A light-emitting module that reflects the illuminated surface of the collector and has a parasitic light shield

Abstract

The present invention relates to a light emitting module (102) comprising a light source (104) capable of emitting a light beam, a concentrator (106) having a reflective surface (102.6), an optical system (110) configured to project a light beam by imaging a portion of the reflective surface (102.6) located behind the light source (104), and a screen (112) located in front of the light source (104) and having a rear surface (112.1) configured to capture light rays (114) emitted forward by the light source (104) and not reflected by the reflective surface (102.6). The screen (112) comprises an end surface (112.2) adjacent to the rear surface (112.1) and facing the reflected light rays (116), the end surface (112.2) being configured to avoid and / or absorb the reflected light rays.

Description

[Technical field]

[0001] The present invention relates to the field of lighting and signalling, more particularly for applications in the motor vehicle field. [Background technology]

[0002] It is a common practice to create an illumination beam with a cut-off using one or more light-emitting modules with a benders. Such light-emitting modules conventionally comprise a collector with a reflecting surface that is a surface of revolution with an elliptical profile. The collector has the shape of a cap in a half-space bounded by a horizontal plane. A light source of the light-emitting diode type, essentially a point source, is located at a first focus of the reflecting surface and emits light in the half-space in the direction of said surface. The light rays are then reflected in a converging manner towards a second focus of the reflecting surface. Another (generally flat) reflecting surface with a cut-off edge at the second focus ensures the upward reflection of the light rays that do not pass exactly through the second focus. These light rays are then refracted towards the bottom of the illumination beam by a thick lens. This reflecting surface is commonly called a "bender" in that it "bends" those light rays (which would otherwise form the upper part of the illumination beam) towards the top of the projection lens. Such a light emitting module has the drawback that it requires high accuracy in the positioning of the benders and the cut-off edges. Moreover, the projection lens must be thick due to its short focal length, which increases its weight and makes it difficult to manufacture (especially in terms of sink marks). Also, the collector has a considerable height and therefore a considerable volume in the height direction.

[0003] WO2020 / 025171A1 discloses a light emitting module, in particular for motor vehicles. The module comprises a light emitting module with a bender, as well as a collector with a reflective surface that collects and reflects the light rays emitted by the light source into a light beam. The light emitting module also comprises a projection optical system, in particular configured to project the light beam by forming an image of the reflective surface of the collector (for example a lens). For this purpose, the projection optical system has a focal point located on the reflective surface, for example at the rear edge of the reflective surface, so as to accurately image (image) the edge and form a sharp cut in the projected light beam. However, certain light rays emitted by the light source and not reflected by the reflective surface of the collector may reach the projection optical system and degrade the projected light beam. For this purpose, a screen is provided that is arranged in front of the light source. However, the screen has some problems, in particular with regard to the influence on the light beam, such as: That is, rays that are reflected by reflective surfaces and strike the screen and are likely to corrupt the photometry of the desired beam, and in particular to produce parasitic rays within the beam. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 025171 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to overcome at least one of the above-mentioned disadvantages in the prior art. [Means for solving the problem]

[0006] The subject of the present invention is a light-emitting module comprising a light source capable of emitting a light beam, a collector having a reflective surface configured to collect and reflect a portion of the light beam, called the reflected light beam, into a reflected light beam along the optical axis of the light-emitting module, an optical system configured to project at least a large portion of the reflected light beam as a projected light beam by imaging a portion of the reflective surface located behind the light source in the general direction of propagation of the reflected light beam along the optical axis, and a screen located in front of the light source in the general direction of propagation of the light beam along the optical axis and having a rear surface configured to capture direct light rays emitted by the light source forward and not reflected by the reflective surface, the screen being notable in that at its free end it comprises an end surface facing the reflected light beam, the end surface being configured to move away from the reflected light beam and / or to absorb a portion of the reflected light beam.

[0007] The invention thus makes it possible to optimize the function of the screen to block the rays emitted directly by the light source, i.e. rays that are not reflected by the reflecting surfaces of the collector and would reach the projection optics and thus degrade the projected light beam (in particular at the cut-off in the case of a cut-off light beam). In fact, this blocking of the direct rays (in particular by absorption or suitable deflection) is performed while preventing the projected light beam from being disturbed in a harmful way.

