Lighting device for a vehicle, configured to project an image onto a surface

Abstract

Lighting device (1) comprising a light source (10) configured to emit light (R) in at least two different wavelengths, characterized in that it comprises: - a collimator optics (11) configured to collimate the light (R) and form a first collimated light beam (Fx'); - a stack (St) of at least two matrices (121, 122) of meta-lenses (1211, 1212) defined for the two wavelengths, each matrix (121, 122) being configured to orient a portion of the first collimated light beam (Fx') in a propagation direction so as to create a portion of a second collimated light beam (Fx'') which is an image (Im) composing an overall image (Ig) and to project it onto a plane parallel to said stack (St), - a deflection optics (13) configured to deflect the second collimated light beam (Fx'') so as to project the overall image (Ig) onto a surface.

Description

Vehicle lighting device configured to project an image onto a surface

[0001] The present invention relates to a lighting device for vehicles. It finds a particular, but not limiting, application in motor vehicles.

[0002] In the field of motor vehicles, a lighting device known to those skilled in the art comprises: - a light source configured to emit light at a given wavelength forming a light beam, - a conventional light collimator configured to collimate said light beam, - a mask or slide with opaque and transparent areas, the latter being crossed by the collimated light to form the image, - a projection lens disposed downstream of the mask / slide and configured to project the image onto the ground.

[0003] One drawback of this state of the art is that the lighting device has low luminous efficacy. Indeed, between the emitted light and the light exiting the lighting device, there is a loss of more than 50%.

[0004] In this context, the present invention aims to provide a lighting device that solves the aforementioned problem.

[0005] To this end, the invention proposes a vehicle lighting device configured to project a global image onto a surface, said lighting device comprising: - a polychromatic light source configured to emit light on at least two different wavelengths, said light forming a light beam; characterized in that said lighting device further comprises: - collimating optics disposed opposite said light source and configured to collimate said light and form a first collimated light beam;- a stack of at least two meta-lens arrays arranged opposite the collimating optics, each meta-lens array being defined for one of said at least two wavelengths, and being configured to orient a part of the first collimated light beam along a propagation direction so as to create a part of a second collimated light beam which is an image composing said global image and to project said image onto a plane parallel to said stack, - a folding optics arranged opposite said at least two meta-lens arrays and configured to deflect the second collimated light beam along an orientation direction so as to project said global image onto said surface.;

[0006] Thus, as we will see in detail below, the light source illuminates the collimating optics with polychromatic uncollimated light. The collimating optics collimate this polychromatic uncollimated light, which then illuminates the metal lens arrays. The collimated light is transmitted through the metal lens arrays, which operate at different wavelengths of the emitted polychromatic light. This polychromatic light is then projected onto the ground with high luminous efficiency using the refracting optics, forming at least two images. These images can be superimposed to obtain an overall image of uniform color, or they can be partially or completely separate to obtain an overall image with different colored areas.

[0007] According to non-limiting embodiments, the vehicle lighting device may further comprise one or more additional features taken alone or in all technically possible combinations, from among the following.

[0008] According to a non-limiting embodiment, the light source includes an emitter configured to emit white light.

[0009] According to a non-limiting embodiment, the light source comprises at least two emitters configured to each emit a different monochromatic light.

[0010] According to a non-limiting embodiment, said at least two monochromatic emitters emit cyan and amber colored light.

[0011] According to a non-limiting embodiment, the light source comprises three emitters configured to each emit a different monochromatic light.

[0012] According to a non-limiting embodiment, the three emitters emit respectively a red, green, blue, or cyan, magenta and yellow colored light.

[0013] According to a non-limiting embodiment, said stacking further comprises a third meta-lens matrix adjacent to the second meta-lens matrix.

[0014] According to a non-limiting embodiment, the collimating optics includes at least one lens or is an array comprising a plurality of groups of microlenses, each group being configured to collimate said light and create a collimated subbeam forming a part of said first collimated light beam.

[0015] According to a non-limiting embodiment, a group of microlenses is formed of a single microlens or two microlenses.

[0016] According to a non-limiting embodiment, each meta-lens of a meta-lens array is arranged opposite each group of micro-lenses and is configured to orient the collimated sub-beam of said group along the propagation direction.

[0017] According to a non-limiting embodiment, the meta-lenses of each meta-lens array comprise nano-pillars defined by a radius, a height and a second pitch between two nano-pillars.

[0018] According to a non-limiting embodiment, the folding optic is a microlens matrix.

[0019] According to a non-limiting embodiment, said surface is the ground on which said vehicle is located or an interior surface within the passenger compartment of the vehicle.

[0020] According to a non-limiting embodiment, said nano-pillars have different radii and the same height.

[0021] According to a non-limiting embodiment, each emitter is traversed by a current whose intensity I is controllable independently of the other emitters.

[0022] According to a non-limiting embodiment, the meta-lenses of said at least two meta-lens matrices have a size equal to a first step defined between two adjacent micro-lenses of two different adjacent groups.

[0023] According to a non-limiting embodiment, said metal lenses have a surface area less than or equal to 1 mm² 2 .

[0024] According to a non-limiting embodiment, said collimation optics has a thickness of between 2 and 3mm.

[0025] According to a non-limiting embodiment, said folding optic has a thickness between 1mm and 3mm.

[0026] According to a non-limiting embodiment, said nano-pillars are made of Silicon Nitride.

[0027] According to a non-limiting embodiment, said lighting device is configured to be positioned outside the vehicle.

[0028] According to a non-limiting embodiment, said lighting device is configured to be placed in the passenger compartment of the vehicle.

[0029] According to a non-limiting embodiment, the first image, the second image and the third image are projected in a superimposed manner so as to obtain an overall image of uniform color.

[0030] According to a non-limiting embodiment, the first image, the second image and the third image are projected in a partially non-superimposed manner so as to obtain an overall image with different areas of different colours.

[0031] According to a preferred embodiment not illustrated, the collimation optics (includes a stack of at least two meta-lenses or two meta-lens arrays, each meta-lens or each meta-lens array being defined for one of said at least two wavelengths and configured to collimate the light (R) at one of said at least two wavelengths, and whose diameter is adapted to that of the light beam.

[0032] According to one embodiment, said stacking further comprises a third meta-lens or meta-lens matrix adjacent to the second meta-lens or meta-lens matrix.

