EP3948069A1

EP3948069A1 - Lighting and communication system comprising an emitter and a receiver of modulated light signals

Info

Publication number: EP3948069A1
Application number: EP20711992.6A
Authority: EP
Inventors: Jorge GARCIA-MARQUEZ; Carlos DOMINGUEZ-GONZALEZ; Juan Camilo VALENCIA-ESTRADA
Original assignee: Oledcomm SAS
Current assignee: Oledcomm SAS
Priority date: 2019-03-29
Filing date: 2020-03-24
Publication date: 2022-02-09
Also published as: CN113748296A; US20220029706A1; FR3094501B1; FR3094501A1; WO2020200929A1

Abstract

The invention relates to a lighting and communication system comprising a first optical fibre portion (31), a second optical fibre portion (32), a third optical fibre portion (33), a fourth optical fibre portion (34) and a fifth optical fibre portion (35) that are distinct, an emitter of visible light (9) being positioned at a first end of the first optical fibre portion (31), an emitter of modulated light signals (15) being positioned at a first end of the second optical fibre portion (32), a second end of the first optical fibre portion (31) and a second end of the second optical fibre portion (32) being connected to a first end of the third optical fibre portion (33), a receiver of modulated light signals (16) being positioned at a first end of the fourth optical fibre portion (34), a second end of the third optical fibre portion (33) and a second end of the fourth optical fibre portion (34) being connected to a first end of the fifth optical fibre portion (35).

Description

Lighting and communication system comprising a transmitter and a receiver of modulated light signals

The invention relates to the field of lighting and communication systems comprising a transmitter and a receiver of modulated light signals.

BACKGROUND OF THE INVENTION

There are known lighting and communication systems comprising a light-emitting diode lamp (referred to herein as an LED lamp) and implementing a so-called “VLC” (for Visible Light Communication) technology. Such a lighting and communication system makes it possible both to illuminate the environment of the LED lamp, and to emit and receive modulated light signals to enable wireless communication between the lighting system and communication device and an electronic device located near the LED lamp.

In this type of lighting and communication system, electric wires are necessary to carry to the LED lamp supply currents of the components with which the LED lamp is provided. These components include a visible light emitter (including one or more LEDs), an emitter of modulated light signals (including one or more LEDs), a receiver of modulated light signals (including for example one or more photodiodes).

However, in certain environments, these electrical wires are very problematic.

We know, for example, that certain aircraft manufacturers seek to install such lighting and communication systems in aircraft cabins, so as to enlighten passengers and create communication networks using VLC technology and integrating passenger electronic devices. These communication networks allow passengers not only to easily and conveniently access various multimedia data, but also, possibly, to access the Internet. VLC technology is particularly interesting in the environment of an aircraft cabin, because, unlike radio communication technologies, VLC technology does not generate electromagnetic interference and does not encounter any problem of availability. of the frequency spectrum.

However, any electrical equipment installed in an aircraft must comply with particularly restrictive standards in terms of emission and susceptibility to radio frequencies.

However, electric wires have a tendency to emit radiofrequencies, and to make the electrical equipment they connect susceptible to radiofrequencies. The number and length of the electric wires required to illuminate all passengers and give them access to VLC technology make it very complex to integrate a lighting and communication system into the cabin using the technology. VLC.

OBJECT OF THE INVENTION

The subject of the invention is a lighting and communication system implementing VLC technology, in which the length of the electric wires is reduced.

SUMMARY OF THE INVENTION

In order to achieve this aim, a lighting and communication system is proposed comprising a visible light emitter, a modulated light signal emitter, a modulated light signal receiver, a first portion of optical fiber. , a second portion of optical fiber, a third portion of optical fiber, a qua- third optical fiber portion and a fifth separate optical fiber portion, the visible light emitter being positioned at a first end of the first optical fiber portion, the modulated light signal emitter being positioned at a first end of the second portion of optical fiber, a second end of the first portion of optical fiber and a second end of the second portion of optical fiber being connected at a first connection zone to a first end of the third portion of optical fiber, the modulated light signal receiver being positioned at a first end of the fourth portion of optical fiber, a second end of the third portion of optical fiber and a second end of the fourth portion of optical fiber being connected at a second connection zone at a first end of the fifth portion of optical fiber, a second end of the fifth me portion of optical fiber leading to the outside to illuminate and exchange modulated light signals.

