FR3074992A1 - MULTI-PARTICIPATING VIDEO BROADCASTING SYSTEM - Google Patents

Abstract

A device for transferring (100,200,300,400) audio-visual signals, comprising a first input video connector (101,201,301,401) and an output video connector (103,203,303,403), each video connector including a pin power supply (Bal, Ba2, Ba3), a control pin (Bc1, Bc2, Bc3), a first set of pins (Bil, Bi2, Bi3) able to carry information (EDID) representative of the signal restitution characteristics audio-visual, and a second set of pins (Btl, Bt2, Bt3) adapted to carry audio-visual signals, the transfer device (100,200,300,400) being arranged to detect a voltage level (Uc) on the control pin ( Bc1) of the first video connector (101, 201, 301, 401), and if the detected voltage level (Uc) belongs to a range of predefined values, applying a predefined power supply signal to the power pin ( Bal) of the first connector video (101, 201, 301, 401).

Description

MULTI-PARTICIPANT VIDEO BROADCASTING SYSTEM

The invention relates to audio-visual sharing systems between several participants of documents on a display device such as a video projector, in particular for meeting rooms.

Nowadays, in meeting rooms, there are multiple solutions that allow each participant to share a document on a display device in the room.

A basic and common solution consists in "doing without" from one speaker to another a single cable connected to the video projector.

Other systems such as that of the company Kramer are also available. They use two types of cables. A first cable is a “twisted pair” type cable for the transport of audio-visual signals and a second cable is a two-wire cable forming a proprietary bus. This second cable makes it possible to convey a control signal activating the connection with the video projector of a chosen video transmitter, which is designated by an address transmitted in this control signal. This activation of a designated transmitter can be done by a user pressing a button located on their respective transmitter in the event that such a user wants to take control, or by selecting an associated button on a central control panel.

We also know the Extron TeamWork ® system, which also uses specific cables, derived from HDMI cables, as well as an HDMI hub to which all participants are connected in a star connection.

Other solutions, using Ethernet type cables, carry the audio-visual signals and the control signals necessary for managing the sharing of the display device and the display parameters over a limited number of wires, which poses a problem for the high speed transmission of video signals and for regular transmission of display parameters, in particular to information of the “EDID” type (from the English Extended Display Identification Data).

These different devices nevertheless form as many networks which are complex to install in meeting rooms and complex to implement in practice.

In addition, the length of the cables is limited, as well as the number of participants who can connect simultaneously to the visual sharing system.

This limitation of the systems of the prior art is due to the characteristics of the audio-visual signals to be transported and to the constraints of electrical supply of a large number of participants, and therefore of connected devices.

Indeed, a power source supplying a voltage of typical value for a system of the prior art, must deliver large currents via conventional cables to supply the electric power necessary for a large number of devices. These high-intensity electric currents can cause problems with disturbance of audio-visual signals, as well as problems of conformity to EMC type certifications.

In addition, to allow easy installation of a large number of participants in the meeting rooms, the lengths of the cables must be greater than the typical lengths of these cables, which is not compatible with the high frequencies of audio signals. visual and control carried by these cables, in conventional operation.

There is therefore a need for an audiovisual document sharing system on a display device, which system is easier to install and implement, and which makes it possible to achieve longer cable lengths.

important as well It is notably that a high number of participants. the invention aims to at this need than respond with devices of signal transfer audio-visual and at a system of audio-visual sharing

comprising such devices.

A first object of the invention is an audio-visual signal transfer device, comprising a first video input connector and a video output connector, each video connector comprising

- a power supply pin,

- a control pin,

a first set of pins capable of transporting information representative of the characteristics of reproduction of the audio-visual signals, and

a second set of pins capable of transporting audio-visual signals, the transfer device being arranged for

- detect a voltage level on the control pin of the first video connector, and

- if the detected voltage level belongs to a range of predefined values,

- apply a predefined power supply signal to the power pin of the first video connector.

According to the embodiments, the audio-visual signal transfer device can comprise one or more of the following characteristics which can be used separately or in partial combination with one another or in total combination with one another:

- The first and second sets of pins of the first video connector are electrically connected to the corresponding pins of the output video connector.

- the video input and output connectors are HDMI type connectors, the power pin being pin 18, the control pin being pin 14 of HEC type, the first set of pins being pins 15 and 16 SCL, SDA type, the second set of pins being pins 1 to 12 of TMDS type.

