Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
  • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
  • F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
  • F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
  • F21S41/141—Light emitting diodes [LED]
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
  • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
  • F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
  • F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
  • F21S41/141—Light emitting diodes [LED]
  • F21S41/151—Light emitting diodes [LED] arranged in one or more lines
  • F21S41/153—Light emitting diodes [LED] arranged in one or more lines arranged in a matrix
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
  • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
  • F21S41/10—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source
  • F21S41/14—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by the light source characterised by the type of light source
  • F21S41/141—Light emitting diodes [LED]
  • F21S41/143—Light emitting diodes [LED] the main emission direction of the LED being parallel to the optical axis of the illuminating device
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
  • F21S41/00—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps
  • F21S41/60—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution
  • F21S41/65—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution by acting on light sources
  • F21S41/663—Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps characterised by a variable light distribution by acting on light sources by switching light sources
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/81—Bodies
  • H10H20/811—Bodies having quantum effect structures or superlattices, e.g. tunnel junctions
  • H10H20/812—Bodies having quantum effect structures or superlattices, e.g. tunnel junctions within the light-emitting regions, e.g. having quantum confinement structures
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/81—Bodies
  • H10H20/817—Bodies characterised by the crystal structures or orientations, e.g. polycrystalline, amorphous or porous
  • H10H20/818—Bodies characterised by the crystal structures or orientations, e.g. polycrystalline, amorphous or porous within the light-emitting regions
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/81—Bodies
  • H10H20/822—Materials of the light-emitting regions
  • H10H20/824—Materials of the light-emitting regions comprising only Group III-V materials, e.g. GaP
  • H10H20/825—Materials of the light-emitting regions comprising only Group III-V materials, e.g. GaP containing nitrogen, e.g. GaN
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/85—Packages
  • H10H20/851—Wavelength conversion means
  • H10H20/8511—Wavelength conversion means characterised by their material, e.g. binder
  • H10H20/8512—Wavelength conversion materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H29/00—Integrated devices, or assemblies of multiple devices, comprising at least one light-emitting semiconductor element covered by group H10H20/00
  • H10H29/10—Integrated devices comprising at least one light-emitting semiconductor component covered by group H10H20/00
  • H10H29/14—Integrated devices comprising at least one light-emitting semiconductor component covered by group H10H20/00 comprising multiple light-emitting semiconductor components
  • H10H29/142—Two-dimensional arrangements, e.g. asymmetric LED layout
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
  • F21Y2113/00—Combination of light sources
  • F21Y2113/10—Combination of light sources of different colours
  • F21Y2113/13—Combination of light sources of different colours comprising an assembly of point-like light sources
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
  • F21Y2115/00—Light-generating elements of semiconductor light sources
  • F21Y2115/10—Light-emitting diodes [LED]

Definitions

• the invention relates to the field of lighting and / or signaling, especially for motor vehicles.
• the light sources used for lighting and signaling in motor vehicles are more frequently constituted by light-emitting diodes, in particular for advantages of space and autonomy compared to conventional light sources.
• the use of light-emitting diodes in lighting and / or signaling modules has also made it possible for market players, such as car manufacturers and designers of lighting and / or signaling devices, to provide creative touch to the design of these devices, especially for the use of an ever greater number of these light emitting diodes to achieve optical effects.
• Such diodes generally have a narrow emission spectrum having the shape of a peak centered around a given wavelength.
• a first known solution consists in using a 2D emitting diode with ultraviolet emission coupled to a phosphorescent phosphor having an emission spectrum covering the whole of the visible range by the human eye.
• An ultraviolet emission is certainly very energetic, but it has the disadvantage of causing degradation of the phosphor and / or optical equipment of the lighting or signaling device. The service life of the lighting / signaling device is thus limited.
• the use of a phosphorescent phosphor implies a low conversion efficiency.
• a second solution is to use a white diode composed of a light emitting diode emitting a spectrum having a peak in the violet blue, centered around 450nm, coupled to a fluorescent phosphor having a spectrum of emission more spread in the yellow -vert, centered around 570nm.
• the spectrum of a such a light source is illustrated with reference to Figure 1, in which the peak in the blue is centered around the wavelength ⁇ and the spectrum spread in the yellow-green is centered around the wavelength ⁇ 2 .
• the present invention improves the situation.
