Light emitting device for motor vehicle configured to project image onto projection surface

Abstract

The invention relates to a light-emitting device (2) for a motor vehicle (1), the light-emitting device (2) being configured to project an image (Im) having at least one fixed-profile illumination zone onto a surface (3) located around the vehicle (1) or onto a surface (3) located inside a passenger compartment of the vehicle (1), the light-emitting device (2) being characterized in that the light-emitting device (2) comprises at least one light source (3), the light emitting device comprises: at least one light source (4) configured to generate a monochromatic light beam (F); at least one optical device (14) juxtaposed with the light source (4) such that the light beam (F) passes through the optical device (14), the optical device (14) comprising at least one super lens (15) configured to modify at least one characteristic of a wavefront of the light beam (F) in order to direct the light beam (F) into a propagation direction.

Description

[0001] This invention relates to a light-emitting device for a motor vehicle, the device being configured to project an image having at least one fixed-contour illumination area onto a projection surface located around the vehicle or inside the passenger compartment of the vehicle. The invention also relates to a motor vehicle equipped with such a light-emitting device.

[0002] Some motor vehicles include one or more signal lights equipped with one or more light-emitting devices configured to project an image having at least one fixed-outline illuminated area onto the ground near the vehicle for steering or maneuvering purposes. These illuminated areas may include images and / or patterns, such as arrows, lines, or pictographs. Such light-emitting devices are intended to display information useful to the driver and / or other road users. Patent publication WO 2016184721 A1 discloses such a light-emitting device.

[0003] In addition, some motor vehicles are equipped with luminous devices configured to project images onto the ground around the vehicle, such as at the front or sides of the vehicle, particularly at the doors, to provide information that helps or guides passengers to leave the vehicle, especially when ambient light is relatively dim. These images may include patterns such as arrows, lines, or pictographs. Such luminous devices can also be designed to display useful information to other road users. Thus, these luminous devices enable the communication of the driver's intentions to other road users, particularly pedestrians. Patent publication EP 3401161 A2 discloses such a luminous device.

[0004] Finally, there are fixed or portable light-emitting devices that allow images to be projected onto surfaces located inside the passenger compartment of a motor vehicle, particularly onto the ceiling of the passenger compartment. In particular, there are small projectors equipped with a light source (such as a light-emitting diode) and a cover penetrated by multiple openings.

[0005] There are also digital dynamic projection systems, such as digital micromirror devices (DMD), microelectromechanical systems (MEMS), micro LEDs, liquid crystal displays, or LCOS projectors.

[0006] Light-emitting devices known from existing technologies are generally difficult to manufacture and use.

[0007] Furthermore, lighting devices known from existing technologies are typically heavy and bulky, making their integration into motor vehicles more complex. Therefore, integrating them discreetly into a vehicle without altering its aesthetic appearance is challenging.

[0008] Furthermore, when a cover is used in the light-emitting device, the cover limits the transmitted light-emitting power, resulting in a limited light-emitting intensity.

[0009] Furthermore, some light-emitting devices known from the prior art include relatively fragile components that may be damaged, malfunction, or even break if these components are exposed to impacts or if the vehicle is used in harsh environments (damaged, dusty, dirty roads, etc.). Subsequently, the resulting vibrations have proven to be highly problematic, as they significantly limit image projection. Invention Overview The object of the present invention is to provide a light-emitting device for a vehicle that overcomes at least one of the above-mentioned disadvantages.

[0011] In particular, the light-emitting device according to the invention is intended to be lightweight and compact, and is configured to easily project an image having at least one fixed contour illumination area onto a projection surface located around the vehicle or inside the passenger compartment of the vehicle.

[0012] Therefore, the first subject of the present invention is a light-emitting device that is easy to manufacture and configured to project a high-quality image with at least one fixed contour illumination area with high luminous efficiency.

[0013] A second aspect of the invention is a more compact light-emitting device that can be easily integrated into a motor vehicle.

[0014] The third subject of the present invention is a light-emitting device that is not affected by any impact and / or vibration caused by the use of a motor vehicle in which the light-emitting device is integrated. Summary of the Invention

[0015] The present invention relates to a light-emitting device for a motor vehicle, the light-emitting device being configured to project an image having at least one fixed contour illumination area onto a projection surface located around the vehicle or onto a surface located inside the passenger compartment of the vehicle, the light-emitting device being characterized in that it comprises: • At least one light source, which is configured to produce a monochromatic light beam; • At least one optical device, juxtaposed with the light source, such that the light beam passes through the optical device, the optical device including at least one superlens configured to modify at least one characteristic of the wavefront of the light beam, such that the light beam is oriented in the propagation direction.

[0016] According to a non-limiting embodiment, the light-emitting device may further include one or more of the following additional features, implemented individually or in any technically possible combination.

[0017] According to a non-limiting embodiment, the superlens of the optical device includes at least one nanostructure configured to modify the amplitude and / or phase of a light beam generated by a light source and passing through the optical device, thereby affecting the orientation of the light beam at the exit of the superlens.

[0018] According to a non-limiting embodiment, the nanostructure of the superlens is configured to influence the orientation of the light beam at the exit of the superlens, such that the light-emitting device emits a conical light beam in a projection direction that is tilted at an angle between 30° and 90° relative to the propagation direction of the light beam generated by the light source.

[0019] According to a non-limiting embodiment, the light-emitting device further includes a liquid crystal layer disposed between the at least one superlens and the at least one light source and configured to exhibit at least two states, namely: - Inactive state: In this inactive state, the liquid crystal layer is not in operation in order to maintain the optical properties of the incident light beam and allow the at least one superlens to obtain the first convergence zone of the light beam on the projection surface. - Active state, in which the liquid crystal layer is activated to modify the optical properties of the incident beam and allow the at least one superlens to obtain a second convergence zone of the beam on the projection surface.

[0020] According to a non-limiting embodiment, the optical properties of the incident beam are phase and polarization.

[0021] According to a non-limiting embodiment, the light-emitting device includes multiple light sources and multiple superlenses.

[0022] According to a non-limiting embodiment, the light-emitting device includes at least one component consisting of three light sources arranged side by side and at least one stack consisting of three superlenses arranged opposite the component, each light source being configured to emit light of a different color than the other light sources in the at least one component, and the three superlenses being designed to be tuned for different wavelengths.

[0023] According to a non-limiting embodiment, each light source is associated with its own specific superlens.

[0024] According to a non-limiting embodiment, the plurality of superlenses are arranged in rows and columns on an optical device to form an array, and the plurality of light sources are also arranged in rows and columns to form an array, such that each beam of light generated by one of the light sources passes through the superlens associated with said light source.

[0025] According to a non-limiting embodiment, the light-emitting device includes at least three components consisting of light sources arranged side by side and at least three components consisting of corresponding superlenses arranged side by side, each light source component being configured to emit monochromatic light of a different color from the other components.

[0026] According to a non-limiting embodiment, each of the three light source assemblies includes three light sources, and each of the three superlens assemblies includes three superlenses.

[0027] According to a non-limiting embodiment, the light-emitting device includes at least three components consisting of light sources arranged side by side and at least three components consisting of corresponding superlenses arranged side by side, each light source in each component being configured to emit monochromatic light of a different color than the other light sources in the same component.

[0028] According to a non-limiting embodiment, each of the three light source assemblies includes three light sources, and each of the three superlens assemblies includes three superlenses.

[0029] According to a non-limiting embodiment, the image includes illuminated areas and shadowed areas, the illuminated areas being those areas in which beams of light from the at least one light source are directed toward it with maximum light transmission.

[0030] According to a non-limiting embodiment, the light-emitting device further includes a projection optics configured to shape a light beam and guide the light beam toward the surface.

[0031] The present invention also relates to a motor vehicle comprising a light-emitting device as described in any of the preceding claims. Attached Figure Description

[0032] These subjects, features, and advantages of the invention will be described in detail in the following description of various specific non-limiting embodiments with reference to the accompanying drawings, in which: [ Figure 1a [Illustration of a motor vehicle equipped with a first light-emitting device according to the prior art]

[0033] [ Figure 1b [Illustration of a motor vehicle equipped with a second light-emitting device according to the prior art]

[0034] [ Figure 1c [Illustration of a motor vehicle equipped with a third light-emitting device according to the prior art]

[0035] [ Figure 2a [Illustration of a motor vehicle equipped with a light-emitting device according to a non-limiting embodiment of the present invention, the light-emitting device including a plurality of light sources and an optical device according to a first non-limiting embodiment, and configured to project an image onto a surface located around the vehicle.]

[0036] [ Figure 2b [Illustration of a motor vehicle equipped with a light-emitting device according to a non-limiting embodiment of the present invention, the light-emitting device including a plurality of light sources and an optical device according to a first non-limiting embodiment, and configured to project an image onto a surface located inside the vehicle.]

[0037] [ Figure 3 [This is a first non-limiting embodiment of the present invention, as shown in [] Figure 2a ]or[ Figure 2b A schematic diagram of the optical device of the light-emitting device in [ ].

[0038] [ Figure 4 ]yes[ Figure 3 ]or[ Figure 16 A schematic three-dimensional diagram showing the details of the nanostructure of the superlens in the optical device.

