• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A semiconductor light source (2) comprises a substrate and a plurality of submillimeter-sized electroluminescent rods (4), said rods extending longitudinally from said substrate. According to the invention, at least one wall (5) also extends projecting from the substrate, between two of said rods, the wall having reflective properties of the rays emitted by at least one of said two electroluminescent rods (4).
    公开号:FR3053435A1
    申请号:FR1656342
    申请日:2016-07-01
    公开日:2018-01-05
    发明作者:Pierre Albou；Zdravko Zojceski
    申请人:Valeo Vision SA；
    IPC主号:
    专利说明:

    (57) A semiconductor light source (2) includes a substrate and a plurality of light emitting rods (4) of submillimetric dimensions, said rods extending longitudinally from said substrate.
    According to the invention, at least one wall (5) also projects from the substrate, between two of said rods, the wall having properties reflecting the rays emitted by at least one of said two light-emitting rods (4).
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    LIGHTING AND / OR SIGNALING DEVICE FOR
    MOTOR VEHICLE
    The invention relates to the field of lighting and / or signaling, and more particularly relates to a semiconductor light source, with a high capacity for emitting light rays.
    Semiconductor light sources are known in the form of two-dimensional light-emitting diodes, in which there is a first semiconductor zone for the injection of electrons, a second semiconductor zone for the injection of holes and a zone so-called “active” semiconductor in which the electrons and the injected holes recombine in a radiative manner. These semiconductor zones are arranged, in this two-dimensional planar technology, on substrates in planar layers.
    The use of these light-emitting diodes, in particular for advantages of space and autonomy compared to conventional light sources, is more and more frequent. The use of light-emitting diodes in lighting and / or signaling modules has also enabled market players (car manufacturers and designers of lighting and / or signaling devices) to bring a creative touch to the design. of these devices, in particular by the use of an ever greater number of these light-emitting diodes to achieve optical effects. One of the disadvantages of using these diodes is their cost.
    In this economic context, it is sought an optimal light output and a low loss of rays emitted by the semiconductor zone, whereas this one tends to generate light rays in a random way which do not leave automatically in the desired direction to exit the device associated with the light source.
    In particular in order to avoid losing the rays which would be emitted towards the substrate, opposite to the desired direction of the light rays, it is possible to insert a reflective surface between the substrate and the first semiconductor zone arranged in the vicinity of this one. Ci, and this in order to return the pbotons towards the exit of the device.
    The present invention aims to propose an alternative to the use of light-emitting diodes in two dimensions as it has just been presented, in a double context, both economic where the cost of light sources are sought as low as possible, and technique where an optimal emission intensity is sought.
    The invention relates to a semiconductor light source comprising a substrate and a plurality of light-emitting rods of submillimetric dimensions, said rods extending longitudinally from said substrate, and in which at least one wall projecting from the substrate, between two of said rods, the wall having properties reflecting the rays emitted by at least one of said two rods.
    The production of a three-dimensional semiconductor light source makes it possible to increase the emitting surface and therefore the current density. It is understood that the production of rods extending parallel to each other from the substrate makes it possible to play on their reciprocal spacing to modify the density of the emitting zones and therefore the luminance of the source. If you want a light source with high luminance, you tighten the rods relative to each other. This density of sticks poses the problem for some of the rays emitted by a stick, namely the rays leaving substantially perpendicular to the stick, to be absorbed by the neighboring stick. The closer the rods are to each other, the greater the number of these rays absorbed by the neighboring rod.
    The presence of reflective walls arranged between the neighboring rods allows according to the invention, in addition to a function to ensure if necessary a contrast between the rays emitted by a stick, or a group of sticks, and the rays emitted by a stick, or a group of rods, neighbor, to optimize the quantity of rays leaving each of these rods, by avoiding a loss of the rays, emitted by a rod, by absorption by a neighboring rod, and on the other hand.
    According to different characteristics of the invention, taken alone or in combination, it can be provided that:
    - The wall is arranged around a stick, so that the latter is separated from neighboring sticks by said wall;
    - The wall is arranged continuously around the stick. ;
    - The wall has a shape of revolution around the stick.
    The light source may advantageously include a plurality of walls with reflective properties projecting from the substrate, being arranged respectively in the vicinity of at least one rod. The walls can be arranged on the substrate so that each rod is surrounded by at least two walls with reflective properties.
    According to a characteristic of the invention, the rods and walls extend from the same substrate.