[0033] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures:

[0034] Laillustrate very schematically a lighting device for a vehicle according to a first non-limiting embodiment of the invention, said lighting device comprising a polychromatic light source, collimation optics, at least two metal-lens matrices, and a folding optics;

[0035] Laillustrate very schematically a lighting device for a vehicle according to a second non-limiting embodiment of the invention, said lighting device comprising a polychromatic light source, a collimation optic, three metal-lens matrices, and a folding optic;

[0036] Laillustre very schematically a first non-limiting embodiment of the light source of the lighting device of laou 1b;

[0037] Laillustre a first non-limiting variant of a second non-limiting embodiment of the light source of the lighting device of laou 1b;

[0038] Laillustre une seconde variant de mise en mise non limiter d'un seconde mode de mise en mise de lumière du dispositif lumineuse de laou 1b ;

[0039] Laillustre the metal-lens matrix of the luminous device of laou 1b traversed by the light emitted by the light source of the ;

[0040] Laillustre very schematically a first non-limiting embodiment of the collimation optics of the luminous device of laou 1b;

[0041] Laillustre a first non-limiting variant of a second non-limiting embodiment of the collimation optics of the luminous device of laou 1b;

[0042] Laillustre une seconde variant de mise en mise non limiter d'un seconde mode de embodiment non limiter de l'optique de collimation du dispositif lumineuse de laou 1b ;

[0043] Laest is a representation of a meta-lens of the meta-lens matrices of the luminous device of laou 1b according to a non-limiting embodiment, the meta-lens comprising a substrate and nano-pillars;

[0044] Laillustre an enlarged view of a plurality of nano-pillars of the meta-lens of laselon an embodiment not limiting;

[0045] Laillustre a highly magnified view of a single nano-pillar of the meta-lens with a portion of the substrate;

[0046] Laillustre des nano-pillars de la meta-lentille de laet une direction de propagation des sous-beaiseaux collimâtes produits par l'optique de collimation du dispositif lumineux de laou 1b quand ils travers les dit nano-pillars;

[0047] Laillustre a first curve indicating a phase variation as a function of the radius of a nano-pillar of a meta-lens of the meta-lens matrices of the luminous device of laou 1b;

[0048] Laillustre a second curve indicating a variation in light transmission as a function of the radius of a nano-pillar of a meta-lens of the meta-lens matrices of the luminous device of laou 1b;

[0049] Laillustre schematically a projection by a matrix of meta-lenses of the luminous device of laou 1b of an image onto a plane parallel to a substrate of the meta-lenses, said image comprising illuminated areas and shadow areas;

[0050] Laillustre schematically un mode de embodiment non limiting de loupe de loupe du dispositif lumineuse de laou 1b ;

[0051] Laillustre une image globale projetée par loupe de optique de floupe du dispositif lumineuse de laou 1b ;

[0052] Laillustre schematically a projection of the global image of lasur on the ground by the folding optics of the luminous device of laou 1b;

[0053] Laillustre schematically a projection of the global image of lasur a surface inside the vehicle by the folding optics of the light device of laou 1b;

[0054] The diagram schematically illustrates a vehicle comprising a lighting device of laou 1b, said lighting device being located outside the vehicle at the level of an exterior rearview mirror;

[0055] The diagram schematically illustrates a vehicle comprising a lighting device of laou 1b, said lighting device being located outside the vehicle, at the level of a bottom of a door;

[0056] The diagram schematically illustrates a vehicle comprising a lighting device of laou 1b, said lighting device being located inside the passenger compartment of the vehicle.

[0057] Identical elements, whether structural or functional, appearing on different figures retain the same references unless otherwise specified.

[0058] The vehicle lighting device 1 according to the invention is described with reference to figures 1a to 16.

[0059] In a non-limiting embodiment, the lighting device 1 is a lighting device of a vehicle 2 (illustrated in Figure 16). In a non-limiting embodiment, the vehicle 2 is a motor vehicle. A motor vehicle is understood to mean any type of motorized vehicle. This embodiment is taken as a non-limiting example in the following description. In the following description, the vehicle 2 is thus also referred to as motor vehicle 2. In a non-limiting variant of the embodiment, the vehicle 2 is a combustion engine, electric, or hybrid vehicle. The vehicle 2 has exterior mirrors 20 (illustrated in Figures 14 and 15), doors 21 (illustrated in Figures 14 and 15), an interior rearview mirror 22 (illustrated in Figure 1), an interior roof 23 (illustrated in Figures 14 to 16), and a passenger compartment 24 (illustrated in Figures 14 and 15).

[0060] In the following description, the terms depth and thickness will be used interchangeably. Depth is understood along a longitudinal axis AA' (illustrated on 1a and 1b) which passes through the entire luminous device 1.

[0061] As will be seen below, the lighting device 1, being relatively shallow, is configured to be located not only inside the passenger compartment 24 of the vehicle 2, but also outside the vehicle 2. Thus, in a first, non-limiting embodiment illustrated in Figure 15, it is placed outside the vehicle. In a second, non-limiting embodiment, the lighting device 1 is placed inside the passenger compartment 24 of the vehicle 2.

[0062] The lighting device 1 is configured to: - signal an orientation or maneuvering function, - produce static or dynamic light signaling around vehicle 2, - signal autonomous driving, - produce a light image inside the passenger compartment 24 of vehicle 2.

[0063] For this purpose, the lighting device 1 is configured to project a global image Ig onto a surface 4 (illustrated in Figures 1a, 1b, 13a, 13b, 14 to 16). The surface 4 may be curved. In a first, non-limiting embodiment illustrated in Figures 1, 14, and 15, the surface 4 is the ground on which the vehicle 2 is located. In a second, non-limiting embodiment illustrated in Figures 1 and 16, the surface 4 is a surface inside the passenger compartment 24 of the vehicle 2. In non-limiting examples, the surface 4 inside the passenger compartment 24 is the dashboard of the vehicle 2 or the ceiling of the vehicle 2.

[0064] When the overall image Ig allows for the signaling of a guidance or maneuvering function, in non-limiting embodiments, the lighting device 1 may, for example, be located at the front of the vehicle 2, at the level of a grille and / or at the level of headlights intended to illuminate the road and make the vehicle 2 clearly visible to other road users. Alternatively, the lighting device 1 may be located on the sides of the vehicle 2 or at the rear of said vehicle 2. When located on the sides of the vehicle 2, it may be at the level of an exterior mirror. When located at the rear of the vehicle 2, it may be at the level of the taillights. It is specified that the front refers to the side of the vehicle 2 towards which it is moving in a straight line, forwards.

[0065] The guidance or maneuvering function is performed during the night or day. The signaling for this guidance or maneuvering function is called extended signaling, also known as extended signaling. This signaling involves projecting a static global image (Ig) onto the ground. Extended signaling thus allows the synchronization of this projected global image with a traditional signaling function, such as guidance or maneuvering.

[0066] In non-limiting examples, the orientation function is a turn signal for changing lanes and the maneuvering function is a reversing light for parking or a brake light.

