Motor-vehicle lighting module that produces a cutoff with a reflector the surface of which is partially grained
Patent Information
- Application Number
- EP2023732617
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-06-22
- Filing Date
- 2023-06-16
- Publication Date
- 2025-04-30
AI Technical Summary
Existing automobile lighting modules produce lighting beams with unclear lower horizontal cut-offs, leading to undesirable luminous irregularities when multiple beams are superimposed, and struggle to control downward luminous extent and intensity effectively.
A lighting module with a reflective surface featuring a grained front area and a cover near the front edge to absorb or reflect light rays, combined with an optical device that projects the reflected beam, allowing for controlled horizontal cut-off and reduced downward light intensity, using a grained front zone that extends over part of the reflective surface and a cover to manage light distribution.
The solution produces a lighting beam with a higher horizontal cut-off and controlled downward luminous intensity, avoiding undesirable lower cut-offs and ensuring compliance with regulatory light intensity values, while maintaining clear upper cut-offs for improved beam quality.
Smart Images
Figure 1.1
Abstract
Description
AUTOMOTIVE LIGHTING MODULE WITH CUT-OFF REFLECTOR WITH PARTIALLY GRAINED SURFACE
[0001] The invention relates to the technical field of lighting, more particularly automotive lighting.
[0002] The published patent document WO 2020 / 025171 A1 discloses an automotive lighting module comprising, essentially, a light source of the light-emitting diode type illuminating upwards, a collector with a reflective surface of elliptical profile configured to collect and reflect the light rays emitted by the light source towards a projection lens configured to image the reflective surface illuminated by the light source. For this purpose, the projection lens comprises a focus located on or near the reflective surface, preferably near a rear edge of the reflective surface, so as to sharply image the rear edge thus forming an upper cut-off. The lighting beam thus produced makes it possible to perform a lighting function of the "code" or "low-beam" type in English.
[0003] In this teaching, the projected light image may also have a lower cut-off, in principle less sharp than the upper cut-off, but producing a potentially undesirable irregularity, particularly when several light images are superimposed, at least one of which is shorter towards the bottom.
[0004] The invention aims to overcome at least one drawback of the aforementioned prior art. More particularly, the invention aims to provide a lighting module capable of producing a lighting beam with a higher horizontal cutoff and whose downward light extent and intensity are controlled. For example, the invention aims to provide a lighting module capable of producing a lighting beam with a higher horizontal cutoff, but without a clear lower horizontal cutoff and / or a lighting beam with a higher horizontal cutoff but whose downward extent is limited.
[0005] The subject of the invention is a lighting module for a motor vehicle, comprising a light source capable of emitting light rays; a collector with a reflective surface configured to reflect the light rays into a reflected beam; an optical device configured to project the reflected beam into a projected beam along an optical axis of the lighting module by imaging a portion of the reflective surface; remarkable in that the reflective surface comprises a front edge and a grained front area comprising the front edge.
[0006] Advantageously, the grained front area has a roughness R a greater than or equal to 0.3 µm
[0007] Advantageously, the optical device comprises a projection lens or a set of projection mirrors.
[0008] According to an advantageous embodiment of the invention, the grained front zone extends from the front edge to a rear edge of the reflective surface over only a portion of the reflective surface.
[0009] According to an advantageous embodiment of the invention, the grained front zone extends over at most 75% of the reflective surface.
[0010] Advantageously, the optical device comprises a focus located on the reflecting surface, preferably on a rear part of said reflecting surface, more preferably still close to a rear edge of said reflecting surface, for example at a distance of less than 10 mm.
[0011] According to an advantageous embodiment of the invention, the grained front area of the reflective surface extends along the entire front edge.
[0012] According to an advantageous embodiment of the invention, the grained front zone of the reflective surface corresponds to at least 50% of the reflective surface.
[0013] According to an advantageous embodiment of the invention, the collector comprises a cover located directly in front of the front edge of the reflective surface, said cover being configured to absorb and / or reflect outside the optical device light rays passing in front of the front edge.
[0014] According to an advantageous embodiment of the invention, the light source is configured to emit the light rays in a main direction transverse, preferably perpendicular, to the optical axis and the reflecting surface forms a cap with an opening directed in the main direction.
[0015] According to an advantageous embodiment of the invention, the reflective surface has a parabolic or elliptical profile. Advantageously, the front edge is part of the parabolic or elliptical profile.
[0016] According to an advantageous embodiment of the invention, the front edge of the reflective surface corresponds to a segment of the light beam projected at 25m, located at or above -4° vertically, when the lighting module is in the mounting position on the motor vehicle.
