TW201540060A - Video transmission system - Google Patents

Abstract

A video transmission system includes a transmitter, a transmission line, and receivers coupled in series. The transmitter is coupled to a first receiver via transmission line. The transmitter includes a modulation module, and a first output module. The modulation module modulates a video input signal into a first pair of middle frequency differential signals corresponding to a first band and transmits them to the first receiver via the transmission line. The first receiver includes a second receiving module, a demodulation module, and a second output module. The second receiving module outputs first pair of middle frequency differential signals to a second receiver. If the first band of first pair of middle frequency differential signals corresponds to a first preset band of the demodulation module, the demodulation module demodulates first pair of middle frequency differential signals into the video input signal and the second output module outputs video input signal.

Description

Video transmission system

The present invention relates to video and audio transmission, and more particularly to a video and audio transmission system that simplifies wiring.

In general, if an audio-visual transmission system is to achieve the function of transmitting a plurality of HDMI signals at the same time, a plurality of transmitters and receivers in the audio-visual transmission system usually adopt a radial wiring manner. For example, if the audio-visual transmission system has four transmitters and four receivers, each of the transmitters needs to pull four transmission lines to be coupled to four receivers, thus causing the wiring of the entire audio-visual transmission system to become very It is complicated and difficult to organize.

Especially in the current trend of more and more transmitters and receivers included in audio and video transmission systems, the problem of complicated wiring and difficult to organize is more serious and urgent to solve.

Accordingly, the present invention provides an audiovisual transmission system to solve the above problems encountered in the prior art.

According to an embodiment of the invention, an audiovisual transmission system is provided. In this embodiment, the video transmission system includes a transmitter, a transmission line, and a plurality of receivers. The plurality of receivers are connected in series, and the transmitter is coupled to the first receiver through the transmission line. The transmitter includes a first receiving module, a first modulation module, and a first output module. The first receiving module is configured to receive the first video input signal. The first modulation module is coupled to the first receiving module for converting the first video input signal into a first pair of intermediate frequency differential signals corresponding to the first frequency band. The first output module is coupled to the first modulation module for outputting the first pair of intermediate frequency differential signals. The transmission line is coupled to the first output module for transmitting the first pair of intermediate frequency differential signals. The first receiver of the plurality of receivers includes a second receiving module, a first demodulation module, and a second output module. Second receiving module coupled transmission And a line for receiving the first pair of intermediate frequency differential signals and outputting the first pair of intermediate frequency differential signals to the second one of the plurality of receivers. The first demodulation module is coupled to the second receiving module, the first demodulation module has a first set frequency band, and the first demodulation module receives the first pair of intermediate frequency differentials from the second receiving module. The first demodulation module demodulates the first pair of intermediate frequency differential signals into a first video input signal if the first frequency band of the first pair of intermediate frequency differential signals corresponds to the first set frequency band. The second output module is coupled to the first demodulation module for outputting the first video input signal.

In one embodiment, the transmission line includes four pairs of twisted pairs for the transmitter to transmit the first pair of intermediate frequency differential signals to the first receiver through the first pair of twisted pairs of the transmission line.

In one embodiment, the transmitter further includes a network signal receiving module for receiving the network signal and transmitting the network signal to the first output module to transmit the network signal to the first receiver through the transmission line.

In one embodiment, the transmission line includes four pairs of twisted pairs for the transmitter to transmit network signals to the first receiver through the second pair of twisted pairs and the third pair of twisted pairs of the transmission line.

In an embodiment, the first receiver further includes a network signal output module coupled to the second receiving module for receiving the network signal and outputting to the outside.

In one embodiment, the transmitter further includes a control module coupled to the modulation module and the first output module to transmit the control signal.

In one embodiment, the transmission line includes four pairs of twisted pairs for the transmitter to transmit control signals to the first receiver through the fourth pair of twisted pairs of the transmission line.

In an embodiment, the first receiver further includes a signal transmission module coupled to the second receiving module for transmitting the first pair of intermediate frequency differential signals to the second receiver.

In an embodiment, the first receiver further includes a control module coupled to the signal transmission module and the first demodulation module to transmit the control signal.

