Patent Publication Number: US-2022227492-A1

Title: Support for connecting a seat to a communication network

Description:
RELATED APPLICATIONS 
     This application is a § 371 application of PCT/EP2020/066037 filed Jun. 10, 2020, which claims priority from French Patent Application No. 19 06362 filed Jun. 14, 2019, each of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The invention relates to a support for reversibly equipping a seat with a connectivity system. In particular, the invention is intended for an application in the aeronautic field, to equip an aircraft. 
     BACKGROUND OF THE INVENTION 
     Conventional cabins of aircrafts, in particular those of long-haul aircrafts, are equipped with onboard entertainment systems (called IFE systems), such as screens, generally placed at the passenger seats, to offer to each passenger, a limited access to media, such as films, proposed by the airline company operating the aircraft. 
     In general, aircraft seats equipped with the onboard entertainment system integrate a video screen and an audio interface, and should consequently be connected by wiring to central processing units. Therefore, they are heavier and more complex to make than conventional seats, without onboard entertainment systems. In addition, the weight of the wiring and of the associated connectors significantly alters the mass balance of the aircraft. Finally, as technology progresses rapidly, the screens become quickly obsolete. 
     These cabins are sometimes equipped with a Wi-Fi® (acronym for Wireless Fidelity) type communication network to offer an Internet connection to the mobile electronic equipment (computer, phone, tablet, etc.) of the passengers. Yet, Wi-Fi has many drawbacks, inter alia, the use of Wi-Fi could cause interferences with other apparatuses present in the aircraft, or raise public health issues regarding risks related to a prolonged exposure to electromagnetic radiations. 
     In turn, some short-haul aircraft cabins are not provided with such onboard entertainment systems and do not necessarily provide an Internet connection. One of the main reasons relates to the impact on the mass balance of the aircraft. Another reason is that the flight is generally too short for a passenger being able for example to watch an entire film. 
     Yet, passengers are increasingly equipped with electronic equipment. There is an increasing need expressed by passengers to have the possibility to access the communication network of the aircraft and/or to the onboard entertainment system, even on short-haul flights. 
     OBJECT AND SUMMARY OF THE INVENTION 
     The present invention aims to overcome the aforementioned drawbacks. 
     In particular, the present invention aims to provide passengers with a connection to the services of the company and to the Internet without resorting to Wi-Fi and without deploying the installation of a dedicated seat. 
     To this end, the present invention proposes a support intended to be reversibly installed at an upper part of an uncovered backrest of a seat. The support comprising:
         a plate, intended to bear, totally or partially, against a rear face of the backrest,   three clamping mechanisms, each clamping mechanism comprising a bearing member and a clamping screw that are intended to cooperate with the plate so as to be able to clamp a structural framework of the backrest between said bearing member and said plate,   a data communication device according to the Li-Fi technology connected to the plate,   a connector intended for the connection of an electronic equipment, said connector being connected to the data communication device by a cable.       

     The rotation of the clamping screws in either direction allows bringing the associated clamping members of the plate close to or away from each other so as to sandwich the structural framework of the backrest, thereby clamping or releasing the support off the structural framework of the backrest. 
     Advantageously, the clamping mechanisms are arranged on the support so as to suppress all degrees of freedom between the support and the structural framework. Thus, the clamping mechanisms allow ensuring a rigid hold of the support on the backrest, without degrading it. 
     Such a support allows adding accessories to a seat, without modifying it (no screwing, no gluing on the backrest itself). Thus, the support could be installed on or removed off the seat depending on need. 
     The installation or the removal of such a support on the seat could be carried out quickly, without the need for specific tools. A screwdriver, for example, is enough. 
     The support is provided with a data communication device configured and oriented to enable a bidirectional communication with a remote communication device placed in an environment close to the seat equipped with the support. 
     Li-Fi (acronym for Light Fidelity) is a wireless communication technology based on the use of light in the visible domain (wavelength comprised between 400 nm and 780 nm) or the infrared domain (wavelength comprised between 780 nm and 2 μm) as an information vector. 
     The principle of Li-Fi is based on encoding and sending of data via an amplitude, frequency or phase modulation of a light source, according to a standardized protocol. 
     The Li-Fi technology allows getting rid of the problems of installation complexity and wiring weight, but also of the constraints related to data security, electromagnetic pollution encountered with Wi-Fi and its problems with regards to health. 