[0008] Advantageously, the end face is adjacent to the rear face.

[0009] The projected light beam may have a (preferably horizontal) cut-off line, and the present invention is particularly advantageous for such beams, since it reduces or even eliminates parasitic, dazzling rays.

[0010] The collector may have a trailing edge where the profile projected by the optics forms the cutoff, eliminating the need for a mask and in particular a benders to create the cutoff line.

[0011] Advantageously, the optical system (particularly behind the light source) can have a focal point located on the reflective surface of the collector, which makes it possible to simply image the portion of the reflective surface located behind the light source.

[0012] More advantageously, the focal spot may be located on the rear edge of the reflective surface.

[0013] In general, this focal site may be a point focal (also called a "foyer") or a ligne focale (also called a "ligne de foyers").

[0014] The optical system may comprise a lens or one or more mirrors whose own focal point is the focal point of the optical system.

[0015] Advantageous, but non-limiting, embodiments of the present invention are described below, one or more of which may be combined with one another.

[0016] The concentrator may be a concave reflector.

[0017] At least some of these reflected rays have an inclination angle with respect to the optical axis of less than 10°, which makes it possible to reach the so-called Gaussian condition and thus to achieve stigmation.

[0018] According to an advantageous embodiment of the invention, the edge face of the screen may have a length of less than 1 mm in the general propagation direction of the light beam along the optical axis, making it possible to avoid reflected rays.

[0019] According to an advantageous embodiment of the invention, the edge of the screen may be angled away from the nearest reflected ray, which is a simple way to create a screen with minimal obstruction to the reflected ray.

[0020] Advantageously, the reflected light ray may have an inclination relative to the optical axis, and the inclination of the edge of the screen relative to the optical axis may be greater than the inclination of the reflected light ray closest to the edge, or even directly adjacent to the edge, and may move away from the reflected light ray.

[0021] The end face may be an inclined face facing the optical system, in particular it may join the rear face at an acute angle to form a ridge, which makes it possible to further reduce the risk of blocking the reflected beam.

[0022] In particular, the ridge may be configured such that at the ridge, the lowest ray of the reflected beam grazes the ridge, while other reflected rays pass above it. Thus, the blocking function is optimized by obstructing the reflected light beam as little (or even slightly) as possible, and the projected beam is optimized.

[0023] According to an advantageous embodiment of the invention, the optical system has a focal spot located behind the light source on a reflecting surface of the collector.

[0024] According to an advantageous embodiment of the invention, the edge of the screen may have a reflectance of less than 0.3 in the visible light spectrum, this characteristic being applicable especially to the edge when it is not tilted.

[0025] According to an advantageous embodiment of the invention, the screen faces a reflective surface.

[0026] According to an advantageous embodiment of the invention, the screen extends transversely to the optical axis from the plate supporting the light source. By way of example, the screen may be a separate component from the plate. Alternatively, the screen may be an integral part of the plate.

[0027] According to one advantageous embodiment of the invention, the screen is an extension of a heat sink for cooling the light source, said heat sink being located on the face of the plate facing away from the light source.

[0028] According to an advantageous embodiment of the invention, the screen is a first screen located on the same side of the optical axis as the light source, and the light-emitting module comprises a second screen with a rear surface located on the opposite side of the optical axis and in front of the reflective surface, the rear surface of the second screen being configured to capture direct light rays emitted forward by the light source and which, without being reflected by the reflective surface, pass near the edge surface of the first screen, between said edge surface and the reflective surface.

[0029] According to an advantageous embodiment of the invention, the second screen comprises an edge face at its free end facing the reflected light rays, which edge face is arranged to move away from the reflected light rays, to absorb said reflected light rays and / or to reflect said reflected light rays towards the lower half of the reflected light beam. Advantageously, the edge face of the second screen is adjacent to the rear face of the second screen.

[0030] According to an advantageous embodiment of the invention, the edge of the second screen has an inclination with respect to the nearest reflected ray so as to move away from said ray.