In an embodiment, the second receiver includes a third receiving module, a second demodulation module, and a third output module. The third receiving module is coupled to the first receiver for receiving the first pair of intermediate frequency differential signals. The second demodulation module is coupled to the third receiving module and has a second set frequency band. The second demodulation module receives the first pair of intermediate frequency differential signals from the third receiving module. If the first frequency band of the first pair of intermediate frequency differential signals corresponds to the second set frequency band, the second demodulation module demodulates the first pair of intermediate frequency differential signals into the first video input signal. The third output module is coupled to the second demodulation mode The group is configured to receive the first video input signal from the second demodulation module and output the first video input signal.

In an embodiment, the video transmission system includes a user interface, and is disposed on the transmitter and/or the first receiver for operation or setting by the user.

Another embodiment of the present invention is also an audiovisual transmission system. In this embodiment, the video transmission system includes a plurality of transmitters, a transmission line, and a plurality of receivers. The plurality of transmitters are connected in series, the plurality of receivers are connected in series, and the first transmitter is coupled to the first receiver through a transmission line. The first transmitter of the plurality of transmitters comprises a first receiving module, a first modulation module and a first output module. The first receiving module is configured to receive the first video input signal. The first modulation module is coupled to the first receiving module for converting the first video input signal into a first pair of intermediate frequency differential signals corresponding to the first frequency band. The first output module is coupled to the first modulation module for outputting a pair of synthesized intermediate frequency differential signals, wherein the pair of synthesized intermediate frequency differential signals includes a first pair of intermediate frequency differential signals and corresponding to the second frequency band The second pair of intermediate frequency differential signals, and the second pair of intermediate frequency differential signals are from the second one of the plurality of transmitters. The transmission line is coupled to the first output module for transmitting the pair of synthesized intermediate frequency differential signals. The first receiver of the plurality of receivers includes a second receiving module, a first demodulation module, and a second output module. The second receiving module is coupled to the transmission line for receiving the pair of synthesized intermediate frequency differential signals and outputting the pair of synthesized intermediate frequency differential signals to the second receiver of the plurality of receivers. The first demodulation module is coupled to the second receiving module, the first demodulation module has a first set frequency band, and the first demodulation module receives the pair of synthesized intermediate frequency differentials from the second receiving module The first demodulation module demodulates the first pair of intermediate frequency differential signals if the first frequency band of the first pair of intermediate frequency differential signals in the synthesized intermediate frequency differential signal corresponds to the first set frequency band Becomes the first video input signal. The second output module is coupled to the first demodulation module for outputting the first video input signal.

Another embodiment of the present invention is also an audiovisual transmission system. In this embodiment, the video transmission system includes a plurality of transmitters, a transmission line, and a receiver. The plurality of transmitters are connected in series, and the first transmitter is coupled to the receiver through the transmission line. The first transmitter of the plurality of transmitters comprises a first receiving module, a first modulation module and a first output module. The first receiving module is configured to receive the first video input signal. The first modulation module is coupled to the first receiving module, and configured to adjust the first video input signal to the first pair corresponding to the first frequency band. Frequency difference signal. The first output module is coupled to the first modulation module for outputting a pair of synthesized intermediate frequency differential signals, wherein the pair of synthesized intermediate frequency differential signals includes a first pair of intermediate frequency differential signals and corresponding to the second frequency band The second pair of intermediate frequency differential signals, and the second pair of intermediate frequency differential signals are from the second one of the plurality of transmitters. The transmission line is coupled to the first output module for transmitting the pair of synthesized intermediate frequency differential signals. The receiver includes a second receiving module, a first demodulation module, and a second output module. The second receiving module is coupled to the transmission line for receiving the pair of synthesized intermediate frequency differential signals. The first demodulation module is coupled to the second receiving module, the first demodulation module has a first set frequency band, and the first demodulation module receives the pair of synthesized intermediate frequency differentials from the second receiving module The first demodulation module demodulates the first pair of intermediate frequency differential signals if the first frequency band of the first pair of intermediate frequency differential signals in the synthesized intermediate frequency differential signal corresponds to the first set frequency band Becomes the first video input signal. The second output module is coupled to the first demodulation module for outputting the first video input signal.

Compared with the prior art, the video transmission system according to the present invention has the following advantages:

(1) It is only necessary to extend the audio and video (HDMI) signal and the network signal through a transmission line such as CAT5, which can effectively improve the shortcomings of the complicated wiring that is difficult to be arranged due to the need to set multiple transmission lines in the prior art.

(2) Applicable to different types of audio and video transmission systems, whether it is a transmitter-to-multiple receiver video signal splitter (Splitter) type, or multiple transmitter-to-multiple receiver matrix (Matrix) The type, or multiple transmitters, can be applied to the audio and video switcher type of a receiver.