In a preferred embodiment, the transfer device further comprises

- a second video input connector,

- an integrated circuit and a memory,

the first set of pins of the video output connector being electrically connected to first input / output ports of the integrated circuit, so as to allow it, when an audio-visual processing equipment is connected to the transfer device, to receive information representative of the characteristics of reproduction of audiovisual signals, and store this information in the memory,

- an input port to detect a routing request signal,

a third set of pins suitable for transporting bidirectional communication signals, and electrical links respectively connecting the third set of pins of the first video connector and of the output video connector, to a bidirectional communication port of the integrated circuit,

- an audio-visual signal reconstruction module, and

- a switching module, configured to connect electrically, according to configuration information

the first set of pins of the first video connector to the memory and the second set of pins of the first video connector to the reconstruction module;

or

the first set of pins of the second video connector to the memory and the second set of pins of the second video connector to the reconstruction module;

the reconstitution module being configured to reconstruct the audio-visual signals received from the second set of pins of the first or second video connector and to transmit the reconstructed audiovisual signals on the second set of pins of the output video connector.

Such a transfer device will be named in the remainder of this document “routing device”.

According to the embodiments,

- the routing device is further configured to transmit information at a reduced rate

- from the first set of pins of the output video connector to the memory; and

- From memory to the first video connector, when the switching module electrically connects the first set of pins of the first video connector to the memory.

the video input and output connectors of the routing device are HDMI type connectors, the power pin being pin 18, the control pin being pin B14 of type HEC, the first set of pins being pins 15 and 16 of type SCL, SDA, the second set of pins (Btl, Bt3) being pins 1 to 12 of type TMDS, the third set of pins being constituted by pin 13 of type CEC.

Another object of the invention is an audio-visual sharing system on a display device provided with an input video connector, the system comprising

- a first transfer device,

- at least one routing device,

a plurality of devices for transmitting audio-visual documents, each provided with at least one output video connector, the input video connector of the display device being connected by a cable to the output video connector of the first device transfer connector, the output video connector of a routing device among the at least one routing device being connected via a cable to the first video connector of the transfer device, each transmission module having a video connector output connected by a cable to a video input connector of a routing device.

According to preferred embodiments, the audio-visual sharing system comprises one or more of the following characteristics:

- The system comprises a single routing device and two transmission devices, an output video connector of each transmission device being connected by a cable to the first video connector, respectively to the second video connector of the routing device.

- the audio-visual sharing system comprises a plurality of routing devices and a plurality of transmission devices, an output video connector of each transmission device being connected by a cable to the second video connector of a routing device corresponding, the routing devices being connected to each other in series via cables connecting the first video connector of a routing device to the output video connector of the following routing device.

- in the audio-visual sharing system, the video input and output connectors of the audio-visual signal transfer and routing devices are HDMI type connectors, the power pin being pin 18, the pin control pin BEC type H14, the first set of pins being pins 15 and 16 of type SCL, SDA, the second set of pins being pins 1 to 12 of type TMDS, and for the routing device, the third set of pins being constituted by pin 13 of CEC type; cables are HDMI cables.

The invention also relates to an audiovisual sharing method in a system as described above, the method being implemented by a routing device, and comprising:

- a step of obtaining configuration information;

a step of configuring the switching module as a function of the configuration information obtained.

In one embodiment, the method can include the following characteristics:

the obtaining step comprises a sub-step for detecting a routing request signal from the input port, and,

- during the configuration step, the switching module electrically connects the first set of pins of the second video connector to the memory and the second set of pins of the second video connector to the reconstruction module, the method further comprising

a step of transmitting an access notification message to the display device on the electrical links respectively connected to the third set of pins of the first video connector and of the output video connector.

In another embodiment, the method can include the following characteristics:

the obtaining step comprises a sub-step of receiving a message for notification of access to the display device from an electrical connection connected to the third set of pins of the first connector or to the third set of pins of the connector exit, and

- During the configuration step, the switching module electrically connects the first set of pins of the first video connector to the memory and the second set of pins of the first video connector to the reconstruction module.

In the remainder of this document, the terms “video connectors” designate connectors able to convey audio-visual signals, control signals and supply signals.

The terms “video input connectors” and “video output connectors” are chosen with respect to the audio-video stream, the signals being able to be exchanged in both directions, in particular for the control signals. It should be noted that a power supply pin is an output pin for a so-called input video connector, and an input pin for a so-called output video connector.

By “audio-visual processing” is meant a transfer or a reconstruction of the audio-visual signals, by a routing device as described, respectively by display equipment, for example a video projector, or a screen.

Other characteristics, objects and advantages of the invention will appear on reading the detailed description which follows, made with reference to the appended figures in which:

- Figure 1 is a block diagram corresponding to a device for transferring audio-visual signals according to a first embodiment of the invention;

- Figure 2 shows a block diagram corresponding to an audio-visual signal transfer device according to a second embodiment of the invention;

- Figure 3 shows a configuration of a system comprising a transfer device as illustrated in Figure 1, and a transfer device as illustrated in Figure 2;

FIG. 4 represents a configuration of a system comprising a transfer device as illustrated in FIG. 1, and a plurality of transfer devices as illustrated in FIG. 2.