[0017] According to an advantageous embodiment of the invention, the projected light beam is restricted horizontally and vertically, and produces at 25m a luminous illumination of less than 1 lux outside an area lying horizontally between -15° and +15° and vertically between -4.5° and +1.5° relative to the optical axis, when the lighting module is in the mounting position on the motor vehicle.
[0018] The invention also relates to a lighting module for a motor vehicle, comprising a light source capable of emitting light rays; a collector with a reflective surface configured to reflect the light rays into a reflected beam; an optical device configured to project the reflected beam into a projected beam along an optical axis of the lighting module by imaging a portion of the reflective surface; remarkable in that the collector comprises a cover located directly in front of a front edge of the reflective surface, said cover being configured to absorb and / or reflect outside the optical device a portion of the light rays reflected by the reflective surface at the front edge.
[0019] The detailed characteristics in relation to the previous automotive lighting module are also applicable and disclosed with the above automotive lighting module.
[0020] The invention also relates to a lighting device for a motor vehicle, comprising a main lighting module configured to project a main light beam, extended horizontally and with a horizontal upper cut-off, when the lighting device is in the mounting position on the motor vehicle; and at least one complementary lighting module configured to project a complementary light beam, restricted and central horizontally and with a horizontal upper cut-off, when the lighting device is in the mounting position on the motor vehicle; remarkable in that the at least one complementary lighting module is a lighting module according to the invention.
[0021] In particular, the horizontal upper cutoff of the main lighting module is aligned with the horizontal upper cutoff of the supplementary lighting module when the main light beam and the supplementary light beam are projected.
[0022] The measures of the invention are advantageous in that they make it possible to produce a light beam with an upper cut-off whose downward luminous extent and intensity is controlled. They are particularly advantageous on one or more lighting modules complementary to a main lighting module with a horizontal upper cut-off.
[0023] is a perspective representation of a lighting device according to the invention;
[0024] is a schematic cross-sectional representation of one of the two additional lighting modules of the lighting device of the, according to the invention;
[0025] is a schematic representation of the combined light image of the lighting device of the. Detailed description
[0026] In the following description, the concepts of relative position and orientation, as expressed by the terms “top”, “bottom”, “front”, “rear”, “upper”, “lower”, are to be understood when the lighting module or device is in the operational position as illustrated in the figures.
[0027] This is a schematic perspective representation of a lighting device for a motor vehicle, in accordance with the invention.
[0028] The lighting device 2 is configured to produce a lighting beam with a higher horizontal cutoff, corresponding to a regulatory lighting function known as dipped beam or commonly referred to as “code”, namely the regulatory function designated by the English term “low-beam”. The lighting device 2 comprises a main lighting module 4, a complementary lighting module 12 and a complementary lighting module 20. The main lighting module 4 produces a horizontally extended lighting beam with a higher horizontal cutoff, commonly referred to as “flat”. The lighting modules 12 and 20 produce horizontally and vertically restricted lighting beams, commonly referred to as “kink1” and “kink2”, respectively.The projected light beams of the complementary lighting modules 12 and 20 are restricted horizontally and vertically, and produce on a screen at 25m, a luminous illumination of less than 1 lux outside an area horizontally between -15° and +15° and vertically between -4.5° and +1.5° relative to the optical axis. The projected light beam of the complementary lighting module 12 has a generally straight horizontal upper cut-off while the lighting beam of the complementary lighting module 20 has an upper cut-off with a projection, in accordance with European regulations for this automotive lighting function.
[0029] The main lighting module 4 essentially comprises light sources 6.1, 6.2 and 6.3, a collector 8 with a wall 8.1 and reflective surfaces 8.2.1, 8.2.2 and 8.2.3 formed on the wall 8.1 and configured to reflect the light rays emitted by the light sources 6.1, 6.2 and 6.3, respectively, into reflected light beams along an optical axis 10 of said main lighting module 4 towards a projection lens 30. The main lighting module 4 in this case comprises three light sources and three corresponding reflective surfaces 8.2.1, 8.2.2 and 8.2.3, it being understood that this number may vary, for example be one, two or four. The wall 8.1 of the collector 8 is however advantageously made of a single piece. Each of the reflecting surfaces has a generally elliptical or parabolic profile with a focus located at the corresponding light source 6.1, 6.2 and 6.3.Each of these reflecting surfaces forming a cap may be a surface of revolution around an axis parallel to the optical axis 10 or may be a surface approaching such a surface of revolution, in particular of free form or even “free form” obtained by numerical calculation. The sub-beams reflected by each of these reflecting surfaces are projected by the projection lens 30 by imaging a portion of these reflecting surfaces, preferably a rear edge, so as to form a clear horizontal upper cut-off.