(3) All transmitters can be connected in series with each other and transmit the received HDMI signal and network signal to a specific transmitter. The specific transmitter outputs the HDMI signal and the network signal to a specific receiver through a CAT5 transmission line, all The receivers are also connected in series with each other, and the HDMI signal and the network signal transmitted by the CAT5 transmission line are received by the specific receiver, and then the HDMI signals and the network signals are respectively transmitted to the corresponding receivers.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

1, 2, 3‧ ‧ audio and video transmission system

TX, TX1~TX4‧‧‧ transmitter

RX, RX1~RX4‧‧‧ Receiver

L‧‧‧ transmission line

L1~L4‧‧‧ four pairs of twisted pair

10, 40, 50‧ ‧ audio and video signal receiving module

12, 42, 52‧ ‧ modulating modules

14, 24, 34, 44, 54, 64‧‧‧ Output modules

16, 26, 36, 46, 56, 66‧‧‧ control modules

17, 47, 57‧‧‧ Network signal receiving module

18, 28, 38, 48, 58, 68‧‧‧ Signal Transmission Module

19, 29, 39, 49, 59, 69‧‧ ‧ hub modules

20, 30, 60‧‧‧ receiving module

22, 32, 62‧‧‧ demodulation module

27, 37, 67‧‧‧ Network signal output module

VS, VS1, VS2‧‧‧ audio and video input signals

NS, NS1, NS2‧‧‧ network signal

IF±, IF1±, IF2±‧‧‧ pair of intermediate frequency differential signals

D±, D1±, D2±‧‧‧ pair of control differential signals

N1±, N2±, N11±, N21±, N12±, N22±‧‧‧ pairs of network differential signals

1 is a schematic diagram of an audio and video transmission system in accordance with an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the circuit structure of the transmitter TX of FIG. 1.

3 is a schematic diagram showing the circuit structure of the first receiver RX1 and the second receiver RX2 in FIG.

4 is a schematic diagram of a video and audio transmission system in accordance with another embodiment of the present invention.

FIG. 5 is a schematic diagram showing the circuit structure of the first transmitter TX1 and the second transmitter TX2 in FIGS. 4 and 6.

6 is a schematic diagram of a video and audio transmission system according to still another embodiment of the present invention.

FIG. 7 is a schematic diagram showing the circuit structure of the receiver RX of FIG. 6.

A preferred embodiment of the present invention is an audiovisual transmission system. In this embodiment, the video transmission system 1 has a video signal splitter type of a transmitter to a plurality of receivers. Please refer to FIG. 1. FIG. 1 is a schematic diagram of a video transmission system in this embodiment.

As shown in FIG. 1, the video transmission system 1 includes a transmitter TX, a single transmission line L, and a plurality of receivers RX1 to RX4. In practical applications, the transmission line L can be, for example, a CAT5 transmission line including four pairs of twisted pairs, for transmitting up to four pairs of differential signals, but not limited thereto. In addition, the number of receivers in the AV transmission system 1 is not limited to the four of the examples, and can be adjusted according to actual needs.

The transmitter TX is coupled to the first receiver RX1 through the transmission line L; the first receiver RX1, the second receiver RX2, the third receiver RX3, and the fourth receiver RX4 are sequentially connected to each other through the transmission line, that is, the first The receiver RX1 is coupled to the second receiver RX2, the second receiver RX2 is coupled to the third receiver RX3, and the third receiver RX3 is coupled to the fourth receiver RX4. In practical applications, the transmission lines used by the receivers RX1 to RX4 to be connected in series may be a CAT5 transmission line including four pairs of twisted pairs, for transmitting up to four pairs of differential signals, but not limited thereto.

Next, please refer to FIG. 2. FIG. 2 is a schematic diagram showing the circuit structure of the transmitter TX in FIG. As shown in FIG. 2, the transmitter TX includes at least an audio-visual signal receiving module 10, a modulation module 12, and an output module 14. The complex includes a control module 16, a network signal receiving module 17, and a signal transmission module 18. And the line assembly module 19. The audio and video signal receiving module 10 is coupled to the modulation module 12; the modulation module 12 is coupled to the output module 14; the control module 16 is coupled to the modulation module 12, the output module 14, and the signal transmission module 18. The network signal receiving module 17 is coupled to the line module 19; the line module 19 is coupled to the output module 14 and the signal transmission module 18.

