WO2017025440A1

WO2017025440A1 - Lighting and/or signalling device for a motor vehicle

Info

Publication number: WO2017025440A1
Application number: PCT/EP2016/068684
Authority: WO
Inventors: Benoit Reiss; Pierre Albou; Vanesa Sanchez
Original assignee: Valeo Vision
Priority date: 2015-08-07
Filing date: 2016-08-04
Publication date: 2017-02-16
Also published as: FR3039881A1; FR3039881B1

Abstract

A luminous device for a motor vehicle includes a semiconductor light source (1) comprising a plurality of light-emitting rods of submillimetre dimensions, and optics for projecting at least some of the light rays emitted by said light source. The light-emitting rods are arranged so as to form a first zone and a second zone that are selectively activatable, the first zone (ZR) being able to generate at least some of a first light beam in a first state and some of a second beam in a second state, the second zone (ZJ) being able to generate some of said second beam conjointly with the first zone in the second state.

Description

LIGHTING AND / OR SIGNALING DEVICE FOR

MOTOR VEHICLE

The invention relates to the field of lighting and / or signaling, especially for motor vehicles. It relates more particularly to a device capable of generating two distinct lighting and / or signaling functions by selective activation of two zones of a light source.

A motor vehicle is equipped with headlamps, or headlights, intended to illuminate the road in front of the vehicle, at night or in the case of reduced luminosity. These headlamps can generally be used in two lighting modes: a first mode "high beam" and a second mode "low beam". The "high beam" mode provides strong illumination of the road far ahead of the vehicle. The "low beam" mode provides more limited road lighting, but still offers good visibility without dazzling other road users. These two modes of lighting are complementary, and one passes from one to the other according to the traffic conditions. The switching from one mode to another can be done manually, the driver deciding the moment of this switching, or it can be done automatically, depending on the detection by appropriate means of the conditions required for such a change of mode. 'lighting. Each lighting function can be provided by a module, and the different modules are arranged side by side in the projector. However, especially for issues of visual comfort for the driver, cost, and aesthetics, the manufacturers wish to propose projectors in which a module is able to perform alternately one or other of the functions, so that the corresponding light beam exits through the same optical output face. We understand that this problem applies regardless of the combination of lighting functions that we want to put in place.

In the last few years, manufacturers have been forced to install devices in the front of their vehicles, enabling them to perform a daytime running function, also known as DRL by the acronym "Daytime Running". Light ". The daytime running light function is to signal the vehicle in conditions of luminosity assimilated to daylight. The activation of a daytime running light is operated by an automatic control means, so that the daytime running light is switched on. when the above-mentioned headlamps, high beam or dipped beam, are switched off.

A known solution in existing automotive headlamps for providing a daytime running light beam is to use, in addition to the module or modules for generating the code and route beams, a separate module, for example, based on light-emitting diodes and electroluminescent light sources. light guides. The main disadvantage of this solution is that the vehicle signature, that is to say the appearance of the projector, differs depending on whether the vehicle is observed day or night. For reasons that are both aesthetic and obstruction of projectors, car market players are seeking to ensure that the signature of their lighting and / or signaling functions is the same day and night.

The aim of the invention is to propose an alternative to these prior solutions, which makes it possible to propose a luminous device with a constant signature, that is to say with an aspect of the device seen from outside the vehicle which remains the same, and This means that the luminous device functions in daytime or nighttime conditions, and allows the respect of the photometric grids to be filled according to the regulations, for both the daylight beam and the Route or Code lighting beam.

In this context, the invention relates to a lighting and / or signaling device for a motor vehicle in which there is provided a semiconductor light source comprising a plurality of electroluminescent rods of submillimeter dimensions, and projecting at least a portion of the light rays emitted by said light source. The electroluminescent rods are arranged to form a first zone and a second selectively activatable zone, the first zone being able to generate at least a portion of a first light beam in a first state and a portion of a second beam in a first zone. second state, the second zone being able to generate a portion of said second beam, together with the first zone in the second state.

By projection optics means means for projecting at infinity an image of the light source directly or indirectly. According to one aspect of the invention, a technology is applied to the automotive field consisting in producing the light-emitting zone by a forest of electroluminescent rods of submillimetric dimensions which is grown on a substrate, to achieve a three-dimensional topology. It will be understood that this three-dimensional topology has the advantage of multiplying the light emission surface with respect to the electroluminescent diodes known hitherto in the automobile field, namely substantially planar diodes. By multiplying the light-generating rods, which can be powered independently of each other, it is possible to provide specific areas that can be under-powered or supercharged depending on the lighting function that is desired realize, without the need to under-power or super-power the entire light source, and the fact that this is done from a single light source and a single projection optics allows to conserve a unique signature regardless of the mode of use of the light source.

