LIGHT CONNECTIBLE TO A TELECOMMUNICATIONS NETWORK

Description

[0001] The present invention relates to the field of lighting and more particularly concerns a luminaire adapted to form an optical data transmission relay in a telecommunications network such as the Internet network.

[0002] It applies particularly, but not exclusively, to a suspended ceiling lighting panel enabling wireless communication via light with a remote terminal according to a wireless communication protocol. The invention is particularly well-suited to lighting interior rooms in commercial buildings.

[0003] To illuminate a room, such as an office or hallway, it is common practice to install lighting panels, also called light panels, in a suspended ceiling fixed below the room's existing ceiling. For this purpose, the suspended ceiling typically consists of a structure with beams, often H-shaped in cross-section, arranged in a horizontal grid. Opaque panels and lighting panels are usually mounted on these beams. Each lighting panel includes, for example, a square frame mounted on the beams, within which the lighting elements are installed.

[0004] The present invention relates to a slab or such a panel adapted to transmit or receive a stream of digital data according to a wireless communication protocol of the "Li-Fi" type.

[0005] A wireless communication protocol allows multiple computer devices to be wirelessly connected within a computer network in order to enable the transmission of data between them.

[0006] A well-known wireless communication protocol from prior art is "Wi-Fi," governed by the "IEEE 802" standard for local area networks based on digital data transmission. Wi-Fi allows, in particular, the creation of a wireless local area network with a transmission rate of approximately 1 gigabit per second, over a radius of several tens of meters, using radio waves from the electromagnetic spectrum.

[0007] Another known wireless digital communication technique from the prior art is that based on "Li-Fi" technology, short for "Light-Fidelity" in Anglo-Saxon terminology, which consists of using the optical part of the electromagnetic spectrum (visible or infrared spectrum) instead of the radio waves used in Wi-Fi, to digitally broadcast multimedia content such as music or video, for example through the Internet network.

[0008] Li-Fi communication involves modulating the light intensity of a light-emitting diode (LED) source connected to the internet. An LED can switch between an "on" and "off" state up to a billion times per second, making these state changes imperceptible to the human eye.

[0009] In simplified terms, a series of on / off states of an LED creates a digital stream corresponding to the input signal received by the light fixture connected to the internet. The very high-frequency switching capability of LEDs allows them to transmit sound, images, videos, or even display the content of a web page on a digital communication terminal adapted to receive LiFi data.

[0010] The advantages of Li-Fi communication technology compared to Wi-Fi communication technology are numerous.

[0011] Among these advantages, we can mention in particular the data transmission speed of Li-Fi which is far superior to that achieved by Wi-Fi technology in that it can reach a speed of more than one gigabit per second, the fact that no radio waves, whose effects on health are still uncertain, are transmitted and finally the absence of interference between radio waves and the absence of electromagnetic jamming.

[0012] Furthermore, the Li-Fi communication protocol advantageously relieves congestion in the 2.4 Gigahertz frequency band currently used by almost all wireless communication protocols.

[0013] Furthermore, the applications of Li-Fi communication technology are numerous. For example, this technology can be used in public spaces such as streets, parks, museums, train stations, etc., as well as in private spaces such as shops and professional environments. For instance, Li-Fi technology makes it possible to simultaneously illuminate a painting in a museum and broadcast content related to that painting.

[0014] There is therefore a need to develop various form factors of luminaires that can be connected to a network using Li-Fi technology, which can meet the various applications already covered by conventional lighting devices.

[0015] Integrating Li-Fi technology into different lighting fixture form factors can be particularly complex, or even unsuitable. Indeed, integrating Li-Fi technology requires a dedicated space within the luminaire to house the Li-Fi module. This Li-Fi module typically consists of a Li-Fi transmitter and a Li-Fi receiver, forming a relatively bulky electronic component. Its integration into the lighting fixture introduces new sizing constraints.

[0016] In particular, integrating Li-Fi technology into a lighting panel is especially complex due to the panel's reduced thickness. Furthermore, lighting panels must provide homogeneous and energy-efficient light, criteria that are difficult to meet when the light source operates using Li-Fi technology.