In fact, the audio and video signal receiving module 10 can be a HDMI video signal receiver for receiving digital audio and video signals; the network signal receiving module 17 can include an RJ45 connector for receiving an Ethernet signal, but none of them Limited.

When the audio and video signal receiving module 10 receives the video input signal VS, the modulation module 12 converts the video input signal VS into one of the first frequency bands and the intermediate frequency differential signal IF± and transmits the signal to the output module. 14. The output module 14 outputs the pair of intermediate frequency differential signals IF± to one of the pair of transmission lines L (eg, the first pair of twisted pairs L1). In an actual application, the video input signal VS received by the video signal receiving module 10 may be provided by a video source device (such as a DVD player) coupled to and corresponding to the transmitter TX; the modulation module 12 is The DVBT modulation module can use the Orthogonal Frequency-Division Multiplexing (OFDM) and H.264 codes to modulate and compress the audio and video input signals, but not limited thereto. In addition, the control module 16 can provide the modulation module 12-band setting.

Since the transmission line L comprises a total of four pairs of twisted pairs L1 to L4, in addition to the first pair of twisted pairs L1 transmitting the first pair of intermediate frequency differential signals IF±, there is a second pair of twisted pairs L2 to Four pairs of twisted pair L4 can be used to transmit differential signals.

In this embodiment, when the network signal receiving module 17 receives the network signal NS, the network signal receiving module 17 transmits the network signal NS to the output module 14 via the hub module 19, and then outputs the module. The group 14 outputs two pairs of network differential signals N1± and N2± through the second pair of twisted pair lines L2 and the third pair of twisted pair lines L3 in the transmission line L.

In addition, the control module 16 sends a control signal D± to the output module 14, and the output module 14 outputs a pair of control differential signals D± through the fourth pair of twisted pairs L4 in the transmission line L. The pair of control differential signals D± can be, for example, DVBT band setting, volume control or any other Control signal.

Next, please refer to FIG. 3. FIG. 3 is a schematic diagram showing the circuit structure of the first receiver RX1 and the second receiver RX2 in FIG. As shown in FIG. 3, the first receiver RX1 includes a receiving module 20, a demodulation module 22, an output module 24, a control module 26, a network signal output module 27, a signal transmission module 28, and a hub module. Group 29. The receiving module 20 is coupled to the demodulation module 22 and the signal transmission module 28; the demodulation module 22 is coupled to the output module 24; the control module 26 is coupled to the demodulation module 22 and the signal transmission module. The network signal output module 27 is coupled to the hub module 29; the signal transmission module 28 is coupled to the hub module 29, the receiver module 20, the demodulation module 22, and the control module 26. The signal transmission module 28 of the first receiver RX1 is coupled to the receiving module 30 of the second receiver RX2 via a transmission line such as CAT-5.

The internal circuit structure of the second receiver RX2 is the same as that of the first receiver RX1, and includes a receiving module 30, a demodulation module 32, an output module 34, a control module 36, a network signal output module 37, and a signal transmission. Module 38 and hub module 39. The receiving module 30 is coupled to the demodulation module 32 and the signal transmission module 38. The demodulation module 32 is coupled to the output module 34. The control module 36 is coupled to the demodulation module 32 and the signal transmission module. The network signal output module 37 is coupled to the hub module 39. The signal transmission module 38 is coupled to the receiver module 30, the demodulation module 32, the control module 36, and the hub module 39.

The receiving module 20 of the first receiver RX1 coupled to the transmission line L receives a pair of intermediate frequency differential signals IF± transmitted by the first pair of twisted pairs L1 to L4 of the transmission line L, respectively. Two pairs of network differential signals N1± and N2± and a pair of control differential signals D±.

When the receiving module 20 receives the pair of control differential signals D±, the receiving module 20 transmits the pair of control differential signals D± to the demodulation module 22 and the signal transmission module 28. When the signal transmission module 28 receives the pair of control differential signals D± transmitted by the receiving module 20, the signal transmission module 28 transmits the pair of control differential signals D± to the receiving of the second receiver RX2. Module 30. Through the pair of control differential signals D±, the demodulation module 22 can perform corresponding operations, such as demodulation of the variable frequency band. In addition, the setting of the demodulation module 22 can also be performed directly through the control module 26 of the first receiver RX1.

