that of the previous document, that is to say with a light return by return faces at the ends of said branches. More precisely, the light sources can not be on the same plate given the spacing between the branches of the U and the fact that the light sources must illuminate in opposite directions. In addition, the use of the two inclined V-shaped profile faces is penalizing in that each of these faces reflects exclusively the rays of one of the two light sources, thus not favoring a mixture of the rays and the homogeneity of the light beam. product. The object of the invention is to propose a luminous device with an output face common to a plurality of light sources, which provides greater freedom as regards the positioning of the light sources and / or a better optical performance. The subject of the invention is an optical element made of transparent or translucent material capable of producing a light beam and comprising: a first input face of light rays produced by a first light source; a first reflection face of the light rays coming from the first input face; a second input side of light rays produced by a second light source; a second reflection face of the light rays coming from the second input face; an exit face of the light rays coming from the first and second reflection faces; remarkable in that the light rays coming from the first reflection face and the second reflection face propagate in the same direction towards one or more reflection faces of said rays towards the exit face.

In the case where there is a single reflection face to the exit face, it is then common to the light rays from the first reflection face and the second reflection face. In the case where there are several reflection faces towards the exit, in this case two, they are then advantageously coplanar or form an angle of less than 30 °, preferably of less than 20 °, more preferably of 10 °.

According to an advantageous embodiment of the invention, at least one, preferably each, of the first and second reflection faces and the reflection face or faces towards the exit face is configured to reflect the rays according to the total reflection principle.

According to an advantageous embodiment of the invention, at least one, preferably each, of the first and second reflection faces and of the reflection face or faces towards the exit face comprises reflection facets or striations.

According to an advantageous embodiment of the invention, at least one, preferably each, of the first and second input faces has an optical input axis of the light which forms an angle with the main direction of the light beam which is between 80 ° and 110 °.

According to an advantageous embodiment of the invention, at least one, preferably each, of the first and second input faces comprises a collimator, preferably of the Fresnel lens type.

According to an advantageous embodiment of the invention, the first and second reflection faces are adjacent, preferably contiguous.

According to an advantageous embodiment of the invention, the first and second reflection faces are distant from each other and at different distances from the reflection face or faces towards the exit face.

According to an advantageous embodiment of the invention, the element comprises a first portion capable of guiding the rays from the first input face to the first reflection face, and a second portion capable of guiding the rays from the second face. to the second reflection face, said portions extending in opposite main directions and forming an angle of between 150 ° and 180 °.

According to an advantageous embodiment of the invention, the principal directions of the first and second portions are parallel and distant from each other.

According to an advantageous embodiment of the invention, the element comprises a third portion able to guide the rays from the reflection face (s) of the rays towards the exit face to the exit face, said portion extending according to a main direction preferentially corresponding to the direction of the light beam.

According to an advantageous embodiment of the invention, the principal direction of the third portion is parallel to the main directions of the first and second portions or forms an angle of less than 30 ° with one or both of said portions.

According to an advantageous embodiment of the invention, the third portion comprises a protuberance forming the exit face. Advantageously, the protuberance has a reduced thickness, preferably at least 30%, relative to the thickness of the third portion at a position adjacent to said protuberance.

According to an advantageous embodiment of the invention, the third portion forms a web, generally flat or curved.

According to an advantageous embodiment of the invention, the element comprises several pairs of first and second portions distributed along the third portion in the form of a sheet.

According to an advantageous embodiment of the invention, the element comprises a first intermediate reflection face capable of reflecting the light rays coming from the first input face towards the first reflection face, and / or a second intermediate reflection face capable of to reflect light rays from the second input face to the second reflection face.

According to an advantageous embodiment of the invention, the first intermediate reflection face is located on the first portion and / or the second intermediate reflection face is located on the second portion.

According to an advantageous embodiment of the invention, the light rays coming from the first reflection face and the second reflection face propagate in parallel directions or at an angle of less than 30 °, preferably less than 20 °, more preferably less than 15 °, more preferably still less than 10 °.