[0031] Advantageously, the reflected ray has an inclination relative to the optical axis, and the inclination of the edge of the second screen relative to the optical axis is greater than the inclination of the reflected ray directly adjacent to that edge, so as to move away from the reflected ray.

[0032] According to an advantageous embodiment of the invention, the edge of the secondary screen has a reflectance of less than 0.3 in the visible light spectrum, this characteristic being particularly applicable to the edge of the secondary screen when said edge is not tilted.

[0033] According to one embodiment of the present invention, the edge of the secondary screen has a reflectance of approximately 0.9 in the visible light spectrum, where "approximately" means consistent within ±10%.

[0034] According to an advantageous embodiment of the invention, the edge of the second screen has a convex curvature capable of reflecting the reflected light rays towards the lower half of the light beam.

[0035] According to an advantageous embodiment of the invention, the second screen is located in front of the reflective surface of the collector.

[0036] According to an advantageous embodiment of the invention, the second screen is supported by the collector, for example the second screen may be formed integrally with the collector.

[0037] The invention also relates to a headlamp of a motor vehicle, comprising a light emitting module according to the invention.

[0038] The inventive solution is advantageous in that it makes it possible in an effective and simple way to prevent the projection light beam from being disturbed by parasitic rays, in particular by providing a screen with edge faces that are specially dimensioned and / or configured to prevent light rays reflected by the reflective surface from being parasitic back into the projection light beam.

[0039] Furthermore, by providing a second screen on the opposite side of the optical axis of the light emitting module to the first screen, it is possible to control the portion of the light beam emitted forward by the light source that is not reflected by the reflective surface. [Brief description of the drawings]

[0040] [Figure 1] 1 is a schematic representation of a light emitting module according to a first embodiment of the invention in a side view. [Diagram 2] FIG. 2 is a perspective view of a concentrator in the light emitting module of FIG. 1; [Diagram 3]2 is a view of the inner surface of the collector of the light emitting module of FIG. 1, viewed from the outside along the optical axis. [Figure 4] 2 is a schematic representation of a light image of an illumination beam produced by the light emitting module of FIG. 1; [Diagram 5] 5 is a schematic representation of a light emitting module according to a second embodiment of the invention in a side view. [Figure 6] 6 is a schematic representation in a side view of a modified example of the light emitting module according to the second embodiment of the present invention in FIG. 5. [Figure 7] 5 is a schematic representation of a light emitting module according to a third embodiment of the invention in a side view. [Figure 8] 8 is a diagram showing the inclination of an edge surface of a screen according to a third embodiment of the present invention, corresponding to FIG. 7; [Figure 9] 5 is a schematic representation of a light emitting module according to a fourth embodiment of the present invention in a side view. [Figure 10] 5 is a schematic representation of a light emitting module according to a fifth embodiment of the present invention in a side view. [Figure 11] 5 is a schematic representation in plan view of a light emitting module according to a fifth embodiment of the invention, but which may also apply to each of the other embodiments of the invention. [Figure 12] 1 is a perspective representation of an embodiment of a screen having angled edges and integrally formed with a heat sink; [Figure 13] 13 is a perspective representation of an embodiment of a screen integrally formed with a heat sink having more angled edges. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] 1 to 4 show a first embodiment of a light emitting module according to the present invention.

[0042] 1 is a schematic representation of the light emitting module in a side view and its working principle. The light emitting module 2 essentially comprises a light source 4, a collector 6 capable of reflecting the light rays emitted by the light source 4 to form a light beam along an optical axis 8 of the light emitting module, and a lens 10 for projecting said beam. The optical axis 8 of the light emitting module coincides with the optical axis of the projection lens 10. Projection optics other than a projection lens are conceivable, in particular one or more reflectors, etc.

[0043] Here, as generally according to the invention, the light source 4 is advantageously of the semiconductor type, in particular a light-emitting diode or the like. The light source 4 in particular emits a light beam in a main direction perpendicular to its main surface and to the optical axis 8, within a half-space bounded by said surface. According to the invention, the main direction of emission can be between 65° and 115° to the optical axis 8.