When the receiving module 20 receives the pair of intermediate frequency differential signals IF±, the receiving module 20 transmits the pair of intermediate frequency differential signals IF± to the demodulation module 22 and the signal transmission module respectively. 28. When the signal transmission module 28 receives the pair of intermediate frequency differential signals IF± transmitted by the receiving module 20, the signal transmission module 28 transmits the pair of intermediate frequency differential signals IF± to the second receiver RX2. Receive module 30. The demodulation module 22 has a first set frequency band. When the demodulation module 22 receives the pair of intermediate frequency differential signals IF± transmitted by the receiving module 20, if the first frequency band of the pair of intermediate frequency differential signals IF± corresponds to the first set frequency band, the solution The modulation module 22 converts the pair of intermediate frequency differential signals IF± into audio and video input signals VS, and outputs the video input signals VS by the output module 24, for example, outputting the video input signals VS to the coupling and corresponding to A video output device (such as a television or a monitor) of the first receiver RX1, but not limited thereto.

When the receiving module 20 receives the two pairs of network differential signals N1± and N2±, the receiving module 20 transmits the two pairs of network differential signals N1± and N2± to the network through the hub module 29. Signal output module 27 and signal transmission module 28. When the signal transmission module 28 receives the two pairs of network differential signals N1± and N2± transmitted by the receiving module 20, the signal transmission module 28 pairs the two pairs of network differential signals N1± and N2. ± transmitted to the receiving module 30 of the second receiver RX2. When the network signal output module 27 receives the two pairs of network differential signals N1± and N2± transmitted by the receiving module 20, if the two pairs of network differential signals N1± and N2± correspond to the first A receiver RX1, the network signal output module 27 outputs the two pairs of network differential signals N1± and N2±, for example, outputting the two pairs of network differential signals N1± and N2± to a network, but Not limited to this.

When the receiving module 30 of the second receiver RX2 receives the pair of intermediate frequency differential signals IF± transmitted by the signal transmission module 28 of the first receiver RX1, the two pairs of network differential signals N1± and N2 And when the pair controls the differential signal D±, the receiving module 30 transmits the pair of control differential signals D± to the demodulation module 32 and the signal transmission module 38, respectively, and the pair of intermediate frequency differentials The signal IF± is transmitted to the demodulation module 32 and the signal transmission module 38, respectively, and the two pairs of network differential signals N1± and N2± are transmitted to the network signal output module 37 and the signal through the hub module 39. Transmission module 38.

When the signal transmission module 38 receives the pair of control differential signals D± transmitted by the receiving module 30, the signal transmission module 38 transmits the pair of control differential signals D± to the third receiver RX3. The demodulation module 32 can be operated by the pair of control differential signals D±, for example, to demodulate the setting of the variable frequency band. In addition, the setting of the demodulation module 32 can also be performed directly through the control module 36 of the second receiver RX2.

When the signal transmission module 38 receives the pair of intermediate frequency differential signals IF± transmitted by the receiving module 30, the signal transmission module 38 transmits the pair of intermediate frequency differential signals IF± to the third receiver RX3. . The demodulation module 32 has a set frequency band. When the demodulation module 32 receives the pair of intermediate frequency differential signals IF± transmitted by the receiving module 30, if the first frequency band of the pair of intermediate frequency differential signals IF± corresponds to the demodulation module 32 The set frequency band, the demodulation module 32 will convert the pair of intermediate frequency differential signals IF± into audio and video input signals VS, and the output module 34 outputs the video input signals VS, for example, output the video input signals VS to An audio-visual output device (such as a television or a monitor) coupled to and corresponding to the second receiver RX2 is not limited thereto.

When the signal transmission module 38 receives the two pairs of network differential signals N1± and N2± transmitted by the receiving module 30, the signal transmission module 38 pairs the two pairs of network differential signals N1± and N2. ± transmitted to the third receiver RX3. When the network signal output module 37 receives the two pairs of network differential signals N1± and N2± transmitted by the receiving module 30, the network signal output module 37 outputs the two pairs of network differential signals. N1± and N2±.

In an actual application, the audio-visual transmission system 1 can include a user interface, and the user interface is coupled to the control module. The user interface can be set only on the transmitter TX or the first receiver RX1, or even any receiver, or at the transmitter TX and the receiver at the same time for the user to perform channel selection operation, frequency band setting or The transmission of other control signals and related settings. The user interface can be a button type or a remote control type, and there is no particular limitation.