Thus, in the lighting and communication system according to the invention, the visible light is emitted via the second end of the fifth portion of optical fiber, and the modulated light signals are exchanged via the second end of the optical fiber. fifth portion of optical fiber. Now, the visible light emitter, the modulated light signal emitter and the modulated light signal receiver are separated from the second end of the fifth portion of optical fiber by a plurality of portions of optical fiber.

These five portions of optical fiber, distinct from each other, may have relatively lengths. important and replace electric wires having equivalent lengths.

The invention will be better understood in the light of the following description of particular non-limiting embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will be made to the accompanying drawings, among which:

[Fig. 1] FIG. 1 represents a lighting and communication system according to a first embodiment of the invention, arranged to illuminate a personal space of a passenger seated in an aircraft cabin;

[Fig. 2] FIG. 2 represents the lighting and communication system according to the first embodiment of the invention;

[Fig. 3] FIG. 3 is a schematic and functional view similar to that of FIG. 2, in which are shown a first dichroic filter and a second dichroic filter;

[Fig. 4] FIG. 4 represents an optical fiber assembly of the lighting and communication system according to the first embodiment of the invention;

[Fig. 5] Figure 5 is a graph showing a transmittance curve and a reflectance curve of the first dichroic filter;

[Fig. 6] Figure 6 is a graph showing a transmittance curve and a reflectance curve of the second dichroic filter;

[Fig. 7] FIG. 7 shows a telescope of the lighting and communication system according to the first embodiment of the invention; [Fig. 8] FIG. 8 represents a telescope of a lighting and communication system according to a second embodiment of the invention;

[Fig. 9] FIG. 9 represents a telescope of a lighting and communication system according to a third embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to Figures 1 to 4, the invention is here implemented in an aircraft cabin. The aircraft cabin comprises a plurality of seats 1 each intended to accommodate a passenger 2. Each passenger 2 thus has a personal space. Each passenger 2 is possibly provided with an electronic device 3, which is for example a laptop computer, a smartphone, a tablet, a connected watch, etc.

The lighting and communication system according to a first embodiment of the invention is intended to light up each passenger 2, and to implement a VLC technology to allow each passenger 2 to communicate, thanks to his electronic device 3, with a computer terminal 4 of the aircraft. Each passenger 2 can thus access various multimedia data stored in the computer terminal 4, and can also access the Internet network via the computer terminal 4.

To communicate with the computer terminal 4 of the aircraft, the electronic device 3 of the passenger 2 must be fitted with a VLC transmission and reception device. The VLC transmission and reception device is either directly integrated into the electronic device 3, or is connected to the electronic device 3. The VLC transmission and reception device is thus for example a dongle (English term , sometimes translated into French as "sentinel") connected to electronic device 3, possibly via a USB port of electronic device 3.

The lighting and communication system here comprises a centralized lighting module 6, a centralized communication module 7, and a plurality of lighting devices 8, each lighting device 8 being associated with a space. staff.

The centralized lighting module 6 comprises visible light emitters 9, each visible light emitter 9 being associated with a personal space, and control components 10. Each visible light emitter 9 comprises a first light emitting diode (LED) 11.

When it is appropriate to illuminate a personal space of a passenger 2, the piloting components 10 generate a supply current to the first LED 11 of the visible light emitter 9 associated with the personal space. - nel. The first LED 11 generates, from the supply current, a light whose spectrum is contained in the visible range.

The centralized communication module 7 comprises a modem 13, and a plurality of modulated light signal transmitters 15 and modulated light signal receivers 16, a pair formed of a modulated light signal transmitter 15 and a signal receiver. modulated light 16 being associated with a personal space of a passenger 2.

Modem 13 is electrically connected to modulated light signal transmitters 15 and to modulated light signal receivers 16.

The modem 13 is also electrically connected to the computer terminal 4 of the aircraft, for example via an Ethernet cable.

Each transmitter of modulated light signals 15 has takes a second LED 20. The second LED 20 produces a light whose spectrum is contained in the infrared range.

Each modulated light signal receiver 16 comprises a photodiode 21. The photodiode 21 is here an avalanche photodiode, sensitive to light whose spectrum is contained in the infrared range.

When a communication is established between the computer terminal 4 and a VLC transmission and reception device of a personal space, the modem 13 acquires downlink data from the computer terminal 4. The modem 13 produces a supply current to destination of the second LED 20 of the corresponding modulated light signal transmitter 15. The supply current switches the second LED 20, so as to switch a light power produced by the second LED 20 to generate downward modulated light signals intended for the VLC transmission and reception device of the personal space, said descending modulated light signals containing the descending data.