- Figure 5 is a block diagram corresponding to an audiovisual signal sharing system according to a third embodiment of the invention.

FIG. 1 represents a device 100 for transferring audio-visual signals according to a first embodiment of the invention. This device 100 comprises a first video input connector 101 and a video output connector 103.

In this example, the video input and output connectors are HDMI type connectors. Each video connector includes:

- a Bal, Ba3 power supply pin, of the HDMI “supply” or “+ 5V” type: this is pin 18 of each connector;

- a Bel control pin, Bc3, of the HDMI “HEC” type: this is pin 14 of each connector;

a first set of pins Bil, Bi3, capable of transporting EDID information representative of the characteristics of reproduction of the audio visual signals, of the HDMI “SCL”, and “SDA” type: these are the pins 15 and 16 of each connector; and

- a second set of pins Btl, Bt3 capable of transporting audio-visual signals, of the HDMI “TMDS” type: these are pins 1 to 12 of each connector.

The transfer device 100 is arranged to detect a voltage level Uc on the control pin Bel, in this example pin 14 of the first video connector 101.

If the detected voltage level Uc belongs to a range of predefined values, the transfer device 100 applies a predefined power supply signal, of value greater than the typical supply voltage of a conventional system, to the pin food Bal. In this example a direct voltage of 24V is applied to pin 18 of the first video connector 101, instead of 5V.

This arrangement is obtained by means of a resistor Ra connected between the control pin Bel, in this example the HDMI pin 14 of the first video input connector 101, and an internal power source, providing for example a DC voltage of 5V. This resistance Ra has a role in identifying the type of audio-visual processing equipment connected to the first video input connector 101, which will be explained below.

In this audio-visual signal transfer device, the first and second sets of pins Bil, Btl of the first video connector 101 are electrically connected to the corresponding pins Bi3, Bt3 of the output video connector 103. In this example, the HDMI SCL pins , SDA and pins 1 to 12 of the TMDS type of the first video input connector 101 are therefore connected respectively to the HDMI SCL, SDA and TMDS pins of the video output connector 103.

In the remainder of this document, such a device will be called a “transfer device”.

A second device 200 for transferring audiovisual signals according to a second embodiment will be described with reference to FIG. 2. This device will be called in the following of this document "routing device".

The routing device 200 comprises, like the transfer device 100 described above, a first video input connector 201 and a video output connector 203. It also has a second video input connector 202.

All of these video connectors include power, control, audiovisual signal transport pins and EDID-type information, as previously described. The video input connectors 201, 202, and output 203 can be of the HDMI type. In this case, the names of the pins are the same as for the transfer device.

The routing device 200 further comprises an integrated circuit 220, for example a microprocessor, a microcontroller, or an ASIC, and a reprogrammable memory 230, for example of the EEPROM type.

The first set of pins Bi3, in this example the pins SCL, SDA of the output video connector 203 are electrically connected to input / output ports of the integrated circuit 220. In this case, the input / output ports of the circuit integrated 220 will also be of SCL, SDA type.

This connection creates a 2-wire communication interface, with a SCL clock wire which will determine the transfer speed on this interface. The presence of the integrated circuit 220, which can program its SCL, SDA type ports has the effect of controlling the transfer speed on this communication interface.

When an audio-visual processing equipment is connected to the output connector 203 of the routing device 200, the integrated circuit 220 can receive EDID information representative of the characteristics of reproduction of the audio-visual signals, and store them in the memory 230. The transfer takes place at the speed imposed by the integrated circuit 220. In the example illustrated, this speed is 9600 bits / sec, therefore much lower than the speed of 100 kbits / sec, conventionally used on HDMI cables. This increases the transmission distances of EDID information, and therefore the use of longer cables.

The routing device 200 also includes an input port 240 for detecting a DEM routing request signal.

It also includes:

a third set of pins Bsl, Bs2, Bs3 able to transport bidirectional communication signals; In the HDMI example, it is pin 13, type CEC.

Electrical connections 250, 260 respectively connect the third set of pins Bsl of the first video connector 201 and of the video output connector 203 to input / output ports of the integrated circuit 220. These connections are made via the components of serial interface type, to allow the routing device 200 to communicate bidirectionally when it is connected to other routing devices 300, 400.

The routing device 200 further comprises a reconstitution module 280 of the audio-visual signals, and a switching module 270, configured to connect electrically, according to configuration information IC,

the first set of pins Bil of the first video connector 201 to the memory 230 and the second set of pins Btl of the first video connector

201 to the reconstruction module 280;

or

- the first set of pins Bi2 of the second video connector 202 to the memory 230 and the second set of pins Bt2 of the second video connector

202 to the reconstruction module 280.