[0044] The collector 6 comprises a body 6.1 in the form of a shell or cap and a reflective surface 6.2 on the inner surface of the body 6.1. The reflective surface 6.2 can advantageously have an elliptical or parabolic profile. The surface is advantageously a surface of revolution about an axis parallel to the optical axis. Alternatively, it may be a free-form surface. The surface may also comprise several portions. The collector 6 in the form of a shell or cap is advantageously made of a material with good heat resistance, for example glass or synthetic polymers such as polycarbonate (PC) or polyetherimide (PEI).

[0045] The expression "parabolic" generally applies to reflectors whose surface has a single focal point, i.e. a single point where light rays converge (where light rays emitted by a light source located at this point of convergence are projected over a long distance after being reflected from the surface). Projected over a long distance means that these rays do not converge towards a point located at least ten times the dimension of the reflector. In other words, the reflected light rays do not converge towards a single point of convergence or, if they do, this point of convergence is located at a distance of ten times the dimension of the reflector or more. A parabolic surface may therefore have or not have a parabolic part. Reflectors with such surfaces are in particular used to create a light beam by themselves.

[0046] The light source 4 is arranged at the focus of the reflecting surface 6.2 so that its light rays are collected and reflected as a reflected light beam along the optical axis. At least some of these reflected light rays have an inclination angle α of less than 10° with respect to said optical axis, such that they are under the so-called Gaussian condition, which makes it possible to obtain astigmatism (i.e. sharpness of the projected image). It is advantageous for the light rays to be reflected by the rear part of the reflecting surface 6.2.

[0047] The projection lens 10 is advantageously a plano-convex lens, i.e. with a flat entrance surface 10.1 and a convex exit surface 10.2. The lens 10 is considered thin (for example less than 6 mm) due to the gentle slope of the light rays to be deflected. The lens 10 has a focal point 10.3 located at or behind the light source 4 along the optical axis 8. In this case, the focal point 10.3 is located on the reflecting surface 6.2 of the collector 6, more precisely at its rear edge (which in this case is also the lower edge).

[0048] The reflecting surface, if it is elliptical, has a second focal point 6.3 located in front of the lens 10 and far away from the optical axis 8. It should be noted that this focal point can also be located behind the lens and / or on the optical axis (preferably closer to the lens) to reduce the width of the beam on the entrance face of the lens.

[0049] The light-emitting module 2 comprises a screen 12 arranged in front of the light source 4 and facing the reflecting surface 6.2 of the collector 6. The screen 12 has a rear surface 12.1 capable of absorbing direct light rays 14 emitted directly forward by the light source 4 in question, i.e. not hitting the reflecting surface 6.2. Such a measure is useful to avoid the presence of parasitic rays that would participate in the formation of the light beam (but without being imaged, strictly speaking). These direct light rays 14 (especially those parallel or somewhat parallel to the optical axis 8) could then illuminate the upper part of the light beam, which is undesirable in the case of a cut-off illumination beam.

[0050] The rear surface 12.1 of the screen 12 is advantageously opaque and non-reflective in order to absorb the direct light rays 14 emitted directly forward by the light source 4. It should be understood that it is also conceivable to make said surface reflective in order to reflect these light rays towards absorbing sites.

[0051] The screen 12 extends in a transverse main direction, which is advantageously perpendicular to the optical axis 8. It has an end face 12.2 facing the light rays 16 reflected by the reflecting surface 6.2. The end face 12.2 is adjacent to the rear face 12.1. In FIG. 1, among the light rays 16 reflected by the reflecting surface 6.2, the nearest rays directly adjacent to the end face 12.2 are only slightly hindered by said face, thanks to the narrow width of said face along the direction of the optical axis 8. The reflected light rays 16 incident on this end face 12.2 are absorbed, reflected or a combination of the two, depending on the optical reflectivity properties of the face. The luminous flux associated with these rays is reduced so that the portion of these reflected rays is negligible. For this purpose, the width of the end face 12.2 is advantageously less than 1 mm.

[0052] In practice, such a thin screen 12 (in the form of a blade) can be made from a piece of sheet metal the thickness of which constitutes the width of the screen 12 .