     Through this data communication device, the support provides access to an internet communication network by the Li-Fi technology. 
     The support allows connecting various types of electronic equipment, such as a screen, a tablet, a laptop. The electronic equipment connected to the support, and to the data communication device, via the connector. 
     Advantageously, the support according to the invention is standalone. No wiring is necessary. Indeed, the battery of the electronic equipment could power, alone, the data communication device. 
     Preferably, the support is intended for the aeronautic field, to equip an aircraft passenger seat, but could also be intended to any other field, such as the railway field or the automotive field, without this list being exhaustive, to equip passenger seats. 
     In particular embodiments, the invention further encompasses the following features, implemented separately or in each of their technically-feasible combinations. 
     In particular embodiments of the invention, the bearing member of at least one clamping mechanism is in the form of a longitudinal leg having, at a so-called free end, a hook-like shape. 
     Preferably, all bearing members are in the form of a longitudinal leg having a hook-like shape at a free end. 
     Such a hook-like shape is advantageous, when the structural framework is in the form of a peripheral frame in the form of a tube. In this configuration, the hook cooperates with the tube, by fitting around said tube, thereby improving the blockage of the support on the backrest. 
     In particular embodiments of the invention, the plate comprises an opening intended for the reception of the electronic equipment. 
     In some embodiments, the plate comprises elements for reversible holding of the electronic equipment in the opening of the plate. 
     In particular embodiments of the invention, the support comprises, within a thickness of the plate, a chimney extending from the opening towards a periphery of the plate. Advantageously, such a chimney allows ensuring the circulation of air and an evacuation of hot air out of the support, when a piece of equipment is placed in the opening of the plate. 
     In particular embodiments of the invention, the communication device comprises an emitter and a receiver disposed in a protective case, the protective case comprising a glazed portion opposite the emitter and the receiver. Such a glazed portion does not hinder the transmission/reception of the optical signals originating from the data communication device or from the remote communication device. 
     In some embodiments, the protective case is secured to the plate by a ball joint connection. 
     By “secured”, when referring to parts with respect to each other in a manner conventional per se, it should be understood that said parts are mutually linked, a relative movement between these could nonetheless be possible. 
     In the present description, by convention, by “secured”, reference is made to parts being linked to each other by a connection enabling a relative movement of one part relative to another. By “fixedly secured”, reference is made to parts that are mutually linked in a fixed manner, i.e. so that a relative movement between these is impossible. 
     Advantageously, the ball joint connection allows orienting the protective case so as to align the data communication device of the support with the remote communication device. 
     In particular embodiments of the invention, the support comprises a casing for receiving the protective case, said casing being fixedly secured to the plate. Advantageously, such a casing allows protecting the positioning of the protective case to hold its orientation. 
     In particular embodiments of the invention, the support comprises two reversible fastening elements, each fastening element linking a lower part of the plate to the free end of a longitudinal leg. 
     The invention also relates to a seat comprising a backrest equipped with a support as defined hereinabove in one of its embodiments. The seat further comprises a padding block and a slipcover covering the padding block and the support. The slipcover comprises a glazed area, preferably arranged opposite the glazed portion of the protective case in order not to hinder the transmission/reception of the optical signals originating from the data communication device or from the remote communication device. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention will be better understood upon reading the following description, provided as a non-limiting example, and made with reference to the following figures: 
         FIG. 1  represents three seats disposed behind each other, the seat the farthest to the right comprising an example of the support according to the invention, the seat the farthest to the left is a standard seat before installation of a support according to the invention, and the seat at the middle is an uncovered standard seat with its structure exposed and ready to receive a support according to the invention; 
         FIG. 2  represents an exploded view of the constitutive elements of an example of a support according to the invention; 
         FIG. 3  represents an exploded front perspective view of a plate and of the clamping mechanisms of an example of a support according to the invention; 
         FIG. 4  represents a photograph of the plate and of the clamping mechanisms of the support of  FIG. 3  installed on an upper part of an uncovered seat; 
         FIG. 5  represents, a rear perspective view of a plate and of the clamping mechanisms of an example of the support according to the invention; 
         FIG. 6  represents a photograph of the plate and of the clamping mechanisms of the support of  FIG. 5  installed on an upper part of an uncovered seat; 
         FIG. 7  represents, a (partial) exploded front perspective view of an example of the support according to the invention; 
         FIG. 8  represents a front view of an example of the support installed on an upper part of an uncovered seat; 
         FIG. 9  represents, a rear perspective view of an example of the support installed on an upper part of an uncovered seat, which support is equipped with a tablet; 
         FIG. 10  represents a perspective detail view of an example of a communication device placed in a casing of the support. 