    According to different characteristics taken alone or in combination, specific to the profile of the walls, it can be provided that:
    - The wall, in a radial plane to a direction of elongation of the rod whose wall reflects the emitted rays, has a substantially parabolic profile;
    By “direction or axis of elongation” of the rod is meant the main direction of the rod, which gives the light source the third dimension allowing the increase in the emission surface, this direction being substantially perpendicular to the layer of substrate from which the rods extend.
    - the focal point of the parabola is centered on the base of the stick, at the junction with the substrate
    - The focal point of the parabola, for a given radial plane, is centered on a circumferential wall of the rod.
    - The wall has a profile with several sections of parabola, a focal point of a first parabola section being centered on the base of the rod whose wall reflects the emitted rays, while the focal point of another parabola section is centered substantially halfway up the stick.
    The reflective properties of the walls of the light source can in particular be obtained by the production of these walls in organic polymer loaded with metallic particles. More particularly, provision may be made for the wall to be made of silicone loaded with titanium oxide.
    It may also be provided in an alternative embodiment that the wall is formed from a non-reflective material, and for example from a material similar to the material of the substrate or to the material of the rods, and that a reflective coating is placed on this wall.
    According to different characteristics of the invention, it can also be provided that:
    - the wall with reflective properties is formed by a network of mirrors with at least two inclined planes, the mirrors of the network extending concentrically around a rod, projecting from the substrate;
    - Each mirror is formed by a first plane, which can be slightly inclined with respect to the plane of the upper surface of the substrate, and by a second plane inclined with respect to the first plane;
    - Each lens of the network has an annular shape around the stick with a succession of flat mirrors inclined between them. As a variant, provision may be made for each lens of the array to be formed by a mirror of substantially parabolic shape;
    - The network can have a sawtooth profile and the height of the teeth can increase as the distance from the corresponding stick increases.
    It is also possible to provide, between two neighboring rods, the presence of a wall with reflecting properties which is common to the two rods and the presence of at least one network of reflecting mirrors with a sawtooth profile specific to one of the rods.
    Furthermore, provision may be made for the semiconductor light source comprising a plurality of light-emitting rods of submillimetric dimensions to further comprise a layer of a polymeric material in which the rods are at least partially embedded; this polymeric material can be based on silicone, it being understood that the polymeric material is based on silicone since it mainly comprises silicone, for example 25% and in practice from 50% to about 99%.
    The layer of polymeric material may include a phosphor or a plurality of phosphors excited by the light generated by at least one of the plurality of rods. A phosphor or light converter is understood to mean the presence of at least one luminescent material designed to absorb at least part of at least one excitation light emitted by a light source and to convert at least part of said light. of excitation absorbed in emission light having a wavelength different from that of the excitation light. This phosphor, or this plurality of phosphors, can be at least partially embedded in the polymer or else disposed on the surface of the layer of polymeric material.
    The layer of polymeric material may also comprise a dye (pigment in English), preferably white, allowing in high concentration a good reflection of light and in low concentration a diffusion of light, sometimes desired so that the light source is uniform. This dye is typically titanium dioxide (TiO2).
    All of the light-emitting sticks can extend from the same substrate, and these sticks can in particular be formed directly on this substrate. Provision may be made for the substrate to be based on silicon or on silicon carbide. It is understood that the substrate is based on silicon when it mainly comprises silicon, for example at least 25% and in practice from 50% to about 99%.
    According to characteristics specific to the constitution of the light-emitting sticks and to the arrangement of these light-emitting sticks on the substrate, it can be provided that, each characteristic being able to be taken alone or in combination with the others:
    - Each rod has a generally cylindrical shape, in particular of polygonal section; we can provide that each stick is the same general shape, and in particular a hexagonal shape;
    - the rods are each delimited by a terminal 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 planar or curved, or pointed, at its center;
    - the rods are arranged in a two-dimensional matrix, whether this matrix is regular, with constant spacing between two successive rods of a given alignment, or that the rods are staggered; it is understood that in this case of a two-dimensional matrix, the waves of rods can be considered as rows of rods;
    - the height of a stick is between 1 and 20 micrometers;
    - the largest dimension of the terminal face is less than 2 micrometers;
    - the distance between two immediately adjacent rods is at least equal to 2 micrometers, and at most equal to 100 micrometers.
    As mentioned above, the invention also relates to a lighting and / or signaling device comprising a light source as described above, as well as an optical system for shaping the rays emitted by the light source for the emission outside the device of a light beam.