[0053] Figure 2 is a rear perspective view of the collector 6 of the light emitting module 2 of Figure 1. One can see the shape of the shell or cap of the body 6.1 and the fact that the reflective surface (not shown) has a front edge 6.2.1 and a rear edge 6.2.2. Consider that the body 6.1 and therefore the reflective surface 6.2 form a (in particular, generally rotationally symmetric) shell. This shell is bounded by a plane, which includes part of the rear edge 6.2.2. The rear edge extends to the left and right on either side of the axis of rotation. When the reflective surface 6.2 is illuminated by a light source, the entire surface is illuminated, which is bounded by the front edge 6.2.1 and the rear edge 6.2.2.

[0054] Figure 3 represents the light intensity on the reflecting surface 6.2 as viewed from the outside along the optical axis. In particular, the illuminance of the surface, i.e. the number of W / m2 of electromagnetic radiation incident perpendicular to the direction of the surface, is given by 2The power per unit area is expressed as λ / 2. The area 6.2.3 covering most of the surface corresponds to a lower illuminance, whereas the central area 6.2.4 corresponds to a higher illuminance. It can be seen that the area 6.2.3 is clearly delimited by the edges 6.2.1 and 6.2.2. In other words, the illuminated surface 6.2 inherently has sharp edges that can form a cut-off in the projection illumination beam that images this surface.

[0055] FIG. 4 is a schematic representation of an image projected by the light-emitting module of FIG. 1 (in particular on a vertical screen located 25 meters from the light-emitting module). A horizontal axis intersects with a vertical axis on the optical axis of the light-emitting module. Each curve is an isolux curve, i.e. a curve corresponding to a portion of the light beam with the same illuminance, expressed in lux. The central curve corresponds to a higher illuminance level than the periphery. It can be seen that the light beam produced has a horizontal cut-off that is essentially on the horizontal axis (slightly, in particular only 1 degree below). The cut-off is practically straight. In any case the horizontal cut-off is produced by the edge 6.2.2 (FIG. 3), which is the rear edge (FIG. 2) of the reflecting surface 6.2 of the collector 6.

[0056] Fig. 5 is a schematic representation in side view of a light emitting module according to a second embodiment of the invention. The reference numerals of the first embodiment of the light emitting module (Figs. 1 to 4) are used to indicate the same or corresponding elements, but these numerals are increased by 100. Also, the description of these elements with respect to Figs. 1 to 4 is incorporated by reference.

[0057] The second embodiment is similar to the first embodiment and differs from it essentially in that the screen 112 is three-dimensional, i.e. it does not form a thin blade like the screen 12 of FIG. 1. Taking into account the three-dimensional nature of the screen 112, the edge 112.2 has a length along the optical axis 108 sufficient for the reflection of the reflected light ray 116 from said edge 112.2 to disturb the reflected light beam (and therefore the projected light beam). For this reason, the edge 112.2 is inclined more towards the optical system with respect to the optical axis 108 than the directly adjacent reflected light ray 116, so as to avoid said light ray. In this way, only the rear surface 112.1 of the screen 112 captures the direct light ray 114 emitted directly forward by the light source 104.

[0058] As can be seen, the light source 104 is arranged on a plate 118 which may also support the screen 112. This approach can be applied to the other embodiments, especially the first embodiment.

[0059] As can also be seen in Fig. 5, the projection lens 110 is of the biconvex type, i.e. each of the light entrance surface 110.1 and the light exit surface 110.2 is convex. It should be understood that the plano-convex lens of the first embodiment can be applied to this second embodiment and vice versa.

[0060] Figure 6 shows a variant of the second embodiment of figure 5. According to this variant, the screen 112' is integrally formed with a heat sink 120 for cooling the light source 104. The heat sink 120 is arranged below the plate 118', i.e. on one of its two main faces (the one opposite to the other one supporting the light source 104). In this case, the plate 118' has an opening through which the screen 112' extends. It should be understood, however, that the screen 112' can also extend in front of the plate 118'.

[0061] Generally according to the invention, the plate 118' can be, as in this case, a printed circuit board carrying the light source, which can also be mounted directly on the heat sink and connected to the printed circuit board by tracks (in particular wire bonds).

