LIGHT MODULE WITH DUAL-FUNCTIONAL LIGHT GUIDE

Abstract

LIGHT MODULE WITH BI-FUNCTIONAL SHEET LIGHT GUIDE A light module (2) comprising a first light source (6) emitting first light rays (8); a light guide (4) forming a sheet with a thickness and comprising a first entrance face (4.1) and a first exit face (4.2), the first light rays (8) propagating from the first entrance face (4.1) to the first exit face (4.2); a second light source (10) emitting second light rays (12); a second entrance face (4.3), and a second exit face (4.4), the second light rays (12) propagating from the second entrance face (4.3) to the second exit face (4.4) along a channel (4.6) delimited by two grooves (4.5) formed in the thickness of the light guide (4), the first light rays passing through the two grooves (4.5) and the channel (4.6). (Figure to be published with the abbreviation: Figure 1)

Description

Title of the invention: LIGHT MODULE WITH BI-FUNCTIONAL LAYER LIGHT GUIDE technical field

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

[0002] Published patent document US 2017 / 0336041 Al discloses a light module for a motor vehicle, 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 rays along the longitudinal direction of the vehicle and also to guide another portion of the light rays along directions including a lateral component so as to 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. Description of the invention

[0003] The invention aims to overcome at least one of the drawbacks of the aforementioned prior art. More particularly, the invention aims to provide a lighting module that enables the performance of several light signaling functions in different directions, in a simple and compact manner, from a construction standpoint.

[0004] The invention relates to a light module 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 of 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; notable in that: the light guide comprises at least one second light entry face opposite at least one second light source, and a second light exit face, the second light rays being capable of propagating in the light guide from at least one 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, at least one groove comprises at least two grooves.

[0006] Advantageously, the first light rays exiting the first light exit face provide a first light signaling function, such as a combined function of daytime running lights, position lights 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 exiting 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, at least one groove comprises two grooves parallel to each other along the corridor.

[0012] According to an advantageous embodiment of the invention, each of the 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 light guide sub-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 and thus allows the light module to achieve satisfactory photometry. Brief description of the drawings

[0020] [Fig-1] is a perspective view of a light module according to a first embodiment of the invention;

[0021] [Fig.2] is a sectional view II-II of the light module of [Fig.1];

[0022] [Fig.3] is a perspective and functional view of the light guide corridor of the luminous module of the [Fig.l];

[0023] [Fig.4] is a sectional view II-II of the light module of [Fig.1], following a variant;

[0024] [Fig.5] is a perspective view of a light module according to a second mode realization of the invention, illustrating the path of light rays of the first light signaling function;

[0025] [Fig.6] corresponds to [Fig.5], illustrating the path of light rays from the second light signaling function Detailed description

[0026] Terms expressing geometric orientations, such as "superior(s)", "inferior(s)", "longitudinal(s)", "lateral(s)", are to be understood when the light module is in operational and normal 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] The [Fig. 1] 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 thickness of the material 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 a first light source 6 is arranged, 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 inlet face 4.3 opposite which is arranged a second light source 10, and a second light outlet face 4.4 associated with the second light inlet face 4.3. The second light rays emitted by the second light source 10 and entering the light guide 4 through the second light inlet 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 outlet face 4.4 and exit the light guide 4.

[0032] It can be observed that the first and second light rays propagate in the light guide 4 in principal directions that intersect. To this end, the second light rays 12 propagate in 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 laterally on either side of the channel 4.5 with the ambient air, 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 ambient 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. It therefore 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 may suffice to form a channel such as the channel 4.6 described above. In this case, a first interface of the channel will be formed by the groove and a second, opposite to 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 2 is a sectional view II-II of the light guide 4 of Figure 1. The section of the channel 4.5 delimited by the two grooves 4.6 can be seen. It can be observed 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 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 l 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 l of the grooves 4.6 is shown in [Fig. 2]. This width l is advantageously reduced in order to minimize the potential shift effect of the first light rays described above. It is advantageously less than or equal to 5mm, preferably less than or equal to 4mm, more preferably less than or equal to 3mm. For ease of manufacturing, particularly by plastic injection, the width l of the grooves is greater than or equal to a minimum value, in this case 0.5mm.

[0037] Each of the grooves 4.6 advantageously has a width l that is constant along its entire height, it being understood, however, that this width l 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 production by plastic injection. This angle is advantageously less than or equal to 10°.

[0038] Figure 3 is a perspective and functional view of the channel 4.5 of the light guide 4 of the light module of Figure 1. It can be seen 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 on the light guide. In other words, the channel 4.5 thus formed in the light guide is equivalent to a light guide with a rectangular cross-section corresponding to the cross-section of the channel. It can be seen that such a channel makes it possible to concentrate the light rays towards the second light exit face 4.4, which in this case can be small while still ensuring sufficient photometry.