    The term “shaping optics” means means making it possible to change the direction of at least part of the light rays. According to the invention, the shaping optic creates a real image, and possibly anamorphic, of a part of the light source at a distance, finite or infinite, very large compared to the dimensions (of a ratio of l '' order of at least 30, preferably 100) from the source. This shaping optic can consist of one or more reflectors, or else a lens, or even a combination of these two possibilities. The shaping optic and the light source can be arranged so that the light source is off-center with respect to the focus object of the shaping optic. This makes it possible in particular to project an image which appears continuous, in direct imagery, without the need to provide a projection system which has to modify the source image before being projected. This is particularly advantageous for simplifying the proposed device, in particular when one or more separation walls are arranged projecting from the substrate to participate in the optical pixelation of the projected regulatory beam.
    Thus, a technology is applied to the automotive field consisting in producing the light-emitting zone by a plurality of light-emitting sticks which are grown on a substrate, in order to produce a three-dimensional topology. It is understood that this three-dimensional topology has the advantage of multiplying the light emission surface compared to the light-emitting diodes known hitherto in the automotive field, namely substantially planar diodes. In this way, it is possible to provide a very bright white light at low cost.
    The device thus takes place both in a headlight and in a rear light of a motor vehicle.
    The present also relates to a method for producing a light source with light-emitting rods of submillimetric dimensions, during which at least the following steps are carried out:
    - the growth of rods and reflecting walls from the substrate, simultaneously or successively;
    - the coating of at least one wall of reflective material by masking the sticks to prevent them from being covered with this reflective material.
    Other characteristics and advantages of the present invention will appear more clearly with the aid of the description and the drawings, among which:
    Figure 1 is a schematic perspective representation of a semiconductor light source according to a first embodiment of the invention, in which there is made visible in section a row of light-emitting sticks and reflective walls surrounding these sticks and grouped into a single unit;
    Figure 2 is a schematic representation similar to that of Figure 1, illustrating a semiconductor light source according to a second embodiment different from the first mode illustrated in Figure 1 in the form of the reflecting walls;
    Figure 3 is a sectional view of a detail of a light source according to the invention, in which an electroluminescent rod has been made visible projecting from a substrate and a reflecting wall arranged near this rod;
    FIG. 4 is a detailed view of a light source according to an embodiment of the invention, in which two rods and a wall with reflective properties have been made visible disposed between these two rods, the wall here having a profile at least partially parabolic;
    Figure 5 is a variant of the embodiment of Figure 4, wherein the wall with reflective properties has a trapezoid shape;
    Figures 6a and 6b are illustrations of alternative embodiments as to the shape of the walls with reflective properties; and FIGS. 7a and 7b are illustrations, respectively in front section and top view, of another alternative embodiment, in which the walls with reflecting properties are formed by a network of mirrors, here parabolic, arranged concentrically around 'a stick.
    A semiconductor light source 2 according to the invention is illustrated in FIG. 1. This source comprises light-emitting sticks of submillimetric dimensions, that is to say semiconductor sources in three dimensions as will be exposed below, unlike conventional two-dimensional sources, assimilated to substantially planar sources due to their thickness of the order of a few nanometers, whereas a source with light-emitting rods has a height at least equal to a micrometer.
    The light source 2 comprises a plurality of light-emitting sticks 4 of submillimetric dimensions, which will hereinafter be called light-emitting sticks, and a plurality of walls with reflecting properties 5 arranged around the sticks. Both the walls with reflecting properties 5 and the light-emitting rods 4 originate on the same substrate 6.
    Each electroluminescent rod, here formed by the use of gallium nitride (GaN), extends perpendicularly, or substantially perpendicularly, projecting from the substrate, here made from silicon, other materials such as silicon carbide which can be used without leave the context of the invention. For example, the light-emitting sticks could be made from an alloy of aluminum nitride and gallium nitride (AlGaN), or from an alloy of aluminum, indium and gallium ( AllnGaN).
    The substrate 6 has a lower face 8, to which a first electrode 10 is attached, and an upper face 12, projecting from which extend the light-emitting rods 4 and to which a second electrode 14 is attached. Different layers of material are superimposed on the upper face 12, in particular after the growth of the light-emitting rods from the substrate here obtained by a bottom-up approach. Among these different layers, one can find at least one layer of electrically conductive material, in order to allow the electrical supply of the rods. This layer is etched so as to connect such and such a stick together, the ignition of these sticks can then be controlled simultaneously by a control module not shown here. Provision may be made for at least two light-emitting sticks or at least two groups of light-emitting sticks of the semiconductor light source 2 to be arranged to be switched on separately by means of an ignition control system. .
