Luminous unit for a motor vehicle

Abstract

The invention relates to a luminous unit (1) for a motor vehicle intended to project a projected beam, comprising: a light source (10); a support (100) for the light source (10) extending in a plane of elongation that is secant with the direction of projection of the projected beam; a first reflector (11) reflecting the light from the light source as a first beam; a second reflector (12); a reflective element (13) having a first reflection face (130) for sending back certain rays of the first beam towards the second reflector; the second reflector reflecting the rays of the first beam that are received directly or after reflection off the reflective element as a second beam, and a projection system (14) arranged to project the second light beam and having a focal point (140) located in the vicinity of the second reflector (121).

Description

LIGHTING UNIT FOR MOTOR VEHICLES

[0001] The invention relates to the technical field of light units for motor vehicles and also to light modules comprising several superimposed light units along a stacking direction, in particular vertical or substantially vertical. State of the art

[0002] In the field of automotive lighting, it is generally known to use light units each comprising a light source mounted on a printed circuit board, a first reflector with a reflective surface, and a projection system arranged to image the reflective surface of the first reflector to form a light beam with a superior cutoff.

[0003] However, for stylistic reasons, car manufacturers require a vertically oriented light signature.

[0004] One known solution involves stacking the light units along a direction that includes a vertical component within a light module. The light module then extends along a direction that coincides with the stacking direction.

[0005] However, using this type of light module requires significant space, necessitating the placement of the light units side by side. This solution is costly. Finally, it should be noted that the efficiency of these light units needs improvement.

[0006] The invention is therefore situated within this context and seeks to resolve all the aforementioned drawbacks. Thus, the invention aims to provide a more efficient lighting unit that can be easily assembled within a lighting module with other lighting units, in a compact size. The invention also aims to provide a lighting module extending along a vertical component that is efficient, inexpensive, and compact. Presentation of the invention.

[0007] The invention relates to a light unit for a motor vehicle, intended to project a light beam projected along a projection direction comprising: - at least one light source capable of emitting light along a light emission direction; - at least one support supporting the light source and extending along an elongation plane perpendicular to the light emission direction and intersecting the projection direction; - a first reflector comprising a reflective surface arranged to collect and reflect the light emitted by at least one light source into a first light beam; - a second reflector delimited by a rear edge along the projection direction and comprising a reflective surface;- a reflective element comprising a first reflective face delimited by an edge, turned towards the rear edge of the second reflector, and by a lower edge opposite said edge, said reflective element being adapted to reflect light rays from the first light beam reflected by the first reflector reaching it towards the second reflector, the reflective surface of the second reflector being arranged to reflect the light rays from the first light beam reaching it, with or without prior reflection on the reflective element, into a second light beam; - a projection system arranged to project the light beam reflected by the second reflector to form the projected light beam, said projection system comprising a focus located at a distance less than or equal to 10 mm from the reflective surface of the second reflector.

[0008] The light unit, notably through the second reflector, projects a beam of light along a specific projection direction. This projection direction can, for example, correspond to a longitudinal direction when the light unit is in its normal mounting position.

[0009] The light unit comprises at least one light source. The light source is mounted on a support. The support may, in particular, be a printed circuit board. The light source is capable of emitting light in a direction perpendicular to the plane of elongation of the support.

[0010] The support extends along a plane of elongation perpendicular to the direction of light emission. Furthermore, this plane of elongation intersects the projection direction. In other words, the plane of elongation of the support is not parallel to the projection direction. Thus, the support has an inclined orientation. In particular, when the projection direction is longitudinal when the light unit is in its normal mounting position, it is clear that the plane of elongation of the support is not horizontal.

[0011] This inclined orientation of the support makes it easier to mount a light module with multiple light units. As will be seen later, the supports for each light unit can then be combined into a single support common to all the light units, thus reducing the cost and size of the light module.

[0012] The light unit includes a first reflector with a reflective surface arranged to collect and reflect the light beam emitted by said light source. For example, the first reflector can be mounted on the support.

[0013] The light unit includes a second reflector delimited by a rear edge along the projection direction. The second reflector has a reflective surface.