Likewise, the photodiode 21 of the corresponding modulated light signal receiver 16 receives upward modulated light signals coming from the transmission and reception device VLC of the electronic device 3 of the passenger 2 of the personal space. The photodiode 21 transforms the rising modulated light signals into electrical signals containing rising data.

The modem 13 acquires the electrical signals containing the uplink data.

The modem 13 therefore receives all of the upstream and downstream data exchanged between the computer terminal 4 and the electronic devices 3 of the passengers 2, and formats these data to make them compatible, on the one hand, with the second LEDs 20, and on the other hand, with the receivers of the computer terminal 4.

It is noted here that the centralized lighting module 6 and the centralized communication module 7 can be arranged on one or more electric boards, separate or not, positioned in the same box or in several boxes. The boxes can be close together or on the contrary far apart, and be located in the cabin or at any other place inside the aircraft.

Each lighting device 8 comprises a light diffuser 25 and an optical fiber assembly 26.

The light diffuser 25 extends above the personal space of a passenger 2 and makes it possible both to illuminate the personal space and to exchange upward and downward modulated light signals with the device. VLC transmission and reception of the electronic device 3 of the passenger 2. The light diffuser 25 thus plays both the role of a lamp lens, and the role of a rising light injector in the light. fiber optic assembly 26.

The optical fiber assembly 26 includes a first portion of optical fiber 31, a second portion of optical fiber 32, a third portion of optical fiber 33, a fourth portion of optical fiber 34 and a fifth portion of optical fiber 35. The five portions of optical fiber are distinct from each other (each portion of optical fiber is distinct from the other four portions of optical fiber).

A visible light emitter 9 is positioned at a first end of the first portion of optical fiber 31. More precisely, the first end of the first portion of optical fiber 31 and a first LED 11 extend opposite each other and are optically coupled via a lens. The first end of the first portion of optical fiber 31 will also be called “lighting end”.

A modulated light signal emitter 15 is positioned at a first end of the second portion of optical fiber 32. More specifically, the first end of the second portion of optical fiber 32 and a second LED 20 extend opposite it. from each other and are optically coupled via a lens. The first end of the second portion of optical fiber 32 will also be called “transmitting end”.

A second end of the first portion of optical fiber 31 and a second end of the second portion of optical fiber 32 are coupled and connected, at a first connection area 40, to a first end of the third portion of optical fiber. 33. The coupling is carried out according to a conventional optical fiber coupling method.

The second end of the first portion of optical fiber 31 and the second end of the second portion of optical fiber 32 therefore meet in the first connection zone 40 to open out at the first end of the third portion of optical fiber 33.

The second end of the first portion of optical fiber 31, the second end of the second portion of optical fiber 32 and the first end of the third portion of optical fiber 33 thus form a first 2x1 coupler.

A first dichroic filter 41 is integrated in the first connection zone 40. The first dichroic filter 41 is composed of a large amount of thin layers. The first dichroic filter 41 extends in a section of the second end of the second portion of optical fiber 32, slightly upstream of the contact zone between the second end of the first portion of optical fiber 31 and the second end. of the second portion of optical fiber 32. The term “upstream” is understood to mean on the side of an LED or a photodiode and not on the side of the light diffuser 25.

The transmittance curve 49 and the reflectance curve 50 of the first dichroic filter 41 are shown in Figure 5.

It can be seen that the first dichroic filter 41 lets pass the light signals whose wavelength is greater than or equal to 850nm and reflects those whose wavelength is less than or equal to 700nm.

The role of the first dichroic filter 41 is to avoid light returns in the second portion of optical fiber 32, and therefore losses on the first portion of optical fiber 31.

The first connection zone 40 is integrated in a first housing 44 of a first multiplexer.

A modulated light signal receiver 16 is positioned at a first end of the fourth portion of optical fiber 34. More precisely, the first end of the fourth portion of optical fiber 34 and a photo-diode 21 extend opposite l. from each other and are optically coupled via a lens. The first end of the fourth portion of optical fiber 34 will also be called the “receiving end”.

A second end of the third portion of optical fiber 33 and a second end of the fourth portion of optical fiber 34 are coupled and connected, at a second connection zone 51, to a first end of the fifth portion of optical fiber 35. The coupling is again carried out according to a conventional optical fiber coupling method.

