Light generator comprising a phosphor layer, a dichroic filter and a polarizer

Abstract

A light generator comprising: - an opto-electronic device for producing a first monochromatic radiation at a first wavelength, - a phosphor layer located away from said opto-electronic device configured to convert all or part of the first monochromatic radiation into a second radiation and to generate light at one or more second, higher wavelengths and to diffuse it, characterized in that it further comprises: - a dichroic filter for transmitting the light emanating from the first monochromatic radiation towards the phosphor layer and for reflecting the converted light towards a polarizer, - the polarizer for reflecting a first polarization direction of 50% of the light converted to the second wavelength(s) so that it returns towards the phosphor layer, and transmitting outwards a second polarization direction of 50% of the light converted to the second wavelength(s).- the phosphor layer being further configured to repeatedly depolarize the converted light reflected from the first direction of polarization by the polarizer and to propagate it randomly towards the dichroic filter and backscatter it towards the polarizer, - the polarizer being further configured to repeatedly transmit 50% of the depolarized light reflected from the dichroic filter and having a second direction of polarization outwards from the light generator and to reflect 50% of the depolarized light reflected from the dichroic filter having a first direction of polarization.

Description

Title of the invention: Light generator comprising a phosphor layer, a dichroic filter and a polarizer

[0001] The present invention relates to a light generator. It also relates to a lighting device comprising such a light generator. It finds particular, but not limiting, application in vehicles or in domestic or industrial applications.

[0002] In the field of vehicle applications, a light generator, known to those skilled in the art, comprises an optoelectronic device made of semiconductor materials configured to produce a first polychromatic or monochromatic radiation so as to generate light. This light generator is integrated into a grid on the front of a vehicle which includes a plurality of light generators.

[0003] This light generator is positioned behind a reflective surface so as to give a metallic appearance to the front panel grid. When the optoelectronic device is off, a mirrored appearance is observed. When the optoelectronic device is on, the mirrored appearance is no longer observed, but the entire front panel grid is illuminated.

[0004] One drawback of this prior art is that such a light generator has very low luminous efficiency. Approximately 3% of the light emitted by the optoelectronic device is transmitted outside the light generator, and 95% is reflected back towards the optoelectronic device, which is thus lost.

[0005] In this context, the present invention aims to provide a light generator which makes it possible to resolve at least one of the aforementioned drawbacks.

[0006] To this end, the invention proposes a light generator comprising: - at least one optoelectronic device composed of semiconductor materials and configured to produce a first monochromatic radiation so as to generate light at a first wavelength, - a phosphor layer offset from said at least one optoelectronic device and comprising a first diopter and a second diopter and configured to convert all or part of the first incident monochromatic radiation into a second radiation so as to obtain converted light at one or more second wavelengths higher than that of the light emanating from the first monochromatic radiation and to diffuse this converted light, characterized in that the light generator further comprises: - a first dichroic filter positioned on the side of the first interface of the phosphor layer and configured to transmit the light emanating from the first monochromatic radiation towards the phosphor layer and to reflect the light converted by the phosphor layer towards a metal grid polarizer, - the polarizer positioned opposite the phosphor layer on the side of its second interface and configured to reflect a first polarization direction of 50% of the light converted to the second wavelength(s) so that it returns towards the phosphor layer, and to transmit a second polarization direction of 50% of the light converted to the second wavelength(s) outwards from the light generator, - the phosphor layer being further configured to repeatedly depolarize the converted light reflected from the first polarization direction by the polarizer and to propagate it randomly towards the first dichroic filter and backscatter it towards the polarizer, - the polarizer being further configured to repeatedly transmit outwards from the light generator 50% of the depolarized light reflected on the first dichroic filter and having a 2nd polarization direction and to reflect 50% of the depolarized light reflected on the first dichroic filter having a 1st polarization direction, - a protective glass positioned opposite the polarizer on the side opposite the phosphor layer.

[0007] Thus, as will be seen in detail later, thanks to the light generator of the invention, a metallic exterior appearance with better luminous efficiency is obtained.

[0008] According to non-limiting embodiments, said light generator may further comprise one or more additional features taken alone or in all technically possible combinations, among the following.

[0009] According to a non-limiting embodiment, said at least one optoelectronic device is disposed opposite the first dichroic filter and the phosphor layer and the first dichroic filter is disposed between the phosphor layer and said at least one optoelectronic device, and according to which the light generator further comprises at least one reflective cavity at the bottom of which said at least one optoelectronic device is disposed.

[0010] According to a non-limiting embodiment, the light generator comprises a plurality of reflective cavities and a plurality of optoelectronic devices.

[0011] According to a non-limiting embodiment, the light generator further comprises a light guide disposed opposite the first dichroic filter on the side opposite the phosphor layer, and configured to refract and reflect the light emanating from the first monochromatic radiation towards the phosphor layer, and according to which said at least one opto-electronic device is disposed at one of the two ends of the light guide.

[0012] According to a non-limiting embodiment: - the polarizer is further configured to reflect a first polarization direction of 50% of the light that has not been converted by the phosphor layer so that it returns to the phosphor layer, and to transmit a second polarization direction of 50% of this light outwards from the light generator, - the phosphor layer is further configured to repeatedly depolarize the unconverted light from the first polarization direction and reflected by the polarizer, to propagate it randomly towards the first dichroic filter and to backscatter it towards the polarizer, - the polarizer is further configured to repeatedly transmit to the outside of the light generator 50% of this depolarized light reflected on the first dichroic filter and having a 2nd polarization direction and reflect 50% of the depolarized light reflected on the first dichroic filter having a 1st polarization direction.

[0013] According to a non-limiting embodiment, said at least one optoelectronic device is a native light-emitting diode or a laser diode.

[0014] According to a non-limiting embodiment, the first polarization direction is vertical and the second polarization direction is horizontal or vice versa.

[0015] According to a non-limiting embodiment, the light generator further comprises a second dichroic filter complementary to the first dichroic filter, disposed between the phosphor layer and the polarizer, and configured to transmit the light converted and scattered by the phosphor layer to the outside of the light generator and to reflect the light emanating from the first monochromatic radiation back to the phosphor layer.

[0016] According to a non-limiting embodiment, the phosphorus layer is mixed with resin.

[0017] According to a non-limiting embodiment, the phosphorus layer is offset by a distance of between approximately 4 millimeters and 10 millimeters.

[0018] According to a non-limiting embodiment, the light generator comprises a plurality of opto-electronic devices.

[0019] According to a non-limiting embodiment, the converted light is visible light.

[0020] A lighting device is further proposed, according to which said lighting device comprises at least one light generator according to any one of the preceding characteristics.