[0039] [ Figure 5 ]yes[ Figure 3 ]or[ Figure 16 Another schematic diagram showing the details of the nanostructure of the superlens in the optical device shown in the image.

[0040] [ Figure 6 ]yes[ Figure 3 ]or[ Figure 16 A schematic perspective view of a superlens in the optical device shown in the figure, which is associated with a liquid crystal layer forming a variable focal length lens.

[0041] [ Figure 7 ] is equipped with, according to a first non-limiting embodiment of the invention, such as [ Figure 2a ]or Figure 2b or[ Figure 16 A schematic diagram of a motor vehicle with a light-emitting device.

[0042] [ Figure 8 ] showed [ Figure 3 ]or[ Figure 16 A non-limiting embodiment of a single nanopillar of a superlens in the optical device and a highly magnified view of a portion of the substrate.

[0043] [ Figure 9 The image shows a non-limiting embodiment as shown below. Figure 3 ]or[ Figure 16 A magnified view of a non-limiting embodiment of a superlens of an optical device in the image.

[0044] [ Figure 10 The first curve is shown, which indicates the phase as […]. Figure 3 ]or[ Figure 16The variation in the radius of the nanopillars of the superlens in the optical device [].

[0045] [ Figure 11 The second curve is shown, which indicates the change in light transmittance with [ Figure 3 ]or[ Figure 16 The variation in the radius of the nanopillars of the superlens in the optical device [].

[0046] [ Figure 12a ]Schematic illustration of [ Figure 2a ]or Figure 2b The light-emitting device is configured to project a light-emitting image onto a plane parallel to the substrate of the superlens of the optical device of the light-emitting device.

[0047] [ Figure 12b ]Schematic illustration Figure 2a or Figure 2b The light-emitting device is configured to project a light-emitting image onto a plane that is not parallel to the substrate of the superlens of the optical device of the light-emitting device.

[0048] [ Figure 13 ]Schematic illustration of [ Figure 2a The light-emitting device in the image further includes a projection optics according to a non-limiting embodiment, the projection optics being configured to project a light-emitting image onto the ground.

[0049] [ Figure 14 ]yes[ Figure 13 The light-emitting device in the figure is a perspective view, and the light-emitting device further includes a housing and a cover.

[0050] [ Figure 15a The illustration schematically depicts an embodiment according to a first non-limiting variant. Figure 2a or Figure 2b The light-emitting device includes three components consisting of side-by-side light sources and an optical device including three components consisting of side-by-side superlenses.

[0051] [ Figure 15b The illustration schematically depicts an embodiment according to a second non-limiting variant. Figure 2a or Figure 2b The light-emitting device in the image includes three components consisting of three light sources and an optical device including three components consisting of side-by-side superlenses.

[0052] [ Figure 16 [Illustration of a motor vehicle equipped with a light-emitting device according to a non-limiting embodiment of the present invention, the light-emitting device including a plurality of light sources and an optical device according to a second non-limiting embodiment, and configured to project an image onto a surface located inside the vehicle.]

[0053] [ Figure 17 The illustration schematically shows a motor vehicle equipped with a light-emitting device according to the invention, which enables the projection of a still image (for example, a logo) onto the ground.

[0054] [ Figure 18 This schematically illustrates a non-limiting example of three images that enable the generation of dynamic luminous carpet projections, the three images being generated by... Figure 2a or Figure 2b or[ Figure 16 The light-emitting device in the image is formed by three superlenses. Detailed Implementation

[0055] The following is a reference [ Figure 1a This describes a first embodiment of a motor vehicle 1' according to the prior art, which is used to indicate steering or handling functions.

[0056] [ Figure 1a The vehicle 1' shown schematically includes a light-emitting device 2' according to an embodiment known from the prior art.

[0057] This light-emitting device 2' includes at least one light source 4' capable of generating a light beam F', a lens array 6' through which the light beam F' is intended to pass, and a light parallelization unit 8'. This light parallelization unit 8' is positioned in the path of the light beam F', between the light source 4' and the lens array 6'. The parallelization unit 8' takes the form of a lens, which is configured to parallelize the light beam F' emitted by the light source 14' in a main emission direction substantially parallel to the optical axis of the microlenses in the array 6'.

[0058] The lens array 6' includes multiple pairs of microlenses 10' distributed on a flat surface perpendicular to the optical axes of the lenses in the array 6'. Each pair of microlenses 10' includes an upstream microlens and a downstream microlens. Conventionally, the term "upstream microlens" refers to the microlens through which the beam F' first passes, while the term "downstream microlens" refers to the microlens through which the beam F' subsequently passes. In other words, the beam F' from the light source 4' first passes through the parallelization unit 8', then through the upstream microlens in the pair of microlenses 10' arranged within the array 6', and finally through the downstream microlens in the same pair of microlenses 10'.

[0059] This embodiment of the light-emitting device 2' known from the prior art has several disadvantages. In particular, a large number of microlenses are required to manufacture such a light-emitting device 2', which not only significantly increases its weight but also makes it large and bulky.

[0060] Furthermore, the optical axis of the downstream microlens in the same pair of microlenses 10' must be coaxial with the optical axis of the upstream microlens. This requires high precision when positioning the microlenses 10' in the array 6', and such positioning can be time-consuming and expensive. This alignment of the optical axes of the microlenses 10' in the same pair can be disrupted by vibrations caused by the use of the motor vehicle 1' or by an impact to the light-emitting device 2', and this risk is not low.

[0061] The following is a reference [ Figure 1b The following describes a second embodiment of a motor vehicle 1' according to the prior art, which is used to generate static or dynamic luminous carpet projection around the vehicle.

[0062] [ Figure 1b The vehicle 1' schematically shown in the diagram includes a light-emitting device 2' according to an embodiment known from the prior art. The light-emitting device 2' is configured to project an image onto the ground 3' in front of the vehicle 1. Note that "in front" refers to the side toward which the vehicle 1' moves in a straight line during forward motion.

[0063] In this embodiment known from the prior art, the light-emitting device 2' includes at least one light source 4' capable of generating a light beam F' and a cover 5' positioned in the path of the light beam F'. The at least one light source 4' is a monochromatic light source. The light from such a light source 4' consists only of light of a single wavelength; in other words, it consists only of light of a specific color.

[0064] The surface of the cover 5' includes opaque areas 8' and transparent areas 9', which are typically shaped to project an image including a pattern. Therefore, the cover 5' allows modification of the light beam F' from the light source 4' to project an image including a pattern onto the ground 3' in front of the vehicle 1'. An optical element 11' (e.g., a projection lens) can be positioned downstream of the cover 5' to shape the light beam F' and guide it toward the ground 3'. Thus, incident light in the transparent areas 9' of the cover 5' passes through the cover 5' and is then guided toward the ground 3' by the optical element 11'.

[0065] This embodiment, as known from the prior art, has several disadvantages. Specifically, the transparent areas are typically located at the edges of the cover 5', leaving the central area of ​​the cover 5' unused, except for the portion of the cover 5' mechanically connected to the actuating member 12', which allows the cover to rotate about a rotation axis. Therefore, the cover 5' is rotatable in order to produce animated images. Consequently, a compromise must be found between the number of transparent areas 9' suitable for projecting images and the size of said transparent areas 9'.

[0066] Furthermore, the actuating component 12' and / or its mechanical connection to the cover 5' may be subjected to shocks or vibrations during the use of the motor vehicle 1', which could cause the cover 5' to become misaligned. Such misalignment of the cover 5' could result in images being projected incorrectly onto the ground 3', which could annoy the driver of the vehicle 1'. For example, the animated image might appear shaky.

[0067] Furthermore, the order in which images are projected onto the ground 3' depends on the arrangement of the transparent areas 9' on the cover 5'. More specifically, only images that are adjacent to each other on the cover 5' can be projected onto the ground consecutively. In other words, arranging the transparent areas 9' with patterns and / or outlines on the edges of the cover 5' greatly limits the choice regarding the order in which the images are projected onto the ground 3'.

[0068] Finally, the cover 5', which functions by absorbing light, blocks a portion of the light, approximately 50%. Therefore, the luminous efficiency of this light-emitting device 2' is reduced.

[0069] The following is a reference [ Figure 1c This describes a third embodiment of a motor vehicle 100' according to the prior art, which is used to create a design inside the passenger compartment of the motor vehicle 100'.

[0070] exist[ Figure 1c In this embodiment, vehicle 100' includes a light-emitting device 2' according to embodiments known from the prior art. The light-emitting device 2' is configured to project images onto a surface 3' inside the passenger compartment 10' of vehicle 100'. Figure 1c In the specific case shown, the surface 3' on which the light-emitting device 2' projects the image is the ceiling of the passenger compartment 10' of the vehicle 100', and more precisely, the interior surface of the roof of the vehicle body 100'.

[0071] In this embodiment known from the prior art, the light-emitting device 2' includes at least one light source 4' capable of generating a light beam F' and a cover 5' positioned in the path of the light beam F'. The at least one light source 4' is a monochromatic light source. The light from such a light source 4 consists only of a single color; it emits only light with a specific wavelength or a wavelength within a precise range. The cover 5' may take the form of a cup or dome placed above the light source 4', such as […]. Figure 1c As shown in the figure, it can at least partially surround the light source 4'.