     
    
    
     In these figures, reference numerals that are identical from one figure to another designate identical or similar elements. Moreover, for clarity purposes, the drawings are not to scale, unless stated otherwise. 
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     A support  10 , as illustrated in  FIGS. 1 to 10 , is intended to be reversibly installed on a seat  50 . Such a support  10  allows equipping a seat with a connectivity system allowing access to entertainment data and/or internet data. 
     In general, the support  10  could equip seats of any means of transport, in particular those of the aeronautic, railroad and automotive industries, without this restricting the invention. Thus, it is also possible to equip seats installed in public places with the support. 
     The invention is described in the particular context of one of its preferred fields of application wherein the support is intended to be installed on a seat disposed in a passenger cabin of an airliner. However, nothing precludes from disposing the support on a passenger seat of any other type of aircraft, whether civilian or military. 
       FIG. 1  illustrates three passenger seats  50  of an aircraft, of the economy class type, disposed behind each other. 
     Conventionally, a seat  50  comprises a sitting portion  51  and a backrest  52 . Preferably, the backrest  52  is linked to the sitting portion  51 . Preferably, the backrest  52  comprises a structural framework  55  that is covered with a padding block and with a slipcover to comfortably receive the back of the passenger. 
     The backrest  52  of the seat located the farthest to the left in  FIG. 1  comprises the padding block and the slipcover. In turn, the backrest  52  of the seat located at the centre of  FIG. 1  is uncovered. 
     In the following description, by uncovered backrest, it should be understood a backrest from which the padding block and the slipcover have been removed. 
     The backrest  52  of the seat  50  located the farthest to the right in  FIG. 1  is equipped with the removable support  10 , and covered with suitable padding block  60  and slipcover  70 , as it will be explained later on. 
     The seat  50  may comprise armrests  53 , as illustrated in a non-limiting manner in  FIG. 1 . 
     The backrest  52  of the seat comprises a front face  521  intended to lie on the side of the passenger sitting on the seat and a rear face  522  intended to be opposite the passenger located on the rear seat. A trim shell  54 , generally made of plastic, of the seat  50  could be disposed at the rear face  522  of the backrest  52 , against the structural framework  55 . Such a trim shell  54  could support a storage space or a cup-holder. 
     In the non-limiting example of  FIG. 4 , the structural framework  55  is in the form of a peripheral frame. The peripheral frame comprises two lateral portions  551 , defining lateral edges of the backrest  52  and an upper portion  552 , defining an upper part  523  of the backrest  52 . 
     For example, the peripheral frame is formed by a bent tube with a square section. 
     The support  10  is intended to be reversibly installed on the upper part  523  of the backrest  52  uncovered beforehand. 
     The support  10  as described advantageously allows equipping a seat  50  enabling the passenger located behind said seat to have access to entertainment data and/or internet data. Thus, as illustrated in  FIG. 1 , the support  10  placed on the seat the farthest to the right in  FIG. 1  allows the passenger sitting on the seat located at the center in  FIG. 1  to access the entertainment data and/or internet data. 
     The support  10  is intended and adapted to communicate with electronic equipment  90 . For example, a piece of electronic equipment  90  may be a laptop, or any other electronic apparatus, such as a tablet or a mobile phone. The electronic equipment may be an apparatus proposed by the airline company operating the aircraft or else be an apparatus belonging to the passenger. The support  10  primarily comprises a plate  11 . Said plate is intended to bear, totally or partially, against the rear face  522  of the uncovered backrest  52 . Said plate bears at least at the upper part  523  of the backrest, as illustrated in  FIGS. 4, 6 to 8 . 
     In the non-limiting example of these figures, said plate extends beyond the upper part  523  of the backrest. The plate  11  lies in the continuation of the rear face  522  of the backrest  52 . 
     In the non-limiting example, the plate  11  bears against the plastic shell  54  of the backrest  52 . Thus, the plastic shell is interposed between the plate  11  and the structural framework  55  of the backrest. 
     The plate  11  comprises a front face  111  and a rear face  112 . The front face  111  of the plate  11  bears against the rear face  522  of the backrest  52 . 