According to various features of the invention, provision may be made for:

the second zone is able to assume a first state in which it is able to generate a portion of said second beam, together with the first zone when it is in said second state, and a second state in which is capable of generating a second state, part of a third beam, together with the first zone when it is in a third state;

the first zone is able to generate on the one hand at least a part of said first light beam when it is electrically powered with an electric power greater than a first determined threshold and on the other hand a part of said second light beam when it is electrically powered with an electric power below a second determined threshold;

the first light beam is a road-type beam, said second light beam being a day-light beam and the third beam a position-light beam.

The electroluminescent rods can extend from the same substrate, and they can in particular be formed directly on this substrate. It can be provided that the substrate is based on silicon or silicon carbide. It is understood that the substrate is based on silicon since it comprises mainly silicon, for example at least 50% and in practice about 99%. Thus, it is possible to reduce the costs of obtaining the device according to the invention, since the silicon plates used can be up to 12 inches in size, up to a maximum of 4 inches for corundum used previously.

According to characteristics specific to the constitution of the electroluminescent rods and the arrangement of these electroluminescent rods on the substrate, it can be provided that each characteristic can be taken alone or in combination with the others:

each rod has a generally cylindrical shape, in particular of polygonal section; it can be expected that each rod is the same general shape, and in particular a hexagonal shape; the rods are each delimited by an end face and by a circumferential wall which extends along a longitudinal axis of the rod defining its height, the light being emitted at least from the circumferential wall; this light could also be emitted by the terminal face;

- Each rod may have an end face which is substantially perpendicular to the circumferential wall, and in different variants, it can be provided that this end face is substantially flat or curved or pointed at its center;

the rods are arranged in matrix, that this matrix is regular, with a constant spacing between two successive rods of a given alignment, or that the rods are arranged in staggered rows; the height of a stick is between 1 and 10 micrometers;

the largest dimension of the end face is less than 2 micrometers;

the distance separating two immediately adjacent rods is at least equal to 2 micrometers, and at most equal to 100 micrometers.

the distance separating two immediately adjacent rods is preferably between 2 micrometers and 10 micrometers.

The luminous flux and the luminance of a light source of the present invention are constrained by the regulations in force concerning lighting and / or signaling in the automotive field and by crosstalk between rods. In addition, current motor vehicle electrical architectures limit the power supply of the light source. So to get a lighting beam and / or signaling according to these regulations with such a light source and within these electrical architectures, the parameters of the light source of the invention such as the height and diameter of the rods or in this case the spacing of the rods on the substrate of the light source can be varied. It has thus been found that the distance separating two immediately adjacent rods must advantageously be between 2 micrometers and 10 micrometers, preferably between 2 micrometers and 10 micrometers.

On the other hand, this range makes it easy to manufacture projection optics adapted to cooperate with the light source and whose resolving power will distinguish two distinct groups of rods and will not distinguish two separate rods.

According to other features, it may be provided that the semiconductor light source comprising a plurality of submillimeter-sized electroluminescent rods further comprises a layer of a polymeric material in which the rods are at least partially embedded; this polymeric material may be based on silicone, it being understood that the polymer material is based on silicone since it comprises mainly silicone, for example at least 50% and in practice about 99%. The layer of polymeric material may comprise a phosphor or a plurality of phosphors excited by the light generated by at least one of the plurality of rods. The term phosphor, or light converter, and for example a phosphor, the presence of at least one luminescent material designed to absorb at least a portion of at least one excitation light emitted by a light source and to convert to at least a portion of said excitation light absorbed into an emission light having a wavelength different from that of the excitation light. This phosphor, or this plurality of phosphors, may be at least partially embedded in the polymer, or rest on the layer of this polymeric material.

According to a series of characteristics specific to the arrangement of the two zones, it will be possible to provide that:

the second zone at least partially surrounds the first zone; - the independent control of the lighting of the two zones between them is a control of ignition intensity; both zones can be powered simultaneously for emitting light rays in a given illumination surface to participate in the formation of a first illumination function, the second zone being undernourished with respect to the supply of the first zone, and the two zones can be powered simultaneously to emit light rays in a given illumination surface to participate in the formation of a second illumination function, the first zone being undernourished with respect to the supply of the second zone.