[0072] The cover 5' has one or more openings 6' configured to allow a portion of the light beam F' to pass through, thereby projecting one or more light spots onto the target surface 3'. Each opening 6' may include an optical element 7', such as a projection lens, to shape the light beam F' and guide it toward the surface 3'.

[0073] When the dome-shaped or cup-shaped cover 5' is movable, the light-emitting device 2' includes an actuating member 8' that is mechanically connected to the cover 5' to rotate the cover about the axis of rotation of the dome. Therefore, a set of points projected by the light-emitting device 2' onto the surface 3' of the passenger compartment 10' appears to be moving, making the viewer see the light points moving on the surface 3' of the passenger compartment 10' inside the motor vehicle 100'.

[0074] This embodiment, as known from the prior art, has several drawbacks. In particular, when the image has a complex shape, this cover 5' makes it impossible to project a high-quality image. Specifically, if the surface 3' inside the vehicle 1' is not flat but curved, this may cause image distortion on the surface 3'. Furthermore, the outline of any pattern projected onto the surface 3' by the prior art light-emitting device 2' may be blurry and unclear, which may impair image quality.

[0075] Furthermore, the actuating component 8' and / or its mechanical connection to the cover 5' may be subjected to shocks or vibrations during the use of the motor vehicle 100', which may cause the position of the luminous device 2' to become misaligned. Such misalignment may result in images being projected incorrectly into the passenger compartment, which could annoy the driver and / or any passengers of the vehicle 100'. In fact, the image may shift due to vibration.

[0076] Finally, the cover 5' blocks a portion of the light, approximately 50%. Therefore, the luminous efficiency of this light-emitting device 2' is low.

[0077] The following is for reference. Figures 2a to 18 This description will depict embodiments of the motor vehicle 1 according to the present invention. Throughout this specification, the motor vehicle 1 is any type of motor vehicle, particularly a passenger car, multi-purpose vehicle, truck, or even a bus. For the remainder of this specification, the motor vehicle 1 will also be referred to as vehicle 1.

[0078] This embodiment aims to provide a solution to the problems pointed out by embodiments known from the prior art by overcoming at least one of the above-mentioned disadvantages and by proposing an improved light-emitting device 2.

[0079] The light-emitting device 2 is configured as follows: - Indicates steering or maneuvering functions, - Creates a static or dynamic luminous carpet projection around (or near) the vehicle, or - Generates a glowing image.

[0080] The light-emitting device 2 is configured to project at least one image Im having at least one illuminated area (described below) onto a surface 3 located around the vehicle 1 or inside the passenger compartment 10 of the vehicle 1. In the remainder of this specification, the illuminated area is also referred to as the illumination area.

[0081] In a non-limiting embodiment, surface 3 is: - The ground surface of the road where vehicle 1 is located. - Surface 3 inside the passenger compartment of vehicle 1.

[0082] In a non-limiting example, surface 3 inside the passenger compartment of vehicle 1 is the dashboard of vehicle 1 or the ceiling of vehicle 1.

[0083] In a non-limiting embodiment, surface 3 is curved.

[0084] Steering or maneuvering functions are functions that are performed at night or during the day. In a non-limiting embodiment, the signal that initiates this steering or maneuvering function is referred to as extended signaling. Signals that initiate steering or maneuvering functions include projecting a still image Im onto the ground.

[0085] Extended signaling capabilities allow the projection of images onto the ground to be synchronized with traditional signaling functions, such as steering or maneuvering functions. In a non-limiting example, a steering function is a turn signal for changing lanes, and a maneuvering function is a reverse light or brake light for parking.

[0086] In a non-limiting example, the image Im is projected onto the ground synchronously with the vehicle's turn signal. Therefore, it appears and disappears at regular intervals. Thus, when the driver of vehicle 1 activates the turn signal, the extended signaling function projects the image onto the ground, informing people around vehicle 1 that vehicle 1 is turning right or left. This is beneficial for any third party (pedestrians, cyclists, etc.) who do not see the turn signal of vehicle 1. The image Im is thus synchronous, appearing on the ground when the turn signal is on and disappearing from the ground when the turn signal is off.

[0087] In another non-limiting example, the image Im projected onto the ground is a static pattern associated with a maneuvering function, namely, the reversing lights of vehicle 1 for parking.

[0088] In a non-limiting example, the static or dynamic luminous carpet projection around the vehicle is: - Welcome Scene Functionality. Welcome scene functionality may include dynamic carpet projection around the vehicle, where animated images are projected. Therefore, the animated images are formed from several images (Im).

[0089] - Static carpet projection, in which a fixed image Im is projected.

[0090] The generation of the luminescent image enables the image to be displayed on the surface 3 inside the passenger compartment 10 of the vehicle 1. In a non-limiting example, the luminescent image Im is displayed on the dashboard of the vehicle 1.

[0091] When the light-emitting device 2 is configured to signal a turn or maneuver function, in a non-limiting embodiment, the light-emitting device may be arranged, for example, at the front of the vehicle 1, on the grille, and / or on headlights designed to illuminate the road and make the vehicle 1 clearly visible to other road users. Alternatively, the light-emitting device 2 may be arranged on the side of the motor vehicle 1 or at the rear of the vehicle 1. When the light-emitting device is arranged on the side of the vehicle 1, it may be on the exterior rearview mirror. When the light-emitting device is arranged at the rear of the vehicle 1, it may be on the taillight. Note that "front" refers to the side towards which the vehicle 1 moves in a straight line during forward motion.

[0092] When the light-emitting device 2 is configured to generate static or dynamic luminous carpet projection around the vehicle 1, in a non-limiting embodiment, the light-emitting device can be arranged on one side of the vehicle 1. When the light-emitting device is arranged on one side of the vehicle 1, it can be as follows: Figure 17 The [location shown] is positioned on the exterior rearview mirror, particularly below the exterior rearview mirror, or at the bottom of the vehicle body or the bottom of the door. [In [ Figure 17 In the non-limiting example shown, the image Im projected onto the ground is a static image comprising a pattern consisting of the logo "UOUO". In [ Figure 18 In a non-limiting example, the image Im projected onto the ground forms an animated image. In another non-limiting example, three images Im of a person in three different locations are shown, which makes it possible to create animated images of a person walking.

[0093] When the light-emitting device 2 is configured to generate a luminous image, in a non-limiting embodiment, the light-emitting device may be arranged in the interior ceiling of the vehicle 1 or below the interior center rearview mirror.

[0094] According to an embodiment of the present invention, the light-emitting device 2 includes at least one light source 4 capable of generating a light beam F, such as a light-emitting diode or a group of light-emitting diodes, or a laser diode or a group of laser diodes. The light beam F is a monochromatic light beam F.

[0095] A light-emitting diode (LED) refers to any type of light-emitting diode, including, by way of non-limiting example, LEDs (light-emitting diodes), OLEDs (organic LEDs), AMOLEDs (active-matrix OLEDs), or FOLEDs (flexible OLEDs). In the absence of a wavelength converter, the light from this light source 4 consists only of a single wavelength; in other words, it consists only of light of a specific color.

[0096] According to a non-limiting embodiment, the light source 4 emits orange monochromatic light with a wavelength λ between 590 nm and 610 nm. Note that the wavelength λ of 590 nm corresponds to amber light.

[0097] According to another non-limiting embodiment, the light source emits red monochromatic light with a wavelength λ between 620 nm and 700 nm.

[0098] According to yet another non-limiting embodiment, the light source emits cyan monochromatic light having a wavelength λ between 490 nm and 500 nm.

[0099] According to yet another non-limiting embodiment, the light source 4 emits blue monochromatic light with a wavelength λ between 450 nm and 490 nm.

[0100] According to yet another non-limiting embodiment, the light source 4 emits green monochromatic light with a wavelength λ between 490 nm and 570 nm.

[0101] According to other non-limiting embodiments, the light source 4 emits yellow or magenta monochromatic light.

[0102] These different colors make it possible to obtain white by mixing colors such as blue, red and green or cyan, magenta and yellow.

[0103] In these various non-limiting embodiments, the light-emitting device 2 is configured, for example, to project one or more colored light strips around the vehicle to let the driver know how much space they have to maneuver.

[0104] The light-emitting device 2 is configured to project an image Im with the same color as the turn signal or steering function. Therefore, for the turn signal function, the projected image Im will be orange; for the reversing light function, the projected image Im will be white; and for the brake light function, the projected image Im will be red.

[0105] In a non-limiting embodiment, the light source 4 may have sufficient power to emit signals for steering or maneuvering functions, or to produce static or dynamic luminous carpet projection, or to produce luminous images visible even in broad daylight.

[0106] Light source 4 has sufficient power to project image Im: - onto the ground 3 in front of vehicle 1 ([ Figure 2a The image is visible even in broad daylight, on the ground at the rear or side of vehicle 1 (as shown in the image), or at the rear of vehicle 1. - Projecting an luminescent image onto surface 3 inside the passenger compartment 10 of vehicle 1 ([ Figure 2b As shown in the image, the luminous image is visible even in broad daylight.

[0107] Light source 4 can be connected to Figure 2a , Figure 2b and Figure 16 The printed circuit board 6 shown. The printed circuit board 6 can be made of support member 7 ( Figure 2a and Figure 2b As shown, the support may include a heat sink.