[0039] In [Fig. 3], 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 which are at a distance from the edges of the light guide 4, namely, in the specific case of [Fig. 3], at a distance from the second light entrance face 4.3 and the second light exit face 4.4. The grooves thus have a length equal to L-2»L r. The length of the portions of the corridor 4.5 free from the grooves 4.6 is therefore 2»L r , where L r is advantageously less than or equal to 5mm, preferably 4mm, more preferably 3mm, more preferably still 2mm.These portions of corridor 4.5, free from grooves 4.6, are advantageously located at both ends of the corridor, along its main direction, it being understood that other configurations are conceivable.

[0040] The [Fig.4] is a sectional view II-II of the light module of the [Fig.1], according to a variant.

[0041] In this variant, the grooves 4.6' do not extend over the entire thickness e of the light guide 4. The depth p of each of the two grooves 4.6' is strictly less than the thickness e of the light guide, more precisely to 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 e, 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 r < 0.1 - e. This residual height r is sufficiently small that its effect on the transmission of the first and second light rays is negligible.

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

[0043] This variant shows that, depending in particular on the dimensions of the light guide and mechanical constraints, at least one of the grooves may not be fully through in order to ensure, in particular, satisfactory mechanical strength. One or both of the grooves may thus not be fully through, either along their entire length or over one or more portions of their length.

[0044] In the foregoing, with reference to Figures 1 to 4, the first light-inlet face 4.1 may be multiple and optionally each associated with a specific first light source. Also, the first light-inlet face 4.1 and the first light-outlet face 4.2 have a certain extent along the extent 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 second light rays 12 of the second light-inlet face 4.3 and the second light-outlet face 4.4 and corridor 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 5 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 6 is a view similar to Figure 5, 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 ribbon, in this case the lower principal face, adjacent to an edge of said ribbon, said edge being beveled and forming 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, in particular, 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 ribbon and generally parallel to the ribbon. The first optical element 104.7 comprises a series of sub-light guides, in this case with a diverging profile, connected to a common portion in contact with the ribbon.Each of the light subguides is provided with one of the first light entry faces 104.1. The common part of the first optical piece 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 piece 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 piece 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 ([Fig. 5]).

[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, said edge being beveled and forming 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, in particular, 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 sub-light guide extending transversely to 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 104.6 formed in the sheet, following a main direction represented by the arrow ([Fig.6]).

[0050] This second embodiment has the particularity of detaching the light sources from the ribbon, by means of the first and second optical parts 104.7 and 104.9. More particularly, 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 the point of view of construction, assembly precision 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] Generally, 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] Generally, each of the first light exit face 4.2 and 104.2 and of the second light exit face 4.4 and 104.4 may have a cushion shape to ensure homogeneous diffusion of light and a uniform illuminated appearance.

[0055] Generally, the first light exit face 4.2 and 104.2 and the second light exit face 4.4 and 104.4 can be adjacent.

[0056] More generally, the first light beams exiting the first light output face may correspond to a motor vehicle signaling function such as a combined daytime running light, position light, and direction indicator function, and the second light beams exiting the second light output face may correspond to a motor vehicle signaling function such as a side marker function. In this specific configuration, the first light output face is directed towards the front of the motor vehicle and partially laterally towards the corresponding outer side, while the second light output face is essentially directed laterally towards the corresponding outer side.

Claims

Demands

1. A 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, 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 second light rays (12; 112); characterized in that: the light guide (4; 104) comprises 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 (4.6; 104.6) delimited by at least one groove (4.5; 104.5) formed in the thickness of the light guide (4; 104), the first light rays passing through at least one groove (4.5; 104.5) and the corridor (4.6; 104.6).

2. The light module (2; 102) according to claim 1, wherein each of the at least one groove (4.5; 104.5) extends over at least 90% of the thickness of the light guide (4; 104).

3. The light module (2; 102) according to any one of claims 1 and 2, wherein at least one groove comprises two grooves (4.5; 104.5) parallel to each other along the channel (4.6; 104.6).

4. The light module (2; 102) according to any one of claims 1 to 3, wherein each of at least one groove (4.5; 104.5) has a width l greater than 0.5mm and / or less than 5mm.

5. The light module (2; 102) according to any one of claims 1 to 4, wherein each of at least one groove (4.5; 104.5) extends over at least 90% of a total principal extent of the corridor (4.6; 104.6).

6. 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°.

7. 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.

8. The light module (102) according to claim 7, wherein each of the transverse extensions (104.7; 104.9) forms a light guide 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.

9. 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).

10. 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.