[0030] The complementary lighting module 12 essentially comprises a light source 14, a collector 16 with a wall 16.1 and a reflecting surface 16.2 formed on the wall 16.1 and configured to reflect the light rays emitted by the light source 14 into a reflected light beam along an optical axis 18 of said complementary lighting module 12 towards the projection lens 30. Similar to the main lighting module, the reflecting surface 16.2 forms a cap, preferably of elliptical or parabolic profile with a focus corresponding to the light source 14, and preferably of revolution around an axis parallel to the optical axis 18. Also similar to the main lighting module 4, the projection lens 30 projects the reflected beam into a projected light beam by imaging a portion of the reflecting surface 16.2, preferably a rear portion adjacent to a rear edge, so as to form a clean horizontal upper cut.
[0031] The complementary lighting module 20 essentially comprises a light source 22, a collector 24 with a wall 24.1 and a reflecting surface 24.2 formed on the wall 24.1 and configured to reflect the light rays emitted by the light source 22 into a reflected light beam along an optical axis 26 of said complementary lighting module 20 towards the projection lens 30. Similar to the main lighting module 4 and the complementary lighting module 12, the reflecting surface 24.2 forms a cap, preferably of elliptical or parabolic profile with a focus corresponding to the light source 22, and preferably of revolution around an axis parallel to the optical axis 26. Also similar to the main lighting module 4 and the complementary lighting module 12, the projection lens 30 projects the reflected beam into a projected light beam by imaging a portion of the reflecting surface 24.2, preferably a rear portion adjacent to a rear edge, so as to form a clear horizontal upper cutoff. Unlike the cutoff of the projected beam of the complementary lighting module 12, the projected light beam of the complementary lighting module 20 has at the level of the horizontal upper cutoff a projection, essentially centered on the optical axis of the lighting device, comparable to the optical axis 10 of the main lighting module 4.
[0032] The projection lens 30 is common to the three lighting modules 4, 12 and 20. For this purpose, it comprises three separate parts, each corresponding to a lens, and adapted to the lighting modules in question, respectively. It is however understood that separate projection lenses can be used.
[0033] Also, other optical devices than a projection lens can be used, such as mirrors, for example a first plane mirror or one having a curved and concave horizontal profile, capable of returning the reflected rays towards the second mirror. The latter is configured to form an image of the reflective and illuminated surface of the corresponding light module. For this purpose, the second mirror can have a concave parabolic vertical profile. Such a profile makes it possible to image with magnification the illuminated reflective surface of the collector of the lighting module. The second mirror can have a convex horizontal profile, in particular when the first mirror has a concave horizontal profile. The first and second mirrors which have just been described can be inverted.
[0034] The images of the light beams projected by each of the main 4 and complementary 12 and 20 lighting modules are represented schematically by contours on two orthonormal horizontal H and vertical V axes. It can be seen that each of the projected light beams has a horizontal upper cutoff and that the light beams projected by the complementary lighting modules 12 and 20 are not only significantly narrower or restricted horizontally but also less extended downwards vertically. The objective of these complementary projected light beams is to produce more light intensity in the center of the overall projected light beam.
[0035] To limit the vertical extent of the complementary projected light beams, the reflective surfaces 16.2 and 24.2 are truncated at their front ends. This shortening or truncation of the reflective surfaces 16.2 and 24.2 has the effect that their front edges are imaged with a certain sharpness causing a second cutoff, namely a lower cutoff. This cutoff is certainly less sharp than the upper cutoff but has the disadvantage of causing an undesirable luminous irregularity. In order to avoid this irregularity, the reflective surface has graining on a front area including the front edge. These measurements will be detailed in relation to the.
[0036] This is a schematic sectional view of one of the additional lighting modules 12 and 20.
[0037] The configuration of the light source 14 or 22, the collector 16 or 24 and the projection lens 30 can be observed relative to the optical axis 18 or 26. The reflective surface 16.2 or 24.2 formed on the wall 16.1 or 24.1 of the collector 16 or 24 has an elliptical profile with two foci, a first of which is located at the light source 14 or 22 and a second of which is located between the collector 16 or 24 and the projection lens 30, on the projection lens or in front of the projection lens. The projection lens 30 comprises a focus 30.1 located on, or at least close to the reflective surface 16.2 or 24.2 in order to image at least a portion thereof. In the example of the, the focus 30.1 of the projection lens 30 is located at a rear edge 16.2.3 or 24.2.3 of the reflective surface 16.2 or 24.2 in order to sharply image the rear edge and thus produce a sharp horizontal top cutoff.It should be noted that the reflecting surface 16.2 or 24.2 may have a parabolic profile with a focus corresponding to the light source and a direction of propagation of the reflected beam essentially along the optical axis 18 or 26. As mentioned previously, the reflecting surface 16.2 or 24.2 forms a cap and is for this purpose advantageously a surface of revolution around an axis parallel to the optical axis 18 or 26.