• One aspect of the invention relates to a semiconductor light source comprising at least a first set of electroluminescent rods of submillimeter dimensions and a second set of electroluminescent rods of submillimeter dimensions, the electroluminescent rods of the first set being able to emit in a first wavelength range and the electroluminescent rods of the second set being able to emit in a second range of wavelengths, the second domain being different from the first domain.
• the first set of sticks and the second set of sticks are entangled.
• the spectrum of the light emitting module is much richer, allowing white light illumination with better color rendering.
• electroluminescent rods of different natures makes it possible to achieve such an enrichment of the spectrum of light, while allowing fine entanglement.
• the light source may further comprise a matrix comprising at least a first luminescent material, at least a portion of the electroluminescent rods being immersed in the matrix and the first luminescent material being able to absorb light in a spectrum.
• absorption device comprising at least one wavelength of the first domain or the second domain and able to emit in a third wavelength domain, the third domain being different from the first domain and the second domain.
• the first luminescent material may be a fluorescent material.
• This variant makes it possible to avoid degrading the luminescent material and / or the optical equipment of the light source, and thus improves its lifetime.
• the sticks of the first set and the sticks of the second set may be entangled by alternating groups of sticks of the first set and groups of sticks of the second set.
• the entanglement of the source is fine and provides a coherent light source.
• electroluminescent rods of each group can be distributed in a single geometric pattern.
• Such an embodiment facilitates the production of the light source and the power supply of the electroluminescent rods.
• the electroluminescent rods of the first set and the electroluminescent rods of the second set may be entangled randomly.
• the coherence of the light source is thus improved.
• two consecutive rods in a given direction of the same set and separated by at least one electroluminescent rod of the other set are separated by a distance of less than 100 micrometers.
• the groups of electroluminescent rods of the first set and the second set are alternated with a pitch less than 100 micrometers.
• the human eye can not distinguish the alternation of groups and the coherence of the light source is improved.
• the first wavelength range may comprise a wavelength of 445 nanometers
• the second wavelength range may comprise a wavelength of 467 nm.
• the first wavelength domain may comprise a wavelength of 445 nm
• the second wavelength range may comprise a wavelength greater than or equal to 600 nm.
• the first luminescent material comprises a cerium-type YAG phosphor having an emission range comprising at least one wavelength between 573 nm and 584 nm.
• the spectrum of light emitted by the light source is enriched.
• the light source may further comprise a third set of electroluminescent rods capable of emitting in a third wavelength range, the third wavelength range possibly comprising a wavelength of 467 nm. .
• the spectrum of light emitted by the light source is enriched.
• the first wavelength range may comprise a wavelength of 445 nanometers
• the second wavelength range may comprise a wavelength of between 573 and 584 nm
• the matrix comprising a second luminescent material being able to absorb light in an absorption spectrum comprising at least one wavelength of the first domain or the second domain and able to emit light in a fourth wavelength range comprising a wavelength of 465nm.
• the spectrum of the light emitted by the light source is thus enriched.
• Examples of luminescent materials are described in the following.
• a second aspect of the invention relates to a light emission module for a motor vehicle comprising a light source according to the first aspect of the invention.
• the module further comprises a first voltage generator adapted to power the first set of electroluminescent rods and a second voltage generator adapted to power the second set of electroluminescent rods.
• the module may further comprise a voltage generator, groups of the first set may be placed in series and fed in parallel with k groups of the second set, where k is defined so that the product of j by the nominal voltage of a group of the first set is substantially equal to produces k by the nominal voltage of a group of the second set.
• the module further comprises a shaping optics adapted to receive light from the light source and to form a light beam.
• a shaping optics deflects at least one ray of light from the light emitted by the light source. By deviated is meant that the direction of entry of the light beam into the shaping optics is different from the output direction of the light beam of the shaping optics.
• the shaping optics comprise at least one optical element such as one or more lenses, one or more reflectors, one or more light guides or a combination of these possibilities.
• a third aspect of the invention relates to a light emitting device, especially a lighting and / or signaling device for a motor vehicle, comprising a light module according to the second aspect of the invention so as to form at least a part of a light bleam.
• the device may further comprise a housing and a closure glass cooperating with each other to internally delimit a cavity comprising the light emission module.