The second end of the third portion of optical fiber 33 and the second end of the fourth portion of optical fiber 34 meet in the second connection zone 51 to emerge at the level of the first end of the fifth portion of optical fiber 35. .

The second end of the third portion of optical fiber 33, the second end of the fourth portion of optical fiber 34 and the first end of the fifth portion of optical fiber 35 thus form a second 2x1 coupler. A second dichroic filter 52 is integrated in the second connection zone 51. The second dichroic filter 52 is composed of a large quantity of thin layers. The second dichroic filter 52 extends in a section of the second end of the fourth portion of optical fiber 34, slightly upstream of the contact zone between the second end of the third portion of optical fiber 33 and the second end. of the fourth portion of optical fiber 34.

The transmittance curve 54 and the reflectance curve 55 of the second dichroic filter 52 are shown in Figure 6.

It can be seen that the second dichroic filter 52 lets through the light signals whose wavelength is greater than or equal to 940nm and reflects those whose wavelength is less than or equal to 850nm.

The role of the second dichroic filter 52 is to separate the different wavelengths. The second connection zone 51 is integrated in a second housing 56 of a second multiplexer.

It is noted that the diameter of each portion of fiber is irrelevant, and could for example be between 0.2mm and 3mm. The fiber portions can be made of glass or plastic or any other material.

It is noted here that the first portion of optical fiber 31, intended for lighting, is a multimode fiber, that the second portion of optical fiber 32, intended for data transmission, can also be a multimode fiber, and that the third portion of optical fiber 33 is therefore also a multimode fiber. This is also true for the fourth portion of optical fiber 34 and the fifth portion of optical fiber 35.

The communication and lighting system works, for each personal space, as follows.

A first LED 11 produces visible light 60. Visible light 60 propagates in the first portion of fiber 31, is reflected by the first dichroic filter 41, which prevents visible light 60 from propagating in the second portion of optical fiber 32. .

The second dichroic filter 52 allows visible light 60 to pass in a downward direction, which propagates in the fifth optical fiber portion 35. The second end of the fifth optical fiber portion 35 opens out to the exterior of the optical fiber. fiber optic assembly 26, in this case in the light diffuser 25. Visible light is emitted via the second end of the fifth fiber optic portion 35 and via the light diffuser 25 to illuminate the personal space of the passenger 2 .

A downward communication is also established between a transmitter of modulated light signals 15 and the dis- positive transmission and reception VLC of the electronic apparatus 3 of the passenger 2. Descending modulated light signals 61, containing descending data coming from the computer terminal 4, are emitted by a second LED 20. The light signals downlink modulated 61 have a wavelength equal to 850nm. The descending modulated light signals 61 propagate in the second portion of optical fiber 32, and are not blocked but are transmitted by the first dichroic filter 41 to propagate in the third portion of optical fiber 33 (see curve transmittance 49 and reflectance curve 50).

The descending modulated light signals 61 then propagate in the third portion of optical fiber 33. The second dichroic filter 52 does not allow the downward modulated light signals 61 to pass through the fourth portion of optical fiber 34 (see the transmit curve). tance 54 and the reflectance curve 55). The descending modulated light signals 61 therefore propagate in the fifth portion of optical fiber 35, are emitted via the second end of the fifth fiber portion 35 and via the light diffuser 25, and are transmitted to the device. transmission and reception VLC of the electronic device 3 of the passenger 2.

The electronic device 3 then acquires the downlink data.

Uplink communication is also established between the transmission and reception device VLC of the electronic device 3 of the passenger 2 and a modulated light signal receiver 16. Uplink modulated light signals 62, containing uplink data intended for the terminal computer 4, are transmitted by the transmission and reception device VLC. Modular light signals the uprights 62 have a wavelength equal to 950nm. The upward modulated light signals 62 are picked up by the light diffuser 25. The upward modulated light signals 62 propagate into the fifth optical fiber portion 35 via the second end of the fifth optical fiber portion 35. The second dichroic filter 52 allows the upward modulated light signals 62 to pass through the fourth portion of optical fiber 34. The upward modulated light signals 62 therefore propagate in transmission in the fourth portion of optical fiber 34 and are picked up by the photodiode 21 of the signal receiver. modulated lights 16.

The modem 13 of the centralized communication module 7 then acquires the upstream data and transmits them to the computer terminal 4.