[0021] According to a non-limiting embodiment, said lighting device is a vehicle lighting device, or a domestic or industrial lighting device.

[0022] According to a non-limiting embodiment, said vehicle lighting device is a lighting and / or signaling device, or a front or rear lighting device, or an interior lighting device.

[0023] The invention and its various applications will be better understood upon reading the following description and examining the accompanying figures:

[0024] [Fig.1] is a schematic representation of a light generator according to the invention, said light generator comprising at least one opto-electronic device, a phosphor layer, a first dichroic filter, a polarizer and a protective layer,

[0025] [Fig.2] illustrates the phosphor layer of the light generator of [Fig.1], said a layer of phosphorus being mixed with resin,

[0026] [Fig.3] is a diagram of the light generator of [Fig.1], said generator of light including, in addition, a second dichroic filter

[0027] [Fig.4] is a diagram of a first non-limiting embodiment of the generator of light from [Fig. 1], said light generator further comprising a reflective cavity,

[0028] [Fig. 5] illustrates the light generator of the preceding figure, said generator of light including, in addition, a second dichroic filter

[0029] [Fig.6] illustrates a non-limiting variant embodiment of the light generator [Fig. 4], the light generator comprising a plurality of reflective cavities and a plurality of optoelectronic devices,

[0030] [Fig.7] is a diagram of a second, non-limiting embodiment of the generator of light from [Fig. 1], said light generator further comprising a light guide and in which said opto-electronic device is disposed at one end of said light guide,

[0031] [Fig.8] illustrates the light generator of the preceding figure, said generator of light including, in addition, a second dichroic filter

[0032] [Fig.9a] is a diagram of a lighting device comprising the generator of light of [Fig.1], said light device being a lighting and / or signaling device for vehicle.

[0033] [Fig.9b] is a diagram of a lighting device comprising the light generator of the [Fig.1], said lighting device being a front-facing lighting device for a vehicle.

[0034] [Fig.9c] is a diagram of a lighting device comprising the light generator of the [Fig.1], said light device being an interior lighting device for a vehicle.

[0035] [Fig. 10] is a diagram of a lighting device comprising the light generator of the [Fig.1], the said light device being a domestic lighting device.

[0036] [Fig. 11] is a diagram of a lighting device comprising the light generator of the [Fig.1], said luminous device being an industrial lighting device.

[0037] Identical elements, by structure or by function, appearing on different figures retain, unless otherwise specified, the same references.

[0038] The light generator 1 according to the invention is described with reference to figures 1 to 11.

[0039] As illustrated in figures 1, 4 and 7, the light generator 1 comprises: - at least one opto-electronic device 11, - a phosphor layer 12, - a first dichroic filter 13, - a metal grid polarizer 14, - a protective layer 15.

[0040] In the rest of the description, the metal grid polarizer 14 is simply referred to as polarizer 14.

[0041] The light generator 1 has a first direction D (also called the observation direction) and a second direction D' opposite to the first direction D and parallel to the first direction D as illustrated in Figures 1 to 8. The first direction D is transverse (in other words perpendicular) to all the layers of the light generator 1. The first direction D corresponds to the direction in which an external observer can, in particular, observe the light generated by the light generator 1.

[0042] The light generator 1 comprises a face turned towards the first direction D and a face turned towards the second direction D'. It has a direction of light emission which corresponds to the first direction D. We will speak of forward direction or backward direction respectively for the first direction D and the second direction D'.

[0043] In a non-limiting embodiment, the light generator 1 comprises a single opto-electronic device 11. In another non-limiting embodiment, the light generator 1 comprises a plurality of opto-electronic devices 11. The non-limiting embodiment of a single opto-electronic device 11 is taken as a non-limiting example in the following description.

[0044] The optoelectronic device 11 is composed of semiconductor materials. It is configured to produce a first monochromatic RI radiation so to generate light L1 at a first wavelength XI. The optoelectronic device 11 emits unpolarized, or depolarized, light L1. The reference used is DP for unpolarized light in Figures 1 to 8. This light L1 is also called the first light wave LL

[0045] In a non-limiting embodiment, the opto-electronic device 11 is a native light-emitting diode or a laser diode.

[0046] By light-emitting diode, we mean any type of light-emitting diode, whether in non-limiting examples LEDs (“Light Emitting Diode” in English), OLEDs (“Organic LED” in English), AMOLEDs (“Active-Matrix-Organic LED” in English), or FOLEDs (“Flexible OLED” in English).

[0047] By native light-emitting diode, it is understood that the color of the light-emitting diode is generated by opto-electronic conversion (before the generated light passes through the phosphor layer 12).

[0048] In a non-limiting embodiment, the first wavelength XI is between 400 and 500 nanometers (nm). This yields, for example, blue light L1 at 400 nm or cyan light at 490 nm. In a non-limiting variant, Xl = 450 nm. In another non-limiting embodiment, XI = 530 nm. This yields green light L1. It should be noted that the advantage of having a native blue LED (or a blue laser diode) is that it consumes less energy than a native green or red LED in terms of optical Amperes / Watts.Furthermore, as described later in the description, since the phosphor layer 12 only converts the first monochromatic radiation RI to second wavelengths X2 greater than its first wavelength XI, using a blue light L1 makes it possible to obtain a yellow or red light L2, for example, which is not possible with a red or green light L1 which has a first wavelength XI greater than that XI of the blue color.

[0049] The phosphor layer 12 is offset from the optoelectronic device 11. In other words, it is not in contact with it. By "offset," we mean that it is located at a certain distance from it. It is therefore not directly encapsulated on the optoelectronic device 11. This avoids thermal heating that leads to a reduction in the light conversion efficiency (described later) of the phosphor layer 12. In a non-limiting embodiment, the phosphor layer 12 is offset by a distance dl (illustrated in Figures 1 to 6, and 7 and 8) of between approximately 4 and 10 millimeters (mm) from the optoelectronic device 11. This distance dl is understood to be along a transverse axis Axl (illustrated in Figures 1 to 8) of the light generator 1 parallel to the first direction D and the second direction D'. This distance dl is sufficient to avoid a temperature increase in the phosphorus layer 12.

[0050] In a first, non-limiting embodiment illustrated in Figures 1 to 6, the phosphor layer 12 is offset from the optoelectronic device 11 along the transverse axis Axl of the light generator 1. Thus, in this case, the optoelectronic device 11 is positioned opposite the first dichroic filter 13 and the phosphor layer 12, and, where applicable, the second dichroic filter 18. In other words, the phosphor layer 12 is positioned opposite the optoelectronic device 11 with the first dichroic filter 13 between the two. In this case, in a non-limiting example, dl = 10 mm.