[0038] It can be seen that the reflective surface 16.2 or 24.2 comprises a front edge 16.2.1 or 24.2.1 and a grained front area 16.2.2 or 24.2.2 comprising the front edge in question. The grained front area makes it possible to cause light diffusion of the rays it reflects and, therefore, to create a diffuse lower area in the projected light beam. This diffuse lower area avoids the previously mentioned and undesirable lower cutoff, in particular when this is located within a projected light beam that is more extensive at least vertically, as is the case with the main projected light beam. The grained front area 16.2.2 or 24.2.2 advantageously extends along the entire front edge 16.2.1 or 24.2.1. It extends rearwardly from the front edge 16.2.1 or 24.2.1 over a portion of the reflecting surface 16.2 or 24.2, preferably over at least 20%, more preferably at least 30% of the profile of said reflective surface 16.2 or 24.2. The grained front zone 16.2.2 or 24.2.2 preferably extends over at least 50% of the reflective surface 16.2 or 24.2. The expression “the grained front zone 16.2.2 or 24.2.2 extends over a portion of the reflective surface 16.2 or 24.2” means that the grained front zone 16.2.2 or 24.2.2 extends over only a portion of the reflective surface 16.2 or 24.2. In other words, the grained front zone 16.2.2 or 24.2.2 extends over less than 100% of the profile of the reflective surface 16.2 or 24.2. Advantageously, the grained front area extends over at most 75% of the profile of the reflective surface 16.2 or 24.2. There is therefore a difference in roughness of the reflective surface 16.2 or 24.2 of the collector 16, 24 between the grained front area and a rear area of the reflective surface comprising a rear edge of the reflective surface.Thus, the reflective surface 16.2, 24.2 can reflect the light rays emitted by the light source 14, 22 to form the projected light beam, the rear, non-grained zone, making it possible in particular to create a clear upper part in the projected light beam, and the grained front zone making it possible to diffuse the light rays that it reflects to form a diffuse lower part in the projected light beam. The grained front zone 16.2.2 or 24.2.2 has a roughness R. a which is preferably greater than or equal to 0.3µm and / or less than 1µm. The grained front area can be produced by sandblasting before depositing a metallized coating forming the reflective surface 16.2 or 24.2.
[0039] The front edge 16.2.1 or 24.2.1 of the reflecting surface 16.2 or 24.2 is advantageously positioned so as to limit the downward extent of the corresponding complementary projected light beam. One objective of the complementary projected light beam(s) is in fact to provide light intensity to a central part of the overall projected light beam. Also, UN (United Nations) regulation or UNECE (acronym for "United Nations Economic Commission for Europe") No. 149, relating to uniform prescriptions for the approval of road lighting devices (lamps) and systems for motor vehicles, provides maximum light intensity values in particular at a segment 10 extending between the following coordinates (-4.5°, -4°) and (2°, -4°) along the V and H axes passing through the optical axis at 25m from the overall projected light beam.For class C, V and E vehicles, the maximum luminous intensity at segment 10 is 12,300 cd. This segment is shown in the HV graph to the right of the. It is then clear that shortening the reflective surface 16.2 or 24.2 by moving the front edge 16.2.1 or 24.2.1 rearward has the effect of shortening the downward extent of the corresponding projected light beam.
[0040] At 1a, it can be observed that the collector 16 or 24 comprises a front portion forming a cover 16.1.1 or 24.1.1. This cover is linked to the wall 16.1 or 24.1 and is advantageously integrally formed with the wall in question. The cover 16.1.1 or 24.1.1 is thus directly adjacent to the front edge 16.2.1 or 24.2.1 of the reflecting surface and is configured to intercept by absorption and / or reflection the light rays reflected by the reflecting surface 16.2 or 24.2 in the vicinity of the front edge 16.2.1 or 24.2.1 which, in the absence of their interception, would extend the corresponding projected light beam downwards. It should be noted that the internal face of the cover 16.1.1 or 24.1.1 may be reflective or not, however it is not part of the reflective surface 16.2 or 24.2 having a unitary geometric profile, in particular parabolic or elliptical.
