Luminous matrix-array monolithic motor-vehicle device for writing on the ground

Abstract

The present invention proposes a lighting device for a motor vehicle comprising a first module that projects a first pixelated high beam, a second module that projects a second pixelated writing beam onto the road, and a third module that projects a third low beam cut-off. The first, second and third modules are arranged such that the first and second beams overlap at least partially vertically; and the second and third beams overlap at least partially vertically.

Claims

1. A lighting device of a motor vehicle, comprising: a first module configured to project a first pixelated partial or full high beam, and a second module configured to project a second pixelated road writing beam, and a third module configured to project a third cut-off low-beam, characterized in that the first, second and third modules are arranged such that the first and second beams overlap at least partially vertically; and the second and third beams overlap at least partially vertically; wherein each pixelated beam has a vertical amplitude of at least 5° (degrees) and a horizontal amplitude of at least 5° (degrees).

2. The lighting device as claimed in claim 1, further comprising a control unit configured to selectively control a light intensity of each of the pixels of the second beam so as to project a pattern in the sub-beam formed by the combination of the second and third beams.

3. The lighting device of claim 1, wherein the sub-beam formed by the combination of the first and second beams has a maximum intensity centered on a horizon line and a vertical axis through which an optical axis of the lighting device passes.

4. The lighting device of claim 1, wherein the first module is able to project a fourth pixelated partial high beam horizontally juxtaposed with the first pixelated partial high beam.

5. The lighting device of claim 4, wherein the second module is arranged such that the second beam is able to overlap at least partially horizontally with the fourth pixelated partial high beam.

6. The lighting device of claim 1, wherein the second module is able to project a fifth pixelated partial high beam that at least partially overlaps or is horizontally juxtaposed with the first pixelated partial high beam.

7. The lighting device of claim 1, wherein the first and second modules are arranged such that the first beam is situated between the fourth and second beams or between the fifth and second beams.

8. The lighting device of claim 1, wherein the resolution of the 1.sup.st beam is substantially identical to the resolution of a 4.sup.th beam.

9. The lighting device of claim 1, wherein the resolution of the 2.sup.nd beam is substantially identical to the resolution of a 5.sup.th beam.

10. The lighting device of claim 9, wherein the resolution of each of the 1.sup.st, 2.sup.nd, 4.sup.th and 5.sup.th beams is substantially identical.

11. An adaptive driving beam assembly that applies pixelated lighting of a motor vehicle, comprising: a first module configured to project a first pixelated partial or full high beam; a second module configured to project a second pixelated road writing beam; and a third module configured to project a third cut-off low-beam, characterized in that the first, second and third modules are arranged such that the first and second beams overlap vertically at least in a partial amount, and characterized in that the second and third beams overlap at least vertically at least in a partial amount.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features and advantages of the invention will become apparent from the following description of several embodiments thereof, given by way of non-limiting example, with reference to the accompanying drawings in which:

(2) FIGS. 1 and 2 show front and plan views of a lighting device according to one preferred embodiment of the invention;

(3) FIG. 3 is an overall beam projected by the lighting device according to a first embodiment;

(4) FIG. 4 is an overall beam projected by the lighting device according to a third embodiment;

(5) FIG. 5 is an overall beam projected by the lighting device according to a fourth embodiment;

(6) FIG. 6 is an overall beam projected by the lighting device according to a fifth embodiment.

DETAILED DESCRIPTION

(7) FIGS. 1 and 2 show, according to a first embodiment, a lighting device 1 according to one embodiment of the invention. This lighting device comprises a first lighting module 2 able to project a first pixelated partial or full high beam HR, a second lighting module 3 able to project a second road writing beam ER, and a third lighting module 3 able to project a third cut-off beam LB, such as a pixelated or non-pixelated low beam. The first, second and third beams HR, ER and LB have been shown in FIG. 3, projected onto a screen placed 25 meters from the lighting device 1 and on which have been formed a horizontal axis H-H representing the horizon and a vertical axis V-V, perpendicular to the horizontal axis H-H and intersecting the optical axis X of the lighting device 1.

(8) The first module 2 comprises: a pixelated light source 21 comprising 1232 pixels, each pixel comprising at least one elementary emitter, arranged in a matrix array of 28 rows of pixels by 44 columns of pixels, each of the pixels being able to be activated selectively to emit an elementary light beam; and an optical projection element 22 associated with said pixelated light source for projecting each of said elementary light beams in the form of a pixel having a width and a length of 0.3°.

(9) The set of pixels projected by the first module 2 forms said first pixelated beam HR. This beam HR has a horizontal amplitude of 12° and a vertical amplitude of 9°. It extends asymmetrically on either side of the vertical axis V-V. In the present case, with the lighting device 1 being a right-hand headlight of the vehicle, the beam HR extends 4° on the interior-vehicle side and 8° on the exterior-vehicle side. It also extends 5° above the horizontal axis H-H and 3° below the horizontal axis H-H.

