Lighting device for a motor vehicle

Abstract

Lighting device for a motor vehicle Lighting device (1) for a motor vehicle comprising: - a light source (2.1), - a light collector (3.1) provided with a reflective surface (4.1) intended to reflect light rays emitted by the light source into a light beam, and - a lens (5.1) intended to shape the light beam coming from the light collector, characterized in that it further comprises - a first mask (20) positioned on an optical path between the reflective surface (4.1) and the lens (5.1), the first mask being intended to intercept a portion of the light rays reflected by the reflective surface and directed towards the lens. Figure for abstract: figure 2

Description

Title of the invention: Lighting device for a motor vehicle Technical field of the invention

[0001] The invention relates to the field of lighting and light signaling, more particularly in the automotive field. State of the prior art

[0002] Motor vehicles are equipped with lighting devices intended to make the vehicle clearly visible and to illuminate the vehicle's surroundings. The shape of the light beams produced by these lighting devices must allow for effective lighting while complying with various automotive legislation, in particular so as not to dazzle other road users.

[0003] Patent document WO 2020 / 025171 A1 discloses a light module, in particular for a motor vehicle, comprising a collector with a reflective surface collecting and reflecting the light rays emitted by a light source into a light beam. The light module also comprises an optical projection device, such as a lens, specifically configured to project the light beam in question by forming an image of the reflective surface of the collector. For this purpose, the optical projection device has a focus located on the reflective surface, for example on a rear edge thereof. This type of light module has advantages of compactness, in particular in height, and simplicity of production.In this teaching, this light module is combined with other light modules to form a projector providing a cut-off lighting function commonly referred to as the "low beam" type, or a non-cut-off lighting function commonly referred to as the "high beam" type.

[0004] However, certain geometric defects of the lens can cause significant dispersion of the light from the light source. This dispersion of the light causes the projection of a locally colored image, which is not desirable. Such dispersion can in particular be observed by a bluish appearance at a projection formed in the cutoff of a cutoff light beam, for example a dipped beam type light beam. To avoid such a phenomenon, attempts are made to improve the geometric shape of the lenses by deploying complex manufacturing processes. This solution nevertheless proves to be insufficient. Presentation of the invention

[0005] The aim of the invention is to provide a lighting device which overcomes the above drawbacks and improves the lighting devices known from the prior art.

[0006] More specifically, a first object of the invention is a lighting device which is simple to manufacture and makes it possible to project a light beam free from an undesirable colored part or comprising an undesirable colored part of minimal size. Summary of the invention

[0007] The invention relates to a lighting device for a motor vehicle comprising: - a light source, - a light collector provided with a reflective surface intended to reflect light rays emitted by the light source into a light beam, - a lens intended to shape the light beam coming from the light collector, and - a first mask positioned on an optical path between the reflecting surface and the lens, the first mask being intended to intercept part of the light rays reflected by the reflecting surface and directed towards the lens.

[0008] The first mask may comprise a pad extending generally perpendicular to said optical path.

[0009] The light collector and the stud may belong to the same reflection element, preferably obtained by injection of plastic into a mold.

[0010] The lens may comprise an entrance surface and / or an exit surface in the shape of a cylinder of revolution, an axis of revolution of the cylinder of revolution shape being parallel to an axis in which the stud extends.

[0011] The stud may comprise a frustoconical shape. Preferably a height of the stud perpendicular to said optical path is between 5 mm and 10 mm inclusive and / or a diameter of the stud is between 1 mm and 3 mm inclusive.

[0012] The light beam reflected by the reflective surface of the light collector may be centered on an optical axis, and the first mask may be offset from the optical axis. The first mask may be positioned on an axis passing through the light source and an edge of the lens.

[0013] The distance between the first mask and the light source may be strictly less than the distance between the first mask and the lens. Preferably, the distance between the first mask and the light source may be strictly less than 50% of the distance between the first mask and the lens.

[0014] The lighting device may further comprise a second mask, distinct from the first mask, positioned on an optical path between the light source and the lens, the second mask being intended to intercept the light rays emitted by the light source and directed directly towards the lens.

[0015] The reflective surface may comprise an elliptical shape, the light source being positioned at a first focus of the elliptical shape. The elliptical shape may comprise a second focus located near the lens, in particular in the lens or at a distance of less than 10 mm from the lens. Alternatively, the reflective surface may comprise a paraboloid shape, the light source being positioned at a focus of the paraboloid shape. The lens may comprise a focus positioned at the reflective surface, in particular at a rear edge of the reflective surface.