According to an advantageous embodiment of the invention, the light rays coming from the first reflection face and the second reflection face are reflected by a common portion of the reflection face of said rays towards the exit face.

According to an advantageous embodiment of the invention, the light rays coming from the first reflection face and the second reflection face are reflected by distinct portions of the reflection face of said rays towards the exit face. The invention also relates to a light device, in particular for a motor vehicle, comprising: at least a first and a second light source, said sources being of different colors; at least one optical element of transparent or translucent material capable of selectively producing two light beams of different colors from the light rays of the first (s) and second (s) light sources; remarkable in that the optical element is in accordance with the invention.

According to an advantageous embodiment of the invention, one of the two light beams of different colors corresponds to a daylight function and / or the other of said beams corresponds to a direction indicator function.

According to an advantageous embodiment of the invention, the luminous device is a motor vehicle headlamp, comprising, in addition, at least one lighting module

The measures of the invention are interesting in that they provide more freedom in positioning the light sources. Indeed, the fact of providing that the light rays coming from the first reflection face and the second reflection face propagate in the same direction towards a common reflection face towards the exit face, or several such reflection faces, allows the light sources to be oriented so as to emit their light essentially in the same direction and in the same direction. In addition, the fact of using a reflection face towards the exit face which is common to these rays, or even such reflection faces, makes it possible to further optimize their design and their optical efficiency. Other features and advantages of the present invention will be better understood from the description and drawings in which: FIG. 1 is a perspective view of a motor vehicle headlamp, comprising two optical elements for light signaling; according to a first embodiment of the invention; FIG. 2 is a representation of the optical light-signaling elements of the projector of FIG. 1; - Figure 3 is a perspective representation from a rear view of a portion of one of the two optical elements of Figures 1 and 2; - Figure 4 is a schematic sectional view of one of the optical elements of Figures 1 to 3 according to the first embodiment of the invention; - Figure 5 is a schematic sectional view of an optical element according to a second embodiment of the invention; - Figure 6 is a schematic sectional view of an optical element according to a third embodiment of the invention; - Figure 7 is a schematic sectional view of an optical element according to a fourth embodiment of the invention. In Figure 1, it can be seen that the front left projector 2 shown thereon comprises a housing 4 containing in particular two optical elements 6 according to a first embodiment of the invention. The housing 4 contains other elements, such as lighting modules. The two optical elements 6 provide a dual function, namely a daylight function, commonly referred to by the acronym DRL (for "Daytime Running Lamp") and a direction indicator function, commonly referred to as flashing. In this case, the daylight function is deactivated when the direction indicator function is activated. The daylight function is provided by a white light while the direction indicator function is provided by an amber light, close to the orange color.

Figure 2 illustrates the two optical elements 6 of the projector of Figure 1.

FIG. 3 is a rear perspective view of a portion of one of the optical elements 6 of FIGS. 1 and 2. The optical element 6 comprises several pairs of first and second portions 10 and 12 that are adjacent and capable of bringing in, by their respective input faces 101 and 121, the rays emitted by light sources (not shown). These are intended to be arranged vis-à-vis the input faces 101 and 121. The first and second portions 10 and 12 are transparent or translucent material, capable of guiding light rays. The optical element also comprises a third portion 8, also of transparent or translucent material, and advantageously in one piece with the first and second portions 10 and 12. The third portion 8 has a generally extended shape, so as to web, it being understood that this web is not necessary flat. The third portion 8 includes a ray exit face 81. This face is located on the front edge of the sheet in question. The third portion 8 comprises reflection faces 82 able to reflect towards the exit face 81 the rays guided by the first and second portions 10 and 12.