[0017] Prior art, notably patent application FR3077619A1, already discloses a lighting panel incorporating Li-Fi technology. The panel includes, on its light-emitting front surface, facing areas that extend above the electronic components constituting the generic Li-Fi module in order to conceal them. Although the electronic components of the Li-Fi module are thus rendered invisible, the presence of the facing areas still disrupts the homogeneity of the surface illumination of the light panel. Document WO2019 / 173543 discloses a luminaire receiving, via an optical fiber, light in which visible illumination and infrared data-encoding light are mixed.

[0018] One object of the present invention is to provide a luminaire suitable for bidirectional data communication by light according to LiFi technology without the disadvantages of the prior art.

[0019] To this end, the invention relates in particular to a luminaire adapted for bidirectional data transmission by Li-Fi, the luminaire being intended to form an optical relay for bidirectional data transmission between a Li-Fi module adapted to the emission and / or reception of an infrared (IR) light beam modulated by data to be transmitted according to Li-Fi technology and a remote terminal, comprising a receptacle delimiting the external dimensions of the luminaire provided with a front wall comprising a lighting window and a light source of illumination in the visible spectrum, the luminaire defines a first optical propagation path of a visible light beam inside the receptacle between the lighting source and the lighting window,characterized in that the luminaire defines a second optical propagation path of an infrared light beam inside the receptacle to the lighting window to form a bidirectional data transmission path via Li-Fi, and in that the luminaire further comprises a spectrally selective optical component between the visible and infrared spectra, disposed at an intersection of the two optical paths, this component being configured so as to transmit the light beam propagating along one of said optical paths and to reflect the other light beam propagating along the other of said optical paths to combine the two visible and infrared light beams between the optical component and the lighting window.

[0020] Thus, because the visible and infrared light beams combine between the optical component and the illumination window, a user receives the reflected visible light beam in an area of ​​the illumination window located directly above a Li-Fi module transmitting / receiving a descending or ascending infrared signal. Therefore, they perceive no inhomogeneity in the surface illumination within the illumination window associated with this bidirectional data transmission zone.

[0021] In another embodiment of the invention, the optical component comprises an optical filter having the property of allowing a light beam in the infrared spectrum to pass through and reflecting a light beam in the visible spectrum, the optical component being in particular a dichroic plate or a dichroic mirror. The filter is, for example, a high-pass optical filter that predominantly reflects a light beam with a wavelength below a predefined cutoff wavelength and predominantly transmits a light beam with a wavelength above the cutoff wavelength. For example, the cutoff wavelength is greater than 750 nanometers, for example, approximately 780 nanometers.

[0022] In another embodiment of the invention, the optical component has an optically structured surface to disperse optical rays from the reflected light beam so as to promote the redirection of optical rays towards the lighting window.

[0023] In another embodiment of the invention, the luminaire forms an optical relay for bidirectional data transmission between a Li-Fi module adapted to the emission and / or reception of an infrared light beam modulated by data to be transmitted and a remote terminal, the luminaire delimits a location, extending inside and / or outside the receptacle configured for receiving the Li-Fi module, said location being arranged upstream of the optical component on the second optical path considering the downward direction.

[0024] In another embodiment of the invention, the luminaire includes a reflector arranged in the receptacle on the first optical path configured to reflect in the visible spectrum mainly towards the lighting window, the optical component extending into a region of the receptacle located substantially at the intersection of the two optical paths so that, in this region, the visible light beam propagating along the first optical path is reflected predominantly by the optical component and the infrared light beam propagating along the second optical path is transmitted predominantly by the optical component.

[0025] In another embodiment of the invention, the receptacle having a general panel shape, the light source is disposed inside the panel to illuminate through the panel along a slice of a peripheral wall of the panel and the reflector forms a back wall of the panel with which the optical component is coupled in the intersection region.

[0026] In another embodiment of the invention, in the intersection region, the reflector is locally provided with a recess configured to receive the optical component.

[0027] In another embodiment of the invention, the light source and the optical component are arranged on a back wall of the receptacle, the receptacle comprising an essentially reflective internal surface forming the reflector, such that the first optical path comprises a plurality of reflections on the reflective internal surface of the receptacle towards the back wall and the second optical path extends directly between the back wall and the front wall.

[0028] In another embodiment of the invention, the first optical path is indirect with a plurality of optical reflections and the second optical path is direct without optical reflection, for example by extending in a substantially straight line between a back wall and a front wall of the luminaire.