[0051] In a second, non-limiting embodiment illustrated in Figures 7 and 8, the phosphor layer 12 is offset from the optoelectronic device 11 along a longitudinal axis Ax2 (illustrated in Figures 7 and 8) perpendicular to the transverse axis Axl. Thus, in this case, the phosphor layer 12 and the first dichroic filter 13, and where applicable the second dichroic filter 18, are not positioned opposite the optoelectronic device 11. In this case, in a non-limiting example, dl = 4 mm.

[0052] The phosphor layer 12 comprises a first diopter 120 and a second diopter 121. The first diopter 120 is turned towards the first dichroic filter 13 and the second diopter 121 is turned towards the polarizer 14 and the protective layer 15, i.e. towards the outside of the light generator 1.

[0053] The phosphor layer 12 is configured to convert all or part of the first incident monochromatic radiation RI into a second radiation R2 so as to obtain a converted light L2 at one or more second wavelengths X2 greater than the first wavelength XI emanating from the first monochromatic radiation RI, and to scatter it. In the following description, the converted light L2 is otherwise referred to as L2 light or the second light wave L2.

[0054] Thus, the converted light L2 is notably scattered by the phosphor layer 12 outwards from the light generator 1. It should be noted that whether the light L2 has a single second wavelength or several second wavelengths is intrinsically linked to the composition of the phosphor in the phosphor layer 12 and to its conversion properties, which are known to those skilled in the art. The converted light L2 is visible light. Thus, the second wavelength(s) X2 are greater than the first wavelength XI and less than or equal to 700 nanometers. The second wavelength(s) X2 obtained are defined by the composition of the phosphor layer 12.

[0055] Thus, in a non-limiting example of blue light L1 Xl=450nm, converted light L2 is obtained at one or more second wavelengths X2 greater than Xl=450 nm, namely in the range of values ​​between 451 nanometers and 700 nanometers. Thus, in another non-limiting example of blue light L1 at Xl=490nm, converted light L2 is obtained at one or more second wavelengths X2 greater than Xl=490 nm, namely in the range of value between 491 nanometers and 700 nanometers.

[0056] In other, non-limiting examples: - with XI = 530nm (green color), we can use a so-called red phosphor which generates a converted light L2 of red color (X2=650nm), - with XI = 450nm (blue color), we can use a so-called red phosphor which generates a converted light L2 of red color (X2=650nm), - with XI = 450nm (blue color), we can use a so-called yellow phosphor (550nm) which generates a converted light L2 of white color at the second wavelengths (X2= 500nm to 700nm) and at the first wavelength Xl=450nm corresponding to a part of the unconverted blue light, - with XI = 490nm (cyan color), we can use a red phosphor (600nm) which generates a converted light L2 of white color at the second wavelengths (X2= 500nm to 700nm) and at the first wavelength Xl=490nm corresponding to a part of the cyan light not converted. - with XI = 450nm (blue color) we can use a so-called green phosphor which generates a converted light L2 of green color (X2=535nm).

[0057] It should be noted that the phosphor layer 12, due to its composition, converts the first monochromatic radiation RI into a second monochromatic radiation R2 to obtain light L2. However, there comes a point where the phosphor layer 12 becomes saturated and can no longer convert the remaining monochromatic radiation RI to obtain light L2, which implies that the color of light L1 emanating from this first monochromatic radiation RI mixes with the color of light L2. Thus, when the phosphor layer 12 is saturated, it converts only a portion of the first monochromatic radiation RI.

[0058] Thus, to obtain white light L2, an additive color mixing process is used. For example, in the non-limiting case of blue light L1, the blue color mixes with the yellow color to produce white. Similarly, in the non-limiting case of cyan light L1, the cyan color mixes with the red color to produce white.

[0059] To choose the colour of the phosphorus layer 12, different materials are used.

[0060] Thus, to obtain yellow phosphorus, in a non-limiting embodiment, the YAG material, which is yttrium and aluminum garnet-based phosphorus powder, is used. To obtain red phosphorus, in a non-limiting embodiment, the Y2O3 material, which is yttrium(III) oxide, is used. To obtain green phosphorus, in a non-limiting embodiment, the orthosilicate ((Ba,Sr)2SiO4:Eu) powder material is used.

[0061] Thus, the phosphor layer 12 is excited by the first wavelength XI and generates light L2 with a longer wavelength X2. It therefore allows the so-called shorter wavelengths to pass through and generates the longer wavelengths. This is the phenomenon known as phosphorescence. It should be noted that the phosphor layer 12 scatters the light L2 thus generated in all directions. It thus scatters light L2, in particular, outwards from the light generator 1. Thus, in the non-limiting example of blue light L1, the phosphor layer 12 converts the first monochromatic radiation RI, of which light L1 is blue, and scatters it in all directions.

[0062] It should be noted that the scattering encompasses the backscattering which occurs towards its original direction and the generation of light which occurs in the opposite direction. Thus, when the phosphor layer 12 receives the light L1 from the opto-electronic device 11, in this case the scattering encompasses the backscattering which occurs towards the rear (namely in the second direction D') of the phosphor layer 12 and the generation of light which occurs towards the front of the phosphor layer 12 (namely in the first direction D), and consequently towards the outside of the light generator 1.

[0063] As illustrated in [Fig. 2], in a non-limiting embodiment, the phosphor layer 12 is mixed with resin 122. This provides a reflective appearance for the aesthetics of the light generator 1, as seen by an external observer. This enhances the metallic exterior appearance obtained with the polarizer 14.

[0064] It should also be noted that the phosphor layer intrinsically has a Lambertian light distribution profile which makes it possible to obtain a homogeneous appearance of light from the point of view of an external observer.

[0065] Furthermore, it should be noted that part of the converted light L2 is backscattered by the phosphor layer 12 and potentially by Fresnel reflections on the phosphor layer 12-polarizer 14 interface, namely on the second diopter 121, the backscattering being towards its original direction, here towards the back of the phosphor layer 12 (namely in the second direction D'), namely towards the optoelectronic device 11 in the case of figures 1 to 7, or towards the light guide 17 described later in the case of figures 7 and 8.

[0066] As we will see below, thanks to the first dichroic filter 13, this converted L2 backscattered light is not lost.

[0067] The first dichroic filter 13 is arranged on the side of the first diopter 120 of the phosphor layer 12. It is positioned opposite and in contact with the phosphor layer. It is thus adjacent to the phosphor layer 12.

[0068] In the case of Figures 1 to 6, it is arranged between the phosphor layer 12 and the opto-electronic device 11. It is arranged opposite the opto-electronic device 11. In the case of Figures 7 and 8, it is positioned between the phosphor layer 12 and the light guide 17. It is positioned opposite the latter and in contact with it. It is thus adjacent to the light guide 17.

