This application claims the benefit of French application Serial No. 1902618 filed Mar. 14, 2019, the disclosure of which is hereby incorporated in its entirety by reference herein.
The invention relates to the field of luminous lighting and signaling field, and more particularly to the motor vehicle.
Published patent document FR 3 047 541 A1 discloses a lighting device comprising two optical modules placed on opposing sides. Each of these two optical modules essentially comprises a light source and a collector with a reflective surface. These two light sources are placed on two opposite faces of a common carrier. Each of the reflective surfaces is a surface of revolution in a half-space bounded by the common carrier of the light sources. The two reflective surfaces thus form two half-shells opposite each other. One of the two optical modules is configured to form a lighting beam containing a flat cut-off, corresponding to a so-called low beam. To do this, the device comprises a reflective surface with an edge referred to as the “cut-off” edge, said edge being located at a focal point of the reflective surface. The rays that encounter the surface in question behind the cut-off edge are reflected toward an upper portion of a projecting lens whereas those that pass in front of the edge in question are not deviated and encounter a lower portion of the lens in-question. This effect ensures an essentially flat cut-off of the beam. The other of the two optical modules essentially works in the same way, with the sole exception that the focal point of the reflective surface is located in front of the cut-off edge. The beam produced by the second optical module is combined with that of the first system to produce a high beam, i.e. a beam without a flat cut-off. This configuration is advantageous in that it exploits the cut-off-containing beam to produce a high beam.
Such a luminous device has the drawback of requiring a high precision in the positioning of the deflector and of the cut-off edge. Thus, the projecting lens must be a thick lens because of its small focal length, which has the effect of increasing its weight and complicating the production thereof. In particular, with regard to sink marks. In addition, the collector has a certain height. Thus, has a certain heightwise bulk.
The objective of the invention is to mitigate at least one of the drawbacks of the aforementioned prior art. More particularly, the objective of the invention is to provide a luminous device that is able to perform a plurality of lighting and/or signaling functions that is compact and that is more economical to produce.
The subject of the invention is a luminous device, in particular for a motor vehicle, comprising: a first light source and a second light source that are each able to emit light rays; a first collector and a second collector each with a reflective surface configured to collect and reflect the light rays emitted by the first light source and the second light source, respectively; an optical system configured to project the rays reflected by the reflective surfaces of the first collector and of the second collector, respectively, into a first light beam and a second light beam along an optical axis of the device; noteworthy in that the optical system is configured to form a luminous image of the reflective surface of each of the first collector and second collector, and each of the first light beam and second light beam forms a portion or the entirety of a lighting or signaling function that is distinct from the lighting or signaling function of the other of said first and second beams.
The luminous device forms a stand-alone assembly in that each of the components thereof, such as for example the light sources, the collectors and the optical system, is rigidly fastened to the other components, in particular via a specific carrier (not detailed), and is thus optically positioned with respect to the other components. One or more luminous devices may thus be placed in a headlamp casing in order to perform, where appropriate in combination, all the required regulatory lighting and signaling functions.
Advantageously, the first collector and the first light source are placed, with respect to the second collector and to the second light source, so that the luminous image of the reflective surface of the first collector is inverted, with respect to the optical axis, versus the luminous image of the reflective surface of the second collector.
According to one advantageous embodiment of the invention, at least one of the first collector and second collector is configured so that the light rays reflected by a rear portion of the reflective surface of said collector are parallel to the optical axis or have, in a vertical plane with respect to said axis, an angle of inclination smaller than or equal to 25°, and preferably an angle of inclination smaller than or equal to 10°.
According to one advantageous embodiment of the invention, the first light source and second light source are configured to emit in a main direction that is perpendicular to the optical axis or that is inclined with respect to a direction perpendicular to said optical axis by an angle smaller than or equal to 25°. Advantageously, the reflective surfaces of the first collector and second collector have an elliptical or parabolic profile. Preferably, it is a surface of revolution of said profile. The revolution is about an axis that advantageously is parallel to the optical axis. According to one variant, the reflective surface is a free-form surface or a swept surface or an asymmetric surface. It may also comprise a plurality of segments.