[0029] In another embodiment of the invention, the optical component is provided with a surface reflecting visible light and is arranged on a back wall opposite the front wall, so that the optical component passes through the thickness of the back wall and presents the surface on the side of an inner face of the back wall.

[0030] In another embodiment of the invention, the luminaire includes a diffuser for diffusing visible light through the lighting window, being locally perforated in an area of ​​intersection of the diffuser with the second optical path.

[0031] The invention further relates to a Li-Fi data communication system comprising a luminaire according to the invention and a Li-Fi module adapted to the emission and / or reception of an infrared light beam modulated by data to be transmitted, including a connector element for connecting the module to an external communication network, such as the Internet network, characterized in that the Li-Fi module extends upstream of the optical component along the second optical path, considering a downward direction between the Li-Fi module and a remote terminal.

[0032] Other features and advantages of the invention will become apparent from the following description, made with reference to the accompanying drawings in which: [ Fig 1 ] : there figure 1 represents a functional diagram of a Li-Fi architecture comprising a Li-Fi communication set according to the invention; [ Fig 2 ] : there figure 2 is a perspective view of a front face of a luminaire according to a first embodiment of the invention of the Li-Fi communication assembly of the figure 1 ; Fig 3 ] : there figure 3 is a perspective view from underneath the light fixture figure 2 and a Li-Fi module to form the Li-Fi communication system according to the invention; [ Fig 4 ] : there figure 4 is a perspective view and in its disassembled state of the light fixture figures 2 And 3 ; Fig 5 ] : there figure 5 is a schematic and perspective view illustrating the operating principle of a light guide for the luminaire according to the first embodiment of the invention; [ Fig 6 ] : there figure 6 is a cross-sectional view of the luminaire of the figure 1 ; Fig 7 ] : there figure 7 schematically illustrates the operating principle of an optical component of the luminaire according to the first embodiment of the invention; [ Fig 8 ] : there figure 8 schematically illustrates, on an enlarged scale, the operating principle of the optical component of the luminaire according to the first embodiment of the invention; [ Fig 9 ] : there figure 9 is a cross-sectional view of a luminaire according to a second embodiment of the invention.

[0033] We have schematically represented on la figure 1 A Li-Fi communication architecture comprising a Li-Fi communication set according to the invention for transmitting data via light to a remote terminal. This Li-Fi architecture is designated by general reference numeral 10 and the communication set is designated by general reference numeral 100.

[0034] For the purposes of this invention, the term "optical path" means the path(s) along which a light beam can propagate in an optical system between two points. The path is said to be direct when the light beam is not reflected, and indirect when the light beam undergoes one or more reflections.

[0035] The communication set 100 includes a luminaire 12 and a Li-Fi module 60 which will be described in detail later.

[0036] On la figure 1 , We have represented three luminaires 12. In the rest of the description, we will only describe one of the three luminaires.

[0037] According to the invention, the luminaire 12 is part of the wireless communication assembly 100 that can be connected to a telecommunications network 14. The telecommunications network 14 can include an Internet network, an Intranet network, an Ethernet network, or any other type of communication network.

[0038] In this example, the telecommunications network is the Internet network and the network communication protocol is the TCP / IP communication protocol.

[0039] The Internet, as is well known, is a global computer network representing the interconnection of a multitude of remote servers. The Internet can include a variety of associated services such as a web service, an email service, a peer-to-peer file-sharing service, and a videoconferencing service. Generally, these different services communicate using protocols such as TCP / IP.

[0040] Alternatively, the wireless communication system 100 can be connected to a local intranet network represented by a local server 20 on la figure 1 .

[0041] The remote terminal 16 is in the described example an electronic tablet 16A. Alternatively, the remote terminal 16 could be a mobile phone 16B, or a work computer 16C, etc.

[0042] In the example described, the communication set 100 is suitable for carrying out data communication with the remote terminal 16 at a theoretical rate greater than one gigabit per second, preferably greater than seven gigabits per second.

[0043] Generally, as illustrated very schematically in the example of la figure 1 ,Each remote terminal 16 is equipped with a LiFi key 22 (referred to in English as a "dongle"). The Li-Fi key 22 includes, in the illustrated example, a photoreceptor 22A for receiving a data signal from the luminaires 12, a unit 22B for transmitting a data signal generated from the terminal 14, and a unit 22C for processing the transmitted or received data signals.

