Lighting module for a motor vehicle with a dual-function light guide sheet

Abstract

Disclosed is a signalling lighting module (2) for a motor vehicle, comprising a first light source (6) emitting first light rays (8); a light guide (4) forming a sheet having a thickness and comprising a first entry face (4.1) and a first exit face (4.2), the first light rays (8) spreading from the first entry face (4.1) to the first exit face (4.2); a second light source (10) emitting second light rays (12); a second entry face (4.3), and a second exit face (4.4), the second light rays (12) spreading from the second entry face (4.3) to the second exit face (4.4) along a corridor (4.5) delimited by two grooves (4.6) formed in the thickness of the light guide (4), the first light rays passing through the two grooves (4.6) and the corridor (4.5).

Description

LIGHTING MODULE FOR MOTOR VEHICLES WITH A DUAL-FUNCTIONAL LIGHT GUIDE

[0001] The invention relates to the field of light signaling, particularly for motor vehicles, involving the use of a sheet light guide.

[0002] The published patent document US 2017 / 0336041 A1 discloses a vehicle signaling light module comprising a light guide made of transparent or translucent material and forming a sheet with a rear light inlet face and a front light outlet face. The rear face includes a series of collimators configured to guide a portion of the light beams along the longitudinal direction of the vehicle and also to guide another portion of the light beams along directions including a lateral component so that they exit the outlet face with a direction including a lateral component. This light module thus makes it possible to emit light beams along a longitudinal direction as well as along laterally inclined directions, i.e., with a lateral component. It therefore ensures lateral visibility and a consistent illuminated appearance from a lateral observation point.This combination of longitudinal and transverse light beams is, however, associated with the same light signaling function. Yet, it is desirable, particularly in the automotive field, to be able to implement several independent light signaling functions, including one producing a predominantly longitudinal light beam and another producing a predominantly transverse light beam.

[0003] The invention aims to overcome at least one of the drawbacks of the aforementioned prior art. More specifically, the invention aims to provide a lighting module that enables the performance of several light signaling functions for motor vehicles in different directions, in a simple, compact design.

[0004] The invention relates to a luminous signaling module for a motor vehicle comprising: - at least one first light source capable of emitting first light rays; - a light guide forming a sheet of transparent or translucent material with a thickness, comprising at least one first light entry face opposite at least one first light source, and a first light exit face, the first light rays being capable of propagating in the light guide from at least one first light entry face to the first light exit face; - at least one second light source capable of emitting second light rays;remarkable in that: the light guide comprises at least a second light entry face opposite at least a second light source, and a second light exit face, the second light rays being able to propagate in the light guide from at least a second light entry face to the second light exit face along a corridor delimited by at least one groove formed in the thickness of the light guide, the first light rays passing through at least one groove and the corridor.

[0005] Advantageously, the light guide includes at least two grooves.

[0006] Advantageously, the first light rays exiting the first light output face provide a first light signaling function, such as a combined function of daytime running light, position light and direction indicator.

[0007] Advantageously, the at least one first light source comprises several first light sources and the at least one first entrance face comprises several first entrance faces arranged opposite the several first light sources, respectively.

[0008] Advantageously, the second light beams coming out of the second light output face provide a second automotive signaling function, such as a side marker function.

[0009] Advantageously, the first light exit face is generally curved over a sector of at least 45°.

[0010] According to an advantageous embodiment of the invention, each of the at least one groove extends over at least 90% of the thickness of the light guide.

[0011] According to an advantageous embodiment of the invention, the light guide comprises two grooves parallel to each other along the corridor, on either side of it.

[0012] According to an advantageous embodiment of the invention, each of at least one groove has a width greater than 0.5mm and / or less than 5mm.

[0013] According to an advantageous embodiment of the invention, each of the at least one groove extends over at least 90% of a total principal extent of the corridor.

[0014] According to an advantageous embodiment of the invention, the first light rays are able to propagate in the light guide along a first principal direction and the second light rays are able to propagate in the light guide along a second principal direction perpendicular to the first principal direction or forming an angle with said perpendicular which is less than or equal to 20°.

[0015] According to an advantageous embodiment of the invention, at least one first light entry face and at least one second light entry face are arranged on a main face of the light guide sheet or on transverse extensions of said main face.