[0108] The light-emitting device 2 also includes at least one optical device 14, which is placed alongside the light source 4 such that the light beam F generated by the light source 4 passes through the optical device 14.

[0109] Additionally, the optical device 14 includes at least one superlens 15, which is configured to modify at least one optical characteristic of the wavefront of the light beam F generated by the light source 4. The light beam F reaching the superlens 15 is also referred to as the incident light beam F.

[0110] Therefore, the transmittance of the monochromatic beam F through the optical device 14, including the superlens 15, is, for example, greater than 75%, particularly greater than 80%, or even higher. This results in a brighter image Im and / or allows the use of a lower-power light source 4 and / or a light source that consumes less energy.

[0111] In a non-limiting embodiment, the optical device 14 has a thickness between 1 mm and 2 mm. In a non-limiting embodiment, the light-emitting device 2, including the at least one light source 4 and the optical device 14, has a thickness substantially equal to 1 cm. Compared to the prior art with a thickness of approximately 4 cm, the compact light-emitting device 2 allows for savings of 1 cm to 3 cm. Thickness corresponds to [ Figure 2a ]or Figure 2b or Figure 16 The length of the light-emitting device 2 shown in the direction of the optical axis AA'.

[0112] The at least one superlens 15 may have an elliptical shape, particularly a circular shape, or a polygonal shape, particularly a quadrilateral shape. According to a non-limiting embodiment, the superlens 15 may have a square or rectangular shape. [According to...] Figure 3 In the non-limiting embodiment shown, the superlens 15 of the optical device 14 can have a rhomboid shape. This shape, particularly as shown in […] Figure 3 The rhomboid shape shown allows several superlenses 15 to be arranged in a compact array.

[0113] The superlens 15 of the optical device 14 typically includes nanostructures 16 ([ Figure 4As shown in the figure, the nanostructure is configured to modify the shape of the wavefront of the light beam F generated by the light source 4 and passing through the optical device 14, in particular modifying the amplitude of the light beam F and thus modifying the intensity and / or phase of the light beam and thus modifying the propagation direction of the light beam.

[0114] In a non-limiting embodiment, the superlens 15 (including a substrate 160 and nanopillars 17, as described below) has a diameter between 1 mm and 2 mm.

[0115] It should be noted that, in the case of monochromatic light source 4, the fabrication and calculation of the nanostructure 16 of the superlens 15 are simpler.

[0116] The nanostructure 16 of the superlens 15 may include an arrangement of nanopillars 17 on its surface. These nanopillars 17 are typically fabricated by nanostructuring (i.e., by electron beam lithography or by nanoimprint lithography in thin films) and are arranged in the form of a quasi-periodic network.

[0117] These nanopillars 17 at the nanoscale can include dielectric materials with high refractive indices (e.g., refractive indices greater than two).

[0118] More specifically, the nanostructure 16 may comprise a quasi-periodic network of nanopillars 17. In this context, "quasi-periodic" means that the nanopillars within the nanostructure 16 are positioned at more or less regular intervals to each other, and that they repeat periodically, and that they have different sizes (in this case, their diameters vary). If they are all the same size, it is called a periodic network. By way of a non-limiting example, the nanopillars 17 of the nanostructure 16 may be placed at intervals between 300 nm and 500 nm. In a non-limiting example, they are placed at intervals of 400 nm. In other words, the centers of two adjacent nanopillars 17 are 400 nm apart.

[0119] Nanopillars 17 are, for example, placed on a transparent substrate 160 ([ Figure 8 As shown in the figure. The material of the transparent substrate 160 is selected to provide suitable structural support and allow most of the light traversing the substrate to pass through it. Such substrate materials include, for example, fused silica, borosilicate glass, or rare earth oxide-based glass.

[0120] like[ Figure 8 As shown, in one embodiment, substrate 160 has a first refractive index n1, and nanopillar 17 has a second refractive index n2. The first refractive index n1 of substrate 160 is lower than the second refractive index n2 of nanopillar 17. These refractive indices n1 and n2 also affect the light beam F passing through nanopillar 17 of nanostructure 16 of superlens 15, and thus make it possible to modify at least one optical property of the wavefront.

[0121] The optical properties of the superlens 15 are primarily defined by the wavelength of the monochromatic light source used, one or more refractive indices n1 and n2 of the materials used for the substrate 160 and the nanopillars 17, the size of the nanopillars 17, and their distribution within the nanostructure 16. In other words, the material density in the nanostructure 16 of the superlens 15 defines the effect of the superlens 15 on the light beam F passing through it.

[0122] The superlens 15 is configured to receive a beam F from the light source 4 and modify its propagation phase φ such that the beam F is directed onto a given propagation direction P. Figure 5 (As shown in the figure). In the remainder of this specification, the propagation phase φ is also referred to as phase φ.

[0123] Typically, the nanopillars 17 can have cross-sections of different sizes. Specifically, the shape and size of the cross-section of the nanopillars 17 of the nanostructure 16 affect the propagation speed of the light beam F passing through the nanopillars 17, thereby modifying at least one optical property of the wavefront of the light beam F passing through the optical device 14.

[0124] Nanopillars 17 can in particular have a cylindrical shape; in this case, they can have a circular base surface bs ([ Figure 8 (As shown in the image). The diameter can vary from one nanopillar (17 nm) to another. Figure 4 An example of an arrangement of cylindrical nanopillars 17 with predetermined heights and different diameters is shown in the figure. Thus, the nanopillars 17 have different sizes (via their diameters). Alternatively, the shape of the base surface bs can be non-circular, such as a polygonal base, especially a square or rectangular one, or an elliptical base.

[0125] Furthermore, these nanopillars 17 can have the same height h ([ Figure 8 As shown in the figure, this height is configured to modify the phase of the light beam F generated by the light source 4. For monochromatic light with a given wavelength λ, the ideal height of the nanopillar 17 can be determined to obtain the highest possible transmittance. The height h of the nanopillar 17 allows the phase to be controlled between 0 and 2π.

[0126] In a non-limiting embodiment, the light source 4 can be configured to emit a light beam with a wavelength λ equal to 590 nm. In this non-limiting example, the refractive index n1 of the material used for the substrate 160 is equal to 1.52, while the refractive index n2 of the nanopillar is equal to 2.36. Still in this non-limiting example, the height h of the nanopillar 17 is 600 nm, and the diameter of the nanopillar 17 can be between 50 nm and 150 nm.

[0127] The distribution of nanopillars 17 within the nanostructure 16 of the superlens 15 can be optimized to facilitate the propagation direction P of the beam F. Figure 5The distribution of nanopillars 17 within the nanostructure 16 can be specifically configured to influence the propagation direction P of the beam F, thereby modifying the beam orientation at the exit of the superlens 15.

[0128] More generally, in a non-limiting embodiment, the superlens 15 comprises a quasi-periodic network of nanopillars 17 with different diameters (i.e., different radii r) to influence the propagation speed of light through the nanopillars 17, thereby modifying at least one optical property of the wavefront of the light beam F passing through the superlens 15. Specifically, for two nanopillars 17 having the same height h and different diameters, the nanopillar 17 with the larger diameter will slow the propagation of light through it more than the nanopillar with the smaller diameter. This is particularly evident in […]. Figure 5 As shown in the image.

[0129] Therefore, the nanostructure 16 of the superlens 15 can be configured to influence the orientation of the beam F at the exit of the superlens 15, such that the light-emitting device 2 emits a conical beam F in the projection direction P, which is tilted at an angle between 30° and 90° relative to the propagation direction P of the beam F generated by the light source 4.

[0130] Furthermore, in the case of a quasi-periodic network, the arrangement of the nanopillars 17 in the nanostructure 16 of the superlens 15 (i.e., the distribution of their radii r) can be configured such that the superlens has a structure suitable for projecting an image Im with at least one fixed contour illumination region z1 onto a surface 3, which: - In the vicinity of vehicle 1 (in other words, around it), for steering or maneuvering functions, for generating static or dynamic luminous carpet projection, or - Inside the passenger compartment 10 of vehicle 1, used to generate luminous images.

[0131] In a non-limiting embodiment, the projected image Im forms a pattern. In a non-limiting variant embodiment, the pattern is a geometric pattern. The geometric pattern of the projected image Im has, for example, a simple geometric shape. Throughout the rest of the specification, the pattern is also referred to as a luminescent pattern. The pattern can be, for example: - Arrows indicating direction, such as [ Figure 7 As shown, or - Pictographs, or - A set of shapes and / or stripes and / or lines, such as Figure 12a , Figure 12b and Figure 13 As shown, or - Logo, such as Figure 17 As shown, or - Test subjects, such as Figure 18 As shown.

[0132] The nanopillar 17 is described in more detail below.

[0133] Nanopillar 17 is defined by parameters including the following: - radius r ( Figure 8 and Figure 9 (as shown) - Height h ( Figure 8 and Figure 9 (as shown) - The spacing ps' between the two nanopillars 17 ([ Figure 9 (As shown in the image). The spacing ps' represents the repetition frequency of the nanopillar 17. - Materials with a refractive index of n2 ([ Figure 8 (as shown in the image) - Bottom surface bs ([ Figure 8 (as shown in the image).