[0044] We will now describe in more detail the wireless communication system 100 shown on la figure 3 . This set 100 includes a luminaire 12 according to a first embodiment and a Li-Fi module 60.

[0045] We have shown in detail on les figures 2 à 5 ,The luminaire 12 according to a first embodiment of the invention. This luminaire 12 comprises a receptacle 30 defining the external dimensions of the luminaire. This luminaire 12 is provided at the front with a front panel 30A comprising a lighting window 32 and a light source 34 providing illumination in the visible spectrum, housed inside the receptacle 30.

[0046] In the illustrated example, the luminaire 12 is a lighting panel, and the receptacle 30 defines the external dimensions of the luminaire 12 in a general quadrilateral shape, for example, square or rectangular. In a variant not shown, the luminaire 12 may have a different form factor than a light panel or tile, and the receptacle may have a general cylindrical, tubular, etc., shape, without departing from the scope of the invention.

[0047] In the illustrated example, panel 12 includes a front face 12A of lighting intended to be oriented towards the ground and a rear face 12B intended to be oriented towards the support to which panel 10 is intended to be fixed, for example a ceiling.

[0048] In this example, the panel 12 also includes at the rear a back wall 30B opposite the front wall 30A, which is generally either designed to extend within a false ceiling opening, to be fixed directly to the ceiling, or suspended by cables. Furthermore, the panel 10 also includes a peripheral wall or edge 30P connecting the two front walls 30A and the back wall 30B. Thus, in the illustrated example, the receptacle 30 of the panel 12 defines a generally square enclosure.

[0049] For the purposes of this invention, a panel or slab is defined as a product whose width and length are of the same order of magnitude, this order of magnitude being significantly greater than that of the height. The panel may optionally have curved, concave, or convex front and rear faces. In the illustrated example, panel 12 has a generally square shape, but of course, the panel can also be round, oval, rectangular, or polygonal.

[0050] In the illustrated example, the peripheral wall 30P of the receptacle 30 includes a peripheral frame 31 made of aluminum, for example formed by the joining of aluminum profiles.

[0051] According to the invention, the luminaire 12 defines, inside the receptacle 30 between the light source 34 and the lighting window 32, a first optical path C1 for the propagation of a beam of visible light V, emitted by the light source 34.

[0052] Visible light, for the purposes of this invention, means light with wavelengths between approximately 450 nanometers and 750 to 800 nanometers.

[0053] On la figure 2 , We can see that the front wall 30A generally delimits the lighting window 32 according to a general plate shape.

[0054] In the preferred embodiment of the invention, the first optical path C1 is an indirect or reflected optical path and includes at least one optical reflection.

[0055] Thus, preferably, the luminaire 12 includes a reflector 40 arranged in the receptacle 30 on the first optical path C1 and provided with an internal reflective surface 42 in the receptacle 30 configured to reflect in the visible spectrum predominantly towards the lighting window 34. In the illustrated example, the reflector 40 has a general plate shape and forms the back wall 30B of the panel 12.

[0056] On la figure 3 , Preferably, the light source 34 is arranged inside the panel 12 to illuminate through the panel 12 along an edge of a peripheral wall 30P of the panel 12.

[0057] Furthermore, the luminaire 12 then includes, following the first optical path C1, upstream of the reflector 40, a guide 50 to guide the light beam V emitted by the lighting source 34 along a transverse direction of the panel 12 by multiple reflections inside the guide 50 and configured to allow the exit of the light from the guide 50 towards the reflector 40.

[0058] Preferably, the guide 50 is, for example, in the form of a guide plate. Preferably, the light source 34 comprises a plurality of light-emitting diodes 38, arranged, for example, in the form of one or more LED strips 36, such as that shown in la figure 5 . The diode strip 36 can for example be placed on an edge of the peripheral edge 30P of the panel 12.

[0059] For example, the panel 12 may include a single strip 36 of light-emitting diodes 38. In this case, opposite the strip 36 of light-emitting diodes 38, a reflective strip 39S is affixed, for example, by gluing to the opposite edge 39 of the panel 12.

[0060] Optionally, panel 12 may include more than one strip of light-emitting diodes, for example two strips arranged on two opposite sides of panel 12.