[0016] The reflective surface of the light collector may be configured to reflect light rays emitted by the light source into a cutoff light beam provided with a step. Presentation of figures

[0017] These objects, characteristics and advantages of the present invention will be explained in detail in the following description of a particular embodiment made without limitation in relation to the attached figures among which:

[0018] [Fig.l] is a front perspective view of a lighting device for a motor vehicle according to one embodiment of the invention.

[0019] [Fig.2] is a rear perspective view of the lighting device.

[0020] [Fig.3] is a view of a projection of a light beam produced by the lighting device.

[0021] [Fig.4] is a perspective view of a reflection element and a printed circuit board of the lighting device, the printed circuit board being provided with a set of light sources.

[0022] [Fig.5] is a top and perspective view of the reflection element and a projection element of the lighting device.

[0023] [Fig.6] is a sectional view in a longitudinal and transverse plane of the projection element.

[0024] [Fig.7] is a front and perspective view of a first mask of the lighting device.

[0025] [Fig.8] is a top view of the reflection element and the projection element of the lighting device. Detailed description

[0026] Figures 1 and 2 illustrate a lighting device 1 for a motor vehicle according to one embodiment of the invention. The lighting device 1 is intended to be integrated into a headlight of the vehicle. In particular, the headlight is a headlight front left, left and right being defined according to the point of view of a driver of the vehicle sitting in the driving position. Of course, the invention could be transposed to a front right headlight or even to any other headlight of the vehicle. The lighting device 1 may be intended to be housed in a housing fixed to the vehicle. The housing may be closed at the front by a transparent protective glass.

[0027] In this document, the X axis designates the longitudinal axis of the vehicle. When moving forward and in a straight line, the vehicle moves from the rear to the front in a direction parallel to its longitudinal axis. The X axis is oriented from the front to the rear of the vehicle, that is to say in the direction of reverse travel. The Y axis designates the transverse axis of the vehicle. The Y axis is oriented from left to right. The Z axis designates the axis perpendicular to the X axis and the Y axis. The vehicle is considered to be resting on horizontal ground. The Z axis is a vertical axis, oriented from bottom to top. The X, Y and Z axes form an orthogonal reference frame. This same reference frame, defined with reference to a vehicle, will also be used to describe the lighting device 1, even when considered outside the vehicle, since it is intended to be mounted in a specific orientation in the vehicle.

[0028] The lighting device 1 is in particular configured to perform a dipped beam type lighting function also called a "code" type lighting function. The dipped beam type lighting function is obtained by projecting a light beam with an upper cut-off with a projection, that is to say with an upper cut-off having an asymmetry between a right part and a left part of the light beam, so as not to dazzle a motorist traveling in an opposite direction. [Fig. 3] illustrates, in projection in a vertical and transverse plane, the shape of the light beam F coming from the lighting device 1. The light beam F is therefore provided with an upper cut-off provided with a projection C, or oblique portion. [Fig. 3] illustrates the case of a light beam adapted to perform a dipped beam type lighting function when driving on the right.Indeed, in countries with right-hand traffic, that is to say in which vehicles are generally instructed to drive on the right-hand side of the roadway, and as seen in [Fig. 3], the light beam of a dipped beam type lighting function comprises a left-hand part illuminating less high than a right-hand part of the light beam. The invention also applies to the case where the lighting device 1 is configured to perform a dipped beam type function suitable for driving on the left. In this case, the light beam comprises a right-hand part illuminating less high than a left-hand part of the light beam.

[0029] Alternatively or additionally, the lighting device 1 may be configured to perform a road type lighting function. Such a function is obtained by projecting a more powerful light beam than the traffic light type light beam. dipped beam. The light beam performing the road type function is not necessarily a cut-off light beam and is rather intended to be used in the absence of any motorist traveling in the opposite direction.

[0030] To perform its lighting functions, the lighting device 1 comprises three light modules M1, M2, M3 arranged next to each other along the transverse axis Y. Each light module M1, M2, M3 is intended to produce a light beam constituting a part of a lighting function. Each light beam produced by a light module is centered on an optical axis. The optical axes of the different light modules may be at least roughly parallel to each other. Alternatively, the lighting device 1 could comprise a different number of light modules, in particular a single light module.