[0134] It should be noted that the spacing ps' is constrained to the two longitudinal axes of two adjacent nanopillars 17 (in [ Figure 9 (shown as dashed lines in the image) between [ ]. Figure 8 In the non-limiting embodiment shown, the nanopillar 17 has a circular bottom surface bs.

[0135] In a non-limiting embodiment, the nanopillar 17 is made of silicon nitride (SiN). Compared to other materials that can be used for the nanopillar 17, such as titanium dioxide (TiO2) or hafnium oxide (HfO2, as non-limiting examples), this material is easier to use and produces less dust pollution.

[0136] In a non-limiting example of the embodiment, a 70 nm SiN layer can be deposited on a substrate 160 with a thickness of E = 5 mm and the SiN layer can be etched to obtain nanopillars 17.

[0137] The nanopillars 17 of each superlens 15 enable modification of the propagation phase φ of the beam F passing through them. In other words, they add a phase delay. As a result, the beam F is deflected, thus giving it the desired propagation direction P.

[0138] All beams F thus deflected lie in a plane parallel to the substrate 160 of the superlens 15 (e.g., […]). Figure 12a (as shown) or on a plane not parallel to substrate 160 (e.g., on ground plane 3, as shown in […]). Figure 12b As shown in the diagram, a clear projected image Im is formed at a distance that is essentially at infinity. Note that this distance depends on the phase shift introduced by the nanopillar 17. Therefore, the light is redirected towards the area to be illuminated. Other areas remain unilluminated and appear dark. The deflected beam F transmits with very good light transmittance. Therefore, very little light is lost.

[0139] like[ Figure 12a ]and Figure 12b As shown, image Im includes an illumination area z1 where the light has been redirected and a shadow area z2 where the light has not been redirected (in the non-limiting example shown, this shadow area is inside and between illumination areas z1). Illumination area z1 is a spotlight area.

[0140] It should be noted that, Figure 12a and Figure 12b In the image, the black border surrounding the illumination area z1 is only used to highlight the illumination area z1.

[0141] To adjust the propagation direction P, the phase shift within the beam F is controlled spatially, which is equivalent to controlling the phase gradient φ of the beam F. This is accomplished using nanopillars 17.

[0142] Therefore, in [ Figure 9 In the non-limiting embodiment shown, the nanopillars 17 have different radii r and the same height h. To avoid cluttering the diagram, only one height h and only one radius r are labeled.

[0143] It should be noted that the smaller the radius r, the less material the nanopillar 17 contains, resulting in minimal change in phase φ, which is equivalent to a slight phase retardation. Conversely, when the radius r is larger, the nanopillar 17 contains more material, resulting in a larger change in phase φ, which is equivalent to a greater phase retardation.

[0144] like[ Figure 9 As shown, the nanopillars 17 have a radius r that increases from left to right. Each nanopillar 17 will cause a phase delay φ different from its neighbors. The larger the radius r, the greater the phase delay φ. Therefore, the radius r plays a role in the phase φ of the beam F. Since the radius r on the left is smaller, the phase delay on the left is smaller, and the degree of delay of light on the left will be less than that on the right.

[0145] It should be noted that light propagates perpendicular to the wavefront. Conventionally, there is zero phase delay along the same line as the wavefront. For example, in [ Figure 5 As can be seen from the image, the input wavefront Fo (also known as the incident wavefront Fo) at the entrance of the superlens 15 is planar and perpendicular to the substrate 160 of the superlens 15.

[0146] Each nanopillar 17 introduces a phase φ delay that differs from its neighbors because they all have different diameters, and this differential phase φ delay then causes wavefront deformation.

[0147] For example in [ Figure 5 As can be seen from the image, the outgoing wavefront Fo' is deformed, which causes the outgoing beam F to deflect after the superlens 15.

[0148] Therefore, at the exit of the superlens 15, light that has always propagated perpendicular to the wavefront (in this case, the tilted outgoing wavefront Fo') will be directed onto a given propagation direction P. Thus, the light is directed onto a propagation direction P that has changed due to the phase shift of the light.

[0149] It should be noted that the outgoing wavefront Fo' is gradually and linearly delayed. Each nanopillar 17 is configured to achieve a linear evolution of the phase φ of the light, in other words, a linear phase shift. This makes it possible to obtain a planar outgoing wavefront Fo'. It should be noted that the phase shift between 0 and 2π is equivalent. Therefore, it is not necessary to generate a linear phase shift along the input wavefront Fo to obtain continuous deflection. The phase shift between 0 and 2π can be performed multiple times as needed. Therefore, a linear phase shift between 0 and 10π is equivalent to five linear phase shifts between 0 and 2π.

[0150] It should be noted that the phase φ is modulated between 0 and 2π. It should also be noted that when the phase φ = 0, there is no delay. When φ = π, there is a delay of λ / 2. From the perspective of the superlens 15, once φ = 2π, it is equivalent to the radius r of the nanopillar 17 corresponding to 0, and therefore equivalent to the same nanopillar 17, to avoid excessive differences between radii r. Therefore, the superlens 15 comprises a plurality of nanopillar 17 assemblies, which are configured to achieve an optical phase shift modulated between 0 and 2π.

[0151] The height h of the nanopillar 17 allows the phase φ to be controlled between 0 and 2π for a given wavelength λ. With a correctly defined height h, all phase variations can be made to be between 0 and 2π.

[0152] As mentioned above, the radius r allows for control of the phase φ of the beam Fx.

[0153] Other parameters (i.e., the height h, spacing ps', and material of the nanopillars 17) are constrained to maximize the light transmittance through the nanopillars 17. Maximizing transmittance is equivalent to minimizing the absorption of light by the material of the nanopillars 17. Therefore, these other parameters are determined to have minimum absorption over a range of radius r with a phase shift (also known as phase difference) between 0 and 2π.

[0154] Calculations show that for the nanopillar 17, given a height h and a given spacing ps' and its material, by way of a non-limiting example, the material is silicon nitride (SiN) with a refractive index n² = 2.04. In the non-limiting example, h = 1.35 μm and ps' = 0.450 μm. Fabrication of the nanopillar 17 is advantageous with a constant height h. With a constant height h, the design of the nanopillar 17 must be adjusted to have a phase shift between 0 and 2π, while simultaneously having the highest possible light transmission to obtain the maximum amount of light.

[0155] To set the height h and the spacing ps', curves showing the change of light transmittance with radius r and the change of phase shift with radius r were established. Figure 10 and Figure 11 The curves in the figure illustrate the optimal trade-off between phase shift and transmittance for a given wavelength λ and a chosen constant height h. Note that this trade-off changes if the wavelength λ is altered.

[0156] [ Figure 10 The phase φ (on the ordinate) of the nanopillar 17, which varies between 0 and 9 in radians, is shown by way of a non-limiting example, for a given wavelength λ (in this case, for λ = 590 nm in the non-limiting example shown), and for a height h = 1.35 µm (micrometers).

[0157] [ Figure 11 The following is illustrated by way of a non-limiting example: for a given wavelength λ (590 nm in this case) and for a height h = 1.35 µm, the light transmittance Tx varies between 0 and 1 as a function of the radius r (on the x-axis) of the nanopillar 17, which varies between 0.04 μm and 0.15 μm. When the transmittance value is 0, no light passes through. When the transmittance value is 1, all light passes through.

[0158] These two curves allow us to find and determine which height h and radius r of the nanopillar 17 enables the acquisition of dynamics for controlling the phase shift, maximizing the light transmittance of the nanopillar 17, and ensuring that fabrication remains feasible. Therefore, it is possible to determine the values ​​of all parameters of the nanopillar 17 to obtain possible phase shift (or phase difference) and transmittance values ​​for a given wavelength λ, particularly transmittance close to 1. Note that if the results are unsatisfactory, the process can be repeated to set another value for the height h.

[0159] The superlens 15 has a focal length f.

[0160] It should be noted that the shape of surface 3 is known in advance. The nanostructure 16 of the superlens 15 is therefore designed such that, depending on the shape of surface 3, the focal length f of the superlens 15 adapts to surface 3, and such that the light beam F passing through the superlens 15 converges at the exit of the superlens 15 toward this surface 3 into a convergence zone marked p in the remainder of this specification, to obtain a clear image Im. The image focal point of the light beam F is obtained, which lies in a plane tangent to surface 3, or even beyond said surface 3.

[0161] Therefore, the adaptive focal length f allows control over the distance at which the beam must converge. Thus, the beam F can be precisely focused on surface 3, and if this surface is curved, it can converge to a different distance to adapt to surface 3.

[0162] A beam F from light source 4 forms a plane wave that illuminates a corresponding superlens 15. In a non-limiting embodiment, the size of light source 4 is smaller than the superlens 15 it illuminates, such that the beam F can be properly collimated; in other words, the cone of light from beam F falls within the superlens 15. In a non-limiting embodiment, light source 4 has a surface area of ​​0.8 mm².

[0163] Especially as Figure 2a , Figure 2b and Figure 16 As shown, according to a preferred embodiment, the light-emitting device 2 includes a plurality of light sources 4 and a plurality of superlenses 15.

[0164] In a first non-limiting embodiment, the superlens 15 is configured to produce an image Im consisting of all or part of at least one monochrome pattern.