[0061] Furthermore, for example, in order to allow light to exit from the guide 50, preferably, the guide plate 50 includes a whole series of light exit points 56 which are distributed on a face 50B of the guide plate 50 arranged opposite the reflector 40. This series of points has, for example, a distribution in the form of a grid formed on one of the faces of the guide plate 50, here the back face 50B.

[0062] Advantageously, the distribution of the points 56 is such that the light coming out of the optical guide plate 50 has a homogeneous intensity over the entire surface of the panel 12.

[0063] These points 56 can be formed for example by openings made in the guide plate 50 or by scratches or by any irregularities allowing an exit from the light guide 50. The light emitted along one of the edges of the guide plate 50 is guided inside the optical guide by multiple reflections and able to exit the guide plate 50 through these points 56.

[0064] This series of points 56 can for example be formed by a flexible polymer coating bonded directly to one of the faces 50B of the guide plate 56. In this case the distribution of the points 56 can be symmetrical with respect to a vertical plane comprising an axis passing through the middle of the panel 12, in order to ensure a globally homogeneous distribution of the light intensity.

[0065] For example, we can predict points that are smaller near the light source 34 and larger as we move away from it, as very schematically represented on la figure 5 . Alternatively, we can vary only the density of light output points and not the size of the points.

[0066] As can be seen from the detailed description of the luminaire 12, in this preferred embodiment of the invention, the first optical path C1 is indirect because the visible light beam V undergoes several reflections, in particular inside the guide 50 (multiple reflections on internal walls of the guide) and on the internal reflective surface 42 of the reflector 40.

[0067] Preferably, the luminaire 12 also includes a diffuser 58, for example extending substantially to the level of the lighting window 32 to provide a further improvement in the homogeneity of the lighting in visible light.

[0068] Furthermore, advantageously, this luminaire 12 forms an optical relay for bidirectional data transmission between the Li-Fi module 60 adapted for the emission and / or reception of an infrared light beam IR modulated by data to be transmitted according to Li-Fi technology and a remote terminal 16. The principle of Li-Fi technology is based in a well known way on the encoding and sending of data via the amplitude modulation of an infrared or visible light source (scintillation imperceptible to the eye), according to a well defined and standardized protocol.

[0069] For the purposes of the present invention, infrared light means light with wavelengths in the near-infrared radiation spectrum, for example from about 700 to 1000 nanometers up to 2500 nanometers.

[0070] According to the invention, this Li-Fi 60 module is adapted for the transmission and / or reception of an infrared IR light beam modulated by data to be transmitted as a downlink signal from the telecommunications network 14 to the remote terminal 16 or as an uplink signal from the remote terminal 16 to the telecommunications network 14. The infrared IR light beam comprises wavelengths greater than, for example, 850 nanometers and preferably between 850 nanometers and 950 nanometers.

[0071] In the example shown in the figure, the Li-Fi module 60 is in the form of a box 62 including a connector element 64 for connection to the telecommunications network, for example an RJ45 socket referenced 80.

[0072] This Li-Fi module 60 further includes a transmitter 68 of a data-modulated signal to be transmitted, comprising, for example, a light source emitting in the infrared spectrum. The Li-Fi module 60 also includes a receiver 66 of a data-modulated signal to be transmitted, comprising a photoreceptor 66 sensitive to infrared light.

[0073] In general, the generic Li-Fi 60 module comprises an electronic board on which several electronic components are mounted, grouped into a Li-Fi receiver module (the Li-Fi receiver 66), a Li-Fi transmitter module (the Li-Fi transmitter 68), and a data signal processing module (not shown). This processing module, in this example, handles upstream and downstream data signals according to at least one communication protocol of the telecommunications network.

[0074] For this purpose, in accordance with the invention, the luminaire 12 defines a second optical path C2 for the propagation of an infrared IR light beam inside the receptacle 30 to the lighting window 32 to form a bidirectional optical data transmission path by Li-Fi through the receptacle 30 of the luminaire 12.

[0075] Preferably, this second optical path C2 is direct, that is to say, it generally follows a trajectory in a straight line, for example extending between the back wall 30B and the front wall 30A of panel 12.

[0076] In particular, the luminaire 12 further includes a spectrally selective optical component 70 between the visible and infrared spectra, arranged at an intersection I of the two optical paths C1 and C2.