It can be provided that the light source comprises a third zone formed of a plurality of said electroluminescent rods and selectively activatable with respect to the first and second zones, said third zone being able to generate at least a portion of a fourth light beam. This fourth light beam may in particular be a beam type dipped beam.

It may also be provided that the device comprises a second light source, and for example a conventional light emitting diode (LED) capable of generating at least a portion of this fourth light beam. In a particular configuration of a device according to the invention, the third zone is controlled so as to be selectively activatable from the first and second zones, the first and second zones being moreover activatable simultaneously, at ignition intensities which can to be distinct.

The electroluminescent rods defining the third zone may in particular be separated from the rest of the electroluminescent rods of the light source by the presence of a separating element, such as a wall projecting from the substrate carrying the rods. The rods can be distributed so that the junction between the third zone on the one hand and the first and the second zone on the other hand forms a line in the light source corresponding to a cut-off of the beam of passing beam projected by the projection device.

According to one characteristic of the invention, the third zone may be in two sub-zones capable of being powered at different current intensities.

For each of the areas mentioned above, it can be provided that the distribution of electroluminescent rods is different or substantially different within each zone. And we can provide a separate ignition control system for each of the areas of the light source.

According to the invention, the shaping optics may comprise an optical projection of the light emitted by the semiconductor light source. This projection optics creates a real, and possibly anamorphic, image of a part of the device, for example the source itself or a cache, or an intermediate image of the source, at a distance (finite or infinite) very large. in front of the dimensions of the device (of a ratio of the order of at least 30, preferably 100) of the device. This projection optics may consist of one or more reflectors, or a lens, or a combination of these two possibilities.

The device thus takes place particularly in a front projector of a motor vehicle, able to emit different lighting functions, such as a daytime running light, a traffic light and a fire code.

Other features and advantages of the present invention will appear more clearly with the help of the description and the drawings, of which: FIG. 1 is a sectional view of a device according to the invention, in which a source has been illustrated; semiconductor light device comprising electroluminescent rods, said rods not being represented to scale in order to make them visible, said source being oriented so that the rays emitted by the rods are directly directed towards an optical setting form of rays; Fig. 2 is a schematic perspective view of a semiconductor light source according to an embodiment of the invention, said light source having two separate areas of light emitting rods; Figure 3 is a schematic perspective view of a semiconductor light source, in which rows of electroluminescent rods have been made visible in section; Figure 4 is a sectional view of a particular embodiment of the invention, wherein two electroluminescent rods project from a substrate, said electroluminescent rods being encapsulated in a protective layer; FIG. 5 is a graph representative of the luminance of the beam to be emitted by the semiconductor source of the device of the invention for producing a road-type lighting light and a diurnal-type light respecting the regulatory photometry; and FIGS. 6 and 7 are diagrammatic representations of embodiments of the semiconductor light source according to the invention, the electroluminescent rods being divided into three distinct zones (FIG. 6) or four distinct zones (FIG. 7). .

A lighting and / or signaling device of a motor vehicle comprises a light source 1, in particular housed in a housing closed by an ice and which defines an internal volume of reception of this light source associated with a projection optics 2 adapted to infinitely image at least a portion of the light rays emitted by the light source. In Figure 1, the light source 1 is centered on the optical axis 40 of the converging lens forming the projection optics 2 adapted to image the light source on the outside of the vehicle. The light source 1 is oriented so that the rays it emits are directly directed towards the lens. For reasons of space of the light device for example, it can be provided that the light source does not emit mainly in the direction of the optical axis of the lens, but substantially perpendicular to it, and that the rays are deviated by an optical means, for example paraboloidal reflector type.

The light source 1 comprises, according to the invention, a plurality of electroluminescent rods 8, of submillimetric dimensions, arranged in a plurality of zones, among which at least a first zone 4 and a second zone 6 (as visible in FIG. 2). . According to the invention, at least one of these zones participates in the formation of two distinct beams, this zone and the rods of which it is composed being placed in a first state, in particular by a power supply with a current of a first intensity, for participate in the formation of the first beam while this zone and the rods that compose it are placed in a second state, in particular by a power supply with a current of a second intensity, distinct from the first intensity, to participate in the formation of the second beam.

It can be provided in this context that the density and / or the height of the rods is such that the light source has at least a first zone and a second zone defined by a plurality of rods and having luminances distinct from a zone to the other when powered by the same electrical current.

The structure of a semiconductor light source 1 having submillimetric size electroluminescent rods will firstly be described, in particular with reference to FIGS. 3 and 4.