[0067] In a non-limiting example, the overall image Ig is projected onto the ground, synchronizing with the vehicle's turn signal. It therefore appears and disappears at regular intervals. Thus, when the driver of vehicle 2 activates the turn signal, the extended signaling function projects an overall image Ig onto the ground so that people around vehicle 2 are informed that vehicle 2 is turning right or left. This is useful for any third party (a pedestrian, a cyclist, etc.) who cannot see vehicle 2's turn signal. The overall image Ig is synchronized by appearing on the ground when the turn signal is activated and disappearing from the ground when the turn signal is deactivated. In another non-limiting example, the overall image Ig projected onto the ground is a static pattern related to a maneuvering function, namely vehicle 2's reversing lights for parking.

[0068] When the overall image Ig allows for the production of static or dynamic signage on the ground 4 around and near vehicle 2 (at the front, rear, or side of vehicle 2), the lighting device 1 is positioned on one side of vehicle 2. When positioned on one side of vehicle 2, it can be located at the level of an exterior mirror as illustrated in Figure 1, particularly below the exterior mirror, or on the lower body or door as illustrated in Figure 2. In other words, the lighting device 1 is configured to project an overall image Ig onto the ground 4, said overall image Ig being either a static or animated image.

[0069] In non-limiting examples, the production of static or dynamic illuminated signage around vehicle 2 is: - a welcome scenario function. The welcome scenario function may include dynamic signage around vehicle 2, also called "dynamic carpet projection," in which an animated global image (Ig) is projected. The animated global image (Ig) is thus composed of several images. - static signage, also called "static carpet projection," in which a fixed global image (Ig) is projected.

[0070] When the overall image Ig indicates autonomous driving and is projected onto the ground 4 around vehicle 2, the light device 1 can be arranged as a taillight or headlight of vehicle 2. This alerts third parties that vehicle 2 is in autonomous driving mode. Note that autonomous driving is indicated by the color cyan in this non-limiting example.

[0071] When the overall image Ig is a luminous image projected onto a surface 4 inside the passenger compartment 24 of vehicle 2, the luminous device 1 can be arranged in the interior roof 23 of vehicle 2 or under the interior central rearview mirror 22 of vehicle 2.

[0072] As illustrated on Figure 1b, the light device 1 comprises: - a light source 10, - a collimation optic 11, - a stack St (called "Stack" in English) of at least two matrices 12 of metal lenses 121, and - a folding optic 13.

[0073] The elements of the lighting device 1 are described in detail below.

[0074] The light source 10 (illustrated on the 2d) is now described in detail below.

[0075] Light source 100 is configured to emit R light. It is a polychromatic light source, meaning it emits light at several different wavelengths λ. It thus emits R light at at least two different wavelengths λ1, λ2.

[0076] In a first non-limiting embodiment illustrated in the figure, the light source 10 includes an emitter configured to emit white light R.

[0077] In a second, non-limiting embodiment illustrated in Figure 1, the light source 10 comprises two emitters 1001, 1002 configured to emit different monochromatic light R1, R2, therefore having different wavelengths λ2. These will be referred to hereafter as monochromatic emitters 100.

[0078] In a third, non-limiting embodiment illustrated in Figure 1, the light source 10 comprises three emitters 1001, 1002, 1003 configured to emit different monochromatic light R1, R2, R3, therefore having different wavelengths λ1, λ2, λ3. These will be referred to hereafter as monochromatic emitters 100.

[0079] In a non-limiting embodiment, each monochromatic emitter 100 is traversed by a current whose intensity is controllable independently of the other monochromatic emitters 100. This allows the intensity of light of each image Im created by the matrix 12 of meta-lenses 121 (matrix 12 described later) cooperating with the light R emitted by each monochromatic emitter 100 to be modulated.

[0080] The light R emitted by the light source 10 forms an incoming light beam Fx, also called the incident light beam Fx or light beam Fx. Because the light source 10 is polychromatic, the light beam Fx is polychromatic. It therefore comprises light rays of different specific colors.

[0081] Thus, in the second non-limiting embodiment illustrated on the, in a non-limiting variant of the embodiment: - a first monochromatic emitter 1001 emits a monochromatic light of cyan color having a first wavelength λ1 between 490 nm (nanometers) and 500 nm, and - a second monochromatic emitter 1002 emits a monochromatic light of orange color having a second wavelength λ2 between 590nm and 610 nm.

[0082] In a non-limiting example, we have λ1 = 482 nm and λ2 = 590 nm. Note that a wavelength λ of 590 nm corresponds to amber-colored light. This non-limiting embodiment allows us to obtain the color white.

[0083] Thus, in the third non-limiting embodiment illustrated on the, in a non-limiting variant of the embodiment: - a first monochromatic emitter 1001 emits a monochromatic light of red color having a first wavelength λ1 between 620 nm and 700 nm, - a second monochromatic emitter 1002 emits a monochromatic light of green color having a second wavelength λ2 between 490 nm and 570 nm, - a third monochromatic emitter 1003 emits a monochromatic light of blue color having a third wavelength λ3 between 450 nm and 490 nm.

[0084] This produces a white color. In another variation, a white color can be obtained by mixing cyan, magenta, and yellow. Thus, the three monochromatic emitters 1001, 1002, 1003, sont respectivement de couleur rouge, et verte, bleue, ou cyan, magenta et jaune.

[0085] In a non-limiting embodiment, the light source 10 is a semiconductor light source. In other non-limiting embodiments, the semiconductor light source is a light-emitting diode (LED) or a laser diode. In the case of monochromatic emitters 100 composing the light source 10, the monochromatic emitters 100 are thus light-emitting diodes or laser diodes.

[0086] The term "light-emitting diode" refers to any type of light-emitting diode, including, but not limited to, LEDs (Light Emitting Diodes), OLEDs (Organic LEDs), AMOLEDs (Active-Matrix Organic LEDs), and FOLEDs (Flexible OLEDs). In another, non-limiting embodiment, the light source 10 is a laser light source. It should be noted that some laser light sources are not semiconductor light sources.

[0087] In a non-limiting embodiment, when the light source 10 comprises a plurality of monochromatic emitters 100, the latter are activatable independently of each other.

[0088] Thus, to produce static light signage, in a non-limiting embodiment, the monochromatic emitters 100 associated with each meta-lens 121 (described later) can be switched on (activated) or off (deactivated) simultaneously. To produce dynamic light signage, in a non-limiting embodiment, the monochromatic emitters 100 associated with each meta-lens 121 can be switched on or off sequentially to form an overall animated image Ig. By "associated" is meant that the light R from the emitters 100 cooperates with the meta-lenses 121.

[0089] Thus, to indicate that vehicle 2 is in autonomous driving mode, only a monochromatic cyan emitter (100) is activated. Indeed, the color cyan indicates that vehicle 2 is in autonomous driving mode.

[0090] In a preferred embodiment not shown, the collimation optics is a stack of metal lenses or a matrix of metal lenses configured to collimate light (R) at a wavelength, and whose diameter is adapted to that of the light beam.