[0016] According to an advantageous embodiment of the invention, each of the transverse extensions forms a sub-light guide made of transparent or translucent material extending along a main direction transverse to the light guide sheet and attached to the main face of said sheet.

[0017] According to an advantageous embodiment of the invention, the light guide sheet comprises at least one reflective surface opposite one of the transverse extensions, configured to reflect the first or second light rays towards the light guide sheet.

[0018] According to an advantageous embodiment of the invention, at least one first light source and at least one second light source are arranged on a common plate, preferably in the same plane.

[0019] The measures of the invention are advantageous in that they allow the second light rays to be channeled transversely to the first light rays, within the same light guide, without disturbing the propagation of the first light rays. The channel also prevents the second light rays from reaching the first light exit face, thus allowing the light module to achieve satisfactory photometry.

[0020] is a perspective view of a light module according to a first embodiment of the invention;

[0021] is a cross-sectional view II-II of the luminous module of the;

[0022] is a perspective and functional view of the light guide corridor of the light module of the;

[0023] is a sectional view II-II of the luminous module of the, according to a variant;

[0024] is a perspective view of a light module according to a second embodiment of the invention, illustrating the path of light rays of the first light signaling function;

[0025] corresponds to the, illustrating the path of light rays of the second light signaling function Detailed description

[0026] Terms expressing geometric orientations, such as "upper(s)", "lower(s)", "longitudinal(s)", "lateral(s)", are to be understood when the light module is in its normal operational mounting position, particularly on a motor vehicle, as illustrated in the figures.

[0027] Figures 1 to 4 illustrate a light module according to a first embodiment of the invention.

[0028] This is a perspective view of a light module according to a first embodiment of the invention.

[0029] The light module 2 comprises a light guide 4 forming a sheet of transparent or translucent material. The term "sheet" refers to a thickness of material extending in two directions, generally perpendicular to the thickness, it being understood, however, that this surface is not necessarily flat and that the material thickness may vary along its length. It is therefore a plate that is not necessarily flat, namely that it may form undulations, and whose thickness is not necessarily constant. The thickness of the sheet is advantageously less than or equal to 7 mm for ease of manufacturing by plastic injection molding.

[0030] The light guide 4 comprises a first light entry face 4.1 opposite which is arranged a first light source 6, and a first light exit face 4.2 associated with the first light entry face 4.1. The first light rays emitted by the first light source 6 and entering the light guide 4 through the first light entry face 4.1 propagate within the light guide 4, as represented by ray 8, and then reach the light exit face 4.2 and exit the light guide 4. Ray 8 is a principal ray propagating parallel to the corresponding principal direction of the light guide 4. Secondary light rays, not shown, may propagate by successive reflections; however, these rays contribute very little to the photometry of the light rays exiting the first light exit face 4.2.

[0031] The light guide 4 also includes a second light entry face 4.3 opposite which is arranged a second light source 10, and a second light exit face 4.4 associated with the second light entry face 4.3. The second light rays emitted by the second light source 10 and entering the light guide 4 through the second light entry face 4.3, propagate in the light guide 4, as represented by the ray 12, by successive total internal reflections, to then reach the light exit face 4.4 and exit the light guide 4.

[0032] It can be observed that the first and second light rays propagate within the light guide 4 in intersecting principal directions. To this end, the second light rays 12 propagate within a channel 4.5 of the light guide 4, delimited by two grooves 4.6 formed in the thickness of the light guide. These two grooves 4.6 form a diopter with the surrounding air on either side of the channel 4.5, allowing the second light rays to undergo total internal reflection, similarly to the two opposite principal faces of the light guide, which also form diopters with the surrounding air, a phenomenon well known to those skilled in the art. The channel 4.5 thus formed by the two grooves 4.6 allows the second light rays to be channeled towards the second light exit face 4.4. This prevents the second light rays 12 from propagating towards and reaching the first light exit face 4.2.

[0033] It should be noted that a single groove 4.6 extending along a lateral face of the light guide can suffice to form a channel such as the channel 4.5 described above. In this case, a first interface of the channel will be formed by the groove and a second, opposite the first, by the lateral face of the light guide.

[0034] It should be noted that the principal directions in which the first and second light rays 8 and 12 propagate in the light guide 4 are advantageously perpendicular or form an angle of less than 20° with respect to this perpendicularity.