     The plate  11  is shaped so as to match with the shape of the rear face  522  of the backrest  52 , at its upper part  523 . The plate  11  is also shaped so as to have a shape substantially equivalent to the shape of the upper part  523  of the backrest, to preserve a visual harmony in the cabin, once the seat is covered again. 
     The support  10  further comprises at least three clamping mechanisms  12 . 
     Advantageously, each clamping mechanism  12  is intended to cooperate with the plate  11  to clamp the structural framework  55  of the backrest  52  to hold the support  10  on the backrest  52  fixedly and rigidly, yet not permanently. 
     Preferably, the clamping mechanisms  12  are arranged on the support  10  so that, when said support is fastened to the structural framework  55  of the backrest, all degrees of freedom (rotations, translations) between the support  11  and the structural framework  55  are suppressed. Thus, such clamping mechanisms  12  advantageously allow ensuring a tight hold of the support  11  on the backrest  52  of the seat. 
     In the example illustrated in  FIGS. 2-5, 7 and 8 , the support  10  comprises four clamping mechanisms  12 :
         two clamping mechanisms  12  configured so as to bear against the upper portion  552  of the peripheral frame belonging to the structural framework  55 ,   two clamping mechanisms each configured so as to bear against a lateral portion  551  of the peripheral frame belonging to the structural framework  55 .       

     Although the clamping mechanisms  12  are illustrated in the figures and described four in number, the number of these clamping mechanisms is not limited to that described and illustrated. Thus, without departing from the scope of the invention, it is possible to make a support with three, five clamping mechanisms or more. 
     Thus, it is possible to consider that the support  10  comprises only one suitably-sized clamping mechanism  12 , disposed so as to bear against the upper portion  552  of the peripheral frame, instead of the two illustrated in the figures. 
     As illustrated in  FIGS. 2-5, 7 and 8 , a clamping mechanism  12  preferably comprises a bearing member  121  and a clamping screw  124  intended to cooperate with the plate  11  to clamp the structural framework  55  of the backrest  52  between said bearing member and said plate. 
     The rotation of the clamping screw  124  of a clamping mechanism  12  in one direction advantageously allows brining the bearing member  121  close to the plate  11 . The rotation of the clamping screw  124  in the other direction allows bringing the bearing member  121  away from the plate  11 . 
     Thus, when the support  10  is disposed at the upper part  523  of the backrest  52 , the rotation of the clamping screw  124  of a clamping mechanism  12  in one direction allows bringing the bearing member  121  close to the plate  11  so as to sandwich the structural framework  55  of the backrest, thereby clamping the support  10  to the structural framework. The rotation of the clamping screw  12  in the other direction allows bringing the bearing member  121  away from the plate  11  so as to release said support off the structural framework  55  of the backrest, to remove it. 
     In another embodiment, when the support  10  is disposed at the upper part  523  of the backrest  52 , the clamping screw  124  is screwed until abutment. Holding of the plate  11  on the structural framework  55  of the backrest is ensured by the elasticity of the bearing member  121  of the clamping mechanism  12 , while avoiding any clamping error. 
     In one embodiment, illustrated in  FIGS. 2 to 4 , a bearing member  121  may be in the form of a longitudinal leg. The longitudinal leg comprises a first end  122  linked to the plate  11 . The first end  122  comprises a threaded hole  125 . Preferably, the plate comprises a hole for the passage of the screw, for example a counterbore-type one, opposite the threaded hole of the longitudinal leg. The longitudinal leg is fastened to the plate  11  by setting up the clamping screw  124  into the passage hole of the plate  11  and then by screwing the clamping screw in the threaded hole of the longitudinal leg. 
     The longitudinal leg comprises a second end  123 , called free end, intended to come into contact with the structural framework  55 . 
     In an embodiment of the longitudinal leg, in the case where the structural framework  55  is in the form of a tubular peripheral frame, the free end  123  of the longitudinal leg has a hook-like shape  126  with a shape complementary to the section of the tubular peripheral frame such that, when the rotation of the clamping screw  124  brings the longitudinal leg close to the plate  11 , the hook  126  cooperates with said tubular peripheral frame, while fitting around said peripheral frame, thereby improving the blockage of the rotation and translation of the support  10  on the structural framework  55 . 