[0014] The light unit includes a reflective element. This reflective element has a first reflective surface designed to redirect light rays from the first beam reflected by the first reflector—rays that are not directly received by the second reflector and would otherwise be wasted—to the second reflector. By using a reflective element to capture some of the light rays from the first beam and redirect them to the second reflector, the lighting efficiency is increased by maximizing the intensity of the resulting light beam.

[0015] This reflective element can also be called a "bender". Indeed, by collecting light rays from the first light beam reflected by the first reflector and which would not be intercepted by the second reflector, in the absence of this reflective element, the reflective element bends part of the first light beam.

[0016] It is thus understood that the reflective surface of the second reflector is arranged to reflect both light rays from the first reflected light beam which directly reach the reflective surface, that is to say without encountering other elements, such as another reflective surface, upstream, and light rays from the first reflected light beam which have been reflected by the reflective element before reaching the reflective surface of the second reflector.

[0017] The projection system projects the second beam of light reflected by the second reflector to form the projected light beam. To achieve this, the projection system includes a focal point located at a distance of 10 mm or less from the reflective surface of the second reflector. The focal point of the projection system can thus be positioned on the reflective surface of the second reflector. The projection system then projects the image of the reflective surface of the second reflector.

[0018] In one example, the focal point could be located at the point of maximum intensity on the reflective surface of the second reflector. In another example, the focal point could be located at the rear edge of the second reflector. In this example, the rear edge of the second reflector could have a specific cutout. For example, the edge could be flat or have a raised edge. The light beam projected by the projection system would then have a cutout at the top resulting from this specific cutout.

[0019] For example, the projection system can be spherical or toroidal.

[0020] In one embodiment, the projection system comprises at least one lens. It will be understood that the projection system may, in particular, consist of a single lens or a combination of several lenses. In another embodiment, the projection system comprises at least one mirror. It will be understood that the projection system may, in particular, consist of a single mirror or a combination of several mirrors. In a different embodiment, and without departing from the scope of the invention, the projection system could be formed by combining one or more lenses with one or more mirrors.

[0021] It is thus understood that the light unit according to the invention makes it possible to solve the aforementioned technical problem.

[0022] Specifically, the first reflector allows the light source to be offset from the second reflector, making it possible to position the light source on a support extending along an inclined plane, i.e., intersecting with the projection direction. It is thanks to the presence of the first reflector that it is possible to easily integrate several light units into a single light module. In particular, as will be seen later, it is possible to stack several light units, with the supports for each unit forming a single support common to all the units. This then reduces the cost and size of the light module.

[0023] Furthermore, thanks to the use of the reflective element, it is possible to recover light rays from the first beam that would otherwise be lost and redirect them to the second reflector. This improves the luminous efficiency of the light unit, since the number of light rays from the first beam reflected by the second reflector is maximized. Light loss is therefore minimized, and optical performance is enhanced.

[0024] Advantageously, the first reflector forms a cavity in which the light source is mounted.

[0025] Each first reflector defines a cavity in which the light source of the light unit to which it is associated is mounted. Each light source can be positioned opposite its corresponding first reflector, so that the reflective surface of said first reflector collects and reflects the light beam emitted by said corresponding light source.

[0026] Advantageously, the first reflector is mounted on the support.

[0027] Advantageously, the first reflector is elliptical and has a first focal point and a second focal point. The light source is positioned at the first focal point of the first reflector, and the rear edge of the second reflector is positioned at the second focal point of the first reflector. Thus, the first reflector directs the light rays emitted by the light source towards the second reflector, and specifically towards the rear edge of the second reflector.

[0028] The light source is mounted near the bottom of the first reflector.

[0029] Advantageously, the reflective element has a second face opposite the first face, mounted on the support.

[0030] The reflective element can extend parallel to the support.

[0031] Advantageously, the focal point of the projection system is located at a distance less than or equal to 10 mm from said rear edge of the second reflector.

[0032] Advantageously, the reflective element and the second reflector are two separate pieces and are positioned so that the edge of the reflective element and the rear edge of the second reflector are joined.

[0033] In this embodiment, the two separate parts are positioned so as to prevent a gap from being created between the rear edge of the second reflector and the reflective element.

[0034] Alternatively, the reflective element and the second reflector form a single piece so that the edge of the reflective element and the rear edge of the second reflector are indistinguishable.