The reconstruction module 280 is configured to reconstruct the audio-visual signals received from the second set of pins Btl, Bt2 from the first or the second video connector 201, 202, and to transmit the reconstructed audio-visual signals on the second set of pins Bt3 of the output video connector 203.

Similar to the transfer device 100, the routing device 200 is arranged to detect a voltage level Uc on the control pin Bel, in the embodiment based on HDMI connectors pin 14, of the first video connector 101, and, if the detected voltage level Uc belongs to a range of predefined values, apply a predefined power supply signal, on the power pin Bal, the HDMI pin 14, of the first video connector 101. This arrangement is obtained by to a resistor Ra similarly connected to the transfer device 100.

The routing device 200 additionally comprises a resistor Rb connected between the control pin Bc3, in this embodiment the HDMI pin 14, of its output video connector 203 and the ground.

When connecting two video devices, by conventional video connectors or according to the invention, a pin Bel of an input video connector of the first video device is electrically connected to a pin Bc3 of the corresponding output video connector of the second equipment.

Suppose that the video equipment considered is a transfer device 100 and a routing device 200, as illustrated in FIG. 5.

The transfer device 100 is provided with a resistor Ra connected between the control pin Bel of its first video input connector 101 and an internal power supply; the routing device 200 is provided with a resistor Rb connected between the control pin Bc3 of its video output connector 203 and the ground.

When the cable 60 is connected, a voltage divider bridge is formed by the resistors Ra and Rb. The value of the voltage Uc detected by the transfer device on its pin Bel will indicate to it that a routing device is connected.

Consequently, the transfer device 100 will apply to its supply type pin Bal of the connector 201 the electrical supply voltage coming from the external power source 3. This signal will supply the routing device 200, via the supply type pin Ba3 of the output connector 203.

The voltage Uc is continuously measured, using a window comparator, to protect the connected equipment. Thanks to this arrangement, the supply voltage delivered by the external source 3 will not be applied to conventional devices, which will thus be protected.

Furthermore, the range of predefined values of the voltage Uc detected on the control pin Bel, for which the external power signal will be applied to the power pin Bal, can be determined as a function of the values of the resistances Ra, Rb , and the internal supply voltage, taking into account the respective tolerances. In the example illustrated, these values are 2.5V ± 1%, for an internal supply voltage of 5V and resistors Ra 15Kohm, Rb 15Kohm.

A routing device 200, 300 is provided with a first video input connector 201, 301, having the same characteristics as that of the routing device 100.

Thus, a routing device 200, powered by an external power source 3, is able to detect if another routing device 300, 400 is connected to its first input connector 201, and, if necessary, supply this another routing device by applying to the corresponding power supply pin the power signal supplied by the external power source 3. This is the case of the devices in a configuration illustrated in FIG. 4.

Audio-visual signal transfer devices as previously described can be used together, to create different audio-visual sharing systems of a display device provided with an input video connector, for example a video projector or a screen. Two embodiments of an audio-visual sharing system are illustrated in FIGS. 3 and 4.

An audio-visual sharing system according to the invention comprises a display device 5 and a first transfer device 100, provided with a single video input connector 101 and with a single video output connector 103, connected by a cable 50 to the input video connector of the display device 5.

The audio-visual sharing system also comprises at least one routing device 200, provided with two video input connectors 201, 202, and with a single video output connector 203. According to the embodiments, the sharing system audio-visual can include one or more routing devices, as will be explained below.

The input video connector 101 of the transfer device 100 is connected via a cable 60 to the output video connector 203 of the routing device 200.

The audio-visual sharing system according to the invention allows the connection of a plurality of devices for transmitting 10, 20, 30, 40 of audio-visual documents, each provided with at least one output video connector. Each transmission device stores data of audio visual documents intended to be viewed in turn thanks to the display device 5.

The transmission devices 10, 20, 30, 40 are connected by conventional cables 61, 62, 72, 82, connecting an output video connector each emission device to an input video connector 201, 202, 302, 402 of a routing device 200, 300, 400.

Preferred embodiments describe HDMI connectors, but the invention may relate to any video connector having enough pins to handle audio-visual, power and control signals, such as DisplayPort ™, USB Type-C ™ and Thunderbolt ™ connectors .

A first audio-visual sharing system according to an embodiment of the invention will now be described with reference to FIG. 3.

This first system comprises a video projector 5, a first audio-visual signal transfer device 100, connected to the video projector 5 by a standard HDMI cable 50. This cable is connected between an input video connector of the display device 5 and the output video connector 103 of the first transfer device 100.