     Advantageously, a support  10  with such clamping mechanisms  12  enables an installation of said support on the backrest  52  without deteriorating it. No fastening by screwing or gluing on the backrest itself is necessary. The support  10  could be removed easily also without degradation, by simple release of the clamping screws  124  of the clamping mechanisms  12 . Thus, the structure of the seat  50  is preserved. No modification of the seat is necessary. Consequently, there is thus no need for certifying a new seat. 
     The support  10  further comprises a connector  13  to connect a piece of electronic equipment  90  thereto. 
     For example, yet without limitation, the connector  13  may be a USB (acronym for Universal Serial Bus) connector. It is clear that any other connector type could be used, for example a type-C USB connector, an RJ 45 connector. 
     Preferably, the connector  13  is accessible from the rear face  112  of the plate  11 . 
     The support  10  further comprises a data communication device according to the Li-Fi technology, called communication device  14 , as illustrated in  FIGS. 2, 7 and 10 . 
     The communication device  14  of the support is configured to be connected to a piece of electronic equipment  90 , as it will be explained later on. 
     The communication device  14  of the support is intended to be associated to an adequate communication device disposed in the aircraft, called remote communication device (not represented in the figures). In particular, the remote communication device is connected with central processing units of the onboard multimedia systems (IFE). Preferably, the remote communication device is disposed in a ceiling of the aircraft. 
     Advantageously, the communication device  14  of the support and the remote communication device enable the establishment of a bidirectional data communication, i.e.:
         in the so-called downlink communication direction, a transmission of the entertainment data and/or of the internet data towards the equipment,   in the so-called uplink communication direction, a transmission of the entertainment data and/or of the internet data from the equipment.       

     In a manner known per se, the communication device  14  of the support comprises an emitter  141  and a receiver  142 . Said emitter is configured to emit a specific signal to a receiver disposed in the remote communication device. The receiver  142  of said communication device  14  of the support is configured to receive a specific signal originating from an emitter disposed in the remote communication device. 
     More specifically, the communication device comprises, as an emitter  14 , a light source adapted to emit, preferably in the infrared domain, a Li-Fi type modulated optical signal, called first signal. 
     In a non-limiting embodiment, this modulation of the optical signal is obtained by controlling the intensity of the light source in a variable manner at a very high frequency. 
     For example, the light source is a light-emitting diode (LED) or a laser. 
     The communication device comprises, as a receiver  142 , a module for acquiring a Li-Fi type modulated optical signal, called second signal, originating from the emitter of the remote communication device. 
     Said acquisition module of the communication device  14  of the support is adapted to detect the variations of intensity of the second signal. The acquisition module converts the data on the variations of intensity of the optical signal into a digital signal for the equipment. 
     In one embodiment, the acquisition module is a photodiode. 
     Preferably, the emitter  141  and the receiver  142  of the communication device  14  of the support are disposed in a protective case  143 . Preferably, said protective case comprises a transparent glazed portion  144 , opposite the emitter  141  and the receiver  142 , in order not to hinder the transmission/reception of the first and second signals. 
     Preferably, the protective case  143  is secured to the front face  111  of the plate  11 . 
     In a preferred embodiment, the protective case  143  is secured to the front face  111  of the plate  11  by a ball joint connection  145 . It should be recalled that a ball-joint connection links the plate  11  and the protective case  143  in translation but leaves them free in rotation. Such a ball-joint connection allows setting the orientation of the protective case  143 , and therefore of the communication device  14  of the support, with respect to the remote communication device depending on its location. The protective case  143  is oriented so that the transmission/reception of the first and second signals between the two communication devices could be achieved. 
     In one embodiment, to adapt to the luminous flux of the remote communication device, the communication device may comprise at least one lens arranged on an optical axis of its emitter  141 , and at least one lens arranged on an optical axis of its receiver  142 . For example, these lenses are installed instead of the glazed portion  144  of the communication device  14 . These lenses could also be installed, in the communication device, between the emitter and/or the receiver and the glazed portion, and in cooperation with said glazed portion  144 . 
     Preferably, the protective case  143  is disposed in a casing  15  fixedly secured to the front face  111  of the plate  11 . 
     Preferably, the casing  15  defines a hollow volume configured to receive the case of the communication device. 
     Advantageously, such a casing  15  allows protecting the protective case  143  and therefore holding the positioning imparted to the protective case. It allows avoiding a disruption of the orientation of the protective case. 