[0062] 7 is a schematic representation in side view of a light emitting module according to a third embodiment of the invention. The reference numerals of the second embodiment of the light emitting module (FIG. 5) are used to indicate the same or corresponding elements, but these numerals are increased by 100. Also, the description of these elements in the context of the second embodiment is incorporated by reference.

[0063] The light emitting module 202 according to this third embodiment comprises a second screen 222, which is placed separately from the first screen 212 on the opposite side of the optical axis 208 to the side on which the first screen 212 is located. The second screen 222 is arranged to block the light rays 214.2, which are emitted forward by the light source and which have passed the first screen 212 without being reflected by a reflective surface. For this purpose, the second screen 222 comprises a rear face 222.1 which captures these light rays 214.2. Like the first screen 212, the second screen 222 extends in a lateral main direction, which is advantageously perpendicular to the optical axis 208. It has an end face 222.2 facing the light rays 216 reflected by the reflective surface 206.2 of the collector 206. This edge 222.2 is directly adjacent to the rear face 222.1. It is tilted more with respect to the optical axis 208 than the most recent reflected rays 216 (i.e. the reflected rays directly adjacent to the face in question) in order to avoid these rays. In other words, these rays pass beside the ridge formed by the intersection of the rear face 222.1 with the edge 222.2 without hitting the edge 222.2. These rays are thus not deflected. Only the direct rays 214.2 emitted directly forward by the light source and hitting the rear face 222.1 of the second screen are blocked by absorption, reflection or a combination of the two.

[0064] FIG. 8 essentially corresponds to FIG. 7 (ie a schematic representation in side view of a light emitting module according to a third embodiment of the invention) and shows the inclination of the respective edge faces of the first and second screens 212 and 222.

[0065] It can be seen that the light ray 216 reflected by the reflecting surface 206.2 of the collector 306 has angles of inclination α1 and α2 with respect to the optical axis 208. The angle α1 is for the ray passing below the optical axis 208 and the angle α2 is for the ray passing above the optical axis 208. The edge face 212.2 of the first screen 212 located below the optical axis 208 is inclined by an angle β1>α1. Similarly, the edge face 222.2 of the second screen 222 located above the optical axis 208 is inclined by an angle β2>α2. The inclinations for the two edge faces 212.2 and 222.2 are considered with respect to the ridge line corresponding to the intersection of the rear face 212.1 or 222.1 with the edge face 212.2 or 222.2. In other words, the slopes β1 and β2 of end faces 212.1 and 222.1, respectively, are such that each end face moves progressively further away (moving away from the ridge in the direction of propagation of reflected ray 216) from the reflected ray 216 passing directly beside the ridge formed by the intersection of rear face 212.1 or 222.1 with end face 212.2 or 222.2.

[0066] Fig. 9 is a schematic representation in side view of a light emitting module according to a fourth embodiment of the invention. The reference numerals of the third embodiment of the light emitting module (Fig. 7) are used to indicate the same or corresponding elements, but these numerals are increased by 100. Also, the description of these elements in the context of the third embodiment is incorporated by reference.

[0067] The light emitting module 302 according to the fourth embodiment essentially differs from the third embodiment in that the edge faces 312.2 and 322.2 of the first and second screens 312 and 322, respectively, are not tilted relative to the reflected light ray 316 passing near the edge faces, but have light absorbing properties represented by a reflectance of 30% (preferably 20%, and even more preferably 10%) or less for visible light. This means that the reflected light ray 316 from both ends of the light beam directed towards the lens 310 that strikes the edge faces 312.2 and 322.2 is at least largely absorbed. If there is reflection, it is slight and negligible.

[0068] Fig. 10 is a schematic representation in side view of a light emitting module according to a fifth embodiment of the invention. The reference numerals of the fourth embodiment of the light emitting module (Fig. 9) are used to indicate the same or corresponding elements, but these numerals are increased by 100. Also, the description of these elements in the context of the fourth embodiment is incorporated by reference.