The light source 1 comprises a plurality of electroluminescent rods 8 which originate on at least one substrate 10. Each electroluminescent rod, here formed using gallium nitride (GaN), extends perpendicularly, or substantially perpendicularly, projecting from substrate, here made based on silicon or silicon carbide other materials that can be used without departing from the context of the invention. By way of example, the electroluminescent rods could be made from a compound based on aluminum nitride and gallium nitride (AlN / GaN), or from an aluminum-based compound, from indium and gallium.

The substrate 10 has a lower face 12, on which is reported a first electrode 14, and an upper face 16, projecting from which extend the electroluminescent rods 8 and on which is reported a second electrode 18. Different layers of materials are superimposed on the upper face 16, in particular after the growth of electroluminescent rods from the substrate here obtained by an ascending approach. Among these different layers, one can find at least one layer of electrically conductive material, in order to allow the power supply of the rods. This layer is etched so as to connect a particular rod between them, the ignition of these electroluminescent rods can then be controlled simultaneously by a control module not shown here. It can be provided that at least two electroluminescent rods or at least two groups of electroluminescent rods are arranged to be lit separately by means of an ignition control system. The electroluminescent rods extend from the substrate and, as can be seen in FIG. 3, they each comprise a gallium nitride core 19 around which are disposed quantum wells 20 formed by a radial superimposition of layers of different materials, here gallium nitride and gallium-indium nitride, and a shell 21 surrounding the quantum wells also made of gallium nitride.

Each electroluminescent rod extends along a longitudinal axis 22 defining its height, the base of each rod being disposed in a plane 24 of the upper face 16 of the substrate 10.

The electroluminescent rods 8 of the same light source advantageously have the same shape. They are each delimited by an end face 26 and a circumferential wall 28 which extends along the longitudinal axis. When the electroluminescent rods are doped and polarized, the resultant light output from the semiconductor source is emitted essentially from the circumferential wall 28, it being understood that light rays may also emerge from the As a result, each electroluminescent rod acts as a single light-emitting diode and the light output of this source is improved on the one hand by the density of the electroluminescent rods 8 present and on the other by the size of the surface. illuminant defined by the circumferential wall and which therefore extends around the entire periphery, and the entire height of the stick.

The circumferential wall 28 of an electroluminescent rod 8, corresponding to the gallium nitride shell, is covered by a transparent conductive oxide (OCT) layer 29 which forms the anode of each rod complementary to the cathode formed by the substrate. . This circumferential wall 28 extends along the longitudinal axis 22 from the substrate 10 to the end face 26, the distance from the end face 26 to the upper face 16 of the substrate, from which the electroluminescent rods 8 originate. , defining the height of each stick. For example, it is expected that the height of a light emitting rod 8 is between 1 and 10 micrometers, while it is expected that the largest transverse dimension of the end face, perpendicular to the longitudinal axis 22 of the rod concerned, ie less than 2 micrometers. It will also be possible to define the surface of a rod, in a sectional plane perpendicular to this longitudinal axis 22, in a range of determined values, and in particular between 1.96 and 4 microns square. It is understood that during the formation of electroluminescent rods 8, the height can be changed from one zone of the light source to another, so as to increase the luminance of the corresponding zone when the average height of the rods the constituent is increased. Thus, a group of electroluminescent rods may have a height, or heights, different from another group of electroluminescent rods, these two groups constituting the same semiconductor light source comprising electroluminescent rods of submillimeter dimensions.

The shape of the electroluminescent rods 8 may also vary from one device to another, in particular on the section of the rods and on the shape of the end face 26. Circular section electroluminescent rods have been illustrated in FIG. FIG. 3 shows electroluminescent rods 8 having a shape of polygonal section, and more particularly hexagonal section. It is understood that it is important that light can be emitted through the circumferential wall, that it has a polygonal or circular shape.

Moreover, the end face 26 may have a substantially planar shape and perpendicular to the circumferential wall, so that it extends substantially parallel to the upper face 16 of the substrate 10, as shown in FIG. 3, or although it may have a domed or pointed form at its center, so as to multiply the directions of emission of light exiting this end face, as shown in Figure 4.