[0091] Each collimating meta-lens is manufactured with the same material and structures as the 12-metal-lens array. The difference lies in the distribution of the nano-pillars. This distribution depends on the type of source, LASER or LED. For a LASER source: the distribution of nano-pillar diameters follows phase polynomials in X and Y, due to the different divergences along the parallel and perpendicular beam directions. For an LED source, the distribution of nano-pillar diameters follows a rotationally symmetrical phase profile.

[0092] The collimation optic 11 (illustrated in figures 1a, 1b and 3a to 3c) is now described in detail below.

[0093] As illustrated on laou 1b, the collimation optic 11 is arranged opposite the light source 10, downstream of it, and upstream of the stack St (described later) of matrices 12 of metal-lenses 121.

[0094] The collimating optics 11 are configured to collimate the light R emitted by the light source 10, thus forming a first collimated light beam Fx'. Indeed, the incident light beam Fx arriving at the collimating optics 11 is not collimated, but divergent. Collimating it allows us to obtain a first collimated light beam Fx' that has a phase profile adapted to the stacking St of arrays 12 of metal lenses 121.

[0095] In a first non-limiting embodiment illustrated in the figure, the collimating optics 11 includes at least one lens 110. Said at least one lens 110 is designed to perform the collimating function of the light R. It is thus designed to collimate this light R so as to create a collimated light subbeam f (also called collimated subbeam f) illustrated in the figure or 1b.

[0096] The size of at least one lens 110 is greater than 1 mm. In a non-limiting embodiment, the collimation optics 11 comprise a lens 110 with a size on the order of several millimeters. In another non-limiting embodiment, the collimation optics 11 comprise two lenses 110. In this non-limiting embodiment, the thickness of the collimation optics 11 is thus between 2 mm and 3 mm.

[0097] In a second, non-limiting embodiment illustrated in Figure 3c, the collimation optics 11 is a matrix comprising a plurality of groups p of microlenses 111, otherwise called a matrix 11 of microlenses 111. In this case, the collimation optics is a matrix known by the acronym MLA for "Matrix Lens Array." A microlens 111 is sub-millimeter in size (from 1 mm and below). In a non-limiting example, the matrix 11 comprises several dozen microlenses 11. This allows for a thin luminous device 1.

[0098] In a non-limiting embodiment, two adjacent microlenses 111 from two different adjacent groups p are spaced by a first step ps equal to the size of a microlens 111. In a non-limiting embodiment, the first step ps is between 50 microns and 1 mm. In this non-limiting embodiment, the second array 11 thus has a thickness between 2 mm and 3 mm. The microlens array 111 is therefore very thin. This allows for a thin luminous device 1.

[0099] Each group p of microlenses 111 is configured to receive the light R emitted by the light source 10.

[0100] A group p is thus configured to collimate this light R so as to create a collimated light subbeam f (also called collimated subbeam f) illustrated on laet 1b. Each collimated subbeam f thus constitutes a substantially plane wave with respect to the stacking St of matrices 12 of metal-lenses 121. Thus, at the output of the stacking St, we obtain a second collimated light beam Fx'' which is formed by the set of collimated subbeams f.

[0101] In a non-limiting embodiment, the microlenses 111 are arranged in rows and columns to form a matrix 11. In a first non-limiting embodiment variant, a common core of an injected part allows for a single transparent substrate to be used to fabricate all the microlenses 111. In a second non-limiting embodiment variant, the microlenses 111 are bonded together to form the second matrix 11.

[0102] In a first non-limiting embodiment variant illustrated on the, each group p is formed of a single micro-lens 111. The MLA matrix is ​​thus a so-called simple matrix.

[0103] In a second, non-limiting embodiment illustrated in Figure 1, a group p of microlenses 111 is formed from two microlenses 111. Thus, a group p forms a pair (or couple) of microlenses 111. The MLA matrix is ​​therefore a so-called double matrix. A pair p (or couple p) comprises an input microlens 111 and an output microlens 111. In a non-limiting embodiment, each microlens 111 of the pair p has a side length between 0.5 and 2 mm, and therefore a surface area between 0.25 mm² and 4 mm². In a non-limiting embodiment, the pair p has a side length of 1 mm². 2of surface. Thus, in a non-limiting embodiment, a micro-lens 111 has a side between 0.5 and 2 mm. The output micro-lenses 111 are arranged opposite the first matrix 12 of meta-lenses 121.

[0104] The St stacking of 12 matrices of 121 meta-lenses (illustrated in figures 1a, 1b, 2d and 4 to 7) is now described in detail below.

[0105] The St stacking comprises at least two matrices 12 of meta-lenses 121. Stacking the matrices 12 of meta-lenses 121 on top of each other does not greatly increase the thickness of the light device 1, the meta-lenses 121 being very thin.

[0106] In a first non-limiting embodiment illustrated on the, the St stacking comprises two matrices 121, 122 of meta-lenses 1211, 1212.

[0107] In a second non-limiting embodiment illustrated in the figure, the St stacking further comprises a third matrix 123 of meta-lenses 1213 adjacent to the second 122 of meta-lenses 1212. It thus comprises three matrices 121, 122, 123 of meta-lenses 1211, 1212, 1213.

[0108] The St stack is arranged between the collimation optic 11 and the folding optic 13. In particular, it is arranged downstream of the collimation optic 11 opposite it, and upstream of the folding optic 13, also opposite it.

[0109] The St stack is configured to receive the first collimated light beam Fx' which thus passes through all the matrices 12 of meta-lenses 121 of the St stack. Each meta-lens 121 receives one or more light sub-beams f of the same wavelength λ.

[0110] Each matrix 12 of the meta-lens 121 of the stacking St is defined for respectively one of the wavelengths λ of the light R emitted by the light source 10. By "defined" (or designed), it is understood that said matrix 12 is designed to be tuned with one of the wavelengths λ of the emitted light R.

[0111] In the case of two matrices 121, 122 of meta-lenses 1211, 1212, they are designed to be tuned with respectively the first wavelength λ1 and the second wavelength λ2 of the emitted R light.

[0112] In the case of three matrices 121, 122, 123 of meta-lenses 1211, 1212, 1213, they are designed to be tuned with respectively the first wavelength λ1, the second wavelength λ2, and the third wavelength λ3 of the emitted R light.

[0113] Note that at the output of the last matrix 12 of the meta-lens 121 of the St stack (either 122 or 123), all the colors are mixed. Thus, at the output of the St stack, we obtain the color white in the example of the cyan and amber colors, or in the example of the green, red, and blue colors.

[0114] It should be noted that the St stacking arrangement eliminates the need for separating walls (which are physical partitions) because each matrix 121, 122, 123 of meta-lenses 1211, 1212, 1213 only processes the portion of light R with the wavelength λ to which it is tuned. Thus, matrix 121 will only process red light, matrix 122 will only process green light, and matrix 123 will only process blue light, for example. Therefore, the light rays emitted by each monochromatic emitter 100 do not mix with the light rays from the other monochromatic emitters if a meta-lens matrix 121 has been designed to have very precise selectivity for the desired wavelength λ. This avoids a phenomenon of stray light known as "light cross talk."