    The electroluminescent rods of submillimetric dimensions stretch from the substrate and each comprise a core of gallium nitride, around which are arranged quantum wells formed by a radial superposition of layers of different materials, here gallium nitride and gallium nitride -indium, and a shell surrounding the quantum wells also made of gallium nitride.
    Each rod extends along a longitudinal axis, or elongation axis 16, defining its height, the base 17 of each rod being arranged in a plane of the upper face 12 of the substrate 6.
    The light-emitting sticks 4 of the semiconductor light source advantageously have the same shape. These rods are each delimited by an end face 18 and by a circumferential wall 20 which extends along the longitudinal axis
    16. When the light-emitting rods are doped and are the subject of a polarization, the resulting light at the output of the semiconductor source is emitted mainly from the circumferential wall 20, it being understood that provision can be made for light rays also emerge, at least in small quantities, from the terminal face 18. As a result, each rod acts as a single light-emitting diode and the density of the light-emitting rods 4 improves the light output of this semi-light source -driver.
    The circumferential wall 20 of a rod 4, corresponding to the gallium nitride shell, is covered by a layer of transparent conductive oxide (OCT) which forms the anode of each rod complementary to the cathode formed by the substrate. This circumferential wall 20 extends along the axis of elongation 16 from the substrate 6 to the end face 18, the distance from the end face 18 to the upper face 12 of the substrate, from which the rods originate. 4, defining the height of each stick. For example, it is expected that the height of an electroluminescent rod 4 is between 1 and 10 micrometers, while it is expected that the largest transverse dimension of the end face, perpendicular to the longitudinal axis 16 of the electroluminescent stick concerned, ie less than 2 micrometers. Provision may also be made to define the surface of a rod, in a cutting plane perpendicular to this longitudinal axis 16, within a range of determined values, and in particular between 1.96 and 4 square micrometers.
    These dimensions, given by way of nonlimiting example, make it possible in particular to demarcate a semiconductor light source comprising electroluminescent rods from a light source from sources with substantially planar diodes as used previously.
    It is understood that during the formation of the rods 4, the height can be changed from one light source to another, so as to increase the luminance of the semiconductor light source when the height is increased. The height of the sticks can also be modified within a single light source, so that a group of sticks can have a height, or heights, different from another group of sticks, these two groups being constitutive of the semiconductor light source comprising light-emitting rods of submillimetric dimensions.
    The shape of the light-emitting sticks 4 can also vary from one device to another, in particular on the section of the sticks and on the shape of the end face 18. It has been illustrated in the figures of the light-emitting sticks having a generally cylindrical shape, and in particular of polygonal section, here more particularly hexagonal. We understand that it is important that light can be emitted through the circumferential wall, whether it has a polygonal or circular shape for example.
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    Furthermore, the end face 18 may have a substantially planar shape and perpendicular to the circumferential wall, so that it extends substantially parallel to the upper face 12 of the substrate 6, as illustrated in the figures, or else it can have a domed or pointed shape at its center, so as to multiply the directions of emission of the light leaving this terminal face.
    In FIG. 1, the light-emitting rods 4 are arranged in a two-dimensional matrix. It is understood that the invention covers other distributions of rods, in particular with densities of rods which can be variable from one light source to another, and which can be variable according to different zones of the same light source. . The number of light-emitting sticks 4 projecting from the substrate 6 may vary from one light source to another, in particular to increase the light density of the light source, but it is agreed that the separation distances between two sticks must be at least equal to 2 micrometers, so that the light emitted by the circumferential wall 20 of each electroluminescent rod 4 can leave the matrix of rods. Furthermore, it is expected that these separation distances will not be greater than 100 micrometers.
    At least one wall with reflective properties 5 is arranged projecting from the substrate, advantageously the same as that from which the rods extend, to be placed in the vicinity of at least two of the light-emitting rods of the light source. This wall allows on the one hand to split the beams that can be emitted by this light source in three dimensions. Thus, the presence of a wall rising between two neighboring rods, or two groups of neighboring rods, makes it possible to segment the beam by preventing the rays emitted by a first group of rods from overlapping with rays emitted by a second group of neighboring sticks.