With reference to FIG. 7, a telescope 70 is positioned at a second end of the fifth portion of optical fiber 35. The second end of the fifth portion of optical fiber 35 will also be referred to as “collecting end”.

By "telescope" is meant here an optical instrument which forms, from an object located on one side of the telescope and at an infinite object distance from the latter, an image of the object located on the other side. telescope and at an infinite image distance from it.

By “infinite object distance” and by “infinite image distance” is meant here very large distances with respect to the diameter of the surface of the corresponding face of the telescope, that is to say typically greater than 10 or 100 times one. larger diameter of the telescope.

The telescope 70 first of all comprises an optical concentrator 71. The concentrator 71 is here a concentrator elliptical compound.

The concentrator 71 has an axis of revolution Z. The concentrator 71 comprises a main portion 72 and a cylindrical portion 73.

The outer shape of the main portion 72 is defined by a side surface 78 which extends between an inlet face 74 and an outlet end 75.

The inlet face 74 of the concentrator 71 is also an inlet face of the telescope 70. The outlet end 75 is in the form of a disc. The inlet face 74 and the outlet end 75 extend perpendicular to the Z axis.

The area of the inlet face 74 is greater than the area of the outlet end 75.

The lateral surface 78 is defined, in a section plane passing through the Z axis, by a first arc of ellipse 76 and by a second arc of ellipse 77.

It is noted here that the concentrator 71 can be designed from any curved surface of the “unregulated” type (ie not containing a straight line). This includes all so-called free surfaces, that is to say the surfaces described by a curve at the top, by a conical constant, by non-zero strain coefficients, and finally by an angle of rotation. This angle of rotation is nothing other than the angle of rotation of the surface defined as being the starting base surface of the optical design of the concentrator 71. The base surface is for example an ellipse of revolution, or else any unregulated surface. The angle of rotation thus characterizes any compound concentrator.

It should be noted that the lateral surface 78 of the main portion 72 of the concentrator 71 of the lighting system may have one or more lateral facets of the type prismatic.

The outlet end 75 opens into the cylindrical portion 73 which has a section equal to the area of the outlet end 75. An outlet face 80 of the cylindrical portion 73 forms an outlet face 80 of the concentrate. - trator 71. The surface of the outlet face 80 of the concentrator 71 is less than the surface of the inlet face 74 of the concentrator 71 and of the telescope 70.

The entry face 74 will now be described.

It would be possible to provide that the entry face 74 has a surface defined by a Cartesian oval.

In the cylindrical frame of reference (r, Z (r)), this Cartesian oval would have the equation:

where c _a is the curvature at the top of the Cartesian oval (we also speak, in English, of vertex curvature), K _a is a conical constant, and the A _2j are _deformation coefficients. Assume that the input face 74 has a relative refractive index n and accepts light from a light source aligned on the optical axis at an object focal length t _a . The input face 74 then produces an image limited by diffraction (because the input face 74 does not introduce spherical aberration) at an image focal length t ' _a .

The parameters of the Cartesian oval equation can be calculated using the recurrent variables: m = nl, p = n + l, U = nt _a- t ' _a , and V = 2mt _a t' _a .

The curvature at the top c _a is such that:

c _a = 2U / V.

An example of a set of deformation coefficients tion A _2j is provided in Annex 1, at the end of this description.

An example of a set of characteristic polynomials P _2j , used in the definition of the deformation coefficients A _2j , is provided in Appendix 2, at the end of this description.

Here, however, as can be seen in FIG. 7, the entrance face 74 has a Fresnel surface as its surface, and therefore acts as a Fresnel lens.

The Fresnel surface is oriented outward and has a plurality of zones 81 having the shape of concentric annular sections centered on the Z axis. The concentric annular sections are defined by steps which extend outwardly from the axis. entrance face 74.

The use of the Fresnel surface makes it possible to reduce the volume of the entry face 74 of the telescope 70 (and therefore the volume and the mass of the telescope 70).

The Fresnel surface is defined by a piecewise function, each piece corresponding to an area 81 having the shape of a concentric annular section centered on the Z axis.

Each piece has an area defined by a Cartesian oval.

The Fresnel surface used here does not introduce spherical aberration, which makes it possible to perfectly concentrate the light rays incident at the level of the image focus of the Fresnel lens formed by the entry face 74. The image focus F is located at the center of the outlet end 75 of the main portion 72 of the concentrator 71.