FIG. 4 is a schematic sectional view of the optical element 6 of FIG. 3 along a plane parallel to the optical axis 7 of the element 6. This optical axis 7 is represented by the generally horizontal axis line crossing through the third portion 8. It is possible to observe the light sources 16 and 18 which, in this case, are arranged on the same support 14. The source 16 is arranged opposite the entry face 101 of the first portion 10 of the optical element 6. The input face is preferably a collimator Fresnel lens type. The first portion 10 comprises a first reflection face 103 of the rays coming from the input face 101. This face ensures reflection of the rays in question towards a reflection face 82 of the third portion 8, by the principle of total reflection. It is indeed oriented so that the angle of incidence of the rays is greater than the limit angle of refraction. It can thus reflect the rays without adding a reflective coating. A first intermediate reflection face 102 may be provided in order to reflect towards the reflection face 103 the rays coming from the input face 101. Similarly to the reflection face 103, the intermediate reflection face ensures reflection of the rays in question. by the principle of total reflection. The rays entering through the input face 101 and reflected by the reflection faces 102 and 103 are then reflected by the reflection face 82 in a direction corresponding to the optical axis of the optical element 6, propagate in the third portion 8 of the optical element 6 to then exit through the exit face 81.

It should be noted that the outlet face 81 is located on a projecting portion 83 whose thickness is reduced relative to the average thickness of the third portion 8.

Similarly to what has just been described in relation to the first portion, the light source 18 is disposed vis-à-vis the input face 121 of the second portion 12. The input face 121 may comprise a collimator of the Fresnel lens type. The rays entering through the input face 121 are reflected by the intermediate reflection face 122 and then by the reflection face 123 to then meet the reflection face 82 of the third portion 8. The rays are reflected in a direction corresponding to the optical axis of the optical element 6, and propagate in the third portion 8 of the optical element 6 and then output by the output face 81.

The light sources 16 and 18 are advantageously oriented along the optical axes 104 and 124 of the input faces 101 and 121, respectively. Each of these optical axes 104 and 124 advantageously forms an angle with the optical axis 7 of the element which is between 80 ° and 110 °.

The first and second portions 10 and 12 extend in principal directions 105 and 125 which form with each other an angle α and with the optical axis 7 angles β and y, respectively. The angle a is advantageously between 90 ° and 180 °. The angles β and γ are advantageously between 0 ° and 45 °.

The reflection face 82 is thus common to the rays coming from the first and second portions, namely first and second light sources 16 and 18. The rays propagating in the third portion 8 of the element 6 are represented as propagating in line line aligned with the optical axis and longitudinal 7 of the third portion in question. In fact, the rays reflected by the common reflection face 82 can propagate by successive reflections on the main faces (upper and lower according to the orientation in Figure 4) to meet the exit face 81. The differences in angle d The incidence between the rays coming from the first light source 16 and those coming from the second light source 18 thus have little influence on the propagation of the rays in the third portion 8.

The fact that the reflection face 82 is common to the rays of the two light sources is interesting from a cost and optical efficiency point of view. Indeed, this surface can be worked, as in particular by means of facets or streaks, to ensure a certain homogeneity to the light beam produced. This work is therefore to be done only on one side of reflection. In addition, this face can be dimensioned without stress relative to its environment, unlike the state of the art, which allows to harvest a maximum of light rays.

The exit face 81 need not be located on a protruding portion 83 of reduced thickness. It may also be on the front face of the third portion 8 devoid of such a protruding portion.

It can be realized, in the light of what has just been described, in particular in relation with FIG. 4, that the first and second portions 10 and 12 confer a great freedom as to the positioning of the light sources 16 and 18, and this while maintaining a satisfactory optical performance and a simple construction.

In practice, the first light source 16 is powered to provide a first signaling function such as a daylighting function. To provide a second function, such as a direction indicator function, the first light source 16 is then unpowered and the second light source 18 is. In the case of a direction indicator function, the second light source is amber in color. It should also be noted that it is possible to feed both light sources at the same time. It should also be noted that what has just been described applies to all pairs of light sources associated with the optical element. It is also possible to feed only a portion of the second light sources to provide the direction indicator function.