The first transfer device 100 includes terminals for connection to an external electrical power source 3, capable of supplying a DC voltage supply signal of a value greater than the typical value of the supply signal associated with this type of cable. A higher voltage limits line losses and reduces the current used, which makes it possible to increase the length of the cables and reduce the disturbance of audio-visual signals. In this example, the voltage supplied by the external power supply source 3 is a direct voltage of 24 V, the typical value of the HDMI power signal being 5 V.

The transfer device 100 is connected to the power source 3 via a power cable 4.

The transfer device 100 comprises a single video input connector 101 and a single video output connector 103. The video input connector 101 is connected by an HDMI cable 60 to a routing device 200, comprising two video connectors d input 201, 202, and a single video output connector 203.

Thanks to the resistances Ra of the transfer device 100, and Rb of the routing device 200, the latter is supplied by the supply signal supplied by the supply source 3, as explained above.

The cable 50, connecting the display device 5 to the transfer device 100, carries EDID information generated by the display device 5.

This information is received on the first set of pins Bi3 of the video output connector 103, electrically connected within the transfer device 100 to the corresponding pins Bil of the first video connector 101, and then, via the cable 60 to the pins Bi3 the output video connector 203 of the routing device 200.

Within the routing device 200, the first set of pins Bi3 of the output video connector 203 are electrically connected to input / output ports of the integrated circuit 220, so as to allow it to receive EDID information generated by the device display 5, and store this EDID information in memory 230.

The routing device 200 is provided with two video input connectors 201, 202 connected by two conventional HDMI cables 61, 62, to two devices for transmitting audio-visual documents 10, 20.

In this audio-visual sharing system, the single routing device 200 is therefore connected to two transmission devices 10, 20. To determine which of these two devices will send audio-visual signals to the display device 5, the routing device 200 will configure its switching module 270 as a function of configuration information IC, obtained in this example via the input port 240. The signal DEM, applied to this input port 240, is representative of a position of a button that can be actuated by a user, to request to display audio-visual signals transmitted from its transmission device 10, 20 on the display device 5.

Depending on the position of the button, and therefore on the value of the signal applied to the input port 240, the routing device 200 configures its switching module 270 to connect electrically, either

the first set of pins Bil of the first video connector 201 to the memory 230 and the second set of pins Btl of the first video connector 201 to the reconstruction module 280, ie the first set of pins Bi2 of the second video connector 202 to the memory 230 and the second set of pins Bt2 from the second video connector 202 to the reconstruction module 280.

Thus, the sending device 10, 20, requesting routing can, thanks to the connection to the input video connector, access the memory 230 to acquire EDID information representative of the characteristics of restitution by the signal display device audiovisual. This information will then be used by this transmission device to generate the audio-visual signals in accordance with the characteristics of the display device.

The audio-visual signals coming from the sending requesting routing device 10, 20, are reconstructed by the reconstruction module 280 and transmitted on the second set of pins Bt3 of the output video connector 203.

The cable 60, connecting the output connector 203 of the routing device to the first input video connector of the transfer device 100, ensures the transmission of the audio-visual signals up to the pins Btl of the transfer device 100. These pins are connected electrically within the transfer device 100 to the corresponding pins Bt3 of the output video connector 103, and then, via a cable 50 to the pins Bt3 of the input video connector of the display device 5.

Thus, the audio-visual signals generated by the sending requesting routing device are displayed by the display device 5, in agreement with the EDID information representative of the characteristics of reproduction of the audio-visual signals of the display device 5.

FIG. 4 illustrates a second audio visual sharing system, according to another embodiment of the invention.

As in the previous example, the second audio-visual sharing system comprises a video projector 5, a first device for transferring audio-visual signals

100, a routing device 200, and an external power source 3. The connections between these elements are similar to those of the first audiovisual sharing system.

The second sharing system comprises, in the example illustrated, two other routing devices 300, 400, in addition to the routing device 200.

Generally, a sharing system according to this second embodiment comprises a plurality of routing devices and a plurality of transmission devices. The routing devices are connected together in series, forming a network of topology known by the English term "daisy-chain".

An output video connector of each transmission device 20, 30, 40 is connected by a video cable 62, 72,

82, to the second video input connector 202, 302, 402 of a corresponding routing device 200, 300, 400.

The routing devices 200, 300, 400 are connected to each other via the cables 70, 80 connecting the first video connector 201, 301, of a routing device to the output video connector of the following routing device 303, 403 .

Each of the transfer devices 100 or routing devices 200, 300, will detect, thanks to the respective resistors Ra, connected to the control pins of the connectors 101, 201, 301, and Rb connected to the control pins of the connectors 203, 303 and 403 of the routing device 200, 300, 400, a voltage level Uc indicating that it is connected to a routing device. Consequently, the transfer device 100 and the routing devices 200, 300 will apply to the power supply type pin Bal, Ba2, Ba3 belonging respectively to the connectors 101, 201, 301 the power supply signal coming from the power source. external 3, of value greater than the conventional supply voltage.