[0069] The first dichroic filter 13 is configured to transmit only the light L1 emanating from the first monochromatic radiation RI towards the phosphor layer 12 and to reflect the converted light L2 by the phosphor layer 12, namely that which has been backscattered towards the rear of the phosphor layer 12. This is referred to as a dichroic mirror. Thus, the first dichroic filter 13 makes it possible to reflect all the light L2 backscattered by the phosphor layer 12, in the first direction D, towards the outside of the light generator 1. This drastically reduces the converted light L2 backscattered towards the optoelectronic device 11 or towards the light guide 17.

[0070] Thus, in the non-limiting example of blue L1 light, the first dichroic filter 13 lets the blue light pass through and reflects the second wavelengths X2.

[0071] Thus, the transmission properties (at the first wavelength XI) and reflection properties (at all wavelengths X2 above) depend on a given wavelength, here the first wavelength XL

[0072] It should be noted that the first dichroic filter 13 reflects the converted light L2 arriving at an angle of incidence on the dichroic filter 13 between 0° and approximately 40°, the remainder being less reflected. It should be noted that the reference for this angle of incidence is the normal to the interface between the dichroic filter 13 and the phosphor layer 12, namely the first interface 120.

[0073] The first dichroic filter 13 is composed of several thin dielectric layers.

[0074] In a non-limiting embodiment, the polarizer 14 (described later) is bonded to the phosphor layer 12, then the thin dielectric layers of the first dichroic filter 13 are vaporized onto a substrate or directly onto the polarizer 14-phosphorus layer 12 assembly, the whole being bonded or overmolded onto the protective layer 15. The vaporization is carried out by a physical vapor deposition process.

[0075] In another non-limiting embodiment, the polarizer 14 is glued onto the phosphor layer 12, then the thin dielectric layers of the first dichroic filter 13 are laminated onto the polarizer 14-phosphor layer 12 assembly and arranged on a substrate, the whole being glued or overmolded onto the protective layer 15.

[0076] In a non-limiting embodiment, the first dichroic filter 13 is between 100 nm and 2000 nm. It can be made on a substrate which is between 50 pm (micrometers) and 300 pm.

[0077] The assembly of the phosphor layer 12-first dichroic filter 13-polarizer 14-protective layer 15 forms an overall film. This overall film is very thin. In a non-limiting embodiment, its thickness is between 5µm and 6mm (where applicable, including the second dichroic filter 18, described later)).

[0078] In non-limiting examples, the substrate is PC (Polycarbonate) or PMMA (Polymethyl methacrylate).

[0079] These two processes allow for cost reduction, are simple to carry out and allow the dichroic filter to be cut into a desired shape so that it can adapt to the protective layer 15.

[0080] Thus, the first dichroic filter 13 and the phosphor layer 12 play an effective light-diffusing role, the phosphor layer 12 diffusing the light and the first dichroic filter 13 not diffusing it, but maximizing the light efficiency.

[0081] The metal grid polarizer 14 is a type of polarizer which includes metal nanowires which are oriented in a given direction and which are smaller than the first wavelength XI which allows the transmission of light in the 2nd polarization direction P2 (described later), the latter being perpendicular to the direction of these metal nanowires.

[0082] In a non-limiting embodiment, the grid polarizer 14 is fabricated on a substrate ranging from 50 µm to 300 µm in thickness. In this case, the polarizer 14 is between 100 nm (without substrate) and 500 µm (substrate included). In a non-limiting embodiment, the thickness of the metal nanowires of the metal grid is between 50 nm and 1 µm.

[0083] The polarizer 14 is arranged opposite the phosphor layer 12 on the side of its second diopter 121, namely on the opposite side to the first dichroic filter 13. It is in contact with the phosphor layer 12. Thus, it is adjacent to the phosphor layer 12.

[0084] The polarizer 14 is configured to reflect a first polarization direction PI of 50% of the converted light L2 so that it returns to the phosphor layer 12.

[0085] The polarizer 14 gives a metallic appearance to the light generator 1 when the latter is switched off (i.e., when the optoelectronic device 11 is not activated) because it reflects 50% of the natural sunlight incident on the light generator 1 when the light generator 1 is observed from the outside. It should be noted that the natural sunlight coming from the outside is unpolarized. The polarizer 14 reflects 50% of this natural light across all wavelengths of natural light. Naturally, natural light is at 50% polarized along the first polarization direction PI and 50% polarized along the second polarization direction P2.

[0086] The polarizer 14 is further configured to transmit outwards from the light generator 1 the 2nd polarization direction P2 of 50% of the light converted L2.

[0087] Thus, the polarizer 14 only allows one direction of polarization to pass through, the other direction of polarization which is reflected by the polarizer 14 being depolarized through the phosphor layer 12.

[0088] The polarizer 14 allows for selective light transmission. Thus, in the non-limiting example of the first monochromatic radiation RI, which generates blue light L1 and is converted into red light L2 by the phosphor layer 12, it allows the second polarization direction P2 of 50% of the red light to pass through, and reflects the first polarization direction PI of 50% of the red light, which then passes back through the phosphor layer 12. This assumes that 100% of the first monochromatic radiation RI is converted. As will be seen later, it is possible that a portion of the first monochromatic radiation RI may not be converted.

[0089] In a non-limiting embodiment, the first polarization direction PI is vertical and the second polarization direction P2 is horizontal. In another non-limiting embodiment, the reverse is true: the first polarization direction PI is horizontal and the second polarization direction P2 is vertical.

[0090] The part of the converted light L2 which is reflected by the polarizer 14 therefore arrives at the phosphor layer 12 and will be depolarized by the phosphor layer 12.

[0091] The phosphor layer 12 is thus configured to repeatedly depolarize the converted light L2 from the first polarization direction PI that has been reflected by the polarizer 14 and to propagate it randomly, isotropically towards the first dichroic filter 13 and backscatter it towards its original direction, namely towards the polarizer 14. In this way, the polarized light loses its polarization properties. It should be noted that the depolarization occurs according to Malus's law. Thus, thanks to the phosphor layer 12, we obtain converted light L2 with 50% in the first polarization direction PI and 50% in the second polarization direction P2.

[0092] Thus, in the non-limiting example of converted red light, the first polarization direction PI of 50% of the red light that has been reflected by the polarizer 14 and depolarized by the phosphor layer 12 will be scattered towards the first dichroic filter 13 and back-scattered towards the polarizer 14. The depolarized light that is scattered towards the first dichroic filter 13 will be reflected by said first dichroic filter 13 towards the polarizer 14 by passing through the phosphor layer 12.