According to one advantageous embodiment of the invention, the optical system has a first focal point located axially behind a front limit of the reflective surface of the first collector, and/or a second focal point located axially behind a front limit of the reflective surface of the second collector.
According to one advantageous embodiment of the invention, the optical system is a lens with a first entrance face for the first light beam and a second entrance face for the second light beam.
According to one advantageous embodiment of the invention, the first and second entrance faces are aligned perpendicular to the optical axis.
According to one advantageous embodiment of the invention, the lens has an exit face common to the first and second entrance faces.
According to one advantageous embodiment of the invention, the first collector and the first light source are opposite, with respect to the optical axis, to the second collector and to the second light source, respectively; or the first collector and the first light source, on the one hand, and the second collector and the second light source, on the other hand, are placed side-by-side.
According to one advantageous embodiment of the invention, the reflective surface of at least one of the first collector and second collector is concave and has, with respect to a general direction of propagation of the corresponding light beam, a front edge and a rear edge, said edges bounding in opposite directions the corresponding luminous image.
According to one advantageous embodiment of the invention, the first collector and the first light source are located above the optical axis when the device is oriented in functional position, the first beam being a lighting beam containing an upper flat cut-off formed by the rear edge of the reflective surface of the first collector.
According to one advantageous embodiment of the invention, said luminous device furthermore comprises a mirror configured to form a virtual image of at least one of the first and second light sources and of the reflective surface of the corresponding first collector and/or second collector.
According to one advantageous embodiment of the invention, the mirror lies in the extension of the reflective surface of the corresponding collector, or the mirror lies on the optical axis.
According to one advantageous embodiment of the invention, the first collector and the first light source are located below the optical axis when the device is oriented in functional position, the first beam being a lighting beam containing an upper flat cut-off formed by the rear edge of the reflective surface of the first collector.
According to one advantageous embodiment of the invention, the second collector and the second light source are located above the optical axis when the device is oriented in functional position, the second beam being a lighting beam with an upper portion without flat cut-off, formed by a front portion of the reflective surface of the second collector.
According to one advantageous embodiment of the invention, the first light beam is a lighting beam with or without an upper flat cut-off and the second beam is a signaling beam, the optical system comprising a grained dioptric interface configured to scatter the second light beam.
According to one advantageous embodiment of the invention, the grained dioptric interface is formed on the second entrance face.
According to one advantageous embodiment of the invention, the lens is a main lens, the optical system comprising an intermediate lens with the grained dioptric interface, said lens being placed optically between the reflective surface of the second collector and the main lens.
According to one advantageous embodiment of the invention, the first light source and the second light source are placed on a common platen.
The measures of the invention are advantageous in that they allow all or some of a plurality of distinct lighting or signaling functions to be performed with the same device having the advantages of compactness and of ease of assembly in that the precision required to align the various components is lower than in the prior art. More particularly, producing an image of each of the illuminated reflective surfaces is advantageous on account of the fact that these images contain a concentration of light in proximity to the rear edge of these reflective surfaces, thus allowing the light to be concentrated on the flat axis.
Other features and advantages of the present invention will be better understood by virtue of the description and the drawings.
In the following description the notions of “above” and “below” the optical axis are to be understood with respect to the luminous device when it is in functional position, i.e. with an orientation that corresponds to that for which it was designed. Similarly, the notions “front” and “rear” are to be understood with respect to the general direction of the light, along the optical axis of the luminous device, when the luminous device is in functional position.
The light sources 4 and 14 are advantageously semiconductor light sources, and in particular light-emitting diodes. Each of the light sources 4 and 14 emits light rays in a half-space bounded by the main plane of said source, in the shown example in a main direction perpendicular to said plane and to the optical axis 8. According to the invention, the main direction of emission will possibly be inclined with respect to a direction perpendicular to the optical axis by an angle smaller than or equal to 25°.