And the case where the pair of intermediate frequency differential signals IF±, the two pairs of network differential signals N1± and N2±, and the pair of control differential signals D± are transmitted to the third receiver RX3 by the second receiver RX2 and The third receiver RX3 transmits the pair of intermediate frequency differential signals IF±, the two pairs of network differential signals N1± and N2±, and the pair of control differential signals D± to the fourth receiver RX4. It is consistent with the foregoing embodiments, and therefore will not be further described herein.

In summary, in the audio and video transmission system 1 having a video signal splitter type, the transmitter TX can simultaneously output the HDMI digital video signal to the plurality of receivers through a CAT5 transmission line, and through the first receiving. The RX1 to the fourth receiver RX4 are connected in series with each other, so that the HDMI digital audio and video signals received by the first receiver RX1 can be transmitted to the corresponding receivers, which can effectively improve the prior art to set multiple transmission lines. The wiring is complicated and difficult to organize. In addition, the AV transmission system 1 only needs one CAT5 transmission line. It can achieve the simultaneous transmission of digital audio and video signals, network signals and control signals.

Another preferred embodiment of the present invention is also an audiovisual transmission system. In this embodiment, the video transmission system 2 is a matrix type having a plurality of transmitters to a plurality of receivers. Please refer to FIG. 4. FIG. 4 is a schematic diagram of the audio and video transmission system in this embodiment.

As shown in FIG. 4, the video transmission system 2 includes a plurality of transmitters TX1 to TX4, a single transmission line L, and a plurality of receivers RX1 to RX4. In practical applications, the transmission line L can be, for example, a CAT5 transmission line including four pairs of twisted pairs, for transmitting up to four pairs of differential signals, but not limited thereto. In addition, the number of transmitters and receivers in the AV transmission system 2 is not limited to the four of the examples, and can be adjusted according to actual needs.

The first transmitter TX1, the second transmitter TX2, the third transmitter TX3, and the fourth transmitter TX4 in the video transmission system 2 are sequentially connected to each other through a CAT5 transmission line, that is, the first transmitter TX1 is coupled to the second. The transmitter TX2, the second transmitter TX2 is coupled to the third transmitter TX3, and the third transmitter TX3 is coupled to the fourth transmitter TX4; the first receiver RX1, the second receiver RX2, the third receiver RX3, and the fourth The receiver RX4 is connected in series with each other through a CAT5 transmission line, that is, the first receiver RX1 is coupled to the second receiver RX2, the second receiver RX2 is coupled to the third receiver RX3, and the third receiver RX3 is coupled to the fourth receiver. Receiver RX4. The first transmitter TX1 is coupled to the first receiver RX1 via, for example, a CAT5 transmission line L.

Next, please refer to FIG. 5. FIG. 5 is a schematic diagram showing the circuit structure of the first transmitter TX1 and the second transmitter TX2 in FIG. As shown in FIG. 5, the first transmitter TX1 includes an audio and video signal receiving module 40, a modulation module 42, an output module 44, a control module 46, a network signal receiving module 47, a signal transmission module 48, and a hub. Module 49. The audio and video signal receiving module 40 is coupled to the modulation module 42; the modulation module 42 is coupled to the output module 44; the control module 46 is coupled to the modulation module 42, the output module 44, and the signal transmission module 48. The network signal receiving module 47 is coupled to the line module 49; the line module 49 is coupled to the output module 44 and the signal transmission module 48.

The second transmitter TX2 has the same circuit structure as the first transmitter TX1, and includes an audio and video signal receiving module 50, a modulation module 52, an output module 54, a control module 56, a network signal receiving module 57, and a signal transmission. Module 58 and hub module 59. The audio and video signal receiving module 50 is coupled to the modulation module 52; the modulation module 52 is coupled to the output module 54; The module module 52, the output module 54 and the signal transmission module 58; the network signal receiving module 57 is coupled to the hub module 59; the hub module 59 is coupled to the output module 54 and the signal transmission module 58.

The audio and video signal receiving modules 40 and 50 can be, for example, HDMI video signal receivers for receiving digital video signals; the network signal receiving modules 47 and 57 can include RJ45 connectors for receiving Ethernet signals, but none of them This is limited to this.

In the case of the second transmitter TX2, when the video signal receiving module 50 receives the video input signal VS2, the modulation module 52 adjusts the video input signal VS2 to correspond to one of the second frequency band and the second intermediate frequency. The differential signal is combined with the synthesized intermediate frequency differential signal from the third transmitter TX3 transmitted by the signal transmission module 58 to form a pair of intermediate frequency differential signals IF2±, and then transmitted to the output module 54, and One of the CAT5 transmission lines L is transmitted to the signal transmission module 48 of the first transmitter TX1.