The video input and output connectors each comprise a third set of pins, capable of transporting bidirectional communication signals, designated Bsl, Bs2, for the first, respectively the second video input connector, and Bs3, for the connector. output video.

In the example of the HDMI connectors, these assemblies can consist of a single pin, pin 13 of the type

CEC.

Each routing device comprises electrical links 250, 260 respectively connected to the third set of pins Bsl of the first video connector 201, 301, 401 and of the output video connector 203, 303, 403.

These electrical connections can transport signals transmitted by one or more transmission ports of the integrated circuit 220, respectively signals intended for one or more reception ports of the integrated circuit 220.

When connecting the cables connecting the first video connector 201, 301, 401 of a routing device to the output video connector of the following routing device 301, 401, a communications bus BC, to which all the routing devices 200, 300, 400 are connected, is formed by the respective electrical connections.

The routing devices thus connected can communicate bidirectionally with one another. The transmission rate, as well as the messages exchanged, are determined by the integrated circuit 220. This feature makes it possible to reduce the transmission speed on this bus, for example at a rate of 9600 bits / sec. For a conventional cable, the transmission rate is typically 100 kHz.

This drop in speed has the effect of being able to reach transmission distances of several tens of meters, and therefore allow the use of longer cables.

As in the previous example, the signals carrying the EDID information are generated by the display device 5 and transmitted to the input / output ports of the integrated circuit 220 via the pins Bi3 of the video connectors 103 and 203, and HDMI 50 and 60 cables.

This EDID information generated by the display device, and representing its characteristics for rendering audio-visual signals, is then stored by the integrated circuit 220 in the memory 230 of the routing device 200.

When connecting a new routing device 300, 400 to a previous routing device 200, 300, via a cable 70, 80, the previous routing device detects, as explained above, that a Power signal must be applied to the Bal power pin of the first video connector.

In a preferred embodiment, the preceding routing device 200 applies the power signal and configures its switching module 270 to electrically connect the first set of pins Bil of its first video connector 201, to the memory 230, which stores the EDID information associated with the display device 5.

This first set of pins Bil of the first video connector 201 of the routing device 200 is connected by cable 70 to the first set of pins Bi3 of the output video connector 303 of the newly connected device 300.

The first set of pins Bi3 of the output video connector 303 of the newly connected device 300 are electrically connected to first input / output ports of the integrated circuit of this device 300, thus enabling it to receive the EDID information stored in the memory 230 from the previous routing device 200.

In turn, the newly connected routing device 300 stores the EDID information received in its own memory 330.

When connecting a new routing device 400, the routing device 300 configures the first set of pins Bil of its first video connector 301, to its memory 330, to give access to the routing device 400 to the EDID information.

In this way, the routing devices 200, 300 ensure the propagation of the EDID information associated with the display device 5 to each new routing device connected to the sharing system, which allows each routing device, whatever its position, to store the EDID information necessary for a reproduction of the audio-visual signals on the shared display device 5.

In this audio-visual sharing system, several transmission devices 20, 30, 40 are connected, each by means of a routing device 200, 300, 400.

To determine which of these transmitting devices will send audio-visual signals to the display device 5, and to ensure the transmission of these signals in accordance with the EDID information representative of the characteristics of reproduction of the audio-visual signals of this device. 'display, each routing device 200, 300, 400 implements an audio-visual sharing process.

Once the connections are in place, a routing device obtains, during a step of obtaining E10, configuration information IC.

Depending on the configuration information IC obtained, the routing device 200, 300, 400 configures, during a configuration step E20, its switching module 270, 370, 470.

To illustrate the sharing method, it is assumed that a user who has connected his audio-visual signal transmission device, for example his laptop 20, to the second video input connector 202 of the routing device 200, requests 1 display of the audio-visual signals generated by this transmission device 20 on the display device 5. To do this, the user presses a button, the position of which is represented by a signal DEM, applied to the port d 'entry 240.

Following this button press, the routing device 200 must configure its switching module 270 to ensure the transmission of signals.

During an obtaining step E10, the routing device 200 obtains configuration information IC. In this example, the step E10 of obtaining the IC information comprises a substep E15 of detecting a routing request signal, generated by pressing the button connected to the input port 240.

Then, during the configuration step E20, the routing device configures its switching module 270, as a function of the configuration information IC obtained in step E10.

In this example, the user has requested the display of the data transmitted by his transmission device 20, on the display device 5. The routing device 200 therefore configures his switching module 270 to electrically connect the second set of pins Bt2 of the second video connector 202 to the reconstruction module 280, and the first set of pins Bi2 of the second video connector 202 to the memory 230. As already explained, the memory 230 of the routing device 200, connected directly to the transfer device 100 , contains EDID information from the display device.