[0093] The depolarized light is recycled by means of the first dichroic filter 13, which increases the transmission of light outwards from the light generator 1. It should be noted that there is no conversion of red light by the phosphor layer 12, since the phosphor layer 12 only functions for the color blue, namely at the first wavelength XL

[0094] The polarizer 14 is thus configured to repeatedly transmit to the outside of the light generator 1 50% of the converted L2 light, depolarized and reflected on the first dichroic filter 13 and having a second polarization direction P2, and to reflect 50% of the converted L2 light, depolarized and reflected on the first dichroic filter 13 having a first polarization direction PL

[0095] This cycle of selective light transmission through the polarizer 14, depolarization of light by the phosphor layer 12, and reflection of light by the first dichroic filter 13 is repeated until there is no more light energy, that is, until there is no more light L2 to convert. Indeed, the various back-and-forth movements of light L2 between the polarizer 14, the phosphor layer 12, and the first dichroic filter 13 increase the transmission of this light L2 to the outside of the light generator 1.

[0096] Thus, at the output of the light generator 1, a high percentage of light polarized along the 2nd polarization direction P2 is obtained with a metallic external appearance.

[0097] In theory, polarization purity is 100% of the light polarized with a polarization direction, here P2, when P2 is oriented at 90° to the direction of the nanowires of the polarizer 14. However, polarization purity may not be 100% depending on the tolerance of the metallic nanowires. Indeed, P2 may be between 89° and 91° relative to the nanowires. Thus, the polarization purity is not 100%, but close to 100%.

[0098] When the phosphor layer 12 is saturated so that it does not convert all of the first monochromatic radiation RI, in this case the polarizer 14 as well as the phosphor layer 12 also act on the unconverted light L1 and in the same way as on the converted light L2, namely: - the polarizer 14 is further configured to reflect a first polarization direction PI of 50% of the light L1 that has not been converted by the phosphor layer 12 so that it returns to the phosphor layer 12, and to transmit outwards from the light generator 1 a second polarization direction P2 of 50% of this light L1, and - the phosphor layer 12 is further configured to repeatedly depolarize the unconverted light L1 of the first polarization direction PI and reflected by the polarizer 14, to propagate it randomly, isotropically towards the first dichroic filter 13 and to backscatter it towards its original direction, namely towards the polarizer 14, and - the polarizer 14 is further configured to repeatedly transmit to the outside of the light generator 1 50% of this depolarized light reflected on the first dichroic filter 13 and having a 2nd polarization direction P2 and reflect 50% of the depolarized light reflected on the first dichroic filter 13 having a 1st polarization direction PI.

[0099] This cycle of selective transmission of light by the polarizer 14 and depolarization of light by the phosphor layer 12 and reflection of light by the first dichroic filter 13 is repeated until there is no more light energy, namely until there is no more unconverted L1 light.

[0100] Thus, the light converted L2 by the phosphor layer 12 and the light L1 emanating from the first monochromatic radiation RI which has not been converted by the phosphor layer 12 form a total light.

[0101] Finally, when the phosphorus 12 layer is saturated: - the polarizer 14 is configured to reflect a first polarization direction PI of 50% of the total light at the first wavelength and at the second wavelength(s), so that it returns to the phosphor layer 12, and transmits outwards from the light generator 1 the second polarization direction P2 of 50% of this total light, and - the phosphor layer 12 is configured to repeatedly depolarize the total light in the first polarization direction PI and reflected by the polarizer 14, to propagate it randomly, isotropically towards the first dichroic filter 13 and to backscatter it towards its original direction, namely towards the polarizer 14, and - the polarizer 14 is configured to repeatedly transmit to the outside of the light generator 1 50% of this total light depolarized and reflected on the first dichroic filter 13 and having a 2nd polarization direction P2 and reflect 50% of the total light depolarized and reflected on the first dichroic filter 13 having a 1st polarization direction PI.

[0102] This cycle of selective transmission of light by the polarizer 14 and depolarization of light by the phosphor layer 12 and reflection of light by the first dichroic filter 13 is repeated until there is no more light energy, that is, until there is no more total light. Indeed, the various back-and-forth movements of the total light between the polarizer 14, the phosphor layer 12, and the first dichroic filter 13, make it possible to increase the transmission of this total light to the outside of the light generator 1.

[0103] Thus, although 50% of the total light is reflected by the polarizer 14, at the output of the light generator 1 up to 80% of total light transmission can be obtained at the end of several cycles of selective transmission by the polarizer 14.

[0104] The protective layer 15 is positioned opposite the polarizer 14 on the side facing the phosphor layer 12. It is in contact with the polarizer 14. It is thus adjacent to the polarizer 14. It forms a protective screen that shields the optoelectronic device 11, the phosphor layer 12, the first dichroic filter 13, and the polarizer 14 from external elements such as dust or water. It thus provides the light generator 1 with good sealing. Furthermore, it enables it to pass the pedestrian impact crash test.

[0105] In a non-limiting embodiment, the protective layer 15 is rigid. In non-limiting examples, it is made of PC for its face facing outwards from the light generator 1 and of PMMA for its face facing inwards from the light generator 1, i.e., facing the other elements 12, 13, 14 and, where applicable, 17 and / or 18. In another non-limiting example, the protective layer 15 is made of resin. In yet another non-limiting embodiment, the protective layer 15 is semi-rigid. In this case, in a non-limiting example, the deformable polyurethane material PUR may be considered.

[0106] In a non-limiting embodiment, the protective layer 15 is between 5 µm and 5000 µm thick. In a non-limiting variant, when made of PUR material, it is between 200 µm and 5 mm thick. In a non-limiting variant, when made of resin, it is between 5 µm and 500 µm thick. In a non-limiting embodiment of this variant, it is between 5 µm and 100 µm thick.

[0107] The protective layer 15 comprises a first face 15.1 and a second face 15.2 opposite the first face 15.1 (illustrated in [Fig. 1]). The first face 15.1 is turned outwards from the light generator 1 while the second face 15.2 is turned inwards from the light generator 1. It should be noted that the bonding or overmolding of the first dichroic filter 13-phosphor layer 12-polarizer 14 assembly is carried out on the face of the protective layer 15 turned inwards from the light generator 1, i.e. the second face 15.2.

[0108] Thus, thanks to the phosphor layer 12-first dichroic filter 13-polarizer 14 assembly, a transmission and conversion of light of approximately 80% is obtained, representing a gain in luminous efficiency of more than 30 points of efficiency compared to the light generator of the prior art.