[0077] This component 70 is configured to transmit the V or IR light beam propagating along one of said optical paths respectively C1 or C2 and to reflect the other IR or V light beam propagating along the other of said optical paths respectively C2 or C1 to combine the two visible V and infrared IR light beams between the optical component 70 and the lighting window 32.

[0078] Preferably, the optical component 70 includes a high-pass optical filter configured to allow an IR light beam to pass through in the infrared spectrum and reflect a V light beam in the visible spectrum. For example, the high-pass optical filter 70 has a cutoff wavelength between approximately 770 nanometers and 800 nanometers.

[0079] Preferably, the optical component 70 is in the form of a dichroic plate or a dichroic mirror. The component 70 has, for example, an optically structured surface 72 to disperse optical rays from the reflected light beam V so as to promote the redirection of visible optical rays towards the illumination window 32.

[0080] The component 70 is preferably arranged on the back wall 30B of the luminaire 12. For example, the component 70 is arranged on the back wall 30B so that the reflective surface 72 faces an inner face of the back wall 30B. Preferably, the component 70 extends across the entire thickness of the back wall 30B so as to completely traverse its thickness. In this case, the back wall 30 is opaque to infrared and visible light, and the optical component 70 defines a region of the back wall 30B that allows infrared light to pass from outside the receptacle 30 to inside the receptacle 30.

[0081] Preferably, the Li-Fi module 60 extends upstream of the optical component 70 along the second optical path C2, considering a downward direction from the Li-Fi module 60 towards a distant terminal. For example, the Li-Fi module 60 is positioned on the back panel 30B on the side of an external face of the back panel 30B, directly above the optical component 70. In this arrangement, the Li-Fi module 60 is invisible to the user when they look towards the front panel 30A of the luminaire 12.

[0082] As an alternative not illustrated, it is possible to consider integrating the Li-Fi module 60 inside the receptacle 30, the Li-Fi module 60 then having to be arranged so that at least the socket 64 remains accessible from outside the receptacle 30.

[0083] In the first embodiment of the invention, the optical component 70 extends into a region 44 of the receptacle 30 located substantially at the intersection I of the two optical paths C1, C2. Consequently, in this region 44, the visible light beam V propagating along the first optical path C1 is predominantly reflected by the optical component 70 and the infrared light beam IR propagating along the second optical path C2 is predominantly transmitted by the optical component 70.

[0084] For example, in the intersection region 44, the reflector 40 is locally provided with a recess configured to receive the optical component 70.

[0085] Preferably, in this first preferred embodiment of the invention, the diffuser 58 is locally perforated in an area 59 where the diffuser 58 intersects with the second optical path C2. This minimizes disturbance to the infrared light beam carrying data while having no effect on the apparent homogeneity of the surface panel. The interruption of a portion of diffusion locally on the diffuser 58 is not perceptible to the naked eye under normal operating conditions of the luminaire 12. However, it is desirable to provide a transparent coating for the visible and infrared spectrum on the exterior of the diffuser 58 to make it impermeable to impurities and dust.

[0086] However, preferably, as shown on la figure 6 which illustrates a cross-sectional view of panel 12, the front wall 30A includes a transparent window in the infrared spectrum and in the visible spectrum, in order to form a closed housing that is sealed against the deposits of dirt or dust on the internal components of the luminaire 12.

[0087] We have represented on la figure 9 a luminaire according to a second embodiment of the invention. In this second embodiment, the elements analogous to the first embodiment bear identical reference numerals.

[0088] As illustrated on la figure 9 , The luminaire 12 comprises a receptacle 30 having a back wall 30B and an opposing front wall 30A as well as a peripheral wall 30P. The front wall 30A generally delimits a lighting window 32.

[0089] In particular, the receptacle 30 defines the external dimensions of the luminaire 12, which, for example, has a parallelepiped shape resembling a slab. However, the peripheral wall 30P may have an annular shape or other geometries.

[0090] For example, the dorsal wall 30B and the frontal wall 30A are connected by this peripheral wall 30P. It is therefore understood that the dorsal walls 30B and frontal walls 30A can have a general shape corresponding to the cross-section of the peripheral wall 30P along a direction transverse to this wall 30P.

[0091] In addition, in the illustrated example, the front wall 30A includes a diffuser 58.

[0092] The luminaire 12 further includes a light source 34 arranged inside the receptacle 30. The light source 34 comprises a plurality of light-emitting diodes 38, in the form, for example, of one or more strips of diodes 38.