Each of the collectors 6 and 16 comprises a carrier 6.1 and 16.1, of shell or cap shape, and a reflective surface 6.2 and 16.2 on the interior face of the carrier 6.1 and 16.1. The reflective surfaces 6.2 and 16.2 advantageously have an elliptical or parabolic profile. At least one thereof is advantageously a surface of revolution about an axis parallel to the optical axis. Alternatively, it may be a question of a free-form surface or a swept surface or an asymmetric surface. It may also comprise a plurality of segments. The shell- or cap-shaped collectors 6 and 16 are advantageously made from materials having a good heat resistance, for example of glass or of synthetic polymers such as polycarbonate PC or polyetherimide PEI. The expression “parabolic” generally applies to reflectors the surface of which has a single focal point, i.e. one region of convergence of the light rays, i.e. one region such that the light rays emitted by a light source placed in this region of convergence are projected to great distance after reflection from the surface. Projected to great distance means that these light rays do not converge toward a region located at at least 10 times the dimensions of the reflector. In other words, the reflected rays do not converge towards a region of convergence or, if they converge, this region of convergence is located at a distance larger than or equal to 10 times the dimensions of the reflector. A parabolic surface may therefore comprise or not comprise parabolic segments. A reflector having such a surface is generally used alone to create a light beam. Alternatively, it may be used as projecting surface associated with an elliptical reflector. In this case, the light source of the parabolic reflector is the region of convergence of the rays reflected by the elliptical reflector.
Each of the light sources 4 and 14 is placed at a focal point of the corresponding reflective surface 6.2 and 16.2 so that the rays thereof are collected and reflected along the optical axis 8. At least some of these reflected rays have angles of inclination a, in a vertical plane, with respect to said axis, that are smaller than or equal to 25°, and preferably smaller than or equal to 10°, so as to be under so-called Gaussian conditions, allowing a stigmatism, i.e. a clearness of the projected image, to be obtained. It is advantageously a question of the rays reflected by the rear portion of the reflective surface 6.2 and 16.2.
The projecting lens 10 has a first entrance face 10.1 for the light rays corresponding to the first light beam 12, a second entrance face 10.2 for the light rays corresponding to the second light beam 18, a first exit face 10.3 for the first light beam 12 and a second exit face 10.4 for the second light beam 18. The first and second exit faces 10.3 and 10.4 advantageously form an exit face common to the two entrance faces 10.1 and 10.2. The lens 10 is said to be thin, for example with a thickness, along the optical axis of the device, that is smaller than 7 mm, in particular because of the small lens height and the long focal length thereof. The lens 10 may have a first focal point 10.5 and a second focal point 10.6, the first focal point 10.5 corresponding to the upper portion of the lens 10 and the second focal point 10.6 corresponding to the lower portion of the lens 10. Each of the first and second focal points 10.5 and 10.6 in question is advantageously located in a region 6.3/16.3 located between the reflective surface 6.2/16.2 of the corresponding first or second collector 6/16 and the corresponding first or second light source 4/14 (these regions have been shown with dashed lines). In the present case, at least one of the focal points may be located on the reflective surface 6.2/16.2 of the corresponding first or second collector 6/16. It will be noted that it is also possible for this focal point to be located behind or in front of the reflective surface 6.2/16.2 provided that it is in proximity, and preferably within less than 10 mm, and preferably less than 5 mm, thereto.
The reflective surface, if it is elliptical, has a second focal point located in front of the lens 10 and at distance from the optical axis 8. It will be noted that it is also possible for this focal point to be located behind the lens and/or on the optical axis, provided that it is in proximity to the lens, so as to decrease the width of the beam on the entrance face of the lens.
Again with reference to
The luminous device advantageously comprises an absorbing screen 26 that lies on the optical axis 8, which is located between the first and second collectors 6 and 16 and the lens 10, so as to absorb any light rays that encounter it and thus prevent parasitic reflections.