[0035] The reflective element and the second reflector are a single unit. Using a single unit eliminates the need to position the reflective element and the second reflector relative to each other, thus minimizing the loss of light rays reflected towards the second reflector. This single unit can also reduce costs.

[0036] When the edge of the reflective element and the rear edge of the second reflector are joined or coincide, the rear edge of the second reflector has a profile identical to the edge of the reflective element.

[0037] Advantageously, the rear edge of the second reflector can form the upper cutoff of the projected light beam.

[0038] Advantageously, the edge of the reflecting element has at least one first step separating a first portion and a second portion of said edge respectively contained in a first and a second plane offset from each other and substantially parallel to each other.

[0039] Advantageously, the edge of the reflecting element has a second ridge separating the second portion and a third portion of said edge contained in a third plane substantially parallel to the first and second planes.

[0040] In one example, the foreground and background planes may be offset from each other. The first and third portions then extend along different planes. In a second example, the foreground and background planes may be identical. The first and third portions then extend in the same plane. The second portion is in the second plane parallel to the foreground. The edge of the reflecting element may include the first and second projections, each of which can create a break in the light beam projected by the projection system, thus creating two breaks.

[0041] The second step can optimize road lighting while ensuring the beam complies with regulations. Specifically, the second section can create a lower cutoff in the upper cutoff of the projected light beam, the first section can create a higher cutoff in the upper cutoff of the projected light beam, and the third section can create an intermediate cutoff in the upper cutoff of the projected light beam.

[0042] Advantageously, the lower edge of the reflective element has a profile identical to the profile of said edge.

[0043] In one embodiment, the edge and the lower edge may have a first step. The first step separating the first portion and the second portion of the edge may extend over the entire length of the reflective element.

[0044] In another embodiment, the edge and the lower edge may have a second ridge. The second ridge separating the second portion and a third portion of the edge may extend along the entire length of the reflective element.

[0045] Advantageously, the lower edge of the reflective element has a flat profile.

[0046] In the various embodiments of the reflective element having a rear edge with a flat profile, the first and / or second ridge of the edge gradually disappear from the edge towards the rear edge.

[0047] Advantageously, the light emission direction is intersecting the projection direction, and in a longitudinal plane encompassing the projection and light emission directions, the support's elongation plane is inclined at an angle between 15° and 25° to a vertical direction defined as perpendicular to the projection direction and to a transverse direction, the transverse direction being defined as the direction perpendicular to the longitudinal plane. In other words, the projection of the support's elongation plane onto the longitudinal plane is inclined between 15° and 25° to a vertical direction. In particular, when the light unit is in its normal mounting position, the support is angled.

[0048] In this embodiment, the angle formed between the support and the vertical axis can optimize the capture of light rays projected onto the road. This orientation also facilitates the assembly of the light unit with other light units to form a light module.

[0049] Another aspect of the invention relates to a light module for a motor vehicle characterized in that it comprises at least two light units according to the invention.

[0050] Advantageously, the light units are stacked one above the other. "The light units are stacked one above the other" means that the supports for the light units all have the same orientation and extend in the same plane of elongation, and that the light units are arranged one above the other in their normal mounting position. In particular, the first and second reflectors of the light units are arranged one above the other in their normal mounting position. The light units are then stacked in a direction parallel to the plane of elongation.

[0051] Advantageously, the supports for each light unit form a single piece so that the light sources of each light unit are positioned on the same support.

[0052] Thanks to the orientation of the support, it is possible to stack several light units sharing the same support for their light source. The overall size of the light module is therefore reduced.

[0053] Two light units can be mounted one above the other on the support common to both light sources. Brief description of the figures.

[0054] Other advantages and features of the present invention are now described by means of purely illustrative and in no way limiting examples of the scope of the invention, and from the accompanying drawings, in which the various figures represent:

[0055] schematically represents a profile view of a principle diagram of the operation of a lighting unit according to one embodiment.

[0056] schematically represents a rear view of a light unit according to one embodiment.

[0057] schematically represents a perspective view of a reflective element and a second reflector according to an embodiment in which the edge and the lower edge of said reflective element have the same profile.

[0058] schematically represents a perspective view of a reflective element and a second reflector according to an embodiment in which the edge and the lower edge of said reflective element have different profiles.

[0059] schematically represents a profile view of a light module according to one embodiment.