[0109] As seen previously, there may be residues of first monochromatic RI radiation (otherwise called L1 light residues) not converted by the phosphor layer 12 and which are also scattered by the phosphor layer 12 in all directions, and in particular backwards (i.e., in the second direction D') and forwards (i.e., in the first direction D). As illustrated in Figures 1, 4, 6, 7 and 9a to 11, the residual light L1 scattered forwards are shown in front of the protective layer 15. Thus, the phosphor layer 12 also scatters some of the L1 light if the first monochromatic radiation RI is not completely converted.This unconverted part of the L1 light is thus backscattered by the phosphor layer 12 and potentially by Fresnel reflections on the phosphor layer 12-polarizer 14 interface, namely on the second diopter 121, the backscattering being towards its original direction, here towards the back of the phosphor layer 12 (namely in the second direction D'), namely towards the opto-electronic device 11 in the case of figures 1 to 7, or towards the light guide 17 described later in the case of figures 7 and 8.

[0110] As we will see below, thanks to the second dichroic filter 18, these unconverted and scattered L1 light residues are not lost.

[0111] In order to be able to further increase the conversion efficiency of the phosphor layer 12, in a non-limiting embodiment illustrated in [Fig.3], the light generator 1 further includes a second dichroic filter 18 complementary to the first dichroic filter 13.

[0112] The second dichroic filter 18 is arranged between the phosphor layer 12 on the side of its second diopter 121 and the polarizer 14. It is therefore arranged opposite these two layers 12 and 14. There is therefore the first dichroic filter 13 positioned on the side of the first diopter 120 of the phosphor layer 12 and the second dichroic filter 18 positioned on the side of the second diopter 121 of the phosphor layer 12.

[0113] The second dichroic filter 18 is configured to: - to transmit the light L2 converted and scattered by the phosphor layer 12 towards the polarizer 14, namely in the first direction D, and - reflecting the light L1 emanating from the first monochromatic radiation RI towards the phosphor layer 12, namely in the second direction D', which was not converted the first time when the first light radiation RI passed through the phosphor layer 12.

[0114] The second dichroic filter 18 thus allows the converted and diffused L2 light from the phosphor layer 12 to the polarizer 14 to pass through. Thus, in the non-limiting example of the first monochromatic RI radiation which generates blue L1 light and which is converted into red L2 light, it allows the red light to pass through.

[0115] We speak of complementarity with respect to the first dichroic filter 13 because, unlike the first dichroic filter 13 which transmits the light L1 emanating from the first monochromatic radiation RI, it does not transmit this light L1, but reflects it. And, unlike the first dichroic filter 13 which reflects the light converted L2 by the phosphor layer 12, it does not reflect this light, converts L2, but transmits it, namely it lets it pass through.

[0116] Thus, the residual light L1 emanating from the first monochromatic radiation RI is reflected by the second dichroic filter 18 towards the phosphor layer 12. This light L1 then passes back through the phosphor layer 12, which converts it into light L2 at one or more second wavelengths X2 above the first wavelength XI. The second dichroic filter 18 thus converts the residuals of the first monochromatic radiation RI that were not converted by the phosphor layer 12 the first time the first monochromatic radiation RI passed through it. In [Fig. 3], the absence of this residual light L1 in front of the protective layer 15 will be noted.

[0117] Thus, the polarizer 14 no longer receives L1 light emanating from the first monochromatic radiation RI unconverted by the phosphor layer 12, since this unconverted L1 light is reflected inwards by this second dichroic filter 18 and is absorbed by the second dichroic filter 18 and the phosphor layer 12. The polarizer 14 will therefore reflect and transmit only converted L2 light. Thus, in this case, the total light seen previously consists only of converted L2 light.

[0118] It should be noted that the second dichroic filter 18, which acts according to the first wavelength XI, allows the converted light L2 of the first polarization direction PI to pass through. This light is reflected by the polarizer 14 towards the phosphor layer 12, since this converted light L2 is at the second wavelength X2. The second dichroic filter 18 does not act on it. It is thus transparent to this converted light L2 of the first polarization direction PL.

[0119] In the non-limiting example of the first monochromatic radiation RI which generates blue L1 light, the second dichroic filter 18 allows the residual blue L1 light to be converted into red L2 light in a non-limiting example. Thus, in the end, the external observer will be able to observe a deeper red than if there had only been the first dichroic filter 13.

[0120] In summary, the second dichroic filter 18: - reflects unconverted blue L1 light inwards, - allows the converted red light L2, diffused by the phosphor layer 12, to pass in one direction towards the polarizer 14, and - allows the converted red light L2 from the first polarization direction PI and reflected by the polarizer 14 to pass in the opposite direction towards the phosphor layer 12.

[0121] As for the polarizer 14, it no longer recovers blue L1 light, it will only transmit and reflect the converted red L2 light.

[0122] In a non-limiting embodiment, the second dichroic filter 18 is between 100 nm and 2000 nm. It can be made on a substrate which is between 50 µm (micrometers) and 300 µm.

[0123] Thus, thanks to the assembly of phosphor layer 12-first dichroic filter 13-polarizer 14-second dichroic filter 18, a light transmission and conversion of approximately 80% is still obtained, as in the case with only the first dichroic filter 13, but in addition, a purer color is obtained at the second wavelength(s). In the example of the native blue color, since no blue residue remains, a brighter red color is obtained at the output of the light generator 1.

[0124] In a first, non-limiting embodiment illustrated in [Fig. 4], the light generator 1 further comprises at least one reflective cavity 16, and said at least one optoelectronic device 11 is disposed at the bottom of the reflective cavity 16. In a non-limiting embodiment, the reflective cavity 16 has a depth of between 3 mm and 2 cm (centimeters). This allows for an overall compact light generator 1.

[0125] The reflective cavity 16 is configured to confine the first monochromatic radiation RI emitted by the optoelectronic device 11, particularly if the light L1 emanating from L1 has a large angle of incidence upon arrival at the first dichroic filter 13. This prevents light loss. It allows for resonant coupling, namely obtaining multiple reflections of light within the reflective cavity 16, which increases the luminous efficiency of the light generator 1.

[0126] In non-limiting embodiments, the reflective cavity 16 is made of silicone or plastic. In one non-limiting embodiment, it is painted white to obtain the reflective effect. In another non-limiting embodiment, it is composed of TiO2-type elements known to those skilled in the art to be highly reflective.

[0127] Thanks to the reflective cavity 16, the loss of light L2 backscattered towards the optoelectronic device 10 that was not reflected by the first dichroic filter 13 is compensated, namely that at high angles of incidence, i.e., beyond 40°. Indeed, by the multiple reflections of light inside the reflective cavity 16, more light arrives at low angles of incidence on the dichroic filter 13.

[0128] Thanks to the reflective cavity 16, light losses due to the dispersion of the phosphor layer 12, which radiates in all directions, are also reduced. In effect, this reflective cavity 16 will therefore, by reflection, redirect the light in the first direction D. This maximizes the luminous efficiency and limits the light losses.