• a fourth aspect of the invention relates to a method for manufacturing a light emission module, in particular for a motor vehicle, comprising a semiconductor light source, the method comprising the following steps: growth, on a substrate, of a first set of electroluminescent rods of submillimetric dimensions capable of emitting in a first wavelength range;
• FIG. 1 illustrates an emission diagram of a light emission module according to the prior art
• FIGS. 2 and 3 illustrate the structure of a plurality of electroluminescent rods of a light emission module according to one embodiment of the invention
• Figures 4a to 4d illustrate entanglements of two sets of electroluminescent rods according to embodiments of the invention
• FIG. 5 shows an emission diagram of a light emission module according to a first embodiment of the invention
• FIG. 6 shows an emission diagram of a light emission module according to a second embodiment of the invention.
• FIG. 7 shows an emission diagram of a light emission module according to the third embodiment of the invention.
• FIGS. 8a and 8b show means for supplying a light source according to two embodiments of the invention.
• Figures 2 and 3 illustrate the structure of a plurality of electroluminescent rods, submillimeter dimensions, a light source according to the invention.
• the light source according to the invention can be integrated in a light emission module, which can further comprise a shaping optics receiving light from the light source so as to form a light beam output.
• a light emission module can be integrated into a light emitting device, especially for lighting and / or signaling in a motor vehicle.
• a light emitting device may further comprise a housing and a closure glass cooperating with each other to internally delimit a cavity comprising the light emitting module.
• the device is for example a lighting device and is then a projector - or headlight - vehicle. It is then configured to implement one or more lighting functions, in particular among a low beam function called "code function”, a high beam function called “road function”, an anti-fog function.
• the device is a signaling device intended to be arranged at the front or rear of the vehicle.
• a signaling device intended to be arranged at the front, it is for example configured to implement one or more signaling functions among a direction change indication function, a daytime lighting function known under the English acronym DRL, for "Daytime Running Light", a front light signature function.
• a direction change indication function a daytime lighting function known under the English acronym DRL, for "Daytime Running Light”
• a front light signature function When it is intended to be arranged at the rear, it is for example configured to implement one or more functions among a function of indication of recoil, a function fog, a function of indication of braking, a function of indication of change of direction, a back light signature function.
• the device is intended for lighting the passenger compartment of a vehicle and is then intended to emit light mainly in the passenger compartment of the vehicle.
• the light source comprises a plurality of electroluminescent rods 8, which originate on at least one substrate 10.
• Each electroluminescent rod 8 extends perpendicularly, or substantially perpendicularly, projecting from the substrate 10, which can be made from silicon, silicon carbide, or other materials that can be used without departing from the context of the invention.
• the light emitting module comprises at least a first set of electroluminescent rods of submillimeter dimensions and a second set of electroluminescent rods of submillimeter dimensions, the electroluminescent rods of the first set being able to emit in a first range of light lengths. and the electroluminescent rods of the second set being able to emit in a second wavelength range, the second domain being different from the first domain.
• the rods of the first set and the second set may for this purpose be made from different compounds, such as, for example, a compound based on gallium nitride GaN, a compound based on aluminum nitride and gallium nitride AlGaN , a compound based on aluminum, indium and gallium AlInGaN.
• the substrate 10 has a lower face 12, to which is attached 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 10 here obtained by an ascending approach.
• This layer is etched so as to connect such rods between them, the ignition of these electroluminescent rods can then be controlled simultaneously by a control module not shown here.
• the rods of the first set and those of the second set can be fed separately or together.
• the electroluminescent rods 8 extend from the substrate and, as can be seen in FIG. 2, they each comprise a core 19, comprising one of the GaN, AlGaN, AlInGaN or other components mentioned above, around which are arranged quantum wells formed by a radial superposition of layers of different materials, for example of galium nitride and galium-indium nitride, and a shell 21 surrounding the quantum wells and can be made of the same material as the core 19.
• Each electroluminescent rod 8 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 emitting module can 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 8 are doped and polarized, the resulting light at the output of the light emitting module is emitted essentially from the circumferential wall 28, it being understood that light rays can also emerge from the 26. As a result, each electroluminescent rod 8 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 hand by the size of the light emitting diode. illuminating surface 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 shell 21, may be covered by a transparent conductive oxide (TCO) layer 29 which forms the anode of each rod complementary to the cathode formed by the substrate 10.
• TCO transparent conductive oxide
• 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 10, from which the electroluminescent rods 8 originate, defining the height of each rod.