[0115] In a non-limiting embodiment, each matrix 12 of meta-lenses 121 has a thickness of approximately 1 mm. Thus, the size of a matrix 12 corresponds to the size of the collimation optics 11 when the latter comprises micro-lenses 111. Each matrix 12 of the St stack is therefore very thin. In a non-limiting embodiment, the St stack is between 2 mm and 3 mm thick.

[0116] In a non-limiting embodiment, the meta-lenses 121 of a matrix 12 are arranged in rows and columns to form the matrix 12. In a first non-limiting embodiment, the meta-lenses 111 are arranged on a common substrate, namely, there is a common substrate with different sets of nano-pillars 121.2 (described later). In a second non-limiting embodiment, the meta-lenses 121 are bonded to an additional common transparent substrate, namely, each set of nano-pillars 121.2 and their substrate 121.1 (described later) is bonded to the additional transparent substrate.

[0117] Each matrix 12 of meta-lenses 121 is configured to orient a portion of the first collimated light beam Fx' along a propagation direction P (illustrated in the figure) so as to form a portion of the second collimated light beam Fx'' which is an image Im composing the global image Ig and to project it onto a plane PL (illustrated in the figure) parallel to a substrate of meta-lenses 121, and therefore onto a plane parallel to the stacking St. Thus, an image Im is formed from each collimated sub-beam(s) f oriented by each meta-lens 121. Each matrix 12 thus creates an image Im which composes the global image Ig.

[0118] In the case where the collimating optic 11 is a matrix 11 of micro-lenses 111, each meta-lens 121 of each matrix 12 is arranged opposite each group p of micro-lenses 111 of the second matrix 11 and is configured to: - orient a collimated sub-beam f of said group p along the propagation direction P so as to form a part of the image Im to be projected.

[0119] The output of the stack St thus yields the second collimated light beam Fx'' illustrated in figure 1b, which forms the overall image Ig. The overall image Ig is therefore composed of several images Im created by each matrix 12 of meta-lenses 121.

[0120] Thus, in the first non-limiting embodiment of the, the global image Ig will be composed of two images Im, and the first matrix 121 and the second matrix 122 are configured to project respectively one of the two images Im onto a plane parallel to said stacking St. In other words, the first matrix 121 creates a first image Im, and the second matrix 122 creates a second image Im.

[0121] Thus, in the second non-limiting embodiment of the, the global image Ig is composed of three images Im, and the first matrix 121, the second matrix 122, and the second matrix 123, are configured to project respectively one of the three images Im onto a plane parallel to said stacking St. In other words, the first matrix 121 creates a first image Im, the second matrix 122 creates a second image Im, the third matrix 123 creates a third image Im.

[0122] With the combination of the different Im images, we obtain an overall Ig image, white or colored, since there is a combination between the different wavelengths λ with which the 12 matrices of 121 metal lenses are tuned.

[0123] In the non-limiting example shown, an image Im created by a matrix 12 of meta-lenses 121 of the St stacking and composed of three geometric patterns is illustrated. This image Im is projected onto a plane parallel to the substrate of the meta-lenses 121 of the matrices 12 of the St stacking.

[0124] In a non-limiting embodiment, a metal lens 121 has a surface area less than or equal to 1 mm² 2If the surface area is larger, it requires excessive computing power to define the optimal distribution of the nano-pillars 121.2 of the metal lens 121. Thus, thanks to these small dimensions, a better manufacturing yield is achieved, resulting in a less expensive lighting device 1. Indeed, since the scrap rate depends on the surface area, smaller metal lenses 121 produce less waste.

[0125] Furthermore, in a non-limiting embodiment, when the collimating optics 11 comprise a plurality of groups p of microlenses 111, a meta-lens 121 of the matrix 12 is associated with a group p of microlenses 111. Thus, there are as many meta-lenses 121 as there are groups p of microlenses 111. Moreover, in this case, in a non-limiting embodiment, the meta-lenses 121 have a size equal to the first step ps defined between two adjacent microlenses 111 of two different adjacent groups p. This allows the surface of the corresponding collimated light subbeam f to be intercepted.

[0126] In other non-limiting embodiments, we may have several meta-lenses 121 associated with a group p of micro-lenses 111 or conversely several groups p of micro-lenses 111 associated with a single meta-lens 121.

[0127] Each meta-lens 121 of an array 12 of meta-lenses 121 is configured to receive a collimated light sub-beam f and modify its propagation phase φ so that it is oriented in a given propagation direction P (illustrated in the figure). In the remainder of the description, the propagation phase φ is otherwise referred to as phase φ.

[0128] As illustrated in the figure, a meta-lens 121 comprises: - a substrate 121.1, and - a plurality of nano-pillars 121.2.

[0129] The substrate 121.1 has a thickness E and a length L. In a non-limiting embodiment, the substrate 121.1 is made of glass.

[0130] The substrate 121.1 has a first refractive index n1 (also more simply called the refractive index n1), and the nanopillars 121.2 have a second refractive index n2 (also more simply called the refractive index n2). The first refractive index n1 is lower than the second refractive index n2. The first refractive index n1 is kept as low as possible to avoid light loss at the entrance to the substrate 121.1 due to partial glass reflections. Each metal lens 121 has a light refractive index n2 for the nanopillars 121.2. The second refractive index n2 is kept as high as possible to ensure the luminous efficiency of the metal lens 121.

[0131] In a non-limiting embodiment, the second refractive index n2 is greater than 2. This allows for optimum light transmission with light arriving perpendicularly on the matrix 12 of metal lenses.

[0132] Thus, in non-limiting examples, from certain materials of the nano-pillars 121.2, we can have the following values:- n2 = 2.1 for λ = 631 nm (red),- n2 = 2.47 for λ = 450 nm (blue),- n2 = 2.38 for λ = 550 nm (green),- n2 = 2.35 for λ = 621 nm (red) and 632 nm (super red),- n2 = 2.37 for λ = 580 nm (yellow).

[0133] In a non-limiting embodiment, all the meta-lenses 121 of the matrix 12 have the same refractive index n2, or different refractive indices n2.

[0134] In the case of monochromatic emitters 100, since they can be activated independently, using different wavelengths λ allows the creation of an overall light beam Fx''' (also simply called the light beam Fx''') of different colors depending on the activation, or of white color. The overall light beam Fx''' is illustrated in Figure 1b and is the emerging beam at the output of the light device 1.