[0060] In the description that follows, identical elements, by structure or by function, appearing on different figures retain, unless otherwise specified, the same references. Description of a method of implementation.

[0061] In the detailed description that follows, the terms "longitudinal," "transverse," and "vertical" refer to the orientation of the light unit according to the invention when it is positioned in the vehicle in its normal mounting position. A longitudinal direction corresponds to the direction of travel of a vehicle equipped with the light unit, this longitudinal direction being parallel to a longitudinal axis X of an orthonormal coordinate system X, Y, Z illustrated in the figures. This longitudinal direction also corresponds to the direction of the optical axis of the light unit. A transverse direction corresponds to a direction perpendicular, in a horizontal plane, to the direction of travel of the vehicle equipped with the light unit, this transverse direction being parallel to a transverse axis Y of the coordinate system X, Y, Z, and this transverse axis Y being perpendicular to the longitudinal axis X.Finally, a vertical direction Z corresponds to a direction parallel to a vertical axis Z of the X, Y, Z coordinate system, this vertical axis V being perpendicular to the longitudinal axis X and to the transverse axis Y.

[0062] A side view of a light unit 1 according to one embodiment is shown. The light unit 1 is also described in relation to the figure representing a rear view of said light unit 1. The light unit 1 is also described in relation to the figures representing two different embodiments of the reflective element 13 and in relation to the figure representing a side view of a light module comprising a plurality of light units 1.

[0063] The two describe a light unit 1. The light unit 1 is intended to project a beam of light projected along a projection direction P. In the illustrated example, the projection direction P is along the longitudinal direction X.

[0064] The light unit 1 comprises a light source 10 capable of emitting light. The light source 10 emits light along a light emission direction P. This light emission direction P corresponds to the average direction of the emission cone of the light source 10. The light source 10 is mounted on a support 100. In the illustrated example, the support 100 is a printed circuit board. The support 100 extends along an elongation plane PA perpendicular to the light emission direction E. The elongation plane PA in which the support 100 extends intersects the projection direction P. The elongation plane PA of the support 100 is therefore not parallel to the projection direction P. Thus, the support 100 has an inclined orientation. In particular, the support 100 can be vertical or inclined with respect to the vertical direction Z, but it is not horizontal.

[0065] More specifically, in the example illustrated on the, the direction of light emission E is secant to the direction of projection P, and in a longitudinal plane XZ comprising the directions of projection P and of light emission E, the plane of elongation PA of the support 100 is inclined at an angle α between 15° and 25° with respect to the vertical direction Z. It should be noted that the longitudinal plane XZ corresponds to the plane of the.

[0066] The light unit 1 also includes a first reflector 11, a second reflector 12, and a reflective element 13. The first reflector 11 forms a cavity in which the light source 10 is mounted. The light source 10 is mounted near the bottom of the cavity. The first reflector 11 is mounted on the support 100. The first reflector 11 has a reflective surface arranged to collect and reflect the light emitted by the light source 10 into a first beam of light.

[0067] The second reflector 12 has a reflective surface 120 arranged to reflect the first light beam reflected by the first reflector 11 into a second light beam. The second reflector 12 is delimited by a rear edge 121 along the projection direction P.

[0068] Specifically, the first reflector 11 can be elliptical and have a first focal point and a second focal point. The light source 10 can then be positioned at the first focal point, and the second focal point can be positioned at the rear edge of the second reflector or on its reflective surface. The light rays from the first beam are then reflected towards the second reflector 12. However, some of the light rays from the first beam may not reach the second reflector 12. The reflective element 13 then redirects the light rays from the first beam that are not directly received by the second reflector 12 back to the second reflector 12.

[0069] Thus, the reflective surface 120 of the second reflector can reflect the light rays of the first light beam that reach it directly, and the light rays of the first light beam that reach the reflective element 13 and are reflected by the reflective element 13 towards the second reflector 12.

[0070] To reflect certain light rays from the first light beam that are not received directly by the second reflector 12, the reflective element 13 has a first face 130 of total internal reflection. The light rays from the first light beam that would be lost, because they are not directed directly towards the second reflector 12, are then recovered by the reflective element 13 and reflected back towards the second reflector 12.