[0165] Therefore, in a non-limiting variant embodiment, in order to signal a steering or maneuvering function, a superlens 15 forms a portion of the pattern of image Im, and a plurality of superlenses 15 form various portions of said pattern.

[0166] Therefore, in a non-limiting variant embodiment, in order to produce a static luminescent carpet projection, if the power of the corresponding light source 4 is large enough to obtain the desired brightness, a single superlens 15 forms a pattern of image Im for the static luminescent carpet projection.

[0167] In a second, non-limiting embodiment, a plurality of superlenses 15 are configured to produce an image Im consisting of one or more monochrome, white, or multicolor patterns.

[0168] Therefore, in a non-limiting variant embodiment, in order to produce a static luminescent carpet projection, a plurality of superlenses 15 can produce the same pattern for the image Im used for the static luminescent carpet projection, and these patterns overlap each other.

[0169] Therefore, these first and second non-limiting embodiments can be used for steering or maneuvering functions, or to generate a static luminous carpet projection around the vehicle 1.

[0170] In a third, non-limiting embodiment, a plurality of superlenses 15 are configured to produce a monochrome dynamic image composed of a plurality of patterns.

[0171] In a fourth non-limiting embodiment, a plurality of superlenses 15 are configured to produce a multicolor or white dynamic image composed of a plurality of patterns.

[0172] Each superlens 15 forms a pattern that can be superimposed on other patterns formed by other superlenses 15 and interchanged with each other to create animated images.

[0173] Therefore, in a non-limiting variant embodiment, in order to generate a dynamic luminous carpet projection, a plurality of superlenses 15 can each generate a plurality of images Im for the animated image of the dynamic luminous carpet projection. Since the light source 4 corresponding to each superlens 15 can be of a different color, it is possible to obtain patterns of different colors or white patterns.

[0174] Therefore, these third and fourth non-limiting embodiments can be used to generate a dynamic luminous carpet projection around the vehicle 1.

[0175] As in Figure 12a and Figure 12b as well as Figure 13 As can be seen, the image Im obtained by the optical device 14 with multiple superlenses 15 includes an illuminated area z1 and a shadowed area z2. In order to obtain the illuminated area z1, for a given set height h and spacing ps', the radius r of the nanopillar 17 is adjusted to obtain maximum light transmission, and the beam F is redirected toward the area to be illuminated as described above.

[0176] For dynamic luminous carpet projection, the image Im formed by each superlens 15 is created at the same location. Therefore, once projected, they end up in the same position on the ground 3. In the context of animated images, this prevents consecutive animated images Im from being in different positions on the ground 3. Otherwise, the desired dynamic effect would not be achieved.

[0177] In special cases Figure 2a , Figure 2b In the first non-limiting embodiment shown, the light-emitting device 2 includes as many superlenses 15 as the light source 4, and each light source 4 is associated with its own specific superlens 15.

[0178] These light sources 4 can be the same as or different from each other. If they are different, each light source 4 can, for example, have a different wavelength λ, and can be associated with a superlens 15 designed for this type of monochromatic wavelength source in order to emit dynamic and unique light waveforms. This provides great flexibility regarding the color obtained at the output of the light-emitting device 2 and the projected image Im.

[0179] In this mode, in a non-limiting variant embodiment, the plurality of superlenses 15 are arranged in rows and columns within the optical device 14 to form an array. The plurality of light sources 4 are also arranged in rows and columns to form an array. The plurality of superlenses 15 and the plurality of light sources 4 are arranged relative to each other such that each beam F generated by one of the light sources 4 passes through the superlens 15 associated with said light source 4.

[0180] Therefore, the light sources 4 in the array of light sources 4 are arranged opposite each superlens 15 in the array of superlenses 15. Thus, each superlens 15 is specifically traversed by a beam F generated by the light source 4 associated with that superlens 15. This array arrangement of the light sources 4 and the superlenses 15 associated with them proves to be more compact than known prior art devices. In other words, this array arrangement of certain components of the light-emitting device 2 contributes to the overall compactness of the light-emitting device 2.

[0181] exist[ Figure 15a In the first non-limiting variant embodiment shown, the light-emitting device 2 includes at least three components ga, gb, gc consisting of light sources 4 arranged side by side, and at least three components g'a, g'b, g'c consisting of corresponding superlenses 15a, 15b, 15c arranged side by side.

[0182] The three components, ga, gb, and gc, are arranged side by side.

[0183] Each component ga, gb, gc includes at least one light source 4. In the non-limiting example shown, each component ga, gb, gc includes three light sources 4, and each component g'a, g'b, g'c includes three superlenses 15a, 15b, 15c.

[0184] Each light source component 4a, 4b, 4c, ga, gb, gc, is configured to emit monochromatic light of a different color than the other components ga, gb, gc. In other words, each light source 4 of each component g emits the same monochromatic light as the other two light sources 4 in the same component g.

[0185] In a non-limiting example, each component ga, gb, gc is represented as 3 × 4a, 3 × 4b, 3 × 4c. The three light sources are configured to emit monochromatic light of red R (λa = 620 nm in the non-limiting example), green G (λb = 550 nm in the non-limiting example), and blue B (λc = 450 nm in the non-limiting example) to obtain white light.

[0186] Therefore, the first component ga includes three light sources 4a configured to emit red monochromatic light, the second component gb includes three light sources 4b configured to emit green monochromatic light, and the third component gc includes three light sources 4c configured to emit blue monochromatic light.

[0187] Therefore, the three superlenses, represented as 3 × 15a, 3 × 15b, and 3 × 15c, which are associated with the three light source components ga, gb, and gc respectively, are designed for three different wavelengths λa, λb, and λc. In other words, they are tuned for these three wavelengths λa, λb, and λc.

[0188] exist[ Figure 15b In the second non-limiting variant embodiment shown, the light-emitting device 2 includes at least three components g1, g2, g3 consisting of light sources 4a, 4b, 4c arranged side by side, and at least three components g'1, g'2, g'3 consisting of corresponding superlenses 15a, 15b, 15c arranged side by side. Each component g1, g2, g3 includes at least one light source 4. In the non-limiting example shown, each component g1, g2, g3 includes three light sources 4a, 4b, 4c, and each component g'1, g'2, g'3 includes three corresponding superlenses 15a, 15b, 15c.

[0189] Each light source 4 in each component g is configured to emit monochromatic light of a different color than the other light sources 4 in the same component g.

[0190] Therefore, the first component g1 includes three light sources 4a, 4b, and 4c, which are configured to emit monochromatic light of red (λa = 620 nm in a non-limiting example), green (λb = 550 nm), and blue (λc = 450 nm in a non-limiting example), respectively, to obtain white light. The same applies to the second component g2 and the third component g3.

[0191] Therefore, the first component g1' includes three superlenses 15a, 15b, and 15c, which are designed for three different wavelengths λa, λb, and λc, respectively; in other words, they are tuned for these three wavelengths λa, λb, and λc. The same applies to the second component g'2 and the third component g'3.

[0192] Compared to the first non-limiting variant embodiment, this second non-limiting variant embodiment enables the acquisition of a white image at a distance closer to the exit of the superlens 15.

[0193] exist Figure 15a and Figure 15bIn the context of this first non-limiting embodiment shown, in order to superimpose the image Im generated by each superlens 15a, 15b, 15c (especially in the context of animated images), since the superlenses 15a, 15b, 15c are arranged side by side, it is necessary to make each beam F from the associated light sources 4a, 4b, 4c have a different linear phase shift, which is obtained by means of the nanopillars 17 as described above.

[0194] exist[ Figure 16 In the second non-limiting embodiment shown, the light-emitting device 2 includes at least one component g consisting of three light sources 4a, 4b, 4c arranged side by side, and at least one stack s' consisting of three superlenses 15a, 15b, 15c arranged opposite to said component g, each light source 4a, 4b, 4c being configured to emit light of a different color than the other light sources 4a, 4b, 4c in said at least one component g.

[0195] Therefore, in a non-limiting example, the three light sources 4a, 4b, and 4c are configured to emit monochromatic light of red (λa = 620 nm in the non-limiting example), green (λb = 550 nm), and blue (λc = 450 nm in the non-limiting example), respectively, so as to obtain white. This produces a component g referred to as RGB.

[0196] Three superlenses 15a, 15b, and 15c are designed to be tuned for different wavelengths λa, λb, and λc, respectively. In a non-limiting example, they are tuned for wavelengths λa (red), λc (green), and λb (blue), respectively.

[0197] It should be noted that stacking the superlenses 15a, 15b, and 15c one on top of the other will not significantly increase the thickness and volume of the light-emitting device 2, because the superlenses 15a, 15b, and 15c are very thin.

[0198] At the third superlens 15c in the stack s', all colors are mixed. Therefore, white is obtained at the output of the stack s'.

[0199] In order to create animated images, the light-emitting device 2 includes at least two components g consisting of three light sources 4a, 4b, and 4c arranged side by side, and two stacked bodies s' consisting of three arrays of corresponding superlenses 15a, 15b, and 15c stacked one on top of the other.

[0200] It is important to note that the stacked configuration allows this to be done without partition walls (which are physical walls), because each superlens 15a, 15b, 15c only processes light with its tuned wavelength λ. Therefore, superlens 15a will process only red light, superlens 15b will process only green light, and superlens 15c will process only blue light. The beam F from each light source 4a, 4b, 4c does not mix with another beam F. This avoids optical crosstalk.