[0135] The nano-pillars 121.2 are arranged on the substrate 121.1. They are defined by parameters including: - a radius r (illustrated in figures 5 and 6), - a height h (illustrated in figures 5 and 6), - a second step ps' between two nano-pillars 121.2. The second step ps' (illustrated in the) represents the repetition frequency of the nano-pillars 121.2, - a material with the second refractive index n2 (illustrated in the) which is the refractive index of the metal-lens 121, - a base bs (illustrated in the).

[0136] Note that the second step ps' is defined between the two longitudinal axes (illustrated with dashed lines in Figure 1) of two adjacent nano-pillars 121.2. In a non-limiting embodiment illustrated in Figure 1, the nano-pillars 121.2 have a disk-shaped base bs.

[0137] In a non-limiting embodiment, the 121.2 nanopillars are made of Silicon Nitride (SiN). This material is easy to work with and produces less dust compared to other materials that can be used for 121.2 nanopillars, such as, but not limited to, Titanium Dioxide (TiO2), Hafnium Oxide (HfO2), or Gallium Nitride (GaN). For SiN, n2 = 2.0454, for TiO2, n2 = 2.6142, and for GaN, n2 = 2.3982 at a wavelength λ of 590 nm.

[0138] In a non-limiting embodiment example, on a substrate 121.1 of thickness E=5 millimeters, a 70 nanometer layer of SiN can be deposited and the SiN layer etched to obtain the nano-pillars 121.2.

[0139] The nano-pillars 121.2 of each meta-lens 121 modify the propagation phase φ of a collimated sub-beam f passing through them. In other words, they add a phase delay. The result is that the collimated sub-beam f is deflected, giving it a desired propagation direction P (illustrated in the figure) so as to obtain a portion of the second collimated light beam Fx''. The set of collimated sub-beams f thus deflected forms the second collimated light beam Fx'', also called the resulting light beam Fx''.

[0140] To adjust the propagation direction P, the phase shift within a collimated light subbeam f is spatially controlled, which amounts to controlling the phase change gradient φ of the collimated light subbeams f. This is done using nano-pillars 121.2.

[0141] To this end, in a non-limiting embodiment illustrated in Figure 1, the 121.2 nanopillars have different radii r and the same height h. For the sake of clarity, only one height ha and one radius ra are referenced. It should be noted that the smaller the radius r, the less material a 121.2 nanopillar contains, which results in a minimal change in the phase φ, leading to a small phase delay. Conversely, when the radius r is larger, the more material a 121.2 nanopillar contains, resulting in a more significant change in the phase φ, leading to a larger phase delay.

[0142] As illustrated in the figure, the 121.2 nano-pillars have a radius r that increases from left to right. Each 121.2 nano-pillar will induce a different phase delay φ compared to its neighbor. The larger the radius r, the greater the phase delay φ. The radius r thus affects the phase φ of the collimated light sub-beam f. Since the radii r are smaller on the left, the phase delays on the left are smaller, and the light will be less delayed on the left than on the right. Note that the greater the delay, the more the wavefront is distorted and the more the resulting light beam Fx'' is deflected.

[0143] As a reminder, light propagates perpendicularly to the wavefront. Typically, there is zero phase delay along the same line of the wavefront. As can be seen in the figure, the incoming wavefront Fo at the entrance of the meta-lens 121 (also called the incident wavefront Fo) is plane and perpendicular to the substrate 121.1 of the meta-lens 121.

[0144] Each nano-pillar 121.2 introduces a phase delay φ different from its neighbor, because they all have a different diameter, this differential phase delay then causes a deformation of the wavefront.

[0145] As can be seen on the figure, the emerging wavefront Fo' is distorted, which therefore causes a deviation of the emerging light beam Fx'', which is the resulting deflected light beam.

[0146] Thus, upon exiting a metal lens 121, the light, which always propagates perpendicularly to the wavefront (here, the emerging wavefront Fo', which is inclined), will be oriented along a given propagation direction P. Consequently, the light is oriented along a propagation direction P that has changed due to the phase shift of the light.

[0147] Note that the emerging wavefront Fo' has been delayed progressively and linearly. Each nano-pillar 121.2 is configured to induce a linearly evolving phase shift φ of the light, i.e., a linear phase shift. This results in a planar emerging wavefront Fo'. A phase shift between 0 and 2π is equivalent. Therefore, it is not necessary to create a linear phase shift along the entire length of the input wavefront Fo to obtain a continuous deflection. A phase shift between 0 and 2π can be performed as many times as needed. Thus, a linear phase shift between 0 and 10π is equivalent to five linear phase shifts between 0 and 2π.

[0148] Note that the phase φ is modulated between 0 and 2π. Note that with a phase φ = 0, there is no delay. With φ = π, there is a delay of λ / 2. From the perspective of the 121 meta-lens, as soon as φ = 2π, we return to a radius r of a 121.2 nano-pillar corresponding to 0, and therefore to the same 121.2 nano-pillar to avoid excessively large differences between the radii r. Thus, the 121 meta-lens comprises several sets of 121.2 nano-pillars defined in such a way as to obtain a phase shift of the light with a phase modulated between 0 and 2π.

[0149] The height h of the 121.2 nano-pillars allows control of the phase φ between 0 and 2π for a given wavelength λ. With the correct height h defined, all phase changes between 0 and 2π can be performed.

[0150] As explained previously, the radius r allows control of the phase φ of the light beam Fx.

[0151] The other parameters, namely the height h, the second step ps', and the material of the 121.2 nano-pillars, are defined to maximize the light transmission rate through the 121.2 nano-pillars. Maximizing the transmission rate means minimizing the absorption of light by the material of the 121.2 nano-pillar. Thus, these other parameters are determined to obtain minimum absorption over the range where the radius r is varied to obtain a phase shift (also called phase difference) between 0 and 2π.

[0152] By calculation, for a 121.2 nanopillar, a given height h and a given pitch ps are fixed, along with its material, which is, for example, Silicon Nitride (SiN) with a refractive index n2 = 2.0454. In the illustrated example (not limiting), h = 1.35 μm and ps = 0.450 μm. Working with a constant height h facilitates the fabrication of 121.2 nanopillars. With a constant height h, the design of the 121.2 nanopillars must be adapted to achieve a phase shift between 0 and 2π while simultaneously maximizing light transmission to retain as much light as possible.

[0153] For a fixed height h and a fixed step size ps, we establish the light transmission curves as a function of the radius r, and the phase shift curves as a function of the radius r. Curves 8 and 9 illustrate the phase shift and light transmission for the best compromise for the chosen constant height h and for a given wavelength λ. Note that this compromise changes if the wavelength λ changes.

[0154] On the, in a non-limiting example, for a height h=1.35µm (micrometers), we can thus observe the phase variation φ in radians (on the ordinates) between 0 and 9 as a function of the radius r (on the abscissas) of the nano-pillars 121.2 which varies between 0.04 and 0.15 μm, for a given wavelength λ, here for λ=590nm in the illustrated non-limiting example.