Again with reference to
It may be seen in
Again in
In this luminous device 102, the second light source 114 and the second collector 116 are no longer opposite, with respect to the optical axis of the device, to the first light source 104 and to the first collector 106, but instead are located beside the latter light source and collector. The first light source 104 and the first collector 106 are not visible because located behind the second light source 114 and the second collector 116. The luminous device 102 furthermore comprises a mirror 126 placed in the extension of the reflective surface 116.2 of the collector 116. The mirror 126 comprises a carrier 126.1 and a planar reflective surface 126.2 formed on the carrier 126.1. The latter may be merged with or adjacent to the carrier 116.1 of the collector 116. The light source 114 is placed at a focal point of the reflective surface 116.2 of the collector 116 so that the rays thereof are collected and reflected toward the mirror 126. The latter reflects, towards the projecting lens 110, a virtual image 116.2 of the reflective surface 116.2, a virtual image 116 of the second collector 116 and a virtual image 114 of the light source 114, these having been shown with dashed lines in
The lens 110 then comprises two distinct portions for the first and second beams 112 and 118, these two portions being side-by-side and no longer on either side of the optical axis as in the first embodiment. The lens 110 then has a first entrance face 110.1 and a first exit face 110.3 for forming the first beam 112 and a second entrance face 110.2 and a second exit face 110.4 for forming the second beam 118. It will however be noted that the two exit faces 110.3 and 110.4 may form a common exit face as in
It will also be noted that the second portion of the lens, namely the portion with the second entrance and exit faces 110.2 and 110.4, is advantageously biconvex and symmetric with respect to the virtual optical axis 108 (dash-dotted line) located above the optical axis 108. This portion of the lens has a focal point 110.6 located on this virtual axis and in proximity to a rear edge of the reflective surface of the virtual collector. This allows this portion of the lens 110 to image the lit surface of the second collector 116 similarly to the first embodiment of the invention.
The configuration that has just been described is advantageous in particular for applications having constraints on downward bulk.
The first entrance and exit faces 110′.1 and 110′.3 of the lens 110′ may be seen, but the second entrance and exit faces 110′.3 and 110′.4 have not been shown. The first portion of the lens 110′ is then, similarly to the second portion of the lens of
Similarly, the configuration that has just been described is advantageous in particular for applications having constraints on upward bulk.
This third embodiment is similar to the second embodiment (
Similarly to the second embodiment, the lens 210 then comprises two distinct portions for the first and second beams 212 and 218, these two portions being side-by-side and no longer on either side of the optical axis as in the first embodiment. The lens 210 then has a first entrance face 210.1 and a first exit face 210.3 for forming the first beam 212 and a second entrance face 210.2 and a second exit face 210.4 for forming the second beam 218. It will however be noted that the two exit faces 210.3 and 210.4 may form a common exit face as in
It will also be noted that the second portion of the lens, namely the portion with the second entrance and exit faces 210.2 and 210.4, is advantageously biconvex and symmetric with respect to the virtual optical axis (dash-dotted line) located under the optical axis 208. This portion of the lens has a focal point 210.6 located on this virtual axis 208 and in proximity to a rear edge of the reflective surface of the virtual collector. This allows this portion of the lens 210 to image the lit surface of the second collector 216 similarly to the first embodiment of the invention.
The first entrance and exit faces 210′.1 and 210′.3 of the lens 210′ may be seen, but the second entrance and exit faces 210′.3 and 210′.4 have not been shown. The first portion of the lens 210′ is then, similarly to the second portion of the lens of
Similarly, the configuration that has just been described is advantageous in particular for applications having constraints on upward bulk.
The luminous device 302 of
In light of these various embodiments and the variants thereof, it will be understood that various combinations of lighting and/or signaling light beams are possible in a given luminous device. In particular, the number of light sources and of corresponding collectors is not limited to two. Specifically, it is contemplated to provide more light sources and more corresponding collectors. As has already been highlighted with the embodiments described above, the various light beams produced by the various pairs of light sources and of collectors may be juxtaposed and/or superposed. In the variant of the third embodiment, in
Non-exhaustively, the following various combinations are possible in a given luminous device, in particular if a greater number of collectors and of light sources associated with said collectors are provided:
A first light beam taking the form of a first lighting beam containing a flat cut-off forming a portion of a first lighting function, a second light beam taking the form of a second lighting beam with a kinked cut-off forming another portion of the same first lighting function, and a third light beam taking the form of a third lighting beam with no cut-off forming all or some of a second lighting function.