[0201] Furthermore, since white light is obtained at the third superlens 15c of the stack s', there is no effect on the color edges of the projected image Im.

[0202] [ Figure 16 A light-emitting device 2 with stacked bodies s' is shown, which is configured to project an image Im onto a surface 3 inside the passenger compartment 10 of the vehicle 1. Naturally, this stacked body s' configuration of the superlens 15 is suitable for projecting an image Im onto a surface 3 surrounding the vehicle 1.

[0203] Please note that blue, green, and red can be replaced with yellow, magenta, and cyan to obtain white.

[0204] In a non-limiting embodiment, if there are several light sources 4, the light-emitting device 2 includes a collimator for each light source 4. This prevents the light beam F from one light source 4 from mixing with another light beam F from another light source 4. This avoids optical crosstalk. Therefore, the obtained pattern will not be blurred.

[0205] This also applies to embodiments with stacking to prevent one color from blending into another color before entering the superlens 15 stack.

[0206] In a non-limiting embodiment, the light source 4 can be turned on or off in a desired order, resulting in the light beam F from the light source 4 passing through the associated superlens 15 in the order in which the light source 4 is activated and deactivated. Therefore, the order is independent of the arrangement of the superlens 15 within the optical device 14, which can provide greater versatility and / or simplicity in signaling steering or maneuvering functions. In particular, it is possible to activate several light sources 4 simultaneously, and thus to signal steering or maneuvering functions around the vehicle 1 in a more intricate and informed manner.

[0207] Therefore, in order to produce a static luminescent carpet projection, in a non-limiting embodiment, the light source 4 (or light source 4 assembly g) corresponding to each superlens 15 can be simultaneously turned on or off. Therefore, in [ Figure 17 In a non-limiting example, in order to obtain an image of the logo “UOUO”, all four light sources will be turned on simultaneously (i.e., activated).

[0208] Therefore, in a non-limiting embodiment, in order to generate a dynamic luminous carpet projection, the light source 4 (or light source 4 component g) corresponding to each superlens 15 can be sequentially turned on (activated) or off (disabled) to form an animated image. Therefore, in Figure 18 In a non-limiting example, the activation / deactivation sequence of the light source 4 illuminating the superlenses 15a, 15b, and 15c will be as follows: - Activate the light source 4a that illuminates the superlens 15a, then - Deactivate the light source 4a illuminating the superlens 15a, and simultaneously activate the light source 4b illuminating the superlens 15b, then - Deactivate the light source 4b that illuminates the superlens 15b, and simultaneously activate the light source 4c that illuminates the superlens 15c.

[0209] Therefore, an animated image of a walking person is obtained in the non-limiting example shown.

[0210] According to a non-limiting embodiment, the optical device 14 further includes a liquid crystal layer 18.

[0211] In a non-limiting embodiment, the liquid crystal layer 18 is a polymer-dispersed liquid crystal (PDLC) layer.

[0212] The liquid crystal layer 18 extends against the superlens 15.

[0213] according to[ Figure 6 In the non-limiting embodiment shown, the liquid crystal layer 18 and a voltage source 19 adapted to control the electric field passing through the liquid crystal layer 18 can be associated with the superlens 15 to form a lens with a variable focal length by means of the phase transition of the liquid crystal 18. Therefore, this variable focal length lens allows the superlens 15 to modify the convergence region p of the light beam F on the surface 3 according to the position of the light-emitting device 2 relative to this surface 3 located around the vehicle 1 or inside the passenger compartment 10 of the vehicle 1, so that the projected image Im is sharp in this convergence region p of the light beam F.

[0214] The liquid crystal layer 18 is arranged in the path of the light beam F generated by the light source 4. The liquid crystal layer is placed between the superlens 15 and the light source 4.

[0215] The liquid crystal layer 18 includes a group of liquid crystals whose orientation can be controlled by means of an electric field applied thereto.

[0216] The liquid crystal layer 18 is configured to display [ Figure 6 The at least two different states s1 and s2 are shown.

[0217] The first state s1 is the non-operating state s1, in which the liquid crystal layer 18 is inactive in order to maintain the optical properties of the incident beam F and allow the superlens 15 to obtain the first convergence region p1 of the beam F on the surface 3. In a non-limiting example, the optical properties are phase and polarization.

[0218] Therefore, the superlens 15 acts on the light beam F passing through it as if the liquid crystal layer 18 were not present, and the focal length of the superlens ([ Figure 6 As shown in the figure, f1 is adjusted according to surface 3 to obtain the convergence region p1 of the beam F on surface 3 (as shown in the figure). Figure 6 As shown in the image above.

[0219] The second state s2 is the working state, in which the liquid crystal layer 18 is active in order to modify the optical properties of the incident beam F and allow the superlens 15 to obtain the second convergence region p2 of the beam F on the surface 3 (e.g., […]). Figure 6 (As shown in the image). The second convergence region p2 is different from the first convergence region p1.

[0220] Therefore, the superlens 15 acts on the modified beam F passing through the superlens by modifying the convergence area of ​​the beam on the surface 3.

[0221] Due to the new optical properties of beam F, the superlens 15 [ Figure 6 The modified effective focal length f2 shown in the figure comes into play.

[0222] In the non-limiting example shown, the focal length f2 is less than the focal length f1, causing the beam F to converge toward the shorter convergence region p2.

[0223] These two states, s1 and s2, are obtained by modifying the electric field applied to the liquid crystal layer 18.

[0224] In a non-limiting embodiment, liquid crystal layer 18: - When an electric field is applied (i.e., voltage source 19 is turned on), it is in its non-operating state s1. - When the electric field is cut off (i.e., the voltage source 19 is turned off), it is in its working state s2.

[0225] It should be noted that the liquid crystal layer 18 is more compact than the projection optics. Compared to projection optics with a thickness of approximately 2 mm to a maximum of 40 mm, the liquid crystal layer has a thickness of less than 1 mm. Therefore, the liquid crystal layer is very thin compared to the projection optics.

[0226] As those skilled in the art will appreciate, the liquid crystal layer 18 requires electrodes (not shown) to create an electric field. In a non-limiting embodiment, the electrodes are transparent to allow light to pass through.

[0227] Therefore, the liquid crystal layer 18 enables the creation of a dynamic light-emitting device 2, which can adapt to the surface 3 on which the image Im is projected. The projection of the image Im onto the surface 3 can be adjusted in real time using an electric field that can be modified in real time, unlike conventional projection optics that include one or more projection lenses.

[0228] Therefore, in a non-limiting example, if the purpose is to project onto surface 3 (the ground 3) at a distance of 5 meters or 3 meters for steering or maneuvering functions, or for static or dynamic luminous carpet projection, the value of the electric field is changed, unlike conventional projection optics which must be changed in this case. The same applies if the purpose is to project onto surface 3 (the dashboard of vehicle 1) at a distance of approximately 1 m.

[0229] In such Figure 2a and Figure 2b In the context of the illustrated array of superlenses 15, in a non-limiting embodiment, each superlens 15 in the array is associated with a liquid crystal layer 18 that can be individually controlled by an electric field. Therefore, in a non-limiting embodiment where the light-emitting device 2 includes an array of a plurality of superlenses 15, the light-emitting device includes a plurality of liquid crystal layers 18, one liquid crystal layer for each superlens 15.

[0230] In another non-limiting embodiment, the light-emitting device 2 comprises only a single liquid crystal layer 18, and each superlens 15 in the array is arranged opposite a different defined region in the single liquid crystal layer 18, and each region can be individually controlled by an electric field. These different regions are opposite each light source 4 corresponding to each superlens 15.

[0231] In such as [ Figure 16 In the context of the stack s' of the superlens 15 shown, in a non-limiting embodiment, the liquid crystal layer 18 extends along the first superlens 15a facing the light source components 4a, 4b, 4c in the stack s'. Therefore, the liquid crystal layer is disposed between the light source components 4a, 4b, 4c and the stack s'.

[0232] The advantage of liquid crystal layer 18 is that it can be adapted to the desired vehicle application according to the manufacturer's requirements without modifying the superlens 15 used in the light-emitting device 2. Therefore, the position where the image is projected onto surface 3 by Im can be modified without changing the design of the superlens 15. Thus, the light-emitting device 2 can be used for several different vehicle layouts. In a non-limiting example, for a given manufacturer, if the pattern projected onto ground 3 needs to be projected at 5 m instead of 3 m, then liquid crystal layer 18 allows the use of light-emitting device 2 in a manufacturer's specific vehicle. In another non-limiting example, if the manufacturer needs interior lighting on surface 3 (for the dashboard), then liquid crystal layer 18 allows the use of light-emitting device 2 in a manufacturer's specific vehicle.

[0233] This is simply a matter of adjusting the electric field applied to the liquid crystal layer 18 for each manufacturer or each type of vehicle required.

[0234] It should be noted that if the light-emitting device 2 includes a collimator, the liquid crystal layer 18 is arranged after the collimator, and therefore is arranged between the collimator and the superlens 15.