• the height of a light-emitting rod 8 may be between 1 and 10 micrometers, while it may be possible for the largest transverse dimension of the end face to be perpendicular to the longitudinal axis. 22 of the rod concerned, is less than 2 micrometers. It is also possible to define the surface of a rod, in a section plane perpendicular to this longitudinal axis 22, in a determined range of values, and in particular between 1.96 and 4 microns square.
• the height can be varied from one set to the other, so as to increase the luminance of one or the other set when the average height of the rods constituting it is increased.
• the shape of the electroluminescent rods 8 may also vary from one assembly to the other, in particular on the section of the rods and on the shape of the end face 26.
• the electroluminescent rods 8 may have a generally cylindrical shape, and may in particular, as shown in Figure 2, have a polygonal section shape, and more particularly hexagonal. It is understood that it is important that the light can be emitted through the circumferential wall, that it has a polygonal or circular shape.
• 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 Figure 2, or although it may have a domed or pointed shape at its center, so as to multiply the directions of emission of light exiting this end face, as shown in Figure 3.
• the electroluminescent rods 8 may be arranged in two-dimensional matrix. This arrangement could be such that the rods are arranged in staggered rows. In general, the rods are arranged at regular intervals on the substrate 10 and the separation distance of two immediately adjacent electroluminescent rods, in each of the dimensions of the matrix, is at least equal to 2 micrometers, so that the light emitted by the circumferential wall 28 of each electroluminescent rod 8 can leave the matrix 30 of electroluminescent rods. Moreover, it can be provided that these separation distances, measured between two longitudinal axes 22 of adjacent rods, are not greater than 100 micrometers.
• the light emission module may further comprise, as shown in Figure 3, a layer or matrix 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.
• this matrix 30 of polymeric material wavelength conversion means, and for example a luminescent material, also called phosphor hereinafter, able to absorb at least a portion of the emitted rays by at least one of the electroluminescent rods 8 and converting at least a portion of the absorbed excitation light into an emission light having a wavelength different from that of the excitation light.
• a luminescent material absorbs light in a first wavelength range and emits light in a second wavelength range distinct from the first, wider range and centered around a wavelength range. different wave. It can be provided that the luminescent material is embedded in the matrix 30, or that it is disposed on the surface of the layer of this matrix 30.
• phosphorescent materials are particularly distinguished from luminescent materials.
• the fluorescent materials absorb light in a narrow absorption domain and re-emit in a wider emission range and offset from the absorption domain, while ensuring a good conversion efficiency.
• phosphorescent materials As for phosphorescent materials, they absorb light whatever its wavelength, and re-emit in a larger emission range than that of fluorescent materials. However, their yields are much lower than those fluorescent materials.
• 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.
• the upper face 16 of the substrate 10 may comprise a reflecting means which reflects the light rays initially oriented towards the upper face 16, towards the output face of the light emission module. It is thus possible to recover light rays that otherwise would be lost.
• This coating 32 is disposed between the electroluminescent rods 8 on the transparent conductive oxide layer 29.
• the light source has a first set and a second set of electroluminescent rods emitting in different wavelength ranges, the first and second sets being entangled with respect to each other.
• entangled assemblies assemblies mixed with each other, which according to the configurations of the light emitting module, can be interleaved or intertwined with each other.
• An entanglement covers any arrangement of rods, wherein for at least one first segment connecting two rods of the first set the first segment passes through at least a portion of the second set, and wherein for at least one second segment connecting two sticks of the second set, the second segment passes through at least a portion of the first set.
• Figures 4a to 4d illustrate entanglement embodiments of the first and second sets of light emitting rods 8.
• the light emission module generally has a rectangular shape, but it will be understood that it can present, without departing from the context of the invention, other shapes. general, and in particular a form of parallelogram.
• each of the first and second sets comprises several groups, hereinafter called groups, of electroluminescent rods 8.
• groups for example, two groups of rods of the first set are separated by a group of rods of the second set, and vice versa. .
• the separation distance between a rod of the first set 4 and a stick directly adjacent and belonging to the second set 6 is substantially equal to the separation distance between two electroluminescent rods of the same set, this separation distance, measured between two longitudinal axes of electroluminescent rods, being 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.
• the sets 4 and 6 are intermixed intrusively, that is to say that each of the sets is divided into groups of sticks, for FIGS. 4a to 4c, and that the groups of sticks of the first set and groups of sticks of the second set are alternated in a geometric pattern.
• the alternation between groups can be random.