    According to the invention, the wall or walls 5 arranged between the rods 4 have reflective properties so that these walls allow, in addition to their function of cutting the beam emitted by the light source 2, the reflection of the rays emitted by a rod, it being understood that these walls with reflecting properties 5 are configured to reflect these rays towards the output of the device equipped with such a light source, that is to say opposite of the substrate 6.
    In the various illustrated embodiments of the invention, the wall with reflective properties 5 comprises lateral faces 22 and an upper face 24, with at least one lateral face 22 which extends from the substrate 6, substantially at the base 17 one of the rods 4, that is to say at the junction of the rod and the substrate, and the upper face 24 which extends parallel to the substrate, between the upper ends of the lateral faces, that is to say the end opposite the substrate.
    As will be described below, the walls with reflective properties 5 can differ from one embodiment to another and in particular by the shape of a lateral face 22, the width of the upper face 24, or even the height of the wall.
    In particular, different profiles of at least one of the side faces 22 can be provided, as soon as it is configured to reflect the rays emitted by the rod. The width of the upper face 24, that is to say the dimension of the upper face between the two lateral faces, can vary and it can, under extreme conditions, be substantially zero, the opposite lateral faces 22 of a same wall then being contiguous at their upper end.
    The height of the walls with reflecting properties 5 is defined by the distance between the upper face 24 of these walls and the substrate 6 from which the wall or walls extend, and it is understood that walls may have heights different from one light source to another, or within the same light source. A wall that is higher than another makes it possible to make the cut in the beam sharper, that is to say a clear segmentation of the rays projected by a rod or a group of rods arranged on one side of the wall and a stick or a group of sticks arranged on the other side of the wall. It is understood that its height makes it possible to have a reflecting action on all of the rays emitted at least by the lower part of the corresponding stick.
    Whatever the variant, one can provide within the light source 2 a single wall with reflecting properties 5 between two sticks, or two groups of sticks, as illustrated in FIG. 2, or a set of walls , distributed independently of each other or grouped in a single unit, as illustrated in FIG. 1.
    In other words, the light source 2 may have one or more walls with reflective properties 5 which project from the substrate 6 in the plurality of light-emitting rods, that is to say between at least two rods or sticks groups.
    According to the invention, the wall with reflective properties 5 should be arranged between two light-emitting sticks 4. Arrangements of reflective walls may be provided which allow such a characteristic and in particular walls arranged around a stick, so that it this is separated from the neighboring rods by the wall (s). A single wall can be used to surround this stick, being arranged continuously all around the stick, and advantageously having a shape of revolution around the stick (as visible in Figures 1, 3, 6a and 6b).
    The rods 4, or groups of rods, separated by a wall with reflective properties 5 are advantageously selectively activatable.
    We will now describe particular embodiments of the invention in that the wall with reflective properties 5 has a side face 22 to the profile, in a radial plane to a direction of elongation of the rod 4 whose wall reflects the emitted rays. , substantially parabolic, in particular with reference to FIGS. 1 to 4.
    In the definition of the shape of the wall which precedes, one can understand by the term “wall”, a portion of wall which is arranged in the vicinity of a determined stick, and by the expression “direction (or axis) of elongation "of the rod, the main direction of the rod, which gives the light source the third dimension allowing the increase of the emission surface, this direction being substantially perpendicular to the layer of substrate from which extend the sticks.
    The wall may be formed of a surface of revolution generated by the rotation of a parabolic arc, with an axis parallel to the axis of extension of the rods. The parabolic shape of the lateral face of the reflecting wall makes it possible to return, substantially parallel to the axis of elongation of the corresponding rod, all of the rays passing through its focal point F. In this case, the focal point of the parabolic reflector is centered on the base 17 of the rod 4, at the junction with the substrate 6, or even that it is centered on the circumferential wall of the rod. An electroluminescent device has a better light output when the temperature is low, and it is understandable that in this context the advantage of concentrating the focus on the lower part of the stick, which is less hot and therefore generates more rays.
    By substantially parabolic profile is meant to cover both a first wall 5a (visible in FIG. 3), having a side face with a continuous and regular parabolic profile from the base of the stick to the upper face, as well as a second wall 5b (visible in FIG. 4) having a plurality of successive parabolic profiles, and having in fact different foci. In the same context of lighting efficiency as a function of the temperature of the source, there is in particular illustrated in FIG. 4 an advantageous embodiment in that the lateral face 22 has two portions of parabolas 22a and 22b, the junction plane is represented by dashed lines, with a focal point F1 of a first parabola section 22a centered on the base 17 of the rod 4 whose wall reflects the emitted rays, and a focal point F2 of a second parabola section 22b centered approximately halfway up the stick 4.