The transmission device 20 can thus access the memory 230 to acquire the EDID information representative of the restitution characteristics by the display device of the audio-visual signals. This information will then be used by this transmission device 20 to generate the audio-visual signals in accordance with the characteristics of the display device.

To prevent the other routing devices 300, 400 from the fact that the display device 5 is requested by the routing device 200, the latter transmits, during a transmission step E30, an access notification message MSG to the display device 5 on the electrical connections 250, 260 respectively connected to the third set of pins Bsl of the first video connector 201 and of the output video connector 203. This message is broadcast on the communications bus BC, and received by each device routing 300, 400.

The other routing devices 300, 400 also implement the sharing method, and will execute steps of obtaining information E10 and of configuration E20. However, the configuration information IC is obtained in step E10 in a different manner by the routing device 200 requesting the display and by the other routing devices 300, 400 of the sharing system.

The reception of the notification message MSG, emitted in step E30 by the routing device 200 which has "taken control", is another form of obtaining the configuration information IC. Thus, in this example, the obtaining step E10 comprises a substep of receiving E17 of the notification message MSG.

The routing devices 300, 400 can receive this notification message MSG from one of the electrical connections 250, 260 connected respectively to the pins Bsl (in this example pin 13 CEC) of the first video input connector 301, 401 and of the connector exit 303, 403.

Then, during the configuration step E20, the routing devices 300, 400, which have not "taken control", configure the respective switching modules 370, 470 to electrically connect the first set of pins Bil of the first respective video connectors 301, 401 to memory 230 and the second set of pins Bt2 from the first video connector 201 to the reconstruction module 280.

By this configuration, the routing devices 300, 400, ensure on the one hand the propagation of any audio-visual signals from the first video input connector 301, 401 to the video output connector 303, 403, via the reconstitution module 280. In this way, the propagated audio-visual signals are reconstituted on each pass in a routing device, which makes it possible to increase the number of participants.

On the other hand, by connecting the first set of control pins Bil of the first video input connector 301, 401 to the memory 230, the routing devices 300,

400, ensure the propagation of EDID information to a possible routing device 400.

Sharing systems as described make it possible to reach longer cable lengths, as well as a high number of participants.

Claims (13)