[0129] The assembly of phosphor layer 12 - first dichroic filter 13 - polarizer 14 - protective layer 15 and where applicable second dichroic filter 18, forms a light-diffusing film which thus covers the reflective cavity 16. It should be noted that the reflective cavity 16 has for this purpose a closed transparent end disposed on the opposite side of its bottom in order to place this light-diffusing film on it.

[0130] It should be noted that in the case where there is no reflective cavity 16 (as in Figures 1 and 3), in order to keep the phosphor layer 12 away from the optoelectronic device(s) 11, in a non-limiting embodiment, pads (not shown) arranged on either side of the optoelectronic device(s) 11 may be used. Thus, the light-diffusing film, composed of the phosphor layer 12, first dichroic filter 13, protective layer 15, and, where applicable, a second dichroic filter 18, may rest on these pads.

[0131] In a non-limiting embodiment illustrated in [Fig.5], the light generator 1 of [Fig.4] further comprises a second dichroic filter 18 as described above.

[0132] In a non-limiting embodiment illustrated in [Fig. 6], the light generator 1 comprises a plurality of reflective cavities 16 and a plurality of optoelectronic devices 11. In a non-limiting example illustrated in [Fig. 5], it comprises three optoelectronic devices 111, 112, and 113 arranged respectively in three corresponding cavities 161, 162, and 163. It should be noted that the assembly of protective layer 15 - phosphor layer 12 - first dichroic filter 13 - polarizer 14 and, where applicable, second dichroic filter 18, covers all the reflective cavities 161, 162, and 163.

[0133] In a non-limiting example, to achieve pixelated lighting, one can use from 2 to more than 3000 optoelectronic diodes 11 and corresponding reflective cavities 16. In a non-limiting example, such a light generator 1 comprises 1700 optoelectronic diodes 11 and corresponding reflective cavities 16. This makes it possible, in particular, to implement a projection and / or signaling function for a lighting device 2 described later in the description, which incorporates the light generator 1.

[0134] In a second, non-limiting embodiment illustrated in [Fig. 7], the light generator 1 further comprises a light guide 17. The light guide 17 is arranged opposite the first dichroic filter 13 on the side opposite the phosphor layer 12, on the side of its first interface 120. Thus, the first dichroic filter 13 is located between the phosphor layer 12 and the light guide 17. The light guide 17 includes a first end 17.1 and a second end 17.2 opposite the first end 17.1.

[0135] It should be noted that the light guide 17 does not heat up. Therefore, there is no heat transfer from the optoelectronic device 11 to the phosphor layer 12 via the light guide 17.

[0136] The light guide 17 is configured to refract and reflect the light L1 emanating from the first monochromatic radiation RI towards the phosphor layer 12.

[0137] The light L1 at the first wavelength XI is thus coupled to the light guide 17. The light guide 17 is composed of a prismatic or diffusing structure which thus directs the first monochromatic radiation RI towards the phosphor layer 12 and the first dichroic filter 13.

[0138] It should be noted that in this second non-limiting embodiment, the optoelectronic device 11 is disposed at one of the two ends of the light guide 17, here at the end referenced 17.1 in [Fig. 7]. In a non-limiting variant of the embodiment, there are two optoelectronic devices 11 disposed respectively at each end 17.1 and 17.2 of the light guide 17.

[0139] In a non-limiting embodiment, the light generator 1 includes a mechanical attachment (not shown) for maintaining the light guide 17 at a distance from the phosphor layer 12-first dichroic filter 13-polarizer 14-protective layer 15 assembly and, where applicable, the second dichroic filter 18. In a non-limiting embodiment, the distance is between 3 mm and 10 mm. In another non-limiting embodiment, after bonding the polarizer 14 and overmolding the phosphor layer 12-first dichroic filter 13-protective layer 15 assembly and, where applicable, the second dichroic filter 18, which forms a single film, the latter is overmolded onto the light guide 17 or bonded onto the light guide 17. In this case, the distance is 0 mm.

[0140] The use of a light guide 17 makes it possible, with a single optoelectronic device 11 (or a maximum of two), to perform the entirety of a desired lighting function, such as, in a non-limiting example, the function of lighting and / or signaling. It is not necessary to use a multitude of optoelectronic devices 11.

[0141] Thanks to the light guide 17, the energy performance of the light generator 1 is optimized, resulting in lower energy consumption. Indeed, there is an overall gain in luminous efficiency when considering the number of optoelectronic devices 11 used, in terms of lumens, which corresponds to the luminous flux output of the light generator 1 per electrical watt.

[0142] The assembly of phosphor layer 12 - first dichroic filter 13 - polarizer 14 - protective layer 15 and where applicable second dichroic filter 18, forms a light-diffusing film which thus covers the light guide 17.

[0143] In a non-limiting embodiment illustrated in [Fig.8], the light generator 1 of [Fig.7] further comprises a second dichroic filter 18 as described above.

[0144] In a non-limiting embodiment, the light generator 1 is part of a lighting device 2 which includes at least one light generator 1.

[0145] When the light generator 1 is integrated into the light device 2, the protective layer 15 is turned outwards from the light device 2, namely in the first direction D.

[0146] In non-limiting embodiments, the lighting device 2 is a vehicle lighting device 3 as illustrated in Figures 9a to 9c or a domestic or industrial lighting device as illustrated in Figures 10 and 11. In non-limiting embodiments, the vehicle 3 is a vehicle with an internal combustion engine, a hybrid engine, or an electric motor. Figure 10 illustrates a house including the lighting device 2, and Figure 11 illustrates an industrial building including the lighting device 2. In Figures 9a to 11, the light generator 1 of Figure 1 has been taken as a non-limiting example. Obviously, this Figure 1 can also be replaced in Figures 9a to 11 by the other examples of the light generator 1 in Figures 3 to 8.

[0147] In non-limiting embodiments, the vehicle 3 lighting device 2 is: - a lighting and / or signaling device as illustrated in [Fig. 9a] where the lighting device 2 is a spotlight in a non-limiting example; it may be a rear light in another non-limiting example, - a front or rear lighting device as illustrated in [Fig.9b] where the lighting device 2 is located on the front of the vehicle 3 in a non-limiting example, - an interior lighting device as illustrated in [Fig.9c] where the light device 2 is located in the passenger compartment of the vehicle 3, here on the ceiling in a non-limiting example.

[0148] In a non-limiting embodiment, the front or rear lighting device enables the creation of an illuminated logo or an illuminated metal grille. When the optoelectronic device 11 is not activated, a metallic, mirror-like appearance is observed. When the optoelectronic device 11 is activated, the entire front grille is illuminated.