[0031] Each light module M1, M2, M3 respectively comprises at least one light source 2.1, 2.2, 2.3, a light collector 3.1, 3.2, 3.3 provided with a reflective surface 4.1, 4.2, 4.3 intended to reflect light rays emitted by the corresponding light source into a light beam. Each light module M1, M2, M3 also comprises a lens 5.1, 5.2, 5.3 intended to shape the light beam coming from the corresponding light collector 3.1, 3.2, 3.3 and to project the light beam reflected by the corresponding reflective surface 4.1, 4.2, 4.3.

[0032] Preferably, the light sources 2.1, 2.2, 2.3 each comprise at least one light-emitting diode. The light-emitting diodes may be fixed to the same printed circuit board 6, notably visible in [Fig.4]. The printed circuit board 6 may extend in a longitudinal and transverse plane. The printed circuit board 6 is further equipped with an electrical connector 7 intended to be connected to an electrical energy source and / or to an electronic control unit capable of controlling the switching on of the different light sources.

[0033] The three light collectors 3.1, 3.2, 3.3 may belong to the same component, hereinafter referred to as "reflection element 8" and visible in [Fig.5]. The reflection element 8 may advantageously be obtained by injection of plastic into a mold. The reflection element 8 is therefore a monolithic part, i.e. in one piece. As can be seen in [Fig.4], the reflection element 8 may extend above the printed circuit board 6. Advantageously, the reflection element 8 comprises positioning pins 9 cooperating with openings provided in the printed circuit board 6 to ensure good positioning of the light sources 2.1, 2.2, 2.3 relative to the light collectors 3.1, 3.2, 3.3.

[0034] The three lenses 5.1, 5.2, 5.3 are positioned respectively in front of the three light collectors 3.1, 3.2, 3.3. The three lenses 5.1, 5.2, 5.3 may each comprise a generally square or rectangular shape when observed in projection perpendicular to the longitudinal axis X. The three lenses 5.1, 5.2, 5.3 are positioned side by side along the transverse axis Y. The three lenses 5.1, 5.2, 5.3 may also belong to the same component, hereinafter referred to as “projection element 10”, and visible in particular in FIGS. 5 and 6. The projection element 10 may advantageously be obtained by injection of plastic into a mold. The projection element 10 is a monolithic part, i.e. a single piece. The projection element 10 is made of a transparent material and is adapted to shape the light beams reflected by the reflecting surfaces 4.1, 4.2, 4.3. Each lens 5.1, 5.2, 5.3 comprises an entry surface of specific shape, defined according to the shape of the light beam produced by the corresponding light module. Each lens 5.1, 5.2, 5.3 also comprises an exit surface.According to the embodiment presented, the exit surfaces of each lens are arranged in the extension of each other, thus giving a smooth appearance to the outer face of the projection element 10.

[0035] The projection element 10 is fixed directly or indirectly to the reflection element 8. For this purpose, the projection element 10 comprises tabs 11 extending longitudinally and transversely at the upper and lower edges of each lens 5.1, 5.2, 5.3. The projection element 10 further comprises side walls 12 extending longitudinally and vertically to the left and right of the projection element 10.

[0036] The lighting device 1 further comprises a heat sink 13 and a housing 14. The heat sink 13 is intended to dissipate the heat produced by the light sources 2.1, 2.2, 2.3. It is advantageously made of a material that is a good conductor of heat such as a metal and comprises a plurality of cooling fins 15. The housing 14 comprises a central opening through which the projection element 10 is arranged.

[0037] The first light module ML is now described in more detail. The first light module M1 comprises a single light source 2.1, in the form of a single light-emitting diode. The reflective surface 4.1 comprises an elliptical shape. The light source 2.1 is positioned at a first focus of the elliptical shape. The elliptical shape comprises a second focus located close to the lens 5.1, in particular in the lens 5.1 or at a distance of less than 10 mm from the lens 5.1. The elliptical shape of the reflective surface 4.1 is configured to converge the light rays coming from the light source 2.1 towards the lens 5.1. In other words, the light rays reflected by the reflective surface 4.1 converge towards the lens 5.1. Having the second focus of the elliptical shape close to lens 5.1 helps to minimize the width of the light beam reflected at lens 5.1, and thus to maximize the amount of light rays transmitted by the lens 5.1. Alternatively, the surface . reflective 4.1 could include a paraboloid shape, the light source would then be positioned at the focus of the paraboloid shape.