    In each of these cases, whether the wall has one or more sections of parabola, we will find the advantage of the presence of this reflective wall in the vicinity of a rod due to the orientation of the rays towards the outlet of the equipped device. from this light source.
    As illustrated in FIG. 4, in which the path of the light rays emitted by the light-emitting rods 4 and passing through the first or the second focal point is shown, it is understood that the presence of this wall with reflective properties 5 makes it possible in particular to avoid rays which emanate from an electroluminescent rod substantially perpendicular to the circumferential wall 20 from arriving on the neighboring rod with a substantially straight impact angle relative to the circumferential wall of the neighboring rod and therefore conducive to absorption by that neighboring stick.
    When the wall with reflecting properties 5 is arranged on the path of the rays emitted by the corresponding light-emitting stick, these rays cannot be absorbed by the neighboring stick, and the reflecting properties of the side face opposite the emitting stick allow the rays to be deflected. until they exit the device equipped with the light source.
    The first rays 30 emitted by the rod and passing through the first, respectively the second focal point of the first, respectively the second, parabola portion of the lateral face exit parallel to the axis of the parabola when they meet the first, respectively the second portion of parabola of the lateral face.
    The rays emitted passing at other points than the hearths, or the second rays 32 emitted passing through one of the hearths but directed towards another portion of parabola than that associated with said hearth are deflected in particular opposite the substrate.
    It should be noted that a wall according to the invention has reflective properties of the rays emitted by at least one of the two rods between which it is arranged. In other words, the wall 5 could have a first lateral face 22 opposite a first rod which has reflective properties, in particular by means of a coating disposed on this first lateral face, and a second lateral face. next to a neighboring rod which does not have reflective properties.
    As just described, or in other embodiments, some of which will be described below, the walls 5 of the light source 2 projecting from the substrate 6 have reflective properties so that at least one of their faces 22, 24 is able to reflect rays emitted by one of the rods. Provision may be made for the reflective properties to be produced in the bulk of the walls or else to be attached to one or more faces of these walls. In particular, these walls can be made from organic polymer, such as silicone (SiO), which has previously been loaded with metallic particles, such as titanium oxide (TiO2). Another embodiment could be to form the wall in a non-reflective material, and for example in a material similar to the material of the substrate or to the material of the rods, and to apply to at least one of the faces of this wall a reflective coating. . In this case, in a method for producing the light source, provision will be made, after the growth of rods and of reflective walls from the substrate, simultaneously or successively, for the coating of at least one wall with a layer of a reflective material by masking the sticks to prevent them from being covered with this reflective material.
    The light source 1 may further comprise, as illustrated in FIG. 3, a layer 26 of a polymeric material in which light-emitting rods 4 and walls with reflective properties 5 are at least partially embedded. The layer 26 can thus extend over the entire extent of the substrate or only around a determined group of light-emitting sticks 4 and walls 5. The polymeric material, which can in particular be based on silicone, makes it possible to protect the sticks electroluminescent 4 without interfering with the diffusion of light rays. In addition, it is possible to integrate into this layer 26 of polymeric material wavelength conversion means, and for example phosphors, capable of absorbing at least part of the rays emitted by one of the rods and at converting at least part of said absorbed excitation light into emission light having a wavelength different from that of the excitation light. It is equally possible to provide that the wavelength conversion means are embedded in the mass of the polymer material, or else that they are arranged on the surface of the layer of this polymer material. Furthermore, it is possible to load the layer of polymeric material, arranged between the rods and the walls with reflective properties, with a pigment, in particular white, which can serve as an optical diffuser.
    We will now describe a first embodiment, which differs from what has been described previously in the shape of the wall with reflective properties, which no longer has a parabolic profile, but which takes the form of a trapezoid, as well as in the height of this wall, which here has a height less than that of the rods.
    In FIG. 5, a reflecting wall 105 has a trapezoidal shape, with the small base substantially halfway up the rods of which it is close. The inclined planes 34 forming lateral faces reflect the rays emanating from the lower part 36 of the stick 4, that is to say the part at the base of the stick in the vicinity of the substrate. The upper face 38 of the trapezoid, corresponding to the small base, is also reflective, and it ensures the reflection of the rays emanating from the upper part 40 of the stick, that is to say the part of the stick opposite the substrate. 6, and which left towards this substrate 6.