To define the Fresnel surface, we implement a definition process comprising the following steps:

Step 1 :

We define a height h for each piece (h can vary or be constant);

2nd step :

We define the diameter d of the surface of the piece;

Step 3:

We initialize a piece counter i = 1 (each piece is associated with a distinct value of i);

Step 4:

As long as the abscissa r _s (i) £ d / 2, the definition process progresses;

Step 5:

We define the piece i using the equation:

The parameters are identical to those used earlier for the Cartesian oval, except that the object focal distance t _a and the image focal length t ' _a are compensated:

t _a = t _a- (il) h;

t ' _a = t' _a + (il) h.

We therefore obtain Z _a which depends on the following parameters:

Z _a [n, t _a- (il) h, t ' _a + (il) h, K _a , rc].

Step 6:

We calculate numerically the positive abscissa r _c [i] of the chord, which corresponds to a height h included in the interval {0, d / 2}, using the function:

FindRoot [(1-i) h + Z _a [n, t _a- (il) h, t ' _a + (il) h, K _a , r _c ] = h; Step 7:

We define, for the following piece i + 1: t _a = t _a- ih;

t'a ⁼ t ' _a + ih;

Step 8:

We define the next piece i using the previous equations while considering the offset offset (ie the translation), as well as the distances compensated to the maximum diameter.

Z _{a [} i + 1] = {-ih + Z _{a [} n, t _a- ih, t ' _a + ih, K _a , r],

(r> -d / 2 and r = -r _c [i]) or (r <d / 2 and r> = r _c [i])};

Step 9:

We then redefine the domain for the previous sector:

(r> -rc [i] and r = -r _c l [-i]) or (r <r _c [i] and r> = r _c [il]);

Step 10:

We add the song to the function:

Rule = Append [fresnel, piece_Z _a [i]];

Step 11:

The song counter is then incremented: i = i + l; Step 12:

The loop is closed, and the definition process goes back to step 4.

Step 13:

We add the last piece:

Rule = Append [fresnel, piece_Z _a [i]].

Step 14:

The correction of the riser of the Fresnel lens is then carried out. To do this, we follow the direction of the emerging rays using ray tracing.

An example of a set of parameters and of implementation of an algorithm associated with the definition method is provided in Appendix 3, at the end of this description.

The concentrator 71 and the Fresnel lens formed by the Fresnel surface of the entry face 74, therefore form a monolithic whole.

The telescope 70 further comprises a gradient index lens 83. The gradient index lens 83 is disposed coaxially with the concentrator 71 along the Z axis. The gradient index lens 83 is fabricated with a material whose refractive index changes in a radial, axial or spherical direction.

Gradient index lens 83 has a cylindrical shape with a cross section equal to that of cylindrical portion 73. Gradient index lens 83 extends from exit face 80 of concentrator 71.

Gradient index lens 83 comprises an inlet face 86 which extends opposite the outlet face 80 of concentrator 71.

The entrance face 86 of the gradient index lens 83 is positioned against the exit face 80 of the concentrator 71 and is glued to the exit face 80. The glue used has a refractive index similar to that of material used to make the concentrator 71 and the gradient index lens 83.

The telescope 70, comprising the gradient index lens 83 and the concentrator 71, thus forms a monolithic assembly.

The second end of the fifth portion of optical fiber 35 here has a section equal to that of the gradient index lens 83. The second end of the fifth portion of optical fiber 35 opens out towards the output face 87. of the telescope 70. The second end of the fifth optical fiber portion 35 is coupled with the exit face 87 of the telescope 70, which is also an exit face 87 of the gradient lens. index 83. The coupling here uses an APC connector, but another type of connector could be used. The coupling could be carried out in a different way, for example by gluing.

A ferrule 84 extends around the cylindrical portion 73, the gradient index lens 83, and a short length of the second end of the fifth optical fiber portion 35. The ferrule 84 consolidates the attachment of the lens between them. concentrator 71, the gradient index lens 83 and the second end of the fifth portion of optical fiber 35.

We now describe the operation of the telescope

70.

As can be seen in FIG. 1, the telescope 70 extends vertically in the light diffuser 25, so that the entrance face 74 of the telescope 70 opens onto the exterior of the lighting and communication system, in sight of the passenger's personal space 2.