In Figures 2 and 3, the electroluminescent rods 8 are arranged in two-dimensional matrix. This arrangement could be such that the rods are arranged in staggered rows. The invention covers other distributions of electroluminescent rods, in particular with rod densities which can be variable from one zone of the light source to another, and which can be variable within the zones of a same source. from light. FIG. 2 shows the separation distance d1 of two immediately adjacent electroluminescent rods in a first transverse direction and the separation distance d2 of two immediately adjacent electroluminescent rods in a second transverse direction. The separation distances d1 and d2 are measured between two longitudinal axes 22 of adjacent rods. The number of electroluminescent rods 8 projecting from the substrate 10 may vary from one zone to another, and therefore the separation distance between each rod may vary, in particular to locally increase the light intensity of the light source. , but it is agreed that one or the other separation distances dl, d2 must be at least equal to 2 micrometers, so that the light emitted by the circumferential wall 28 of each stick 8 can exit the matrix of electroluminescent rods. Furthermore, it is expected that these separation distances are not greater than 100 micrometers. It will be understood, as may have been previously stated for the height of the rods, that it is possible, with respect to the separation distances imposed between two adjacent rods, that during the formation of the electroluminescent rods 8, to modify the density of the rods from one zone of the light source to another, so as to increase the luminance of the zone comprising the highest density of rods. Thus, one group of electroluminescent rods may have a density different from another group of electroluminescent rods, these two groups constituting the same semiconductor light source comprising electroluminescent rods of submillimeter dimensions.

The semiconductor light source 1 may further comprise, as illustrated in FIG. 4, a layer 30 of a polymeric material in which the electroluminescent rods 8 are at least partially embedded. The layer 30 may thus extend over the whole extent of the substrate or only around a given group of electroluminescent rods 8. The polymer material, which may in particular be based on silicone, creates a protective layer which makes it possible to protect the electroluminescent rods 8 without hindering the scattering of light rays. In addition, it is possible to integrate in this layer 30 of polymeric material wavelength converting means, and for example phosphors, able to absorb at least a portion of the rays emitted by one of the rods and to converting at least a portion of said absorbed excitation light into an emission light having a wavelength different from that of the excitation light. It can be provided without distinction whether the wavelength conversion means are embedded in the mass of the polymer material, or that they are arranged on the surface of the layer of this polymeric material.

The light source may further comprise a coating 32 of light reflective material which is disposed between the electroluminescent rods 8 to deflect the rays, initially oriented towards the substrate, towards the end face 26 of the electroluminescent rods 8. In other words , the upper face 16 of the substrate 10 may comprise a reflecting means which returns the light rays, initially oriented towards the upper face 16, towards the exit face of the light source. This recovers rays that otherwise would be lost. This coating 32 is disposed between the electroluminescent rods 8 on the transparent conductive oxide layer 29.

According to the invention, the light source 1 has electroluminescent rods arranged and configured to form zones among which at least one first zone participates in the formation of two distinct beams, this zone and the rods that compose it being placed in a first zone. state, in particular by a power supply with a current of a first intensity, to participate in the formation of the first beam while this zone and the rods that compose it are placed in a second state, in particular by a power supply with a current of a second intensity, distinct from the first intensity, to participate in the formation of the second beam. The set of rods is fed at a current of a first intensity or a current of a second intensity, according to the conditions of circulation and the state of the lighting and / or signaling device. In Figure 2, the light source generally has a rectangular shape, but it will be understood that it can present without departing from the context of the invention other general forms, including a parallelogram shape. And that according to the invention, the electroluminescent rods may extend projecting from the substrate in a predetermined configuration, or may be connected or not to define a non-necessarily rectangular lighting surface.

In a first example illustrated in FIGS. 2 and 3, the light source 1 has an emitter portion 33 divided into two contiguous zones, among which a first zone 34 and a second zone 36, these two zones being arranged in series along the optical axis 40 defined by the light source and the shaping optics. The first zone 34 is disposed further than the second zone 36 with respect to the optical axis 40 and the main direction of emission of the rays, that is to say that it is located on the optical axis, compared to the second zone, closer to the exit of the light device. The separation 37 between the two zones 34, 36 follows here in the form of a right portion. As will be described in more detail below, this separation 37 can be obtained by the physical realization of a wall projecting from the substrate, but it can only be achieved by the determined wiring of a particular rod 8 between them. In each of these zones 34, 36 are arranged a plurality of electroluminescent rods of submillimetric dimensions, the rods associated respectively with each of these two zones being electrically connected so that the zones can be activated selectively on either side of the separation. FIG. 2 shows the separation distance d3, in the first transverse direction, between a rod of the first zone 34 and a rod directly adjacent and of the second zone 36. It is agreed that this separation distance d3, measured between two longitudinal axes of electroluminescent rods, must be at least equal to 2 micrometers, so that the light emitted by the circumferential wall 28 of each rod 8 can exit the matrix of electroluminescent rods, and it seeks to have a separation distance d3 between two rods from two different sources that is substantially equal to the separation distance dl or d2 of two rods of the same zone of the light source.