For example, the first lighting beam may be a beam containing a flat cut-off forming a portion of a low-beam function, and the second lighting beam may be a beam with a kinked cut-off, forming a second portion of a low-beam function, the superposition of the first lighting beam and of the second lighting beam forming a low-beam function. The third lighting beam may form one portion of a high-beam function, called the complementary high-beam function and that forms a high-beam function when it is super-imposed with the first and second lighting beams.
Alternatively, the third light beam may be a third lighting beam taking the form of a luminous segment forming one portion of a second lighting function, and the luminous device emits a plurality of supplementary light beams taking the form of luminous segments forming one portion of this second lighting function, each of the luminous segments being selectively activated.
For example, the luminous segments formed by the third lighting beam forms one portion of a high-beam function and the superposition of all of the luminous segments formed by the third lighting beam and by the supplementary light beams with the first and second lighting beams forms a high-beam function.
In each of the above alternatives, the luminous device 2; 102; 202; 302 may also emit an additional light beam taking the form of a lighting or signaling beam.
A first light beam taking the form of a lighting beam without a cut-off forming a first lighting function, and a second light beam taking the form of a signaling beam forming a signaling function.
For example, the lighting beam may form a high-beam function and the signaling beam may form a signaling function chosen from among a direction-indicating function, a daytime-running-light function and a position-light function.
Alternatively, the first light beam may take the form of a first lighting beam containing a flat cut-off forming one portion of a first lighting function, and the device may emit a third light beam taking the form of a second lighting beam with a kinked cut-off forming another portion of the same first lighting function.
For example, the first lighting beam may be a beam containing a flat cut-off forming a portion of a low-beam function, and the second lighting beam may be a beam with a kinked cut-off, forming a second portion of a low-beam function, the superposition of the first lighting beam and of the second lighting beam forming a low-beam function.
The luminous device 2; 102; 202; 302 then emits a beam containing a flat cut-off, a beam containing a kinked cut-off and a signaling beam.
It is also possible, for each of the alternatives, for the luminous device 2; 102; 202; 302 to emit an additional light beam taking the form of a second signaling beam. For example, this second signaling beam may form a signaling function chosen from among a direction-indicating function, a daytime-running-light function and a position-light function.
In addition, the light sources on the one hand and the associated collectors on the other hand may be placed side-by-side. Alternatively, one portion of the light sources and their associated collectors may be opposite to the other portion of the light sources and their associated collectors, with respect to the optical axis.
According to one variant, provision may be made to have all of the collectors placed side-by-side.
For example, in its functional position, the luminous device may thus comprise a collector that participates in the formation of a lighting beam containing a flat cut-off, a collector that participates in the formation of a beam with a kinked cut-off and a collector that participates in the formation of a light beam forming one portion of a high-beam function, these collectors being placed side-by-side.
According to another variant, it is possible to have first and second light sources, associated with first and second collectors, respectively, that are opposite, with respect to the optical axis, to a third light source and to the third collector with which the third source is associated.
For example, in its functional position, the luminous device may comprise a first collector and a second collector that participate in the formation of a lighting beam containing a flat cut-off and of a beam with a kinked cut-off above the optical axis, respectively, and a third collector that participates in the formation of a light beam forming one portion of a high-beam function below the optical axis.
In another example, in its functional position, the luminous device may thus comprise a first collector and a second collector that participate in the formation of a lighting function and of a signaling function above the optical axis, respectively, and a third collector that participates in the formation of a light beam forming all or some of a signaling function below the optical axis.
According to another variant, it is possible to have a first light source associated with a first collector, both thereof being located opposite, with respect to the optical axis, to a second light source and to the second collector with which the second source is associated.
For example, in its functional position, the luminous device may thus comprise a first collector that participates in the formation of a lighting beam without cut-off forming a first lighting function above the optical axis, and a second collector that participates in the formation of a signaling beam below the optical axis.
Number | Date | Country | Kind |
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1902618 | Mar 2019 | FR | national |