[0071] The reflective element 13 extends parallel to the support 100. The first reflective face 130 of the reflective element 13 is delimited by an edge 132, turned towards the rear edge 121 of the second reflector 12, and by a lower edge 133 opposite the edge 132. The edge 132 is intended to form an upper cut in the projected light beam.

[0072] The reflective element 13 has a second face 131 opposite the first reflective face 130. The second face 131 is mounted opposite the support 100.

[0073] In the illustrated example, the reflective element 13 and the second reflector 12 form a single piece. The edge 132 of the reflective element 13 and the rear edge 121 of the second reflector 12 coincide. Consequently, the rear edge 121 of the second reflector 12 has a profile substantially identical to the profile of the edge 132 of the reflective element 13.

[0074] Alternatively, the reflective element 13 and the second reflector 12 could be two separate pieces and could be positioned so that the edge 132 of the reflective element 13 and the rear edge 121 of the second reflector 12 are joined.

[0075] As described in [reference], the edge 132 of the reflecting element 13 has a first step 132a separating a first portion 132.1 and a second portion 132.2 of said edge 132. The first portion 132.1 lies in a first plane and the second portion 132.2 lies in a second plane, the first and second planes being parallel to each other. The edge 132 of the reflecting element 13 has a second step 132b separating the second portion 132.2 and a third portion 132.3 of said edge 132. The third portion 132.3 lies in a third plane, parallel to the first and second planes. The first 132a and the second step 132b each form a break in the projected light beam.

[0076] On the set, the lower edge 133 of the reflective element 13 has a profile identical to that of the edge 132. Both the edge 132 and the lower edge 133 have a first step 132a, 133a. Thus, the first step 133a of the lower edge 133 separates a first portion 133.1 and a second portion 133.2 of said lower edge 133. The first portion 133.1 lies in a first plane and the second portion 133.2 lies in a second plane, the first and second planes being parallel to each other. The first step 132a, 133a extends along the entire length of the reflective element 13.

[0077] The edge 132 and the lower edge 133 of the reflective element 13 also have a second step 132b, 133b. The second step 133b of the lower edge 133 separates the second portion 133.2 and a third portion 133.3 of said lower edge 133. The third portion 133.3 is contained in a third plane, parallel to the first and second planes. The second step 133a, 133b extends along the entire length of the reflective element 13.

[0078] Therefore, in this embodiment, the reflective element 13 has the shape of the first step 132a, 133a and the second step 132b, 133b over its entire extent.

[0079] In this embodiment, the lower edge 133 of the reflective element 13 has a different profile from that of the edge 132. Indeed, in this embodiment, the lower edge 133 has a flat profile. The first step 132a and the second step 132b gradually disappear from the edge 132 towards the rear edge 133.

[0080] The light unit includes a projection system 14. The projection system 14 is arranged to project the second light beam reflected by the second reflector 13 to form a light beam projected onto the road. In Figures 1 and 5, it can be seen that the projection system 14 is formed by a projection lens. The projection direction P is given by the direction of the optical axis of the projection system 14.

[0081] The projection system 14 has a focus located at a distance less than or equal to 10 mm from the reflective surface 120 of the second reflector 12. In particular, the focus of the projection system can be located at a distance less than or equal to 10 mm from the rear edge 121 of the second reflector 12. The projection system 14 then makes it possible to make the image of the reflective surface of the second reflector, and more particularly of the rear edge 121 of the second reflector 12. Now, as the rear edge 121 of the second reflector 12 coincides with the edge 132 of the reflecting element, and as the edge 132 includes bumps 132a, 132b, these bumps are imaged in the projected light beam to form an upper cut with bumps.

[0082] Several light units 1 according to the invention can be integrated together to form a light module 100. Such a light module 100 is described with reference to the figure. The illustrated light module 100 comprises five superimposed light units 1, it being understood that a different number of light units could have been used without departing from the scope of the invention.

[0083] The light units 1 are superimposed one on top of the other, following a stacking direction parallel to the elongation plane of the support and perpendicular to the transverse direction Y. This superposition of the light units 1 is facilitated by the orientation of the elongation plane PA of the support 100 of the light units 1.

[0084] The light sources of the five light units 1 are all mounted on the same support 100, that is to say that the supports 100 of the light units form a single support, common to all the light units 1. This makes it possible to reduce the number of components and the size of the light module.