It is notable that the two zones of the semiconductor light source may have distinct luminances, especially in the context of an application to a "multi-function" device, that is to say able to perform several different lighting functions. In the following description, particular attention is paid to an application in which the device can perform a first code-type lighting function, a second road-type lighting function, a third fire-type lighting function. diurnal and a fourth function of the position light type (or "lantern"). Several distinctions can be made between the two zones of the emitting surface, respectively associated with one or the other of the lighting functions, it being understood that in this application, it is desired that activation of the first zone of rods 34 allow the performing the first lighting function, that is to say the emission of a code beam, which therefore requires a moderate luminance but a strong flux, while activation of the second zone of rods 36 allows the realization of the second lighting function, ie the emission of a road beam, which therefore requires a high luminance, but with a moderate flow. Without departing from the context of the invention, it is possible to provide that the second lighting function is carried out solely by activating the second zone 36, while the first zone of rods 34 is extinguished, or that this second function of lighting is achieved by simultaneous activation of the first and second zones of rods, activation of the rods of the second zone generating a beam complementary to the beam formed by the activation of the rods of the first zone to achieve by combining the road-type beam.

In the examples that follow, it is desired that at least the zone capable of participating in the formation of a Route-type beam comprises a sub-zone, selectively activatable with a power supply distinct from the zone to which this sub-zone zone is associated. According to the invention, the zone and the sub-zone are fed with different currents according to the lighting function that one wishes to achieve. In particular, these undernourishment and supercharging of one area and the other allow the realization with a common signature of a road lighting function and a daylight function. The graph of FIG. 5 is shown in solid lines, the distribution curve

50 of luminance L to be observed on the source, depending on the position relative to the center of the source, to obtain a road-type beam complying with the regulations, and is shown on the same graph, in dashed lines , the luminance distribution curve 51 to be observed on the source, as a function of the position relative to the center of the source, to obtain a diurnal-type beam complying with the regulations. It can be seen that for a Route beam, the light intensity must be strong in the center of the source and gradually decrease towards the outside of the source, while for a daytime beam, the luminous intensity must be more regular of a edge to the other of the source, without peak of intensity in the center. Advantageously, the substrate is common to all the rods composing the different zones of the semiconductor light source. The joined character of this arrangement being particularly advantageous for obtaining a homogeneous flux when the two zones of the semiconductor light source are simultaneously activated.

Various embodiments of a light device comprising, on the one hand, a semiconductor light source comprising electroluminescent rods grouped into a plurality of electrically powered zones according to several currents to take different states and, on the other hand, an optical system, will now be described. projection capable of imaging at infinity at least a portion of the light rays emitted by the different rod areas of the light source. In FIGS. 2 and 7 to 9, the emitting zones are not the same size and they do not have the same number of electroluminescent rods of dimensions submillimeter. In the case illustrated in FIG. 2, where the light source has two zones of identifiable rods, the first zone 34 is larger than the second zone 36, at least in the direction of the optical axis 40 defined above, in a a ratio of approximately one to two. The two zones have a substantially rectangular shape, with a large side and a small side, and the areas are joined at one of their small side, which extends substantially perpendicular to the optical axis, in a provision of the so-called axial source, along the optical axis. By way of example, provision may be made for the second zone, that is to say the largest zone of the two zones of the light source, to have a large side having a first dimension substantially equal to 4 millimeters and a small side having a second dimension substantially equal to 1 millimeter. It can be provided as an alternative embodiment that the zones are joined at one of their long side, in a so-called transverse arrangement of the light source.

The different areas of the light source are selectively activatable from each other. In particular, it will be possible for one of these zones, when activated, to emit rays which form, after projection by the associated optics, a complementary beam of a projected beam when it is another zone of the transmitting part which is activated. The term "complementary beam" means a beam which, with another beam, forms a coherent beam when the zones are controlled so as to simultaneously produce the emission of the light beam of their own. These complementary beams are superimposed to form a regulatory light beam for a motor vehicle.