(10) In the embodiment described, the pixelated light source 21 comprises a monolithic matrix array, as described above. Provision may be made to replace the pixelated light source 21 with any other type of pixelated light source described above, such as for example a matrix array of light-emitting diodes or a light source associated with a matrix array of optoelectronic elements, such as micromirrors. The first lighting module may comprise elements other than those described above. These elements will not be described in the context of the present invention since they do not interact functionally with the arrangements according to the invention.

(11) The third module 4 comprises: a light source 41 comprising a plurality of emitters, for example nine light-emitting diodes arranged along a row, each diode being able to emit an elementary light beam; a plurality 42 of primary optical elements arranged in front of the matrix array 41 for collecting, formatting and guiding the elementary light beams originating from each of the light-emitting diodes; and a projection optical element 43 arranged in front of the primary optical elements for projecting each of said elementary light beams originating from the primary optical elements in the form of a pixel having a width of 3° and a length of 5°.

(12) In one variant of this embodiment, the nine light-emitting diodes are able to be activated selectively.

(13) The set of pixels projected by the third module 4 forms the third beam LB. This beam LB has a horizontal amplitude of 20° and a vertical amplitude of 8°.

(14) The third lighting module 3 is arranged such that the third low beam has a low-beam upper cut-off LB_CO. In the present case, the primary optical elements 42 are arranged such that their exit surfaces abut such that the lower edges of these surfaces are contiguous and aligned and the optical projection element 43 is focused on these exit surfaces. The optical projection element 43 thus images these lower edges at an upper cut-off LB_CO, defined by the upper edges of the pixels forming this third light beam.

(15) In the example described, the upper cut-off comprises a single flat horizontal portion, arranged at 0.57° below the horizontal axis H-H.

(16) The second module 3 comprises: a pixelated light source 31 comprising 1232 pixels, each pixel comprising at least one elementary emitter, arranged in a matrix array of 28 rows of pixels by 44 columns of pixels, each of the pixels being able to be activated selectively to emit an elementary light beam; and an optical projection element 32 associated with said pixelated light source for projecting each of said elementary light beams in the form of a pixel having a width and a length of 0.3°.

(17) The set of pixels projected by the first module 2 forms said second pixelated beam ER. This beam ER has a horizontal amplitude of 12° and a vertical amplitude of 8°. It extends symmetrically on either side of the vertical axis V-V. In the present case, with the lighting device 1 being a right-hand headlight of the vehicle, the beam HR extends 6° on the interior-vehicle side and therefore 6° on the exterior-vehicle side. It extends asymmetrically 3° above the horizontal axis H-H and 5° below the horizontal axis H-H.

(18) In the embodiment described, the pixelated light source 31 comprises a monolithic matrix array, as described above. Provision may be made to replace the pixelated light source 31 with any other type of pixelated light source described above, such as for example a matrix array of light-emitting diodes or a light source associated with a matrix array of optoelectronic elements, such as micromirrors. The first lighting module may comprise elements other than those described above. These elements will not be described in the context of the present invention since they do not interact functionally with the arrangements according to the invention.

(19) The superposition of the various beams that are obtained is shown in FIG. 3. Thus the beams HR and ER, in particular at the intersection of lines H-H and V-V. The light intensity of the overall beam is thus increased, thus improving the visual comfort of the driver.

(20) It is also seen that the beams ER and LB overlap. In terms of this superposition, several scenarios arise: the beam ER has a light intensity greater than that of the beam LB, and it is then possible to write on the ground through positive contrast so that this is seen by the driver and/or the other users; the beam LB is produced by a pixelated light source of the third module 4, the pixels of which are able to be addressed and activated individually, then the pixels of the beam LB of the area in common with the beam ER will be turned off to reveal the pattern produced by the beam ER.

(21) Finally, the lighting device 1 comprises a control unit 5 each able to selectively control the light intensity of each of the pixels of the first and second beams HR and LB on the basis of control instructions that it receives, for example by switching on and by selectively switching off the elementary emitters of the light sources 21 and 31 or else by varying, in an increasing or decreasing manner, the electric power supplied to each of these elementary emitters.

(22) In a second embodiment, the first module 2 is able to project a fourth pixelated partial high beam HR-CO horizontally juxtaposed with the first pixelated partial high beam HR. The first module 2 then comprises a second pixelated light source of the same type as the pixelated light source 21, that is to say comprising 1232 pixels, each pixel comprising at least one elementary emitter, arranged in a matrix array of 28 rows of pixels by 44 columns of pixels, each of the pixels being able to be activated selectively to emit an elementary light beam. An optical projection element is associated with said second pixelated light source of this first module 2 in order to project each of said elementary light beams in the form of a pixel having a width and a length of 0.3°.

(23) The beam HR-CO has a horizontal amplitude of 12° and a vertical amplitude of 8°. In the present case, with the lighting device 1 being a right-hand vehicle headlight, the beam HR-CO extends 12° from the right-hand edge of the beam HR, that is to say from the edge of the exterior-vehicle side. It also extends 5° above the horizontal axis H-H and 3° below the horizontal axis H-H.