[0235] according to[ Figure 13 In the non-limiting embodiment shown, the light-emitting device 2 further includes a projection optics 20, which includes one or more projection lenses to shape and direct the light beam F in a desired direction and to project the light beam F onto a given surface 3 of the substrate 160 that is not parallel to the superlens 15, in which case it is projected onto the ground 3 or onto a surface 3 inside the passenger compartment 10 of the vehicle 1.

[0236] The advantage lies in its adaptability to the desired application according to the manufacturer's requirements without modifying the superlens 15. Therefore, the position where the image is projected onto the surface 3 can be modified without altering the design of the superlens 15. Consequently, the light-emitting device 2 can be used in several different vehicle layouts. The projection optics 20 are significantly cheaper than the molds used to manufacture the superlens 15. This allows for the low-cost manufacture of various projection optics 20 for different types of vehicles.

[0237] It should be noted that the projection optics 20 can be replaced by a diffraction prism.

[0238] Typically, a projection lens can shape a light beam within a defined spatial field, allowing the light beam F to be projected according to the function that the light-emitting device 2 must perform. In other words, the projection lens allows the shape of the light beam to be defined at the exit of the light-emitting device 2. Therefore, the projection lens can define the width and / or height of the light beam F, as well as its length (in other words, how far the light beam F can illuminate) and / or its tilt angle. In particular, such a projection lens can be configured to guide the light beam F toward the ground so as to project the image Im onto the ground 3 near the vehicle 1 (e.g., […]). Figure 13 (as shown in the image), or projected onto the surface 3 inside the passenger compartment 10 of the motor vehicle 1.

[0239] It should be noted that if the optical device 14 projects the image Im at a limited distance (e.g., 5 meters), and if the light-emitting device 2 is intended to be adjusted to project at a greater distance (e.g., 6 meters), then the projection optics 20 must have a negative focal length.

[0240] Conversely, if the optical device 14 projects an image Im at a limited distance (e.g., 5 meters), and if the light-emitting device 2 is intended to be adjusted to project at a shorter distance (e.g., 3 meters), then the projection optics 20 must have a positive focal length.

[0241] exist[ Figure 14 In the non-limiting embodiment shown, the light-emitting device 2 further includes: - A housing 21, in which the at least one light source 4, the optical device 14 having the at least one superlens 15, and, where appropriate, the liquid crystal layer 18 or projection optics 20, are placed, and - Protective cover 22. Cover 22 includes an opening 220 for projecting an image Im onto the surface 3.

[0242] Therefore, it is possible to design a more compact and lighter light-emitting device 2 that can be easily integrated into a motor vehicle 1. This light-emitting device 2 can project an image Im with one or more fixed contour illumination areas z1 in a simple manner for steering or maneuvering functions, to produce static or dynamic carpet projection, or to produce luminous images on the surfaces 3 inside the passenger compartment 10 of the vehicle 1.

[0243] The light-emitting device 2 according to the invention is not affected, or is only slightly affected, by possible shocks and / or vibrations caused by the use of the motor vehicle 1 in which the light-emitting device 2 is integrated, and exhibits better thermal performance.

[0244] Therefore, the light-emitting device 2 according to the present invention provides a more robust and reliable alternative than the light-emitting device 2' known from the prior art.

[0245] The light-emitting device 2 according to the present invention enables the creation of an image Im with a complex light-emitting pattern that can be individually controlled for light emission.

[0246] Using the light-emitting device 2 according to the invention, when the light-emitting device 2 is turned on or off, external viewers will not notice any difference; in other words, the style and appearance of the vehicle 1 will not be modified due to the activation of the light-emitting device 2. Specifically, the light-emitting device 2 is small and flat and is hidden inside the vehicle 1.

[0247] It should be noted that the light-emitting device 2 according to the present invention does not include any optical cover, which typically also allows the creation of one or more light-emitting patterns.

[0248] Therefore, for example, with the light-emitting device 2 according to the invention, it is no longer necessary to use an optical cover to create the pattern to be projected onto the ground. The light-emitting device 2 uses all or at least almost all the light from the light source 4 to project the image Im. Furthermore, the light-emitting device 2 gets slightly hot because it does not block the light.

[0249] Therefore, the light-emitting device 2 according to the invention allows the image Im to be projected onto the ground, and this projection is especially synchronized with steering or maneuvering functions.

[0250] Unlike existing DMD systems, the light-emitting device 2 according to the present invention does not generate any hot spots and has higher energy efficiency in the sense that it does not need to operate at high temperatures.

[0251] Furthermore, colored luminescent patterns can be easily obtained using the luminescent device 2 according to the present invention, while existing DMD systems are typically used for black and white luminescent patterns. When used to obtain colored luminescent patterns, DMD systems become very expensive.

[0252] Unlike existing MEMS systems that use mirror systems that are easily moved by vibrations from motor vehicles, the light-emitting device 2 according to the invention is not sensitive to such vibrations.

[0253] Unlike existing microLEDs that suffer from wavelength mismatch due to significant heat loss, the light-emitting device 2 according to the present invention does not consume much energy and is more efficient.

Claims

1. A light-emitting device (2) for a motor vehicle (1), the light-emitting device being configured to project an image (Im) having at least one fixed contour illumination area (z1) onto a projection surface (3) located around the vehicle (1) or onto a surface (3) located inside the passenger compartment of the vehicle (1), the light-emitting device (2) being characterized in that the light-emitting device comprises: • At least one light source (4), said at least one light source being configured to produce a monochromatic light beam (F); • At least one optical device (14) is juxtaposed with the light source (4) such that the light beam (F) passes through the optical device (14), the optical device (14) including at least one superlens (15) configured to modify at least one characteristic of the wavefront of the light beam (F) such that the light beam (F) is oriented in the propagation direction (P).

2. The light-emitting device (2) as described in claim 1, characterized in that, The superlens (15) of the optical device (14) includes at least one nanostructure (16) configured to modify the amplitude and / or phase of a light beam (F) generated by the light source (4) and passing through the optical device, thereby affecting the orientation of the light beam (F) at the exit of the superlens (15).

3. The light-emitting device (2) as described in the preceding claim, characterized in that, The nanostructure (16) of the superlens (15) is configured to influence the orientation of the light beam (F) at the exit of the superlens (15), such that the light-emitting device (2) emits a conical light beam (F) in a projection direction that is tilted at an angle between 30° and 90° relative to the propagation direction of the light beam (F) generated by the light source (4).

4. The light-emitting device (2) as described in any of the preceding claims, characterized in that, The light-emitting device (2) further includes a liquid crystal layer (18) disposed between the at least one superlens (15) and the at least one light source (4) and configured to present at least two states (s1, s2), namely: - In the non-working state (s1), the liquid crystal layer (18) is not working in order to maintain the optical properties of the incident beam (F) and allow the at least one superlens (15) to obtain the first convergence zone (p1) of the beam (F) on the projection surface (3). - Operating state (s2), in which the liquid crystal layer (18) is operational in order to modify the optical properties of the incident beam (F) and allow the at least one superlens (15) to obtain a second convergence zone (p2) of the beam (F) on the projection surface (3).

5. The light-emitting device (2) as described in any one of the preceding claims, characterized in that, The optical properties of the incident beam (F) are phase and polarization.

6. The light-emitting device (2) as described in any of the preceding claims, characterized in that, The light-emitting device (2) includes multiple light sources (4) and multiple superlenses (15).

7. The light-emitting device (2) as described in claim 6, characterized in that, The light-emitting device (2) includes at least one component (g) consisting of three light sources (4a, 4b, 4c) arranged side by side and at least one stack (s') consisting of three superlenses (15a, 15b, 15c) arranged opposite to the component (g). Each light source (4a, 4b, 4c) is configured to emit light of a different color than the other light sources (4a, 4b, 4c) in the at least one component (g), and the three superlenses (15a, 15b, 15c) are designed to be tuned for different wavelengths (λa, λb, λc).

8. The light-emitting device (2) as described in claim 6, characterized in that, The plurality of superlenses (15) are arranged in rows and columns on the optical device (14) to form an array, and is characterized in that the plurality of light sources (4) are also arranged in rows and columns to form an array such that each beam (F) generated by one of the light sources (4) passes through the superlens (15) associated with the light source (4).

9. The light-emitting device (2) as described in claim 6 or claim 8, characterized in that, The light-emitting device (2) includes at least three components (g) consisting of light sources (4a, 4b, 4c) arranged side by side. a g b g c ) and at least three components consisting of corresponding superlenses (15a, 15b, 15c) arranged side by side (g' a , g' b , g' c ), each light source (4a, 4b, 4c) component (g a g b g c ) is configured to emit in conjunction with other components (g a g b g c Monochromatic light of different colors.

10. The light-emitting device (2) as claimed in claim 6 or claim 8, characterized in that, The light-emitting device (2) includes at least three components (g1, g2, g3) consisting of light sources (4a, 4b, 4c) arranged side by side, and at least three components (g'1, g'2, g'3) consisting of corresponding superlenses (15a, 15b, 15c) arranged side by side. Each light source (4a, 4b, 4c) in each component (g1, g2, g3) a 4 b 4 c ) is configured to emit light from other light sources (4) in the same component (g1, g2, g3). a 4 b 4 c Monochromatic light of different colors.

11. A motor vehicle, characterized in that, The motor vehicle includes a light-emitting device (2) as described in any of the preceding claims.

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