[0035] Figure II-II shows a cross-sectional view of the light guide 4. The section of the channel 4.5, delimited by the two grooves 4.6, can be observed. It can be seen that the first light rays 8 propagate essentially parallel to the corresponding principal direction of the light guide 4 and pass through the two grooves 4.6 and the channel 4.5 with essentially no deviation, given the perpendicularity or near-perpendicularity of the grooves 4.6 with respect to the propagation direction in question. It can also be observed that the first secondary light rays 8' can propagate by successive reflections and pass through the two grooves 4.6 and the channel 4.5 with very little deviation, essentially due to the reduced width of the grooves. These first secondary light rays 8' originate from the first light entrance face 4.1. The light rays undergo a first refraction upon entering the first groove, followed immediately by a second refraction upon exiting the same groove. These two refractions cancel each other out, with the difference that the width of the groove causes a slight shift in the light rays. In other words, the double refraction upon passing through the first groove (4.6) slightly shifts the light rays without altering their angles. The same phenomenon occurs upon passing through the second groove (4.6).

[0036] The width of the grooves 4.6 is shown in Figure 1. This width is advantageously reduced to minimize any potential shift effect of the first light rays described above. It is advantageously less than or equal to 5 mm, preferably less than or equal to 4 mm, and more preferably less than or equal to 3 mm. For ease of manufacturing, particularly for plastic injection molding, the width of the grooves is greater than or equal to a minimum value, in this case 0.5 mm.

[0037] Each of the grooves 4.6 advantageously has a width that is constant along its entire height, it being understood, however, that this width may vary along the main extent of the groove. The groove may also have a draft angle, intended to facilitate the removal of a mold part after plastic injection molding. This angle is advantageously less than or equal to 10°.

[0038] This is a perspective and functional view of the 4.5 channel of the light guide 4 of the light module. It can be observed that the second light rays 12 are reflected by total internal reflection not only at the interfaces formed by the two grooves 4.6 but also at the interfaces formed by the opposing principal faces of the light guide. In other words, the 4.5 channel thus formed in the light guide is equivalent to a light guide with a rectangular cross-section corresponding to the channel's cross-section. It can be observed that such a channel allows the light rays to be concentrated towards the second light exit face 4.4, which in this case can be small while still ensuring sufficient photometry.

[0039] At this point, it can be observed that the grooves 4.6 do not necessarily extend over the entire length L of the channel 4.5, given that the grooves 4.6 pass through the thickness of the light guide 4 and thus require the presence of material to ensure that the portion of the light guide 4 forming the channel 4.5 is held in relation to the rest of the light guide 4. In this case, the grooves 4.6 have ends along the main direction of the channel that are at a distance from the edges of the light guide 4, namely, in this specific case, at a distance from the second light entry face 4.3 and the second light exit face 4.4. The grooves thus have a length equal to L - 2L r The length of the portions of corridor 4.5 free from grooves 4.6 is therefore 2∙L r , whereL ris advantageously less than or equal to 5mm, preferably 4mm, more preferably 3mm, more preferably still 2mm. These portions of the corridor 4.5 free from the grooves 4.6 are advantageously located at the two ends of the corridor, along its main direction, it being understood that other configurations are conceivable.

[0040] This is a sectional view II-II of the light module, according to a variant.

[0041] In this variant, the grooves 4.6' do not extend over the entire thickness of the light guide 4. The depth p of each of the two grooves 4.6' is strictly less than the thickness of the light guide, more precisely, less than a portion of said light guide directly adjacent to the groove in question. Advantageously, p is greater than or equal to 90% of the thickness, i.e., p ≥ 0.9·e, so that the transparent or translucent material remaining between the bottom of the groove 4.6' and the adjacent main face of the light guide 4' has a residual height ≤ 0.1·e. This residual height remains sufficiently small that its effect on the transmission of the first and second light rays is negligible.

[0042] It is understood that the above may apply to one or both of the grooves 4.6.

[0043] This variant demonstrates that, depending on factors such as the dimensions of the light guide and mechanical constraints, at least one of the grooves may not be fully continuous in order to ensure adequate mechanical strength. One or both of the grooves may therefore not be fully continuous, either along their entire length or along one or more portions thereof.