The telescope 70 first of all has the advantages of the concentrator 71 and of the Fresnel lens formed by the Fresnel surface of the entry face 74. The telescope 70 thus makes it possible to collect incident light rays with an angle of acceptance. important. The acceptance angle is here equal to 34 °. The incident light rays entering the concentrator 71 through the entry face 74 are concentrated by reflection at the level of the internal side surface of the main portion 72 of the compound elliptical concentrator 71.

If only a conventional optical concentrator were used, the incident light rays would be focused on an edge of the exit end 75 of the main portion 72. Through the use of the concentrator 71 described. here, the incident light rays are focused on the center of the exit end 75, then redistributed in the gradient index lens 83 and throughout the section of the second end of the fifth portion of optical fiber 35.

The use of the telescope 70 therefore makes it possible to optimize the collection and concentration, in the second end of the fifth portion of optical fiber 35, of incident light rays coming from outside the light diffuser 25 and therefore, in particular. , of the passenger's personal space 2. The reception, by the lighting and communication system, of the up-modulated light signals emitted by the transmission and reception device VLC of the electronic device is therefore greatly improved. 3 of passenger 2 and intended to be received by a modulated light signal receiver 16.

Visible light and downlink modulated light signals propagate from the second end of the fifth portion of optical fiber 35 into the personal space of passenger 2 via telescope 70.

With reference to FIG. 8, a telescope 90 of a lighting and communication system according to a second embodiment of the invention again comprises an optical concentrator 91 and a gradient index lens 92. .

One entrance face of the gradient index lens

92 is glued against an exit face of optical concentrator 91. Optical concentrator 91 and gradient index lens 92 thus form a monolithic telescope 90. Note that the exit face 93 of the gradient index lens 92, which is also the exit face of the telescope 90, is flat. This makes it possible to facilitate the coupling of the second end of the fifth portion of the optical fiber 35 on the output face 93.

The input face 94 of the optical concentrator 91 of the telescope 90 has a convex surface defined by the equation:

The exit face 93 is defined by the equation:

Z _b = t = f _a +1, with f _a , l> 0.

In these equations, f _a is the image focal length of the lens formed by the convex surface of the entrance face 94, and n is the index of the material from which the optical concentrator 91 is made.

With reference to FIG. 9, a telescope 100 of a lighting and communication system according to a third embodiment of the invention is similar to that of the second embodiment, except that the surface lateral is defined, in a section plane passing through the Z axis, by a first arc of ellipse 106 and by a second arc of ellipse 107.

The internal lateral surface of the telescope makes it possible to increase the angle of acceptance. The internal lateral surface in fact completely reflects the incident light rays.

The input face 104 of the optical concentrator 101 of the telescope 100 again has a convex surface defined by the equation:

The invention is not limited to the particular embodiments which have just been described, but, on the contrary, covers any variant coming within the scope of the invention. the invention as defined by the claims.

Each lighting device, comprising a light diffuser and an optical fiber assembly, has been associated here with an emitter of modulated light signals and a receiver of modulated light signals. It is also possible to have several emitters and / or several receivers associated with a single lighting device, each emitter and each receiver being positioned at one end of an optical fiber portion of the optical fiber assembly. It is also possible to have the same transmitter and / or the same receiver connected to a plurality of lighting devices. The communication module can include one or more communication channels. Any type of network can thus be implemented using any type of connection and multiplexing configuration, and in particular MIMO (for Multiple Input Multiple Output) or MISO (for Multiple Input Single Output) type links.

It would have been possible to replace at least one of the two dichroic filters by a reflective thin layer constituted by a reflective material deposited in the corresponding connection zone.

To make the telescope, any kind of optical concentrator can be used, and in particular a compound parabolic concentrator (or CPC), a coupled concentrator comprising a first concentrator integrated into a second concentrator, a solid or hollow concentrator, a concentrator. Lens-walled type, etc.

The telescope could be a compound focal telescope, a compound afocal telescope, a monolithic focal telescope, a monolithic afocal telescope, etc.

An example of a monolithic afocal telescope is a telescope comprising a bi-elliptical and bicon- vexed. The focal plane of such a telescope is located inside the monolithic block forming the telescope.

It has been indicated that the entrance face of the gradient index lens extends opposite the exit face of the optical concentrator. Here we mean either that the gradient index lens is positioned against the exit face of the optical concentrator, as is the case in this description, or that the gradient index lens and the exit face of the optical concentrator. are separated only by an at least partially transparent element (another lens, any fixing element, etc.). This is also the case between the receiving end of the optical fiber assembly and the exit face of the gradient index lens.