• the patterns of Figures 4a to 4d may be considered as basic patterns that can be repeated and / or combined.
• Figures 4a and 4b show regular arrangements, in which the groups of rods are strips, broad of a rod for Figure 4a, and two rods wide for Figure 4b.
• each group of rods of the first set 4 or the second set 6 comprises four light emitting rods, while in Figure 4b, each group comprises eight light emitting rods. It will be possible for the groups of electroluminescent rods of the first set 4 and the groups of electroluminescent rods of the second set 6 to comprise different numbers of electroluminescent rods 8.
• the groups of the sets 4 and 6 do not have the same size and each have a number of different electroluminescent rods 8.
• the groups are arranged around each other so that a group of the first set 4 is surrounded by two groups of the second set 6, and vice versa.
• the successive layers have the form of squares arranged around each other, but it would be possible for the electroluminescent rods to be arranged in substantially circular and concentric groups.
• the entanglement of the assemblies 4 and 6 can be achieved by intrusive shapes of electroluminescent rods of one set within an area specific to the other set.
• the electroluminescent rods of the first set 4 and the electroluminescent rods of the second set 6 are able to emit light in different wavelength ranges.
• the entanglement of the first and second sets is such that the distances 54 are always smaller at 100 micrometers, corresponding to the optical resolution of the human eye).
• the invention also relates to a method of manufacturing the light source presented above.
• the method comprises a step of growing on a substrate of a first set of electroluminescent rods of submillimetric dimensions capable of emitting in a first wavelength domain, and a growth step, on the same substrate, of a second set of electroluminescent rods of submillimetric dimensions capable of emitting in a second wavelength range, the first set and the second set being entangled, as illustrated in FIGS. 4a to 4d for example.
• the first and second wavelength domains are different.
• the growth step of the first set of electroluminescent rods can be performed using a mask, the mask covering an area for the subsequent growth of the electroluminescent rods of the second set.
• the electroluminescent rods 8 of first set 4 are formed from gallium nitride and are capable of emitting in a first wavelength range comprising a wavelength of 445 nanometers, abbreviated nm hereinafter (for example the domain is centered around 445 nm) and the electroluminescent rods of the second set 6 are formed from doped gallium nitride and capable of emitting in a second wavelength range comprising a wavelength of 467 nm (for example, the domain is centered around 467 nm).
• the matrix 30 may further comprise a YAG cerium-type phosphor for example, which absorbs light in the ultraviolet and blue, and therefore the light of the two sets of rods, and emits in the yellow, that is to say that the emission domain comprises at least one wavelength between 573 nm and 584 nm.
• a YAG cerium-type phosphor for example, which absorbs light in the ultraviolet and blue, and therefore the light of the two sets of rods, and emits in the yellow, that is to say that the emission domain comprises at least one wavelength between 573 nm and 584 nm.
• FIG. 5 illustrates an emission diagram of the light energy of a light source according to the first embodiment of the invention, as a function of the wavelength.
• the second set of electroluminescent rods 8 is able to emit in a range of lengths.
• the luminescent material is capable of emitting in a wavelength range centered around ⁇ 13 , ⁇ 13 being between 573 and 584 nm.
• the spectrum of the light emitting module is much richer, especially in blue, which allows white light illumination with better color rendering.
• the electroluminescent rods of the first set 4 are formed from gallium nitride and are capable of emitting in a first wavelength range comprising a wavelength of 445 nm.
• the first domain is centered around 445 nm.
• 5 electroluminescent rods of the second set 6 are formed from aluminum indium gallium phosphide AlInGaP and capable of emitting in a second wavelength range comprising a wavelength greater than or equal to 600 nm.
• the second domain is centered around a wavelength greater than or equal to 600 nm.
• the matrix 30 may further comprise a YAG cerium-type phosphor for example, which absorbs light in the ultraviolet and blue, and therefore the light of the first set of electroluminescent rods, and emits in the yellow, the emission domain comprises at least one wavelength between 573 nm and 584 nm.
• a YAG cerium-type phosphor for example, which absorbs light in the ultraviolet and blue, and therefore the light of the first set of electroluminescent rods, and emits in the yellow, the emission domain comprises at least one wavelength between 573 nm and 584 nm.
• FIG. 6 illustrates an emission diagram of the light energy of a light source according to the second embodiment of the invention, as a function of the wavelength.