[0085] The preceding description clearly explains how the invention achieves its objectives, namely to offer an efficient, economical light unit that can be easily assembled within a light module with other light units, and a light module comprising several light units by offering a light unit comprising a substantially inclined support and comprising a reflective element adapted to recover light rays that would normally be lost.

[0086] In any event, the invention cannot be limited to the embodiments specifically described in this document, and extends in particular to all equivalent means and to any technically operative combination of these means.

Claims

Light unit (1) for motor vehicle, intended to project a light beam projected along a projection direction (P) comprising: at least one light source (10) capable of emitting light along a light emission direction (E); at least one support (100) supporting the light source (10) and extending along an elongation plane (PA) perpendicular to the light emission direction (E) and intersecting the projection direction (P); a first reflector (11) comprising a reflective surface (110) arranged to collect and reflect the light emitted by the at least one light source (10) into a first light beam; a second reflector (12) delimited by a rear edge (121) along the projection direction and comprising a reflective surface (120);a reflective element (13) comprising a first reflective face (130) delimited by an edge (132), turned towards the rear edge (121) of the second reflector, and by a lower edge (133) opposite said edge (132), said reflective element being adapted to reflect light rays from the first light beam reflected by the first reflector reaching it towards the second reflector (12); the reflective surface (120) of the second reflector (12) being arranged to reflect the light rays from the first light beam reaching it, with or without prior reflection on the reflective element, into a second light beam; a projection system (14) arranged to project the second light beam reflected by the second reflector (12) to form the projected light beam, said projection system (14) comprising a focus (140) located at a distance less than or equal to 10 mm from the reflective surface (120) of the second reflector (12). Light unit (1) according to the preceding claim, characterized in that the first reflector is elliptical and has a first focus and a second focus, and in that the light source is disposed at the first focus of the first reflector and the rear edge of the second reflector is disposed at the second focus of the first reflector. Light unit (1) according to one of the preceding claims, characterized in that the reflective element (13) has a second face (131) opposite the first face (130), mounted on the support (100). Light unit (1) according to any one of claims 1 to 3, characterized in that the focus (140) of the projection system (14) is located at a distance less than or equal to 10 mm from said rear edge (121) of the second reflector (12). Light unit (1) according to any one of claims 1 to 4, characterized in that the reflective element (13) and the second reflector (12) are two separate pieces and are positioned so that the edge (132) of the reflective element (13) and the rear edge (121) of the second reflector (12) are joined. Light unit (1) according to any one of claims 1 to 4, characterized in that the reflective element (13) and the second reflector (12) form a single piece such that the edge (132) of the reflective element (13) and the rear edge (121) of the second reflector (12) are coincident. Light unit (1) according to one of the preceding claims, characterized in that the edge (132) of the reflecting element (13) has at least one first step (132a) separating a first portion (132.1) and a second portion (132.2) of said edge (132) respectively contained in a first plane and a second plane offset from each other and substantially parallel to each other. Light unit (1) according to claim 7, characterized in that the edge (132) of the reflective element (13) has a second bump (132b) separating the second portion and a third portion of said edge (132) contained in a third plane substantially parallel to the first and second planes. Light unit (1) according to any one of claims 1 to 8, characterized in that the lower edge (133) of the reflective element (13) has a profile identical to the profile of said edge (132). Light unit (1) according to any one of claims 1 to 8, characterized in that the lower edge (133) of the reflective element (13) has a planar profile. Light unit (1) according to any one of the preceding claims, characterized in that the direction of light emission (E) is secant to the direction of projection (P), and in a longitudinal plane comprising the directions of projection and of light emission, the plane of extension (PA) of the support (100) is inclined at an angle (α) between 15° and 25° with respect to a vertical direction (Z) defined as being perpendicular to the direction of projection and to a transverse direction, the transverse direction being defined as being the direction perpendicular to the longitudinal plane. Light module for motor vehicle characterized in that it comprises at least two light units (1) according to one of the preceding claims. Light module according to claim 12, characterized in that the light units are superimposed one on top of the other. Light module according to one of claims 12 or 13 characterized in that the supports of each light unit (1) form a single piece so that the light sources of each light unit are positioned on the same support.

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