    Other variants are illustrated in FIGS. 6a and 6b, in which once again the reflective walls differ from what has been previously described in the form of the lateral faces 22 opposite the rods 4, which can be in the form of a regular ramp ( Figure 6a) or in the shape of a multifaceted bowl (Figure 6b).
    It will be understood that the same rod could be surrounded by walls whose profiles are different from one wall to the other, the rays emitted by this rod in a given radial direction relative to its axis of elongation may then not be deflected in the same way as rays emitted by this same rod in another radial direction and therefore meeting a wall of different shape.
    Another variant is illustrated in FIGS. 7a and 7b, in which the wall with reflecting properties is formed by a network of mirrors 42 which extends concentrically around a rod, projecting from the upper face of the substrate. We thus reproduce, around at least one stick, Fresnel lenses arranged concentrically and formed respectively by a first plane 44, here slightly inclined relative to the plane of the upper surface of the substrate, and by a second plane 46 inclined relative to in the foreground. Each lens of the array thus has an annular shape around the rod with a succession of plane mirrors, it being understood that it can be provided that each mirror of the annular lens can be of substantially parabolic shape. In Figure 7b, there is illustrated by way of example the arrangement of two concentric mirrors 42 formed respectively around four neighboring rods.
    This creates a network with a sawtooth profile (visible in Figure 7a), in which, according to the illustrated embodiment, the height of the teeth, that is to say the distance between the free end and the substrate, increases gradually as the distance from the corresponding rod, until meeting the network extending concentrically around the neighboring rod.
    It is possible according to the invention to combine the presence of a wall with reflecting properties which is common to two neighboring rods, as illustrated in FIGS. 1 to 6, and the presence of a network of reflecting mirrors with a profile in sawtooth as just described with reference to Figures 7a and 7b. The network of mirrors then extends directly from the stick, between the wall with reflective properties and this stick.
    It is understood from the description of the different variants which precedes that they could be combined with one another on the same light source, a wall possibly having a certain shape in one zone of the source and another wall another shape in another area, while a network of reflecting mirrors could be provided on the surface of the substrate in an area still different from the light source.
    The present invention applies to a headlight as well as to a rear light of a motor vehicle. The foregoing description clearly explains how the invention makes it possible to achieve the objectives which it has set itself and in particular to propose a lighting and / or signaling device which makes it possible to improve the performance of light-emitting diodes in two dimensions. known from the prior art, this better light output being obtained on the one hand by the presence of sticks projecting from a substrate and the combined presence of reflective walls, these walls making it possible to increase the quantity of rays emitted in the direction of the output of a lighting device equipped with such a light source.
    权利要求:
    Claims (15)
    [1" id="c-fr-0001]
    1. A semiconductor light source (2) comprising a substrate (6) and a plurality of light-emitting rods (4) of submillimetric dimensions, said rods extending longitudinally from said substrate, and in which at least one wall (5 105) extending projecting from the substrate, between two of said rods, the wall having properties reflecting the rays emitted by at least one of said two rods.
    [2" id="c-fr-0002]
    2. Light source according to claim 1, characterized in that the wall with reflective properties (5) is arranged around an electroluminescent rod (4), so that the latter is separated from the neighboring rods by said wall.
    [3" id="c-fr-0003]
    3. Light source according to claim 2, characterized in that the wall with reflecting properties (5) is arranged continuously around the electroluminescent rod (4).
    [4" id="c-fr-0004]
    4. Light source according to one of claims 1 to 3, characterized in that the wall with reflective properties (5) has a shape of revolution around the electroluminescent rod (4).
    [5" id="c-fr-0005]
    5. Light source according to one of the preceding claims, characterized in that it comprises a plurality of walls with reflective properties (5) projecting from the substrate (6) being arranged respectively in the vicinity of at least a stick.
    [6" id="c-fr-0006]
    6. Light source according to the preceding claim, characterized in that each electroluminescent rod (4) is surrounded by at least two walls with reflective properties (5).
    [7" id="c-fr-0007]
    7. Light source according to one of the preceding claims, characterized in that the rods (4) and walls with reflecting properties (5) extend from the same substrate (6).
    [8" id="c-fr-0008]
    8. Light source according to one of the preceding claims, characterized in that the wall with reflecting properties (5), in a radial plane to an elongation axis (16) of the electroluminescent stick (4) whose wall reflects the rays emitted, has a substantially parabolic profile.