[0155] In a non-limiting example, for a height h = 1.35 µm, we can observe a variation in light transmission Tx (on the y-axis) between 0 and 1 as a function of the radius r (on the x-axis) of the 121.2 nanopillars, which varies between 0.04 and 0.15 μm, for the given wavelength λ, here 590 nm. At a value of 0, no light passes through. At a value of 1, all light passes through.

[0156] Using these two curves, we can determine the height h and radius r of the 121.2 nanopillars that provide dynamic phase shift control while maximizing light transmission through the nanopillars, all while maintaining manufacturability. We can thus find the values ​​of all the parameters of a 121.2 nanopillar to obtain the possible phase shift (or phase difference) and transmission values, and in particular a transmission rate close to 1 for a given wavelength λ. Note that if the results are not satisfactory, the procedure can be repeated by setting a different value for the height h.

[0157] The set of collimated sub-beams f thus deviated form a sharp projected image Im at approximately a certain distance d onto a plane PL (illustrated in the figure) parallel to the substrate of the metal lenses 121 as illustrated in the figure. In a non-limiting embodiment, the distance d is between 30 cm and 2 m.

[0158] It should be noted that the distance d depends on the phase shift introduced by the nano-pillars 121.2. Thus, the light is redirected towards the areas to be illuminated. The other areas are not illuminated and appear dark. The deflected collimated sub-beams f are transmitted with a very high light transmission rate, between 80% and 90%. There is therefore very little light loss. The remaining 20% ​​to 10% of the light is lost because it is reflected by the substrate of the nano-pillars 121.2 of the metal-lenses 121.

[0159] As illustrated in Figure 1, the image Im comprises illuminated areas z1 towards which the light has been redirected, and shaded areas z2 (within the illuminated areas z1 in the non-limiting example shown and between the illuminated areas z1) towards which the light has not been redirected. The illuminated areas z1 are areas of light concentration.

[0160] Note that the black frame surrounding the illuminated areas z1 is only present to highlight the illuminated areas z1 on the.

[0161] To obtain the illuminated areas z1, for a fixed height h and a fixed second step ps', we play on the radius r of the nano-pillars 121.2 to obtain a maximum of light transmission and we redirect the light beams F towards the areas to be illuminated as described previously.

[0162] Thus, with two or three matrices 12 of meta-lenses 121 we obtain two or three images Im composing the global image Ig, the different images Im being able to overlap or not.

[0163] To produce a static global image Ig, in a first non-limiting embodiment, the plurality of matrices 12 in the stacking St is designed to project superimposed images Im so as to obtain a global image of uniform color (white or another color). In a second non-limiting embodiment, the plurality of matrices 12 in the stacking St is designed to project images Im wholly or partially non-superimposed so as to obtain a global image with different colored areas.

[0164] To produce an animated global image Ig, each matrix 12 of meta-lenses 121 forms an image Im that can be superimposed on the other images Im formed by the other matrices 12 of meta-lenses 121 and replace one another to create the animated global image Ig. Thus, in a non-limiting example, to produce dynamic light signage, the matrices 12 of meta-lenses 121 can each produce several images Im of the animated image for said dynamic light signage. Since the monochromatic emitters 100 associated with each matrix 12 of meta-lenses 121 can be of different colors, an animated global image Ig can be obtained in different colors, or in white.

[0165] It should be noted that the metal-lens matrix 12 121 closest to the collimation optic 11 (referenced 121 in Figures 1a and 1b) is positioned at a distance of approximately 10 èmemillimeters of collimation optics 11. This allows for an ultra-thin luminous device 1.

[0166] Thus, while the meta-lenses 121 allow the projection of an image Im and therefore of the global image Ig, the folding optics 13 allow the folding of the global image Ig onto the ground 4.

[0167] The folding optic 13 (illustrated in figures 1a, 1b, 11a to 12) is now described in detail below.

[0168] The folding optic 13 is positioned opposite the stack St of metal-lens arrays 121, downstream of it. It is positioned at a distance of approximately 10 ème millimeters of said stacking St. This allows for an ultra-thin lighting device 1.

[0169] The refracting optic 13 is adapted to the polychromatic light R emitted by the light source 10 by partially correcting chromatic aberrations, thus preventing an overall blurred image Ig and / or one with colored edges. It directs the second collimated light beam Fx'' along a specific direction, called the orientation direction O'. It thus collects the light R emitted at different wavelengths λ and directs it along the orientation direction O' onto the surface 4.

[0170] The folding optic 13 is thus configured to deflect the second collimated light beam Fx'' along the orientation direction O' so as to project the global image Ig formed by this second collimated light beam Fx'' onto the surface 4. The light beam emerging from the folding optic 13 is the global light beam Fx'''.

[0171] Laillustre un exemple non limiting d'une image global Ig projetée par la rabattement optics 13 selon la direction d'orientation O'.

[0172] As can be seen, this global image Ig has exactly the same patterns as the image Im of the. This means that the plurality of matrices 12 of the St stacking made it possible to create images Im with the same three geometric patterns and that they were superimposed on each other during the projection of the images Im and therefore of the global image Ig onto the surface 4, or that the plurality of matrices 12 of the St stacking made it possible to create images Im with a different geometric pattern, for example, so that they would be side by side during the projection of the images Im and therefore of the global image Ig onto the surface 4.

[0173] On the, we can observe the global image Ig illustrated as a non-limiting example of the one that has been projected onto the ground 4. On the, we can observe the global image Ig illustrated as a non-limiting example of the one that has been projected inside the passenger compartment 24 of the vehicle 2, in particular onto the inner roof 23 of the vehicle 2. On the, in order to show the global image Ig, it has been illustrated in projection outside the frame defining the passenger compartment 24.

[0174] In a first, non-limiting embodiment not shown, the folding optic 13 is a Fresnel lens. In another, non-limiting embodiment, the Fresnel lens has a thickness between 1 mm and 3 mm.

[0175] In a second, non-limiting embodiment illustrated in Figure 4, the folding optics 13 are a microlens array 131. In this case, the microlenses 131 are designed to obtain the desired orientation angle θ for projecting the overall image Ig onto the surface 4. In this non-limiting embodiment, the microlenses 131 have a thickness of approximately 2 mm–3 mm. These microlenses 131 are calculated to perform the folding.

[0176] Thus, due to the very thin thickness of the various elements of the lighting device 1 and their close proximity to one another, a very thin lighting device 1 is obtained. Indeed, the collimation optics 11 (lenses or MLA), the stack St of arrays 12 of metal lenses 121, and the refracting optics 13 together have a thickness E approximately equal to 8-9 mm. And by adding the light source 10, the entire assembly has a thickness E' of less than 20 mm.