Figure 5 is a schematic sectional view of an optical element according to a second embodiment of the invention. The reference numerals of the first embodiment are used to designate the same or corresponding elements, but these numbers are increased by 100 for purposes of distinguishing embodiments. Reference is also made to the description of the first mode for these identical or corresponding elements. Specific reference numbers between 100 and 200 are used to designate the specific elements.

The ray path in FIG. 5 is schematic, particularly at reflection faces 1102 and 1122, for clarity of presentation. The optical element 106 of Figure 5 differs from that of Figures 3 and 4 essentially in that the exit face 1081 is located directly on the edge of the third portion 108 and not on a projecting portion and narrowed. It is interesting to observe that the rays coming from the first and second light sources are reflected by a common reflection face 1082 before propagating in the third portion 108 and exit through the exit face 1081. The optical element 106 of the FIG. 5 is also different from that of FIGS. 3 and 4 in that it comprises a connecting portion 120 between the first and second portions 110 and 112 and the third portion 108. The optical element 106 of FIG. of that of Figures 3 and 4 in that the longitudinal axis 1105 and 1125 of the first and second portions 110 and 112 are parallel to the optical axis 107.

Figure 6 is a schematic sectional view of an optical element according to a third embodiment of the invention. The reference numerals of the first and second embodiments are used to designate the same or corresponding elements, however, these numbers are increased by 200 or 100, respectively, for purposes of distinguishing embodiments. Reference is also made to the description of these modes for these identical or corresponding elements.

The ray path in FIG. 6 is schematic, particularly at reflection faces 2102 and 2122, for clarity of presentation. The optical element 206 of FIG. 6 differs from that of FIGS. 3 and 4 and that of FIG. 5 essentially in that the radii of the first and second portions 210 and 212 are reflected on the common reflection face 2082 by means of distinct portions of said face.

Figure 7 is a schematic sectional view of an optical element according to a fourth embodiment of the invention. The reference numerals of the first, second, and third embodiments are used to denote the same or corresponding elements, but these numbers are increased by 300, 200, or 100, respectively, for purposes of distinguishing embodiments. Reference is also made to the description of these modes for these identical or corresponding elements.

The ray path in Fig. 7 is schematic, particularly at the reflection faces 3102 and 3122, for clarity of presentation. The optical element 306 of FIG. 7 differs from those of FIGS. 3, 4, 5 and 6 essentially in that the distance of the input faces 3101 and 3121 from the third portion 308 are different. Indeed, the input face 3121 of the second portion 312 is further apart than that of the first portion 310, while the ray path remains substantially the same. The longitudinal axes 3105 and 3125 of the first and second portions are spaced apart from each other. This embodiment illustrates the advantage of the invention, namely to confer a great freedom as to the positioning of the light sources.

Claims (15)