[0038] As is clearly visible in Figures 5 or 7, an edge of the reflecting surface 4.1 comprises a projection 16. The first light module M1 is thus intended to reflect light rays emitted by the light source 2.1 into a light beam with a cut-off provided with a projection. The first light module M1 is thus configured to produce all or part of a dipped beam type lighting function. In particular, the first light module M1 can produce a light beam, called a “kink” beam, corresponding to an intense light beam and covering the central part of a dipped beam type lighting function. The “kink” beam can comprise the projection C of the upper cut-off of the dipped beam type beam.

[0039] The lens 5.1 comprises a focus positioned at the reflective surface 4.1, in particular at a rear edge of the reflective surface 4.1. Preferably, the distance between the focus of the lens 5.1 and the rear edge of the reflective surface is less than or equal to 10 mm. With reference to [Fig.6] it is observed that the lens 5.1 comprises a convex shape. More precisely, the lens 5.1 comprises an entrance surface 17 in the shape of a cylinder of revolution, an axis of revolution of the cylinder of revolution shape is parallel to the vertical axis Z. The axis of revolution is positioned at the front of the lens 5.1. The shape of the lens 5.1 makes it possible to shape the light beam reflected by the reflective surface 4.1 of the light collector 3.1.

[0040] It is also noted that the lens 5.1 is bordered by one of the side walls 12. The side wall 12 extends in a plane substantially perpendicular to the plane in which the lens 5.1 extends. The edge 18 formed at the intersection between the lens 5.1 and the side wall 12 can disperse the light when it is reached by light rays. This dispersion of the light results in the appearance of an undesirable bluish band BB at the cut-off, and particularly at the oblique portion of the cut-off, of the light beam projected by the first light module ML

[0041] In order to reduce or even eliminate the bluish band BB, the lighting device advantageously comprises a first mask 20 positioned on an optical path between the reflecting surface 4.1 and the lens 5.1. The first mask 20 is intended to intercept a portion of the light rays reflected by the reflecting surface 4.1 and directed towards the lens. 5.1.

[0042] Of course, the first mask 20 is intended to intercept only a portion of the light rays reflected by the reflecting surface and directed towards the lens 5.1. A major portion of the light rays reflected by the reflecting surface 4.1 directly reaches the lens 5.1. Preferably, the first mask 20 is dimensioned so that the luminous flux reflected by the reflective surface 4.1 is reduced by at most 5%, or even at most 3%, preferably at most 1%, and / or so that the maximum luminous intensity of the light beam reflected by the reflective surface 4.1 is reduced by at most 5%, or even at most 3%, preferably at most 2%.

[0043] Preferably, the first mask 20 comprises a non-reflective coating. Alternatively, the first mask 20 could comprise a reflective surface intended to direct the light rays towards a light well.

[0044] The first mask 20 is offset relative to the optical axis XO. In particular, the first mask 20 is positioned on an axis D passing through the light source 2.1 and the lateral edge 12 of the lens 5.1. The first mask 20 is thus intended to intercept the light rays reflected by the reflecting surface 4.1 and directed towards the edge 18 formed at the intersection between the lens 5.1 and the lateral wall 12, that is to say the light rays capable of producing the bluish band BB at the level of the projection C.

[0045] The first mask 20 is positioned closer to the light collector 3.1 than to the lens 5.1. This makes it possible to avoid a darker area in the light beam coming from the light module ML. In particular, the distance DI between the first mask 20 and the light source 2.1 is strictly less than the distance D2 between the first mask 20 and the lens 5.1. Preferably, the distance between the first mask 20 and the light source 2.1 is strictly less than 50% of the distance between the first mask 20 and the lens 5.1.

[0046] The lighting device 1 may further comprise a second mask (not shown) positioned on an optical path between the light source 2.1 and the lens 5.1. The second mask is intended to intercept all the light rays emitted by the light source and directed directly towards the lens 5.1. The second mask is arranged under the reflective surface 4.1 and for example at a maximum distance of 5 mm from the light source 2.1. The second mask aims to prevent direct illumination of the lens 5.1 by the light source 2.1. Thus, only the light rays reflected and shaped by the reflective surface 4.1 are likely to reach the lens 5.1. The second mask may be formed for example by means of a fin fixed to the printed circuit board 6 or fixed to the heat sink 13. The first mask 20 is distinct from the second mask.