[0177] Of course, the description of the invention is not limited to the embodiments and the field described above. Thus, in other, non-limiting embodiments, the base bs of the nano-pillars 121.2 is oblong or elliptical in shape. Thus, in another, non-limiting embodiment, the nano-pillars 121.2 have the same radius r but different heights h.

[0178] Thus, the described invention offers the following advantages: - by replacing a conventional collimator with collimation optics (lenses or MLA without a mask) and by replacing a mask / slide with conventional projection optics (focused objective comprising several lenses) with a stack St of matrices 12 of meta-lenses 121, it makes it possible to obtain a very compact lighting device 1, particularly in depth compared to the prior art, which has a depth of approximately 3 to 4 cm; - by replacing a conventional collimator with collimation optics, which is an MLA, the depth of the lighting device 1 is further reduced; - it thus makes it possible to obtain a less bulky and lighter lighting device 1; - it allows for a lighting device 1 that is easily integrated into a vehicle: the lighting device 1 can be positioned in unusual locations within the vehicle 2.- It allows for a miniaturized lighting device 1 which significantly contributes to reducing the weight of the vehicle 2 in which it is integrated and can also enable a more aerodynamic vehicle design to lower its energy consumption and CO2 emissions; - It allows for the creation of an overall image Ig with complex lighting patterns that can be individually controlled by light; - It allows an external observer to see no difference when the lighting device 1 is on or off, meaning that neither the style nor the appearance of the vehicle is altered by the activation of the lighting device 1. Indeed, the lighting device 1 is small and flat; - Thus, thanks to the lighting device 1 according to the invention, it is no longer necessary to use optical masks to create patterns to be projected onto the ground, for example.- It allows for very good luminous efficiency since it uses all, or at least almost all, of the light R emitted by the light source 10 for the projection of an image Im, unlike the prior art; thus, between 80% and 90% light transmission is obtained for a wavelength λ of 590nm. - It allows for a luminous device 1 that heats up less since it does not block the light: there is no light absorption as in the case of the prior art: an overall image Ig is thus created without loss of light. Thus, the luminous device 1 requires less energy than that of the prior art. - It allows for the easy acquisition of two or three images Im of different colors, superimposed or not, to obtain an overall image Ig of white color or with a colored effect, which is static or animated.- it allows for better luminous efficiency than a lighting device comprising a light source, a conventional collimator, an MLA with a mask (which would replace the slide and the conventional projection optics) forming the patterns of the image Im to be projected, and allows for better luminous efficiency since there is no mask and therefore no light loss in a mask.

Claims

1. Lighting device (1) for vehicle (2) configured to project an overall image (Ig) onto a surface (4), said lighting device (1) comprising: - a polychromatic light source (10) configured to emit light (R) on at least two different wavelengths (λ1, λ2), said light (R) forming a light beam (Fx); characterized in that said lighting device (1) further comprises: - collimating optics (11) disposed opposite said light source (10) and configured to collimate said light (R) and form a first collimated light beam (Fx');- a stack (St) of at least two arrays (121, 122) of meta-lenses (1211, 1212) arranged opposite the collimating optics (11), each array (121, 122) of meta-lenses (1211, 1212) being defined for one of said at least two wavelengths (λ1, λ2), and being configured to orient a portion of the first collimated light beam (Fx') along a propagation direction (P) so as to create a portion of a second collimated light beam (Fx'') which is an image (Im) composing said global image (Ig) and to project said image (Im) onto a plane (PL) parallel to said stack (St), - a rewinding optics (13) arranged opposite said at least two arrays (12) of meta-lenses (121) and configured to deflect the second beam luminous collimated (Fx'') along an orientation direction (O') so as to project said global image (Ig) onto said surface (4).; 2. Light device (1) according to claim 1, characterized in that the light source (10) comprises an emitter (100) configured to emit a white light (R).

3. Light device (1) according to claim 1, characterized in that the light source (10) comprises at least two emitters (1001, 1002) configured to each emit a different monochromatic light (R1, R2).

4. Light device (1) according to the preceding claim, characterized in that said at least two monochromatic emitters (1001, 1002) emit a light (R1, R2) of cyan and amber color.

5. Lighting device (1) according to claim 3, characterized in that the light source (10) comprises three emitters (1001, 1002 , 1003) configured to each emit a light (R1, R2 , R3) different monochromatic.

6. Luminous device (1) according to the preceding claim, characterized in that the three emitters (1001, 1002 , 1003) emit light respectively (R1, R2 , R3) of red, green, blue, or a light color (R1, R2) , R3) in cyan, magenta and yellow colors.

7. Light device (1) according to claim 5 or claim 6, characterized in that said stack (St) further comprises a third matrix (123) of meta-lenses (1213) adjacent to the second matrix (122) of meta-lenses (1212).

8. Light device (1) according to any one of the preceding claims 3 to 7, characterized in that said at least two monochromatic emitters (1001, 1002) are activatable independently of each other.

9. Light device (1) according to any one of the preceding claims, characterized in that the collimating optics (11) comprises at least one lens (110) or is an array (11) comprising a plurality of groups (p) of microlenses (111), each group (p) being configured to collimate said light (R) and create a collimated subbeam (f) forming a part of said first collimated light beam (Fx').

10. Light device (1) according to the preceding claim, characterized in that a group (p) of micro-lenses (111) is formed of a single micro-lens (111) or of two micro-lenses (111).

11. Light device (1) according to claim 9 or claim 10, characterized in that each meta-lens (121) of a matrix (12) of meta-lenses (121) is arranged opposite each group (p) of micro-lenses (111) and is configured to orient the collimated sub-beam (f) of said group (p) along the propagation direction (P).

12. Light device (1) according to any one of the preceding claims, characterized in that the meta-lenses (121) of each matrix (12) of meta-lenses (121) comprise nano-pillars (121.2) defined by a radius (r), a height (h) and a second pitch (ps') between two nano-pillars (121.2).

13. Light device (1) according to any one of the preceding claims, characterized in that the folding optics (13) is a micro-lens matrix (131).

14. Lighting device (1) according to any one of the preceding claims, characterized in that said surface (4) is the ground on which said vehicle (2) is located or an interior surface within the passenger compartment (24) of the vehicle (2).

15. A light device (1) according to any one of claims 1 to 8, characterized in that the collimation optics (11) comprises a stack of at least two meta-lenses or two arrays (121, 122) of meta-lenses (1211, 1212), each meta-lens or each array (121, 122) of meta-lenses (1211, 1212) being defined for one of said at least two wavelengths (λ1, λ2) and configured to collimate the light (R) at one of said at least two wavelengths (λ1, λ2), and whose diameter is adapted to that of the light beam.

16. Light device (1) according to claim 15, characterized in that said stack further comprises a third meta-lens or meta-lens matrix adjacent to the second meta-lens or meta-lens matrix (1212).

Images