FIG. 6 illustrates a particular embodiment of the invention according to which the semiconductor source comprises three contiguous zones ZR, ZJ and ZC from which can be identified a zone ZC disposed on one side of a cutoff line 54, and two zones ZR, ZJ disposed on the other side of this cutoff line. The zones are selectively activatable, and at least the zones ZR, ZJ arranged on the same side of the cut-off line are electrically powered with a variable supply current, the zone ZC disposed on the other side of the cut-off line. which can be supplied indifferently according to the invention by a variable or constant supply current. According to one variant, the zone ZC is absent, only zones ZR and ZJ being present.

In order for the Code beam to be legal, the cutoff must have sufficient contrast. For this purpose, a physical separation, non-emitting, of the zone ZC code and ZR road zone, ZJ, the separation being able to be formed by an opaque wall extending protruding from the substrate between the electroluminescent rods arranged at the edge of each zone. This separation creates in the Route beam, obtained by the combined emission of the two zones 34,36 of the transmitting part, a zone darkened relative to the rest. In order to have a Route beam as homogeneous as possible, it is important that this darkened zone is reduced to the maximum, that is to say that the zones 34,36 are as close as possible and that the wall can have a height less than 0.1 millimeter, and preferably less than 0.05 millimeter.

It will be understood that, in order to obtain a code beam, only the zone ZC is energized, zones ZR and ZJ are not activated. For obtaining a Route beam as well as for obtaining a diurnal beam, all the zones of the source are electrically powered, it being understood that according to the invention, at least one of the zones is powered with two currents of different intensity according to whether one seeks to obtain a Route beam or a diurnal beam. To obtain a Route beam, the first zone ZR, that is to say the zone which is arranged substantially in the center of the source while the second zone ZJ is arranged around the first zone, is fed with a strong current, that is to say a current of intensity greater than a first determined threshold. Simultaneously, the second zone ZJ is driven with a low current or even off, so that the luminance of the second zone is very low or zero. A Route beam corresponding to the characteristics of the graph of FIG. 5 is thus produced, with low intensity edges, since the rods on the sides of the source are grouped in the second zone ZJ driven with a weak current, and a peak of intensity in the center, since the rods grouped in the first zone ZR supercharged are all in the center of the source. Conversely, for producing a diurnal beam, at least the zones ZR and

ZJ are fed, optionally the zone ZC, but the balance of light intensity between the center and the edges of the source is reversed. The first zone ZR is undernourished, with a current of intensity less than a second determined threshold. Simultaneously, the second zone ZJ is fed with a standard intensity. A diurnal beam corresponding to the characteristics of the graph of FIG. 5 is thus produced, with a substantially constant intensity over the whole area, since the rods grouped in the first zone ZR are undernourished and do not create a peak of central intensity. In this way, we ensures, when changing from a road function to a daytime function, that the maximum value of the overall beam decreases more than the level of the edges, in order to obtain the desired diurnal day beam.

To achieve a position-light beam, the zone ZR is even more undernourished with respect to its state for producing a diurnal beam, and zone ZJ is undernourished with a current of lower intensity than the current used to perform the daytime running function.

According to another embodiment, illustrated in FIG. 7, a subzone ZC is provided in the zone Code ZC, which extends to the right of the first zone ZR, on the other side of the cutoff line 54. Like the first zone ZR and the second zone ZJ, the zone Code ZC and the zone ZC can be supplied with different currents.

When performing a Code beam, this ZC subfield is used to supercharge the central part of the Code area. During the construction of a Route beam, the central zones are supercharged, namely the ZR Route zone and the ZC sub-zone that extends to the right of the Route zone, while the peripheral zones are under-fed. , namely zones ZC and ZJ. And for the realization of a diurnal beam, it feeds the rods and the areas they form in a reverse manner to what has been said, that is to say by undernourishing the central areas, namely the zone ZR Road and subzone ZC which extends to the right of the zone Road, while one feeds in a normal way the zones in periphery, namely the zones ZC and ZJ.

It will be understood that in the application cases just described, the rods are configured to form at least a first zone ZR and a second zone ZJ that can be activated selectively: the first zone ZR is capable of generating at least a portion of a first light beam, namely a Route beam, in a first state, electric supercharging or at least standard power supply, and a part of a second beam, namely a diurnal beam, in a second state of subtraction. power supply; and the second zone ZJ is able to generate a part of this second beam, namely the diurnal beam, together with the first zone in the second undernourishment state. Moreover, this second zone ZJ can be driven to move from a first state, close to or equal to a standard state, in which it is able to generate a part of the beam diurnal, together with the first zone when the latter is in the state of undernourishment, to a second state of undernourishment, in which, optionally, it is able to generate a part of the Route beam, together with the first zone ZR when it is in said first state. In addition, the first zone ZR and the second zone ZJ can be driven in a third state, in which they are able to jointly generate a beam of the position light type.