claims An optical element (6; 106; 206; 306) of transparent or translucent material capable of producing a light beam and comprising: - a first input face (101; 1101; 2101; 3101) of light rays produced by a first light source (16); a first reflection face (103; 1103; 2103; 3103) of light rays coming from the first input face (101; 1101; 2101; 3101); a second input face (121; 1121; 2121; 3121) of light rays produced by a second light source (18); a second reflection face (123; 1123; 2123; 3123) of light rays coming from the second input face (121; 1121; 2121; 3121); - an output face (81; 1081; 2081; 2081) light rays from the first (103; 1103; 2103; 3103) and second (123; 1123; 2123; 3123) reflection faces; characterized in that: the light rays from the first reflection face (103; 1103; 2103; 3103) and the second reflection face (123; 1123; 2123; 3123) propagate in the same direction to one or more reflection faces (82; 1082; 2082; 3082) of said spokes to the exit face (81; 1081; 2081; 3081). 2. Optical element (6; 106; 206; 306) according to claim 1, characterized in that at least one, preferably each, first (103; 1103; 2103; 3103) and second reflection faces (123; 2123; 3123) and the reflection face (s) (82; 1082; 2082; 3082) to the output face (81; 1081; 2081; 3081) is configured to reflect the rays according to the total reflection principle. 3. Optical element (6; 106) according to one of claims 1 and 2, characterized in that at least one, preferably each, first (103; 1103) and second faces (123; 1123) of reflection and the at least one reflection face (82; 1082) towards the exit face (81; 1081) comprises reflection facets or striations. 4. Optical element (6; 106; 206; 306) according to one of claims 1 to 3, characterized in that at least one, preferably each, first (101; 1101; 2101; 3101) and second (121; 1121; 2121; 3121) input faces has an optical input axis (104; 124) which forms an angle with the main direction of the light beam which is between 80 ° and 110 °. 5. Optical element (6; 106; 206; 306) according to one of claims 1 to 4, characterized in that at least one, preferably each, first (101; 1101; 2101; 3101) and second (121; ; 1121; 2121; 3121) input faces comprises a collimator, preferably of the Fresnel lens type. 6. optical element (6; 106; 206) according to one of claims 1 to 5, characterized in that the first (103; 1103; 2103) and second (123; 1123; 2123) reflection faces are adjacent, preferably contiguous. Optical element (306) according to one of claims 1 to 5, characterized in that the first (3103) and second (3123) reflection faces are spaced from each other and at different distances from the or reflection faces (3082) to the output face. 8. optical element (6; 106; 206; 306) according to one of claims 1 to 7, characterized in that it comprises a first portion (10; 110; 210; 310) adapted to guide the rays since the first input face (101; 1101; 2101; 3101) to the first reflection face (103; 1103; 2103; 3103); and a second portion (12; 112; 212; 312) capable of guiding the rays from the second input face (121; 1121; 2121; 3121) to the second reflection face (123; 1123; 2123; 3123), said portions extending in principal directions (105,125; 1105,1125); 2105, 2125, 3105, 3125) and forming an angle α between 150 ° and 180 °. 9. Optical element (6; 106; 206; 306) according to claim 8, characterized in that it comprises a third portion (8; 108; 208; 308) capable of guiding the rays from the reflection face (s) ( 82; 1082; 2082; 3082) to the exit face (81; 1081; 2081; 3081), said portion extending in a principal direction (7; 107; 207; 307) preferentially corresponding to the direction of the beam; luminous. 10. Optical element (6; 206) according to claim 9, characterized in that the third portion (8; 208) comprises a protuberance (83; 2083) forming the exit face. 11. Optical element (6; 106; 206; 306) according to one of claims 1 to 10, characterized in that it comprises a first intermediate reflection face (102; 1102; 2102; 3102) capable of reflecting the rays. light source from the first input face (101; 1101; 2101; 3101) to the first reflection face (103; 1103; 2103; 3103); and / or a second intermediate reflection face (122; 1122; 2122; 3122) adapted to reflect light rays from the second input face (121; 1121; 2121; 3121) to the second reflection face (123; 1123; 2123; 3123). 12. Optical element (6; 106; 206; 306) according to one of claims 8 to 10 and according to claim 11, characterized in that the first intermediate reflection face (102; 1102; 2102; 3102) is located on the first portion (10; 110; 210; 310) and / or the second intermediate reflection face (122; 1122; 2122; 3122) is located on the second portion (12; 112; 212; 312). 13. Optical element (6; 106) according to one of claims 1 to 12, characterized in that the light rays coming from the first reflection face (103; 1103) and the second reflection face (123; 1123). are reflected by a common portion of the reflection face (82; 1082) of said spokes toward the exit face (81; 1081). 14. Optical element (206; 306) according to one of claims 1 to 12, characterized in that the light rays coming from the first reflection face (2103; 3103) and the second reflection face (2123; 3123). are reflected by discrete portions of the reflection face (2082; 3082) of said rays toward the exit face (2081; 3081) 15. Luminous device (2), especially for a motor vehicle, comprising: - at least a first (16) and a second light source (18), said sources being of different colors; at least one optical element made of transparent or translucent material capable of selectively producing two light beams of different colors from the light rays of the first and second light sources; characterized in that the optical element (6; 106; 206; 306) is according to one of claims 1 to 14.