(24) In a third embodiment, this taking up the configuration of the second embodiment, the second module 3 is able to project a fifth pixelated partial high beam HR-CO2 at least partially overlapping or horizontally juxtaposed with the first pixelated partial high beam HR. This is illustrated in FIG. 4.

(25) The second module 3 then comprises a second pixelated light source of the same type as the pixelated light source 31, that is to say comprising 1232 pixels, each pixel comprising at least one elementary emitter, arranged in a matrix array of 28 rows of pixels by 44 columns of pixels, each of the pixels being able to be activated selectively to emit an elementary light beam. An optical projection element is associated with said second pixelated light source of this second module 3 in order to project each of said elementary light beams in the form of a pixel having a width and a length of 0.3°.

(26) The beam HR-CO2 has a horizontal amplitude of 12° and a vertical amplitude of 8°. In the present case, with the lighting device 1 being a right-hand vehicle headlight, the beam HR-CO extends 12° from the left-hand edge of the beam HR, that is to say from the edge of the interior-vehicle side. It also extends 5° above the horizontal axis H-H and 3° below the horizontal axis H-H of the interior-vehicle side.

(27) In this configuration, there is limited bulk and a pixelated high beam that extends over the entire width of the cut-off beam LB in addition to the previous advantages.

(28) A fourth embodiment is identical to the third embodiment except for the first module 2. This comprises: a pixelated light source comprising 2464 pixels, each pixel comprising at least one elementary emitter, arranged in a matrix array of 28 rows of pixels by 88 columns of pixels, each of the pixels being able to be activated selectively to emit an elementary light beam; and an optical projection element associated with said pixelated light source for projecting each of said elementary light beams in the form of a pixel having a width and a length of 0.3°.

(29) The set of pixels projected by the first module 2 forms a pixelated beam HR-D. This beam HR-D has a horizontal amplitude of 24° and a vertical amplitude of 9°. It extends asymmetrically on either side of the vertical axis V-V. In the present case, with the lighting device 1 being a right-hand headlight of the vehicle, the beam HR extends 4° on the interior-vehicle side and 20° on the exterior-vehicle side. It also extends 5° above the horizontal axis H-H and 3° below the horizontal axis H-H.

(30) The first module 2 is thus more compact, as is also therefore the lighting device 1 in comparison with the third embodiment. The various light beams that are obtained are illustrated in FIG. 5.

(31) In a fifth embodiment, the first module 2 comprises: a pixelated light source comprising 3696 pixels, each pixel comprising at least one elementary emitter, arranged in a matrix array of 28 rows of pixels by 132 columns of pixels, each of the pixels being able to be activated selectively to emit an elementary light beam; and an optical projection element associated with said pixelated light source for projecting each of said elementary light beams in the form of a pixel having a width and a length of 0.3°.

(32) The set of pixels projected by the first module 2 forms the pixelated beam HR-G. This beam HR-G has a horizontal amplitude of 36° and a vertical amplitude of 9°. It extends asymmetrically on either side of the vertical axis V-V. In the present case, with the lighting device 1 being a right-hand headlight of the vehicle, the beam HR extends 16° on the interior-vehicle side and 20° on the exterior-vehicle side. It also extends 5° above the horizontal axis H-H and 3° below the horizontal axis H-H.

(33) The first module 2 is thus more compact, as is also therefore the lighting device 1 in comparison with the third embodiment. The various light beams that are obtained are illustrated in FIG. 5.

(34) The second and third modules remain identical to the first embodiment.

(35) In one variant of the embodiments described above, the pixelated light sources may also have different resolutions from one another depending on the requirements needed.

(36) It is understood that, in each of the cases of implementing a monolithic source according to the invention, it is thus possible, through the electrical connection of the electroluminescent elements that are distinct from the others or else through the shape of the slicing of the electroluminescent blocks, to achieve particular arrangements of the portions able to be activated selectively in the emission surface, whether in terms of their shapes or in terms of their dimensions.

(37) As has been explained above, the substrate may be common to all of the electroluminescent elements forming the various portions of the monolithic matrix array. This thus optimizes the number of electrical connection wires, and makes it easier to bring together the portions of the light source, the contiguous nature of this arrangement being particularly beneficial for obtaining a homogeneous flow when both portions of the electroluminescent light source are activated simultaneously.

(38) The above description clearly explains how the invention makes it possible to achieve the objectives that it has set for itself and in particular to propose a lighting device that makes it possible to achieve multifunction lighting at a lower cost, and without loss of photometric quality, that is to say lighting that makes it possible to produce a glare-free lighting function with cut-off, a long-range lighting function with a single shaping optic and a signaling function via writing on the road. It is particularly advantageous according to the invention to combine a monolithic source, and for example a semiconductor source comprising electroluminescent rods, and a simple shaping optic, that is to say by way of example a converging lens and/or a parabolic mirror, without the need for intermediate optical surfaces between these two elements.

(39) Unless specified otherwise, the technical features that are described in detail for one given embodiment may be combined with the technical features that are described in the context of other embodiments described by way of example and without limitation.