[0093] In this second embodiment, the light source 34 is arranged on an inner face of the back wall 30B. Furthermore, in this second embodiment, at least one inner face of the receptacle 30 reflects visible light. Preferably, the receptacle 30 comprises a predominantly reflective inner surface 42 forming the reflector 40. For example, the receptacle 30 is made of a metallic material that reflects visible light.

[0094] The receptacle 30 behaves within its volume as a multidirectional reflector of the visible light emitted by the light source 34, mainly through a multidirectional diffusion phenomenon of the light emitted by the light source 34. For example, each light-emitting diode 38 may include a primary optic diffusing the light emitted by each of the diodes in a multidirectional manner, which is reflected on the internal faces of the receptacle 30.

[0095] It will be understood that, in this second embodiment, it is possible for beams of visible light to propagate in a straight line between the dorsal wall 30B and the frontal wall 30A. However, a non-negligible proportion of the visible light beams emitted by the lighting source 34 undergoes multiple reflections on the internal surface 42 of the receptacle 30 and in particular in the direction of the dorsal wall 30B.

[0096] Thus, in this second embodiment, the first optical path C1 comprises a plurality of reflections on the internal reflective surface 42 of the receptacle 30 towards the back wall 30B. The reflector 40 is thus arranged in the receptacle 30 on the first optical path C1 and is configured to reflect in the visible spectrum mainly towards the illumination window 32.

[0097] As in the first embodiment, preferably, the optical component 70 is arranged on a back wall 30B of the luminaire 12. The optical component 70 has its reflective surface 72 oriented substantially parallel to the inner face of the back wall 30B. This reflective surface 72 behaves overall as a mirror reflecting visible light. The optical component preferably extends over the entire thickness of the back wall 30B such that, in region 44, infrared light passing through the optical component 70 can pass through the back wall 30B.

[0098] Thus, in this example, the second optical path C2 extends directly in a substantially straight direction between the dorsal wall 30B and the frontal wall 30A so that the intersection of the two optical paths C1 and C2 is located at the dorsal wall 30B.

[0099] Optical component 70 extends in the example of la figure 9 in region 44 of receptacle 30 located substantially at the intersection (represented by a star) of the two optical paths C1, C2 so that, in this region 44, the visible light beam V propagating along the first optical path C1 is reflected predominantly by the optical component 70 and the infrared light beam IR propagating along the second optical path C2 is transmitted predominantly by the optical component 70.

[0100] For example, the optical component 70 is arranged on the back wall 30B in a space devoid of light-emitting diodes 38 of the light source 34.

[0101] It should be noted that although in both embodiments described the optical component 70 is arranged locally on a wall of the receptacle 30, it can extend extensively over an entire wall of the receptacle and form, for example, the entire reflector 40.

[0102] The operating principle of the communication system according to one of the two embodiments of the invention will be briefly described.

[0103] It is clear that the invention makes it possible to integrate Li-Fi technology into a light fixture without compromising the quality of the lighting homogeneity and the overall perception of the light fixture by a user.

[0104] Thus, the Li-Fi module 60, when mounted for example on the rear of the luminaire 12, for example on the back wall 30B, emits and receives an infrared light beam that can pass through the receptacle 30 at the location of the optical component 70. As the internal surface 72 of this optical component 70 reflects visible light, the user does not perceive any difference in lighting related to the presence of the Li-Fi module 60.

[0105] The invention is not limited to the embodiments described above. Other embodiments within the grasp of a person skilled in the art may also be envisaged without departing from the scope of the invention as defined by the following claims. Thus, in particular, modifying the detailed shape of the luminaire would not depart from the scope of the invention.