It has also been indicated that the entrance face of the telescope can have a surface defined by a Cartesian oval or a Fresnel surface. It would be possible to replace this entry face by a corresponding lens, that is to say by a lens having a surface defined by a Cartesian oval or else by a Fresnel lens, and to position this lens against the face of input of the optical concentrator.

Annex 1

The strain coefficients A2 _j are for example the following:

Annex 2

The characteristic polynomials P _2j are for example the following:

Annex 3

An example of implementation of the method is as follows: ** Initial variables: **;

h = 0.3; d = 20; t _a = -1500; t ' _a = 70; n = 1.7; K _a = -0.47; fresnel = {}; r _c [0] = 0; r _c [1] = 0; i = 1; While [r _c [i] <= d / 2,

** Calculation of the maximum radius of the rope for a height h:

* *.

{r _c [i] = Replace [r with

FindRoot [(1-i) h + Z _a [n, t _a- (il) h, t ' _a + (il) h, K _a , r _c ] = h, {r, 0, d / 2}] ];

** Definition of the following piece i + 1 up to the maximum diameter. **;

** Object and image distances are compensated: **;

Z _a [i + 1] = {- ih + Z _a [n, t _a- ih, t ' _a + ih, K _a , r],

(r> -d / 2 and r = -r _c [i]) or ((r <d / 2 and r> = r _c [i]))}; ** Redefinition of the domain of the previous sector: **;

piece_Z _a [i] = {(1-i) h + Z _a [n, t _a - (il) h, t ' _a + (il) h, K _a , r _c ],

(r> - r _c [i] and r = r _c [l- i]) or ((r <r _c [i] and r> = r _c

[i -1]))};

Rule = Append [fresnel, piece_Z _a [i]];

i ++;

];

Rule = Append [fresnel, piece_Z _a [i]];

Piecewise [fresnel]

Claims

1. Lighting and communication system comprising a visible light emitter (9), an emitter of modulated light signals (15), a receiver of modulated light signals (16), a first portion of fiber separate optical fiber (31), a second optical fiber portion (32), a third optical fiber portion (33), a fourth optical fiber portion (34) and a fifth optical fiber portion (35), the visible light emitter (9) being positioned at a first end of the first portion of optical fiber (31), the emitter of modulated light signals (15) being positioned at a first end of the second portion of fiber optical fiber (32), a second end of the first optical fiber portion (31) and a second end of the second optical fiber portion (32) being connected at a first connection area (40) to a first end of the third optical fiber portion (33), the light signal receiver modu the strips (16) being positioned at a first end of the fourth optical fiber portion (34), a second end of the third optical fiber portion (33) and a second end of the fourth optical fiber portion (34) being connected at a second connection zone (51) to a first end of the fifth portion of optical fiber (35), a second end of the fifth portion of optical fiber (35) opening onto outside to illuminate and exchange modulated light signals.

2. A lighting and communication system according to claim 1, wherein the visible light emitter (9) comprises a first LED (11) producing light. a spectrum of which is contained in the visible range, the modulated light signal transmitter (15) comprises a second LED (20) producing light of which a spectrum is contained in the infrared range, and the modulated light signal receiver (16 ) comprises a photodiode (21) sensitive to light, a spectrum of which is contained in the infrared range.

3. Lighting and communication system according to one of the preceding claims, in which the first connection zone (40) comprises a first dichroic filter.

The lighting and communication system of claim 3, wherein the first dichroic filter extends into a section of the second end of the second portion of optical fiber (32).

5. Lighting and communication system according to one of the preceding claims, in which the second connection zone (51) comprises a second dichroic filter (52).

The lighting and communication system of claim 5, wherein the second dichroic filter (52) extends into a section of the second end of the third portion of optical fiber (33).

7. Lighting and communication system according to one of the preceding claims, comprising a telescope (70) positioned at a second end of the fifth portion of optical fiber (35).

8. The lighting and communication system according to claim 7, the telescope (70) comprising an optical concentrator (71) and a gradient index lens (83) positioned at the output of the optical concentrator, the second end of the lens. the fifth portion of optical fiber opens edge facing an exit face of the index gradient lens.

9. A lighting and communication system according to claim 8, a lateral surface (78) of the concentrator (71) having one or more lateral facets of the prismatic type.