[0047] Figures 5 and 7 allow the first mask 20 to be observed in more detail. The first mask 20 comprises a pad 21 extending generally perpendicular to said optical path. In particular, the pad 21 extends parallel to the Z axis from a wall 22 of the reflection element 8. In this case, the pad 21 extends downwards from the wall 22. Alternatively, it could extend in a different direction, for example upwards. The wall 22 may be a structured wall, i.e. a wall provided with a series of reliefs intended to diffuse any light rays incident on this wall.

[0048] The pad 21 and the reflection element 8 belong to the same component, preferably obtained by injection of plastic into a mold. The integration of the first mask 20 into the lighting device therefore only requires an adaptation of the mold used to manufacture the reflection element 8. No assembly operation of the first mask 20 to the lighting device is necessary.

[0049] The stud 21 may comprise a frustoconical shape, that is to say a shape which gradually thins away from the wall 22. In this case, the stud comprises a frustoconical shape, with circular symmetry, and with a cone angle of between 5° and 10° inclusive. This makes it easier to demould the reflection element 8 during its manufacture. A height H1 of the stud 21 along the vertical axis Z may be between 5 mm and 10 mm inclusive. A diameter D3 of the stud 21 may be between 1 mm and 3 mm inclusive. The dimensions of the stud 21 thus allow the use of a relatively simple manufacturing mould and effective blocking of unwanted light rays. In particular, it is not useful to provide a specific ejector at the level of the stud 21 in the manufacturing mould.

[0050] Finally, thanks to the invention, there is a lighting device that is simple to manufacture, producing a light beam without a colored zone or comprising a colored zone of smaller size compared to an equivalent lighting device that would be without the first mask.

Claims

Claims

1. Lighting device (1) for a motor vehicle comprising: - a light source (2.1), - a light collector (3.1) provided with a reflecting surface (4.1) intended to reflect light rays emitted by the light source into a light beam, and - a lens (5.1) intended to shape the light beam coming from the light collector, characterized in that it further comprises - a first mask (20) positioned on an optical path between the reflecting surface (4.1) and the lens (5.1), the first mask being intended to intercept a portion of the light rays reflected by the reflecting surface and directed towards the lens.

2. Lighting device (1) according to the preceding claim, characterized in that the first mask (20) comprises a pad (21) extending generally perpendicular to said optical path.

3. Lighting device (1) according to the preceding claim, characterized in that the light collector (3.1) and the stud (21) belong to the same reflection element (8), preferably obtained by injection of plastic into a mold.

4. Lighting device (1) according to one of claims 2 or 3, characterized in that the lens (5.1) comprises an entry surface (17) and / or an exit surface in the form of a cylinder of revolution, an axis of revolution of the cylinder of revolution shape being parallel to an axis in which the stud (21) extends.

5. Lighting device (1) according to one of claims 2 to 4, characterized in that the stud (21) comprises a frustoconical shape, preferably a height (Hl) of the stud perpendicular to said optical path is between 5 mm and 10 mm inclusive and / or a diameter (D3) of the stud is between 1 mm and 3 mm inclusive.

6. Lighting device (1) according to one of the preceding claims, characterized in that the light beam reflected by the reflecting surface (4.1) of the light collector (3.1) is centered on an optical axis (XO), and in that the first mask (20) is offset relative to the optical axis, in particular in that the first mask (20) is positioned on an axis (D) passing through the light source (2.1) and an edge (12) of the lens.

7. Lighting device (1) according to one of the preceding claims, characterized in that the distance (Dl) between the first mask (20) and the light source (2.1) is strictly less than the distance between the first mask (20) and the lens (5.1), preferably the distance between the first mask and the light source is strictly less than 50% of the distance between the first mask and the lens.

8. Lighting device (1) according to one of the preceding claims, characterized in that it further comprises a second mask, distinct from the first mask, positioned on an optical path between the light source (2.1) and the lens (5.1), the second mask being intended to intercept the light rays emitted by the light source and directed directly towards the lens.

9. Lighting device (1) according to one of the preceding claims, characterized in that: - the reflecting surface (4.1) comprises an elliptical shape, the light source (2.1) being positioned at a first focus of the elliptical shape, and / or in that - the lens (5.1) comprises a focus positioned at the reflecting surface (4.1), in particular at a rear edge of the reflecting surface.

10. Lighting device (1) according to one of the preceding claims, characterized in that the reflective surface (4.1) of the light collector (3.1) is configured to reflect the light rays emitted by the light source into a cut-off light beam provided with a projection (C).

Images