[0041] The three measures described above, namely (i) providing a grained front area for the reflective surface, (ii) limiting the forward extent of the reflective surface and (iii) providing a cover adjacent to the front edge of the reflective surface, each have the effect of avoiding exceeding the maximum luminous intensity value permitted in segment 10 of UNECE Regulation No. 149. They are advantageously used in combination but can also be used individually or in different combinations, namely (i)+(ii), (i)+(iii) or (ii)+(iii).
[0042] This is a schematic representation of the light image on the screen at 25m of the overall projected light beam of the lighting device, namely a combination of the main light beam, called "flat", and the two complementary projected beams, called "kink 1" and "kink 2". Segment 10 of UNECE Regulation No. 149 is represented there. It can be seen that the specific light images of the complementary projected light beams are limited downwards to segment 10, so that the total light intensity, resulting from the combination of all the projected light beams, does not exceed the maximum value permitted in segment 10, and also so that a too sharp lower horizontal cut-off is absent.
Claims
Lighting module (12; 20) for motor vehicle, comprising: - a light source (14; 22) capable of emitting light rays; - a collector (16; 24) with a reflective surface (16.2; 24.2) configured to reflect the light rays into a reflected beam; - an optical device (30) configured to project the reflected beam into a projected beam along an optical axis (18; 26) of the lighting module (12; 20) by imaging a part of the reflective surface (16.2; 24.2); characterized in that the reflective surface (16.2; 24.2) comprises a front edge (16.2.1; 24.2.1) and a grained front area (16.2.2; 24.2.2) comprising the front edge (16.2.1; 24.2.1). Lighting module (12; 20) for a motor vehicle according to claim 1, wherein the grained front area (16.2.2; 24.2.2) has a roughness R a greater than or equal to 0.3 µm. Lighting module (12; 20) according to claim 1 or 2, wherein the grained front area (16.2.2; 24.2.2) extends from the front edge (16.2.1; 24.2.1) to a rear edge of the reflective surface (16.2; 24.2) over only a part of the reflective surface (16.2; 24.2). Lighting module (12; 20) according to any one of claims 1 to 3, wherein the grained front area (16.2.2; 24.2.2) extends over at most 75% of the reflective surface (16.2; 24.2). Lighting module (12; 20) according to any one of claims 1 to 4, wherein the optical device (30) includes a focus (30.1) located near a rear edge of the reflective surface (16.2; 24.2), for example at a distance of less than 10 mm. Lighting module (12; 20) according to any one of claims 1 to 5, wherein the grained front area (16.2.2; 24.2.2) of the reflective surface (16.2; 24.2) extends along the entire front edge (16.2.1; 24.2.1). Lighting module (12; 20) according to any one of claims 1 to 6, wherein the grained front area (162.2; 24.2.2) of the reflective surface (16.2; 24.2) corresponds to at least 50% of the reflective surface (16.2; 24.2). Lighting module (12; 20) according to any one of claims 1 to 7, wherein the collector (16; 24) includes a cover (16.1.1; 24.1.1) located directly in front of the front edge (16.2.1; 24.2.1) of the reflective surface (16.2, 24.2), said cover being configured to absorb and / or reflect away from the optical device a portion of the light rays reflected by the reflective surface (16.2, 24.2) at the front edge (16.2.1; 24.2.1). Lighting module (12; 20) according to any one of claims 1 to 8, wherein the light source (14; 22) is configured to emit light rays along a main transverse direction, preferably perpendicular, to the optical axis (18; 26) and the reflective surface (16.2; 24.2) forms a dome with an opening directed along the main direction. Lighting module (12; 20) according to any one of claims 1 to 9, wherein the reflective surface (16.2; 24.2) has a parabolic or elliptical profile. Lighting module (12; 20) according to any one of claims 1 to 10, wherein the front edge (16.2.1; 24.2.1) of the reflective surface (16.2; 24.2) corresponds to a segment of the light beam projected at 25m, located at or above -4° vertically, when the lighting module is in the mounting position on the motor vehicle. Lighting module (12; 20) according to any one of claims 1 to 11, wherein the projected light beam is restricted horizontally and vertically, and produces at 25m a luminous illumination of less than 1 lux outside an area horizontally between -15° and +15° and vertically between -4.5° and +1.5° relative to the optical axis, when the lighting module is in the mounting position on the motor vehicle. Lighting device (2) for motor vehicle, comprising: - a main lighting module (4) configured to project a main light beam, horizontally extended and with a horizontal top cutoff, when the lighting device is in the mounting position on the motor vehicle; and - at least one supplementary lighting module (12; 20) configured to project a supplementary light beam, narrowed and centrally horizontal and with a horizontal top cutoff, when the lighting device is in the mounting position on the motor vehicle; characterized in that the at least one supplementary lighting module is a lighting module (12; 20) according to any one of claims 1 to 12.