It should be noted that the pair of synthesized intermediate frequency differential signals from the third transmitter TX3 includes a pair of third intermediate frequency differential signals corresponding to the third frequency band of the third transmitter TX3 and corresponding to the fourth transmission. A pair of fourth intermediate frequency differential signals in the fourth frequency band of the TX4, since the CAT5 transmission line L can transmit a relatively wide bandwidth, generally at least 15 different channels having a 6M bandwidth can be transmitted, so even The pair of second intermediate frequency differential signals corresponding to the second frequency band, the pair of third intermediate frequency differential signals corresponding to the third frequency band, and the pair of fourth intermediate frequency differential signals corresponding to the fourth frequency band are combined into a pair The intermediate frequency differential signal IF2±, when the CAT5 transmission line L transmits the pair of intermediate frequency differential signals IF2±, the pair of second intermediate frequency differential signals corresponding to different frequency bands, the pair of third intermediate frequency differential signals, and the The fourth intermediate frequency differential signal does not interfere with each other.

In addition, the output module 54 can also receive the differential signal D2± of the network differential signals N12± and N22± from the third transmitter TX3 and the fourth transmitter TX4, and the other one of the CAT5 transmission lines L. The three pairs of twisted pairs are respectively transmitted to the signal transmission module 48 of the first transmitter TX1. The hub module (HUB) 49 will process the network signals according to the Ethernet protocol.

In the case of the first transmitter TX1, when the video signal receiving module 40 receives the video input signal VS1, the modulation module 42 adjusts the video input signal VS1 to correspond to one of the first frequency bands and the first intermediate frequency. The differential signal IF1± is combined with the pair of intermediate frequency differential signals IF2± from the second transmitter TX2 transmitted by the signal transmission module 48 to form a pair of intermediate frequency differential signals IF±, and then transmitted to the output module 44. And outputting the pair of intermediate frequency differential signals IF± to the transmission line L by the output module 44 One of the pair of twisted pairs (for example, the first pair of twisted pairs L1) is transmitted to the first receiver RX1.

It should be noted that since the CAT5 transmission line L can transmit a relatively wide bandwidth, generally at least 15 different channels having a 6M bandwidth can be transmitted, so even if the pair of intermediate frequency differential signals IF2± (including corresponding The pair of second intermediate frequency differential signals in the second frequency band, the pair of third intermediate frequency differential signals corresponding to the third frequency band, and the pair of fourth intermediate frequency differential signals corresponding to the fourth frequency band) and corresponding to The pair of first intermediate frequency differential signals IF1± of the first frequency band are combined into the pair of intermediate frequency differential signals IF±, and when the transmission line L transmits the pair of intermediate frequency differential signals IF±, respectively corresponding to the pair of different frequency bands The first intermediate frequency differential signal, the pair of second intermediate frequency differential signals, the pair of third intermediate frequency differential signals, and the pair of fourth intermediate frequency differential signals do not interfere with each other.

Similarly, the output module 44 will also receive the network differential signals N1± and N2± from the other transmitters and the control differential signal D±, and transmit them through the other three pairs of twisted pairs L2 to L4 in the transmission line L. To the first receiver RX1.

In the above manner, assuming that the transmission line L can transmit at least 15 different channels having a 6M bandwidth, the video transmission system 2 can even include 15 transmitters connected in series with each other and 15 receivers connected in series with each other.

In addition, regarding the circuit configuration of the first receiver RX1 and the second receiver RX2 of the video transmission system 2, the circuit of the first receiver RX1 and the second receiver RX2 of the video transmission system 1 shown in FIG. The structure is the same, and the difference is that the pair of intermediate frequency differential signals IF± in the audio-visual transmission system 2 includes the pair of first intermediate frequency differential signals corresponding to different frequency bands, the pair of second intermediate frequency differential signals, The pair of third intermediate frequency differential signals and the pair of fourth intermediate frequency differential signals, and the pair of intermediate frequency differential signals IF± in the audiovisual transmission system 1 only include the pair of first intermediate frequencies corresponding to the first frequency band For the differential signal, please refer to FIG. 3 and related descriptions, and details are not described herein.