• the luminescent material is capable of emitting in a wavelength range centered around ⁇ 23 , ⁇ 23 being between 573 and 584 nm.
• the spectrum of the light emitting module is much richer, especially in the red, which allows white light illumination with better color rendering.
• electroluminescent rods of different natures makes it possible to achieve such an enrichment of the spectrum of light, while allowing a fine entanglement not perceptible by the eye.
• the light source may further comprise a third set of electroluminescent rods, for example formed from doped gallium nitride and able to emit in a third range of lengths. wave comprising a wavelength of 467 nm.
• the third domain is centered around 467 nm.
• the emission spectrum is thus even more enriched.
• the electroluminescent rods of the first set 4 are formed from gallium nitride and able to emit in a first wavelength range comprising a wavelength of 445 nm.
• the first domain is centered around 445 nm.
• the electroluminescent rods of the second set 6 are formed from aluminum indium gallium phosphide AlInGaP capable of emitting in a second wavelength range comprising a wavelength of between 573 and 584 nm.
• the second domain is centered around a wavelength equal to 580 nm.
• the matrix 30 may further comprise two luminescent materials, for example Europium-doped Strontium sulfide and cerium-doped YAGs, one emitting in the red, or of wavelength emission comprising a wavelength equal to 630nm, and the other emitting in the yellow-green, a wavelength emission domain comprising at least one wavelength equal to 570 nm.
• two luminescent materials for example Europium-doped Strontium sulfide and cerium-doped YAGs, one emitting in the red, or of wavelength emission comprising a wavelength equal to 630nm, and the other emitting in the yellow-green, a wavelength emission domain comprising at least one wavelength equal to 570 nm.
• FIG. 7 illustrates an emission diagram of the light energy of a source according to the third embodiment of the invention, as a function of the wavelength.
• the luminescent materials are respectively capable of emitting in a wavelength range centered around ⁇ 33 and ⁇ 34 , ⁇ 33 being equal to 465nm and ⁇ 34 being equal to 630 nm.
• a luminescent material capable of emitting in a wavelength range centered around 465 nm is Coumarin 314, which can be stabilized by the addition of a buffer material, such as simple lamellar zinc hydroxides. or double for example, to be used in solution in a polymer, such as a polysiloxane.
• a buffer material such as simple lamellar zinc hydroxides.
• a polymer such as a polysiloxane.
• the extreme viscosity of the polymer advantageously limits the risk of leakage of the solution.
• Examples of luminescent materials capable of emitting in a field of 7 wavelengths centered around 630 nm are the following compounds:
• these luminescent materials can be embedded in a polysiloxane coating electroluminescent rods.
• the spectrum of the light source is much richer, allowing white light illumination with better color rendering.
• electroluminescent rods of different natures makes it possible to achieve such an enrichment of the spectrum of light, while allowing a fine entanglement not perceptible by the eye.
• the electroluminescent rods of the first set are able to natively emit white light.
• the second wavelength range is included in the first wavelength range and the electroluminescent rods of the second set enhance the illumination in the second wavelength range.
• FIGS. 8a and 8b illustrate two light emission modules comprising a light source according to the invention and alternative supply means.
• electroluminescent rods of different natures generally admit different supply voltages. It is therefore not possible to supply all the groups in parallel with a single voltage generator.
• a first voltage generator 81 is dedicated to the parallel supply of the groups of the first set 4 while a second voltage generator 82 is dedicated to the supply in parallel of the sets of the second set 6 (for the sake of simplification only one group of the second set 6 is shown in Figure 8a).
• the generators 81 and 82 can deliver different voltages.
• ppcm (M, N) denotes the smallest common multiple of the voltages M and N.

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• 2016
  • 2016-06-30 FR FR1656265A patent/FR3053434B1/fr not_active Expired - Fee Related
• 2017
  • 2017-06-23 EP EP17734689.7A patent/EP3479014A1/de not_active Withdrawn
  • 2017-06-23 WO PCT/EP2017/065602 patent/WO2018001911A1/fr not_active Ceased
  • 2017-06-23 CN CN201780040777.2A patent/CN109417083A/zh active Pending
  • 2017-06-23 KR KR1020187037915A patent/KR20190024908A/ko not_active Withdrawn
  • 2017-06-23 JP JP2018568813A patent/JP2019525460A/ja active Pending
  • 2017-06-23 US US16/314,245 patent/US20190170313A1/en not_active Abandoned

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