     In a preferred example, illustrated in  FIGS. 7 to 9 , in order to limit the bulk of the support  10  in thickness, the casing  15  is disposed above the upper part  523  of the backrest  52  of the seat. 
     Preferably, the casing  15  comprises at least one opening  151 , whether glazed or not, opposite the transparent glazed portion  144  of the protective case  143 , in order not to hinder the transmission/reception of the first and second signals between the two communication devices. 
     Said opening of the casing  15  is disposed opposite the remote communication device. In the example where the remote communication device is arranged in the floor of the aircraft, said opening faces the floor, on an upper part of the casing, as illustrated in  FIGS. 7 to 10 . 
     The casing  15  may be made integral with the plate  11  or be a part attached and fixedly secured on the plate  11 , for example by means of screws. 
     In a preferred embodiment, and as illustrated in  FIGS. 7 to 9 , the support  10  comprises two casings  15 , disposed symmetrically on the plate  11 , disposed above the upper part  523  of the backrest  52  of the seat. The two casings  15  have an external shape with a curvature substantially similar to the curvature of a portion of an upper part of the plate. 
     In such a configuration, the support  10  comprises one single communication device  14 , which will be disposed in one amongst the two casings. In this configuration, for the casing that does not receive the communication device  14 , a closure plate  152  is disposed so as to cover the opening  151  of said casing, as illustrated in  FIG. 2 . 
     The choice of the positioning of the communication device  14  of the support in either one of the casings  15  depends on the positioning of the remote communication device. Thus, for illustration, when the remote communication device is disposed in the ceiling of the aircraft, at the aisle, the seats disposed on the side of the left wing of the aircraft comprise a support  10  with a communication device  14  preferably disposed in the right-side casing  15  of the support (i.e. the casing located on the aisle side). The seats disposed on the side of the right wing of the aircraft comprise a support  10  with a communication device  14  preferably disposed in the left-side casing of said support (i.e., the casing located on the aisle side). 
     It could also be considered to equip the support  10  with a communication device  14  in each casing  15 . In this case, only one communication device  14  will be connected to the connector  13 . 
     In another embodiment, the support  10  may comprise one single casing  15 , disposed above the upper part  523  of the backrest  52  and which has an external shape with a curvature substantially similar to the curvature of an upper part of the plate  11 . 
     Advantageously, the communication device  14  is connected to the connector  13  via a cable  16 . In the illustrated example, the cable  16  runs along the structural framework  55  of the backrest. When the backrest will be covered again, the cable will be invisible. In another embodiment, the cable  16  may have a visible portion protruding out of the rear face  112  of the plate  11  and of the support  10 , and terminating, at one end, called first end, by the connector  13 . 
     Preferably, the cable  13  is connected to the protective case  143  by complementary connection means  17 , such as a USB port on the protective case  14  and a USB connector to a second end of the cable  16 , or vice versa. Of course, the invention is not limited to USB connection means but could comprise other complementary connection means without departing from the scope of the invention. 
     In one embodiment, the plate  11  of the support  10  comprises, at its rear face  112 , an opening  113  configured to receive a tablet  90 , or a screen, distributed by the airline company. Said opening has a dimension adapted to said tablet. 
     In the embodiment described in  FIGS. 2, 3, 5 to 7 and 9 , said opening for receiving the tablet is a through opening, i.e., the opening is formed across the thickness of the plate  11 . Such a through opening configuration has the advantage of reducing the weight of the support. 
     The plate  11  of the support  10  may comprise elements  114  for reversible holding of the tablet in the opening  113  of the plate  11 . The tablet may comprise holding elements complementary to the holding elements  114  of the plate. 
     In a non-limiting example of the invention, the holding elements  114  are magnets. 
     Advantageously, the tablet  90  comprises connection means complementary to the connector  13  of the support  10 . 
     In one embodiment, to add in holding of the support  10  on the backrest  52 , complementary to the clamping mechanisms  12 , the support  10  comprises two reversible fastening elements  18 , each fastening element linking a lower part of the plate  11  to the free end  123  of a leg bearing on a lateral portion  551  of the peripheral frame. Such fastening elements allow ensuring that the lower part of the plate  11  remains well pressed against the backrest  52 , and does not separate, in particular due to the vibrations in the aircraft. In one embodiment, the fastening elements are flexible fastening elements such as textile straps with loops and hooks (straps of the Velcro® type), which fit to the complex geometry and to the variations of thickness of the uncovered backrest. 