[0044] In the preceding discussion, with reference to Figures 1 to 4, the first light-inlet face 4.1 may be multiple and possibly each associated with a specific first light source. Furthermore, the first light-inlet face 4.1 and the first light-outlet face 4.2 have a certain extent along the length of the light guide, essentially transverse to the principal direction of propagation of the first light rays 8. The first light-outlet face 4.2 is advantageously curved over a sector of at least 45°. Alternatively, the first light-inlet face 4.1 and / or the first light-outlet face 4.2 may have a significantly smaller extent transverse to the principal direction of propagation of the first light rays 8, similar to the extent transverse to the direction of propagation of the second light rays 12 of the second light-inlet face 4.3, the second light-outlet face 4.4, and the channel 4.5. Also, the second light entry face 4.3, the second light exit face 4.4, and the corridor 4.5 can have a significantly larger transverse extent to the direction of propagation of the second light rays 12. In particular, the second light entry face 4.3 can be multiple and possibly each associated with a specific second light source.

[0045] Figures 5 and 6 illustrate a light module according to a second embodiment of the invention. The reference numbers of the first embodiment are used to designate identical or corresponding elements, these numbers being increased by 100. Reference is also made to the description of these elements in relation to the first embodiment. Specific reference numbers for the specific elements of this embodiment, ranging from 100 to 200, are used.

[0046] Figure 1 is a perspective view of a light module according to the second embodiment of the invention, illustrating the path of the first light rays. Figure 2 is a view similar to Figure 3, but illustrating the path of the second light rays.

[0047] The light module 102 of the second embodiment differs from the light module of the first embodiment, essentially in that the first light entry face and the second light entry face are at a distance from the sheet formed by the light guide 104.

[0048] To this end, the light module comprises a first optical element 104.7 attached to one of the two opposite principal faces of the sheet, in this case the lower principal face, adjacent to an edge of said sheet. This edge is beveled and forms a first reflective surface 104.8 opposite the first optical element 104.7. The reflective property can be obtained by depositing a reflective coating on the beveled edge, such as metallization, or by total internal reflection, depending on the angles of incidence of the light rays to be reflected. The first optical element 104.7 then comprises a series of first entrance faces 104.1 located at a distance from the sheet and generally parallel to it. The first optical element 104.7 comprises a series of sub-light guides, in this case with a diverging profile, connected to a common section in contact with the sheet.Each of the light subguides is provided with one of the first light entry faces 104.1. The common part of the first optical part 104.7, in direct contact with the ribbon, ensures a homogeneous distribution of the first light rays along the principal direction of the first optical part 104.7 in question. The first light rays 108 emitted by the first light sources 106 propagate along the light subguides, then through the common part of the first optical part 104.7, to then penetrate the ribbon and be reflected by the first reflective surface 104.8 towards the first exit face 104.2, propagating along the ribbon in a principal direction represented by the arrow ().

[0049] The light module 102 also includes a second optical element 104.9 attached to one of the two opposite principal faces of the sheet, in this case the lower principal face, adjacent to an edge of said sheet. This edge is beveled and forms a second reflective surface 104.10 opposite the second optical element 104.9. The reflective property can be obtained by depositing a reflective coating on the beveled edge, such as metallization, or by total internal reflection, depending on the angles of incidence of the light rays to be reflected. The second optical element 104.9 forms a light subguide extending transversely across the sheet, similarly to the first optical element 104.7. The second light entry face 104.3 is then on an end and entry face of the light subguide, the opposite face of said light subguide being in contact with the sheet.The second light rays 112 emitted by the second light source 110 propagate along the light subguide to then penetrate the sheet and be reflected by the second reflective surface 104.10 towards the second exit face 104.4, propagating along the channel 104.5 formed in the sheet, following a main direction represented by the arrow ().

[0050] This second embodiment is distinguished by detaching the light sources from the tablecloth by means of the first and second optical components 104.7 and 104.9. More specifically, the first light sources 106 and the second light source 110 are located in the same plane and supported by a common plate 114. This configuration is advantageous from a construction point of view, precision of assembly and management of the heat produced by the light sources.

[0051] Each of the first optical part 104.7 and the second optical part 104.9 can be made in one piece with the ribbon cable or attached to the ribbon cable, in particular by gluing.