The present invention is particularly applicable to a front projector of a motor vehicle. The foregoing description clearly explains how the invention makes it possible to achieve the objectives that it has set itself and in particular to propose a light device that makes it possible to achieve, at a lower cost, and without loss of photometric quality, multi-function lighting. , that is to say a different lighting with a single optical shaping, including a device for achieving a code-type lighting, road-type lighting, a daytime lighting function and a fire function position. It is particularly advantageous according to the invention that a semiconductor source comprising electroluminescent rods is used and that these rods are grouped into different zones which are fed to different feed streams so that they each participate in different lighting functions according to their state. It is thus possible to propose a common signature for several lighting functions and in particular a Route fire function, a daytime running light function and a position light function.

Of course, various modifications may be made by those skilled in the art to the structure of the light device which has just been described by way of non-limiting example, since it uses at least one semiconductor light source. electroluminescent rods comprising distinct zones of identifiable rods, in particular to play easily on variations of the power supply from one zone to another. In any event, the invention can not be limited to the embodiment specifically described in this document, and extends in particular to all equivalent means and any technically operating combination of these means.

Claims

Motor vehicle light device, comprising a semiconductor light source (1) comprising a plurality of submillimeter-sized electroluminescent rods (8), and an optical projection (2) of at least a portion of the light rays emitted by said light source, said electroluminescent rods being arranged to form a first zone (34, ZR) and a second zone (36, ZJ) selectively activatable, the first zone being able to generate at least a portion of a first light beam in a first state and a portion of a second beam in a second state, the second zone being adapted to generate a portion of said second beam together with the first zone in the second state.

2. Device according to one of claims 1, characterized in that the first zone (34, ZR) is in said first state, capable of generating on the one hand at least a portion of said first light beam, when electrically powered with a current of electrical intensity greater than a first determined threshold and in said second state, capable of generating at least a portion of said second light beam, when it is electrically powered with a current of electrical intensity lower than a second determined threshold .

3. Device according to one of the preceding claims, characterized in that said first light beam is a road-type beam, said second light beam being a diurnal-type beam.

4. Device according to any one of the preceding claims, characterized in that the second zone (36, ZJ) is adapted to take a first state in which it is able to generate a portion of said second beam, together with the first zone ( 34, ZR) when the latter is in said second state, and a second state in which the second zone is able to generate a portion of a third beam, together with the first zone when the latter is in a third state.

5. Device according to the preceding claim, characterized in that said third beam is a beam of the position light type.

Device according to one of the preceding claims, characterized in that the semiconductor light source (1) comprises a plurality of electroluminescent rods (8) projecting from a substrate (10).

7. Device according to the preceding claim, characterized in that the substrate (10) is based on silicon.

8. Device according to any one of the preceding claims, characterized in that the electroluminescent rods (8) are each delimited by an end face (26) and a circumferential wall (28) which extends along an axis length of the rod defining its height, the light being emitted at least from the circumferential wall.

9. Device according to the preceding claim, characterized in that the height of a rod (8) is between 1 and 10 micrometers.

10. Device according to one of the preceding claims, characterized in that the second zone (ZJ) surrounds at least partly the first zone (ZR).

11. Device according to one of the preceding claims, characterized in that the two zones (ZR, ZJ) are simultaneously electrically powered to emit light rays in a given lighting surface to participate in the formation of a first function d lighting, the second zone being undernourished with respect to the supply of the first zone.

12. Device according to the preceding claim, characterized in that the two zones (ZR, ZJ) are electrically powered simultaneously to emit light rays in a given lighting surface to participate in the formation of a second lighting function, the first zone being undernourished with respect to the supply of the second zone.

13. Device according to one of the preceding claims, characterized in that the light source (1) comprises a third zone (ZC) formed of a plurality of said electroluminescent rods (8) and selectively activatable relative to the first (ZR) and second (ZJ) zones, said third zone being able to generate at least a portion of a fourth light beam.

14. Device according to the preceding claim, characterized in that said fourth light beam is a beam type dipped beam.

15. Device according to one of claims 12 or 13, characterized in that the electroluminescent rods (8) defining the third zone (ZC) are separated from the rest of the electroluminescent rods of the light source (1) by the presence of a separating element.

16. Device according to any one of claims 12 to 14, characterized in that the third zone is arranged in two sub-areas adapted to be powered at different current intensities.