[0149] In non-limiting embodiments, the signaling device enables the stop function or the rear light function (also called in English "TAIL") to be performed.

[0150] In non-limiting embodiments, the lighting device enables the function of a projector or the daytime running lamp (called in English "Daytime Running Lamp" whose acronym is DRL).

[0151] Of course, the description of the invention is not limited to the embodiments and the field described above. Thus, the invention can be applied to any lighting product in any application that complies with regulations. Thus, in another non-limiting embodiment, in the non-limiting example of a lighting and / or signaling device, the light device 2 can be arranged in a rear light or in a third brake light.

[0152] Thus, the described invention has, in particular, the following advantages: - It allows for a metallic exterior appearance for the light generator 1 with very good luminous efficiency, - it allows for a thin and therefore compact light generator, - it allows for an increase in the luminous efficiency of light generator 1, - it prevents the phosphorus 12 layer from heating up, which would limit its light conversion efficiency, - it allows the converted and backscattered L2 light to be recycled through reflection on the first dichroic filter 13, which increases the light conversion efficiency, - it allows the conversion of the residues of the first monochromatic RI radiation thanks to the second dichroic filter 18, - it allows, from a monochromatic opto-electronic device 11, to obtain different monochromatic colors or a white color, - It helps reduce light loss due to light being scattered within the phosphor and radiating in all directions. - thanks to the fact that the phosphor layer 12 is offset, there is better light conversion compared to a solution which would stick the phosphor layer 12 to the opto-electronic device 11, because there is less thermal heating.

Claims

1. Demands Light generator (1) comprising: - at least one opto-electronic device (11) composed of semiconductor materials and configured to produce a first monochromatic radiation (RI) so as to generate light (Ll) at a first wavelength (XI), - a phosphor layer (12) offset from said at least one optoelectronic device (11) and comprising a first diopter (120) and a second diopter (121) and configured to convert all or part of the first incident monochromatic radiation (RI) into a second radiation (R2) so as to obtain a converted light (L2) at one or more second wavelengths (X2) greater than that (XI) of the light (L1) emanating from the first monochromatic radiation (RI) and to diffuse this converted light (L2), characterized in that the light generator (1) further comprises: - a first dichroic filter (13) arranged on the side of the first diopter (120) of the phosphor layer (12) and configured to transmit the light (L1) emanating from the first monochromatic radiation (RI) towards the phosphor layer (12) and to reflect the light converted (L2) by the phosphor layer (12) towards a polarizer (14) with a metal grid, - the polarizer (14) arranged opposite the phosphor layer (12) on the side of its second diopter (121) and configured to reflect a first polarization direction (PI) of 50% of the converted light (L2) at the second wavelength(s) (X2) so that it returns towards the phosphor layer (12), and transmit to the outside of the light generator (1) a second polarization direction (P2) of 50% of the converted light (L2) at the second wavelength(s) (X2), - the phosphor layer (12) being further configured to repeatedly depolarize the converted light (L2) reflected from the first polarization direction (PI) by the polarizer (14) and to propagate it randomly towards the first dichroic filter (13) and to back-scatter it towards the polarizer (14), - the polarizer (14) being further configured to repeatedly transmit 50% of the depolarized light reflected on the first dichroic filter (13) and having a 2nd polarization direction (P2) and reflect 50% of the depolarized light reflected on the first dichroic filter (13) having a 1st polarization direction (PI), - a protective glass (15) arranged opposite the polarizer (14) on the side opposite the phosphor layer (12).

2. Light generator (1) according to claim 1, wherein said at least one opto-electronic device (11) is disposed opposite the first dichroic filter (13) and the phosphor layer (12) and the first dichroic filter (13) is disposed between the phosphor layer (12) and said at least one opto-electronic device (11), and wherein the light generator (1) further comprises at least one reflective cavity (16) at the bottom of which said at least one opto-electronic device (11) is disposed.

3. Light generator (1) according to the preceding claim, wherein the light generator (1) comprises a plurality of reflective cavities (16) and a plurality of opto-electronic devices (H).

4. Light generator (1) according to claim 1, wherein the light generator (1) further comprises a light guide (17) disposed opposite the first dichroic filter (13) on the side opposite the phosphor layer (12), and configured to refract and reflect the light (L1) emanating from the first monochromatic radiation (RI) towards the phosphor layer (12), and wherein said at least one optoelectronic device (11) is disposed at one of the two ends (17.1, 17.2) of the light guide (17).

5. A light generator (1) according to any one of the preceding claims, wherein: - the polarizer (14) is further configured to reflect a first polarization direction (PI) of 50% of the light (L1) that has not been converted by the phosphor layer (12) so that it returns to the phosphor layer (12), and to transmit outwards from the light generator (1) a second polarization direction (P2) of 50% of this light (L1), - the phosphor layer (12) is further configured to repeatedly depolarize the unconverted light (L1) of the first direction of polarization (PI) and reflected by the polarizer (14), to propagate it randomly towards the first dichroic filter (13) and to backscatter it towards the polarizer (14), - the polarizer (14) is further configured to repeatedly transmit to the outside of the light generator (1) 50% of this depolarized light reflected on the first dichroic filter (13) and having a 2nd polarization direction (P2) and to reflect 50% of the depolarized light reflected on the first dichroic filter (13) having a 1st polarization direction (PI).

6. Light generator (1) according to any one of the preceding claims, wherein said at least one optoelectronic device (11) is a native light-emitting diode or a laser diode.

7. Light generator (1) according to any one of the preceding claims, wherein the first wavelength (XI) is between 400 and 500 nanometers.

8. Light generator (1) according to any one of the preceding claims, wherein the first polarization direction (PI) is vertical and the second polarization direction (P2) is horizontal or vice versa.

9. Light generator (1) according to any one of the preceding claims, wherein the light generator (1) further comprises a second dichroic filter (18) complementary to the first dichroic filter (13), disposed between the phosphor layer (12) and the polarizer (14), and configured to transmit the light (L2) converted and scattered (L2) by the phosphor layer (12) out of the light generator (1) and to reflect the light (L1) emanating from the first monochromatic radiation (RI) back to the phosphor layer (12).

10. Light generator (1) according to any one of the preceding claims, wherein the phosphor layer (12) is mixed with resin (122).

11. Lighting device (2), wherein said lighting device (2) comprises at least one light generator (1) according to any one of the preceding claims.

12. 26 Lighting device (2) according to the preceding claim, wherein said lighting device (2) is a lighting device for a vehicle (3), or a domestic or industrial lighting device.

13. Light device (2) according to the preceding claim, wherein said light device (2) for vehicle (3) is a lighting and / or signaling device, or a front or rear lighting device, or an interior lighting device.

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