[0052] It is understood that an optical part allowing the light source(s) to be detached can be applied to only one of the two light signaling functions provided by the first light beams and the second light beams.

[0053] In general, each of the first light entry faces 4.1 and 104.1 and of the second light entry face 4.3 and 104.3 can include a collimator, in a manner which is in itself well known to the person skilled in the art.

[0054] In general, each of the first light output face 4.2 and 104.2 and the second light output face 4.4 and 104.4 may have a cushion shape to ensure homogeneous diffusion of light and a uniform illuminated appearance.

[0055] In general, the first light output face 4.2 and 104.2 and the second light output face 4.4 and 104.4 can be adjacent.

[0056] More generally, the first beams of light exiting the first light output face can correspond to a vehicle signaling function, such as a combined daytime running light (DRL), position light, and turn signal function, while the second beams of light exiting the second light output face can correspond to a vehicle signaling function, such as a side marker light. In this specific configuration, the first light output face is directed towards the front of the vehicle and partially laterally towards the corresponding outer side, while the second light output face is directed primarily laterally towards the corresponding outer side.

Claims

A motor vehicle signaling light module (2; 102) comprising: - at least one first light source (6; 106) capable of emitting first light rays (8; 108); - a light guide (4; 104) forming a sheet of transparent or translucent material with a thickness of, comprising at least one first light entry face (4.1; 104.1) opposite the at least one first light source (6; 106), and a first light exit face (4.2; 104.2), the first light rays (8; 108) being capable of propagating in the light guide (4; 104) from the at least one first light entry face (4.1; 104.1) to the first light exit face (4.2; 104.2); - at least one second light source (10; 110) capable of emitting of the second light rays (12; 112); characterized in that: the light guide (4; 104) includes at least one second light entry face (4.3; 104.3) opposite at least one second light source (10; 110), and a second light exit face (4.4; 104.4), the second light rays (12; 112) being able to propagate in the light guide (4; 104) from at least one second light entry face (4.3; 104.3) to the second light exit face (4.4; 104.4) along a corridor (4.5; 104.5) delimited by at least one groove (4.6; 104.6) formed in the thickness of the light guide (4; 104), the first light rays passing through at least one groove (4.6; 104.6) and the corridor (4.5; 104.5). The light module (2; 102) according to claim 1, wherein each of the at least one groove (4.6; 104.6) extends over at least 90% of the thickness of the light guide (4; 104). The light module (2; 102) according to any one of claims 1 and 2, wherein the light guide (4; 104) comprises two grooves (4.6; 104.6) parallel to each other along the channel (4.5; 104.5). The light module (2; 102) according to any one of claims 1 to 3, wherein each of at least one groove (4.6; 104.6) has a width greater than 0.5mm and / or less than 5mm. The light module (2; 102) according to any one of claims 1 to 4, wherein each of at least one groove (4.6; 104.6) extends over at least 90% of a total principal extent of the corridor (4.5; 104.5). The light module (2; 102) according to any one of claims 1 to 5, wherein the first light rays (8; 108) are able to propagate in the light guide (4; 104) along a first principal direction and the second light rays (12; 112) are able to propagate in the light guide (4; 104) along a second principal direction perpendicular to the first principal direction or forming an angle with said perpendicular which is less than or equal to 20°. The light module (2; 102) according to any one of claims 1 to 6, wherein at least one first light entry face (4.1; 104.1) and at least one second light entry face (4.3; 104.3) are arranged on a main face of the light guide mat (4; 104) or on transverse extensions (104.7; 104.9) of said main face. The light module (102) according to claim 7, wherein each of the transverse extensions (104.7; 104.9) forms a light sub-guide of transparent or translucent material extending along a main direction transverse to the light guide sheet (104) and attached to the main face of said sheet. The light module (102) according to any one of claims 7 and 8, wherein the light guide sheet (104) comprises at least one reflective surface (104.8; 104.10) opposite one of the transverse extensions (104.7; 104.9), configured to reflect the first or second light rays (108; 112) towards the light guide sheet (104). The light module (102) according to any one of claims 1 to 9, wherein at least one first light source (106) and at least one second light source (110) are arranged on a common plate (114), preferably in the same plane.

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