1. Device for transferring (100,200,300,400) audio-visual signals, comprising a first video input connector (101, 201, 301, 401) and an output video connector (103,203,303,403), each video connector comprising - a power supply pin (Bal, Ba2, Ba3), - a control pin (Bel, Bc2, Bc3), a first set of pins (Bil, Bi2, Bi3) capable of transporting information (EDID) representative of the characteristics of reproduction of audiovisual signals, and - a second set of pins (Btl, Bt2, Bt3) capable of transporting audio-visual signals, the transfer device (100,200,300,400) being arranged for - detect a voltage level (Uc) on the control pin (Bel) of the first video connector (101, 201, 301, 401), and - if the detected voltage level (Uc) belongs to a range of predefined values, - apply a predefined power supply signal to the power supply pin (Bal) of the first video connector (101, 201, 301, 401). 2. transfer device (100) for audio-visual signals according to claim 1, characterized in that the first and second sets of pins (Bil, Btl) of the first video connector (101) are electrically connected to the corresponding pins (Bi3 , Bt3) of the output video connector (103). 3. Transfer device (100) for audio-visual signals according to claim 2, characterized in that the video input and output connectors are connectors of the HDMI type, the power supply pin (Bal, Ba3) being the pin 18, the control pin (Bel, Bc3) being pin 14 of the HEC type, the first set of pins (Bil, Bi3) being pins 15 and 16 of the SCL, SDA type, the second set of pins (Btl, Bt3) being pins 1 to 12 of the TMDS type. 4. An audio-visual signal transfer device (200, 300, 400) according to claim 1, further comprising - a second input video connector (202, 302, 402), - an integrated circuit (220) and a memory (230), - the first set of pins (Bi3) of the output video connector (203, 303, 403) being electrically connected to first input / output ports of the integrated circuit, so as to allow it, when an audio processing equipment -visual is connected to the transfer device (200, 300, 400), to receive information (EDID) representative of the characteristics of restitution of the audio signals- visual, and store these informations (EDID) in the memory, the device transfer (200, 300, 400) comprising in outraged - a port entry (240 ) to detect a signal of routing request (DEM), a third set of pins (Bsl, Bs2, Bs3) capable of transporting bidirectional communication signals, and electrical connections (250, 260) respectively connecting the third set of pins (Bsl) of the first video connector (201, 301, 401) and from the output video connector (203, 303, 403), to a bidirectional communication port of the integrated circuit (220) - a reconstruction module (280) of the audiovisual signals, and - a switching module (270), configured to connect electrically, according to configuration information (IC) - the first set of pins (Bil) of the first video connector (201) to the memory (230) and the second set of pins (Btl) of the first video connector (201, 301, 401) to the reconstruction module (280); or - the first set of pins (Bi2) of the second video connector (202) to the memory (230) and the second set of pins (Bt2) of the second video connector (202) to the reconstruction module (280); the reconstruction module (280) being configured to reconstruct the audio-visual signals received from the second set of pins (Btl, Bt2) of the first or second video connector (201,202) and to transmit the reconstructed audio-visual signals on the second set of pins (Bt3) of the video output connector (203). 5. A device for transferring (200, 300, 400) audio-visual signals according to claim 4, characterized in that it is further configured to transmit information (EDID) at a reduced rate. - from the first set of pins (Bil) of the output video connector (203) to the memory (230); and - From the memory (230) to the first video connector (201,301,401), when the switching module (270) electrically connects the first set of pins (Bil) of the first video connector (201) to the memory (230). 6. Device for transferring (200, 300, 400) audio-visual signals according to one of claims 4 or 5, characterized in that the video input and output connectors are connectors of the HDMI type, the power supply pin (Bal, Ba2, Ba3) being pin 18, the control pin (Bel, Bc2, Bc3) being pin B14 of type HEC, the first set of pins (Bil, Bi3) being pins 15 and 16 of type SCL , SDA, the second set of pins (Btl, Bt3) being pins 1 to 12 of TMDS type, the third set of pins (Bsl, Bs2, Bs3) being constituted by pin 13 of CEC type. 7. Audio-visual sharing system on a display device (5) provided with an input video connector, the system comprising - a first transfer device (100) according to claim 2, - at least one transfer device according to claim 4, known as routing device (s) (200, 300, 400), - a plurality of devices for transmitting (10, 20, 30, 40) audio-visual documents, each provided with at least one output video connector, the input video connector of the display device (5) being connected by a cable (50) to the output video connector of the first transfer device (100), the output video connector (203) of a routing device (200) among the at least one routing devices being connected by the through a cable (60) to the first video connector of the transfer device (100), each transmitting module (10, 20, 30, 40) having an output video connector connected by a cable to a video connector d input (201, 202, 302, 402) of a routing device (200, 300,400). 8. Audio-visual sharing system according to the preceding claim, characterized in that it comprises a single routing device (200) and two transmitting devices (10, 20), a video output connector of each device. transmission (10, 20) being connected by a cable to the first video connector (201), respectively to the second video connector (202) of the routing device (200). 9. Audio-visual sharing system according to claim 7, characterized in that it comprises a plurality of devices Routing (200 , 300, 400) and a plurality of devices resignation (20, 30, 40), a connector so video rtie of each device transmission (20, 30, 40) being connected by a cable to the second video connector (202, 302, 402) of a corresponding routing device (200, 300, 400), the routing devices (200, 300, 400) being connected to each other in series via cables connecting the first video connector (201, 301, 401) of a routing device to the output video connector of the following routing device (301, 401). 10. Audio-visual sharing system according to one of claims 7 to 9, characterized in that - the first transfer device (100) is a transfer device according to claim 3 - the at least one routing device (200, 300, 400) is a transfer device according to claim 6, and in that - the cables are HDMI cables. 11. A method of audio-visual sharing in a system according to one of claims 9 or 10, the method being implemented artwork by a device transfer according to a of the claims 4 to 6, said routing device (200, 300 400), the process comprising: - a step obtaining (E10) of a information of configuration (IC); a configuration step (E20) of the switching module (270) as a function of the configuration information (IC) obtained. 12. Audio-visual sharing method according to the preceding claim, in which the obtaining step (E10) comprises a detection sub-step (E15) of a routing request signal (DEM) from the input port (240), and in which, - during the configuration step (E20) the switching module (270) electrically connects the first set of pins (Bi2) of the second video connector (202) to the memory (230) and the second set of pins (Bt2) from the second video connector (202) to the reconstruction module (280), the method further comprising a step of transmitting (E30) a message (MSG) of notification of access to the display device (5) on the electrical links (250, 260) respectively connected to the third set of pins (Bsl) of the first video connector (201, 301, 401) and the output video connector (203, 303, 403). 13. The audio-visual sharing method according to claim 11, in which the obtaining step (E10) comprises a substep of reception (E17) of a message (MSG) of notification of access to the device. display (5) from an electrical connection (250, 260) connected - to the third set of pins (Bsl) of the first connector (201, 301, 401) or - to the third set of pins (Bsl) of the output connector (203, 303, 403), and in which, during the configuration step (E20), the switching module (270) electrically connects the first set of pins (Bi2) from the first video connector (201) to the memory (230) and the second set of pins (Bt2) from the first video connector (201) to the reconstruction module (280).