    [9" id="c-fr-0009]
    9. Light source according to the preceding claim, characterized in that the focal point of the parabola is centered on the base (17) of the electroluminescent rod (4).
    [10" id="c-fr-0010]
    10. Light source according to one of claims 8 or 9, characterized in that the focal point of the parabola, for a given radial plane, is centered on a circumferential wall (20) of the electroluminescent rod (4).
    [11" id="c-fr-0011]
    11. Light source according to one of claims 1 to 7, characterized in that the wall with reflective properties (5) has a profile with several portions of parabola (22a, 22b), a focus (Fl) of a first parabola section (22a) being centered on the base (17) of the light-emitting stick (4) whose wall reflects the emitted rays, while the focal point (Fl) of another parabola section (22b) is centered substantially at mid - height of the stick.
    [12" id="c-fr-0012]
    12. Light source according to one of the preceding claims, characterized in that the wall with reflective properties (5) is made of organic polymer loaded with metallic particles.
    [13" id="c-fr-0013]
    13. Light source according to one of the preceding claims, characterized in that a layer of polymer material (26) is disposed between the wall with reflecting properties (5) and the electroluminescent rod (4) whose wall reflects the rays. issued.
    [14" id="c-fr-0014]
    14. Light source according to one of the preceding claims, characterized in that the wall with reflecting properties is formed by a network of mirrors with at least two inclined planes, the mirrors of the network extending concentrically around a stick, projecting from the substrate (6).
    [15" id="c-fr-0015]
    15. Method for producing a light source (2) with light-emitting sticks of submillimetric dimensions, during which light-emitting sticks (4) and walls (5) are grown, between at least two sticks, from a substrate ( 6), then one proceeds to coating at least one wall with a material with reflective properties by masking the rods to prevent them from being covered with this reflective material.
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    WO2003017320A1|2001-08-21|2003-02-27|Nam-Young Kim|Lamp utilizing a light emitted diode|
    WO2008079076A1|2006-12-22|2008-07-03|Qunano Ab|Led with upstanding nanowire structure and method of producing such|
    US20110193105A1|2010-08-27|2011-08-11|Quarkstar, Llc|Solid State Light Sheet for General Illumination Having Substrates for Creating Series Connection of Dies|
    US20130313583A1|2012-05-22|2013-11-28|Samsung Electronics Co., Ltd.|Light-emitting device and method of manufacturing the same|
    US20130313514A1|2012-05-23|2013-11-28|Samsung Electronics Co., Ltd.|Semiconductor light emitting device|
    US20140166974A1|2012-12-14|2014-06-19|Samsung Electronics Co., Ltd.|Nano-structured light-emitting devices|
    FR3016463A1|2014-01-16|2015-07-17|Commissariat Energie Atomique|MICRO-DISPLAY SCREEN WITH HIGH LUMINANCE.|
    FR3080670A1|2018-04-27|2019-11-01|Valeo Vision|OPTICAL MODULE PROJECTING A PIXEL LUMINOUS BEAM|
    FR3082657B1|2018-06-19|2021-01-29|Aledia|MANUFACTURING PROCESS OF AN OPTOELECTRONIC DEVICE WITH SELF-ALIGNED LUMINOUS CONTAINMENT WALLS|
    FR3082662B1|2019-06-14|2020-11-13|Aledia|A method of manufacturing an optoelectronic device with self-aligned light confinement walls|
    法律状态:
    2017-07-31| PLFP| Fee payment|Year of fee payment: 2 |
    2018-01-05| PLSC| Search report ready|Effective date: 20180105 |
    2018-07-27| PLFP| Fee payment|Year of fee payment: 3 |
    2019-07-31| PLFP| Fee payment|Year of fee payment: 4 |
    2020-07-31| PLFP| Fee payment|Year of fee payment: 5 |
    2021-07-29| PLFP| Fee payment|Year of fee payment: 6 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1656342|2016-07-01|
    FR1656342A|FR3053435B1|2016-07-01|2016-07-01|LIGHTING AND / OR SIGNALING DEVICE FOR A MOTOR VEHICLE|FR1656342A| FR3053435B1|2016-07-01|2016-07-01|LIGHTING AND / OR SIGNALING DEVICE FOR A MOTOR VEHICLE|
    PCT/EP2017/066181| WO2018002251A1|2016-07-01|2017-06-29|Lighting and/or signaling device for a motor vehicle|
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