     In one embodiment, when the plate  11  of the support  10  comprises an opening  113  for a tablet  90 , the support  10  comprises, within the thickness of the plate  11 , at least one chimney  19  extending from said opening towards a periphery of the plate, preferably towards the upper part of the plate  11 , as illustrated in  FIGS. 3 and 4 . The at least one chimney  19  allows ensuring the circulation of air and an evacuation of the hot air out of the support  10 . 
     To advantageously reduce the weight of the support  10 , the plate and the casings are perforated for example, as illustrated in  FIGS. 2 to 10 . 
     Preferably, the plate  11 , the casings  15  and the clamping mechanisms  12  of the support  10  are made of an aluminum material. Of course, the invention is not limited to the aluminum material but could also be carried out in other materials, such as a composite material. 
     Once the support  10  is set in place on the backrest  52 , the backrest is covered again. 
     An elastically-compressible foam-based padding block  60 , for example made of polyurethane, is placed at the front face  521  of the backrest  52 , said padding block over-molding the structural framework  55  and the support  10  at its front face. 
     Afterwards, a slipcover  70 , with a suitable dimension, advantageously covers the padding block  60  and the support  10  and is fastened, in a conventional manner, on the backrest  52 , like existing slipcovers, for example via textile straps with loops and hooks (such as Velcro® straps). 
     Advantageously, the slipcover  70  entirely covers the support  10 , which becomes invisible to the passengers. 
     In the embodiment where the plate  11  of the support  10  comprises an opening  151  for receiving the tablet  90 , the slipcover  70  partially covers the support  10 , leaving only said opening apparent. 
     Preferably, the slipcover is made of a mesh fabric, in particular to enable the evacuation of hot air originating from the tablet  90 , when it is installed in the opening  113  of the plate  11  of the support  10 , and flowing in at least one chimney  19 . 
     Preferably, the slipcover  70  comprises a glazed area (not represented in the figures), opposite the transparent glazed portion  144  of the protective case  14  and the opening  151 , whether glazed or not, of the casing  15 , in order not to hinder the transmission/reception of the first and second signals between the two communication devices. 
     The installation of the slipcover of the seat ensures a long-lasting use of the support. It reduces the risk of deterioration, vandalism, theft, and ensures a visual harmony compliant with current seats that are not equipped with a screen or with seats originally equipped with a screen. 
     The seat located to the right in  FIG. 1  comprises the support  10  installed on the upper part of the backrest. There are also represented the adapted padding block  60  and slipcover  70  (shown by a dotted line). For comparison, there is also represented the padding block and the slipcover of the backrest, when the support is not installed. 
     In this figure, it is clearly shown that the support  10  forms a continuation of the upper part  523  of the backrest  52  of the seat. 
     The support has many advantages, described hereinafter in a non-exhaustive manner. 
     When installed on the seat, the support has a reduced bulk, in terms of height (in order not to hide the instructions), of width (substantially the same width as the width of the seat) and of depth (in order not to hinder the passage, in particular for safety reasons in case of evacuation). 
     When installed on the seat, in addition to offering access to entertainment data and/or Internet data to the passenger located behind the seat, the support creates a headrest for the person sitting on the seat. 
     The support advantageously allows the passengers to have access to entertainment data and/or Internet data, with their personal electronic equipment, in a determined privileged space, around his/her seat, via the Li-Fi technology. By privileged space, it should be understood a unique and personal connection space enabling a passenger to receive and/or send data internal and/or external to the aircraft in a secure and customised manner in a predetermined physical location, in this instance his/her seat. The passenger enjoys a unique and personal connection space to receive and transmit data in a confidential manner. 
     The support allows equipping a conventional seat that is not provided with an onboard entertainment system IFE, or equipping a seat provided with an onboard entertainment system with an obsolete screen, and also allows connecting the personal equipment of the passengers. 
     Equipping a seat with such a support may have be economically interesting for the company operating the aircraft rather than replacing all seats equipped with an obsolete screen with new seats equipped with a new-generation screen. 
     Mounting the support on the seat by means of a simple clamping does not deteriorate the seat. Thus, the support can be removed depending on the needs of operation of the aircraft to return to the original configuration, or to future evolutions. 
     The installation of the support by means of the setting mechanisms is quick and could adapt to different types and sizes of seats.