[0069] The light emitting module 402 according to the fifth embodiment essentially differs from the fourth embodiment in that the edge face 422.2 of the second screen 422 is rounded and reflective.

[0070] As can be seen in Fig. 10, the direct light rays 414.2 that strike the edge 422.2 are reflected towards the lower part of the projection lens 410 (in this case the lower half). The inclination of the reflected light rays is such that they end up being projected towards the lower part of the light beam. With reference to Fig. 4, which shows the light image of the illumination beam produced by the light emitting module as in Fig. 1, but also by the light emitting module as in Figs. 5 to 10, the light rays reflected by the edge 422.2 of the second screen would take part in the formation of a light image that, if projected by the projection lens 410, would be far from the horizontal cut-off edge. These light rays therefore do not significantly interfere with the light image produced. This measure additionally makes it possible to optimise the light output by recovering light that would otherwise have been lost. The reflective properties of the edge can be easily obtained if the screen is made of an inherently reflective material, such as aluminium.

[0071] FIG. 11 is a schematic representation in plan view of a light emitting module according to a fifth embodiment of the invention but which may apply to each of the different embodiments of the invention.

[0072] It can be seen that the first screen 412 has a limited width in the direction perpendicular to the optical axis 408, determined by the light beam formed by the light ray 414 emitted directly forward by the light source 404 and likely to strike the lens 410. It can also be seen that the second screen 422 has a width, which is greater than the width of the first screen 412 in the direction perpendicular to the optical axis 408, determined by the light beam formed by the light ray 416 reflected by the reflective surface 406.2 of the collector 406 and likely to strike the lens 410. For this purpose, the second screen 422 can have a curved profile in the plane viewed in FIG. 11. In this case, the rear surface 422.1 of the second screen has a concavely curved profile.

[0073] FIG. 12 is a perspective representation of an embodiment of a screen having angled edges and integrally formed with a heat sink, as in the second embodiment of FIGS.

[0074] Figure 12 shows a plate 118 supporting a number of light sources 104 and a screen 112 placed in front of each light source 104. In this case, the screen 112 is integrally formed with a heat sink made of a thermally conductive material such as aluminum or certain plastic materials. The geometry of the screen 112, located in the center of the figure, is schematized by an inverted U-shaped enclosure. The tilt at angle β1 can be seen.

[0075] FIG. 13 is a perspective representation of an embodiment (as an alternative to FIG. 12) of a screen having angled edges and integrally formed with a heat sink, as in the second embodiment of FIGS. 5 and 6.

[0076] It can be seen that edge 112.2 has a larger inclination angle β1 than in Figure 13. Also, unlike Figure 13 where the screen has a separate front surface, edge 112.2 merges with the front surface of the screen.

[0077] Generally, the various light emitting modules described above can be combined with other light emitting modules to be integrated into a lighting device. Also, for reasons of clarity of description, the light source and the collector are shown as being separate. However, a certain light emitting module according to the invention may comprise multiple light sources and / or multiple collectors, in particular multiple collectors arranged side by side, each having a light source and an associated screen.

Claims

1. A light emitting module, a light source capable of emitting a light beam; a collector having a reflective surface adapted to collect and reflect a portion of said light ray, called the reflected light ray, into a reflected light beam along the optical axis of the light emitting module; an optical system configured to project at least a major portion of the reflected light beam as a projected light beam by imaging a portion of the reflecting surface that is located behind the light source in the general direction of propagation of the reflected light beam along the optical axis; a screen located in front of the light source in the general direction of propagation of the reflected light beam along the optical axis and having a rear surface adapted to capture direct light rays emitted forward by the light source and not reflected by the reflective surface; A light emitting module comprising: the screen comprises an edge surface at a free end of the screen facing the reflected light beam, the edge surface being configured to move away from the reflected light beam and / or to absorb a portion of the reflected light beam, the screen extends from a plate supporting the light source in a direction transverse to the optical axis; the screen is an extension of a heat sink for cooling the light source, the heat sink being located on a surface of the plate opposite the light source; The plate has an opening through which the screen extends.