Claims

1. Light fixture (12) adapted for bidirectional data communication via Li-Fi, the luminaire (12) being intended to form an optical relay for bidirectional data transmission between a Li-Fi module (60) adapted to transmit and / or receive a beam of infrared (IR) light modulated by data to be transmitted using Li-Fi technology and a remote terminal (16), the luminaire comprising a receptacle (30) defining the external dimensions of the luminaire (12) provided with a front wall (30A) comprising a lighting window (32) and a lighting light source (34) in the visible spectrum, the luminaire (12) defines a first optical path (C1) for propagating a visible light beam (V) inside the receptacle (30) between the lighting source (34) and the lighting window (32), characterized in that the luminaire (12) defines a second optical path (C2) for propagating an infrared light beam (IR) inside the receptacle (30) to the lighting window (32) to form a bidirectional data communication path via Li-Fi, and in that the luminaire (12) further comprises an optical component (70) that is spectrally selective between the visible and infrared spectra, disposed at an intersection (I) of the two optical paths (C1, C2), this component (70) being configured to transmit the light beam (IR, V) propagating along one of said optical paths (C2, C1) and to reflect the other light beam (V, IR) propagating along the other of said optical paths (C1, C2) in order to combine the two light beams, visible (V) and infrared (IR), between the optical component (70) and the illumination window (32).

2. Lighting fixture (12) according to the main claim, wherein the optical component (70) comprises an optical filter having the property of transmitting a light beam (IR) in the infrared spectrum and reflecting a light beam (V) in the visible spectrum, the optical component (70) being in particular a dichroic plate or a dichroic mirror.

3. Lighting fixture (12) according to any of the preceding claims, wherein the optical component (70) has an optically structured surface (72) to scatter optical rays of the reflected light beam (V, IR) so as to promote the redirection of the optical rays toward the lighting window (34).

4. Lighting fixture (12) according to any of the preceding claims, forming an optical relay for bidirectional data transmission between a Li-Fi module (60) adapted to transmit and / or receive an infrared (IR) light beam modulated by data to be transmitted and a remote terminal (16), the luminaire (12) delimits a location, extending inside and / or outside the receptacle (30) configured for receiving the Li-Fi module (60), said location being disposed upstream of the optical component (70) on the second optical path (C2) considering the downward direction.

5. Light fixture (12) according to any of the preceding claims, wherein the optical component (70) is provided with a surface (72) reflecting visible light and is arranged on a rear wall (30B) opposite the front wall (30A), so that the optical component (70) passes through the thickness of the rear wall (30B) and has the surface (72) on the side of an inner face of the rear wall (30B).

6. A luminaire (12) according to any of the preceding claims, comprising a reflector (40) arranged in the receptacle (30) on the first optical path (C1) configured to reflect in the visible spectrum mainly in the direction of the lighting window (32), the optical component (70) extending into a region (44) of the receptacle (30) located substantially at the intersection (I) of the two optical paths (C1, C2) such that, in this region (44), the visible light beam (V) propagating along the first optical path (C1) is mainly reflected by the optical component (70) and the infrared light beam (IR) propagating along the second optical path (C2) is mainly transmitted by the optical component (70).

7. Lighting fixture (12) according to the preceding claim, wherein the receptacle (30) has a general panel shape, the light source (34) is disposed inside the panel (12) to illuminate through the panel (12) along an edge of a peripheral wall (30P) of the panel (12), and the reflector (40) forms a back wall (30B) of the panel (12) with which the optical component (70) is coupled in the intersection region (44).

8. Lighting fixture (12) according to claim 6, wherein the light source (34) and the optical component (70) are disposed on a back wall (30B) of the receptacle (30), the receptacle (30) comprising a substantially reflective inner surface (42) forming the reflector (40), such that the first optical path (C1) includes a plurality of reflections on the reflective inner surface (42) of the receptacle (30) toward the back wall (30B) and the second optical path (C2) extends directly between the back wall (30B) and the front wall (C1).

9. Lighting fixture (12) according to any of the preceding claims, wherein the first optical path (C1) is indirect with a plurality of optical reflections and the second optical path (C2) is direct without optical reflection, for example by extending substantially straight between a rear wall (30B) and a front wall (30A) of the luminaire (12).

10. Lighting fixture (12) according to any of the preceding claims, comprising a diffuser (58) for diffusing visible light through the lighting window (32), being locally perforated in an area of intersection of the diffuser (58) with the second optical path (C2).

11. Li-Fi data communication assembly (100) comprising a luminaire (12) according to any of the preceding claims and a Li-Fi module (60) adapted to transmit and / or receive a beam of infrared (IR) light modulated by data to be transmitted, comprising a connector element (64) for connecting the module to an external communication network, such as the Internet, characterized in that the Li-Fi module (60) extends upstream of the optical component (70) along the second optical path (C2) when considering a downstream direction between the Li-Fi module (60) and a remote terminal (16).