2. A light emitting module, a light source capable of emitting a light beam; a collector having a reflective surface adapted to collect and reflect a portion of said light ray, called the reflected light ray, into a reflected light beam along the optical axis of the light emitting module; an optical system configured to project at least a major portion of the reflected light beam as a projected light beam by imaging a portion of the reflecting surface that is located behind the light source in the general direction of propagation of the reflected light beam along the optical axis; a screen located in front of the light source in the general direction of propagation of the reflected light beam along the optical axis and having a rear surface adapted to capture direct light rays emitted forward by the light source and not reflected by the reflective surface; A light emitting module comprising: the screen has an end surface at a free end of the screen facing the reflected light beam, the end surface being configured to face away from the reflected light beam; the screen extends from a plate supporting the light source in a direction transverse to the optical axis; the screen is an extension of a heat sink for cooling the light source, the heat sink being located on a surface of the plate opposite the light source; The screen extends forward of the plate. Light emitting module.

3. A light emitting module, a light source capable of emitting a light beam; a collector having a reflective surface adapted to collect and reflect a portion of said light ray, called the reflected light ray, into a reflected light beam along the optical axis of the light emitting module; an optical system configured to project at least a major portion of the reflected light beam as a projected light beam by imaging a portion of the reflecting surface that is located behind the light source in the general direction of propagation of the reflected light beam along the optical axis; a screen located in front of the light source in the general direction of propagation of the reflected light beam along the optical axis and having a rear surface adapted to capture direct light rays emitted forward by the light source and not reflected by the reflective surface; A light emitting module comprising: the screen comprises an edge surface at a free end of the screen facing the reflected light beam, the edge surface being configured to move away from the reflected light beam and / or to absorb a portion of the reflected light beam, the screen extends from a plate supporting the light source in a direction transverse to the optical axis; The plate supports both the light source and the screen, the plate being a printed circuit board.

4. 4. The light emitting module according to claim 1, wherein the edge of the screen has a length of less than 1 mm in the overall propagation direction of the reflected light beam along the optical axis, making it possible to avoid the reflected light rays.

5. 5. The light emitting module according to claim 1, wherein the reflected light ray has an inclination relative to the optical axis, and the edge of the screen has an inclination relative to the optical axis that is greater than the inclination of the reflected light ray adjacent to the edge, so as to move away from the reflected light ray.

6. 6. A light emitting module according to claim 1, wherein the optical system has a focal spot located on the reflective surface of the collector behind the light source.

7. 7. A light emitting module according to claim 1, wherein the edge of the screen has a reflectance of less than 0.3 in the visible light spectrum.

8. 8. A lighting module according to claim 1, wherein the screen faces the reflective surface.

9. 9. The light emitting module according to claim 1, wherein the screen is a first screen located on the same side of the optical axis as the light source, and the light emitting module comprises a second screen having a rear surface located on the opposite side of the optical axis in front of the reflective surface, the rear surface of the second screen being configured to capture direct light emitted forward by the light source and passing near the edge of the first screen between this edge and the reflective surface without being reflected by the reflective surface.

10. 10. The light emitting module of claim 9, wherein the second screen has an end surface at a free end thereof facing the reflected light beam, the end surface being configured to move away from the reflected light beam, to absorb the reflected light beam, and / or to reflect the reflected light beam towards a lower half of the reflected light beam.

11. 11. The light-emitting module of claim 10, wherein the reflected light ray has an inclination relative to the optical axis, and the edge of the second screen has an inclination relative to the optical axis that is greater than the inclination of the reflected light ray adjacent to the edge, so as to move away from the reflected light ray.

12. 11. The light emitting module of claim 10, wherein the edge of the second screen has a reflectance of less than 0.3 in the visible light spectrum.

13. 11. The light emitting module according to claim 10, wherein the edge surface of the second screen has a convex curvature capable of reflecting the reflected light ray towards a lower half of the reflected light beam.

14. 14. A light emitting module according to any one of claims 9 to 13, wherein the secondary screen (12) is located in front of the reflective surface (14) of the collector (12).

15. 15. A light emitting module according to any one of claims 9 to 14, wherein the second screen is supported by the concentrator.

16. A headlamp for a vehicle, comprising a light emitting module according to any one of the preceding claims.

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