For example, suppose that the user desires that the display corresponding to the second receiver RX2 can play the digital video signal VS2 provided by the DVD player corresponding to the second transmitter TX2, and the user can set it to any transmitter or receive. The user interface of the device is set such that the demodulation module 32 of the second receiver RX2 sets the bandwidth to correspond to the frequency band of the intermediate frequency differential signal output by the modulation module 52 of the second transmitter TX2. The modulation module 52 of the second transmitter TX2 adjusts the video input signal VS2 to correspond to one of the second frequency bands and the second intermediate frequency difference motion. And the pair of second intermediate frequency differential signals included in the pair of intermediate frequency differential signals IF± are first transmitted to the first transmitter TX1, and then transmitted to the first receiver RX1 through the transmission line L, and The sequence is transmitted to the second receiver RX2 to the fourth receiver RX4.

As shown in FIG. 3, when the demodulation module 32 of the second receiver RX2 receives the pair of intermediate frequency differential signals IF± transmitted by the receiving module 30, the pair of intermediate frequency differential signals IF± The second frequency band of the pair of second intermediate frequency differential signals corresponds to the second set frequency band of the demodulation module 32, and the demodulation module 32 pairs the pair of intermediate frequency differential signals IF± The second intermediate frequency differential signal is demodulated into the video input signal VS2, and the output module 34 outputs the video input signal VS2 to the display corresponding to the second receiver RX2 for playing. Therefore, the demodulation module of the receivers can correspondingly set the required frequency band, so that the intermediate frequency differential signal corresponding to the pair of intermediate frequency differential signals IF± is demodulated into an audio and video input signal, and then the corresponding output is output. The audio and video input signal, in contrast, the other intermediate frequency differential signal IF± is not matched with the frequency band set by the demodulator variable module of the receiver, and the intermediate frequency differential signal is continuously transmitted to the next receiver until Demodulation becomes a video input signal when the demodulation module of a receiver is set to match the frequency band.

In summary, the video and audio transmission system 2 of the present invention first converts the digital video signal into an intermediate frequency differential signal, and the first transmitter TX1 to the fourth transmitter TX4 are serially connected to each other. The first receiver RX1 to the fourth receiver RX4 are connected in series with each other, so that the digital audio and video signals received by the first to fourth transmitters TX1 to TX4 can be transmitted to the first transmitter TX1. The transmitter TX1 can simultaneously modulate the digital video signal received by each transmitter through a CAT5 transmission line, and then output the intermediate frequency differential signal to the first receiver RX1, and then transmit it to the first receiver RX1 to all The receiver is then outputted by the demodulation module of each receiver to restore the corresponding intermediate frequency differential signal to digital audio and video signals, thereby effectively improving the wiring complexity caused by the prior art setting of multiple transmission lines. Disadvantages.

Another preferred embodiment of the present invention is also an audiovisual transmission system. In this embodiment, the video transmission system 3 has a plurality of transmitter-to-one receiver audio and video switcher types, and the receiver can select the video source output of one of the transmitters. Please refer to FIG. 6. FIG. 6 is a schematic diagram of the audio and video transmission system in this embodiment.

As shown in FIG. 6, the video transmission system 3 includes a plurality of transmitters TX1 to TX4, a single transmission line L, and a single receiver RX. In practical applications, the transmission line L can be, for example, a CAT5 transmission line including four pairs of twisted pairs, for transmitting up to four pairs of differential signals, but not limited thereto. In addition, the number of transmitters in the audio-video transmission system 3 is not limited to the four of the examples, and can be adjusted according to actual needs.

The first transmitter TX1, the second transmitter TX2, the third transmitter TX3, and the fourth transmitter TX4 in the video transmission system 3 are serially connected to each other through a CAT5 transmission line, that is, the first transmitter TX1 is coupled to the second. The transmitter TX2, the second transmitter TX2 is coupled to the third transmitter TX3, and the third transmitter TX3 is coupled to the fourth transmitter TX4. The first transmitter TX1 is coupled to the receiver RX via, for example, a CAT5 transmission line L.

Please refer to FIG. 5 for a schematic diagram of the circuit configuration of the first transmitter TX1 and the second transmitter TX2 in the audio-video transmission system 3. As shown in FIG. 5, the first transmitter TX1 includes an audio and video signal receiving module 40, a modulation module 42, an output module 44, a control module 46, a network signal receiving module 47, a signal transmission module 48, and a hub. Module 49. The audio and video signal receiving module 40 is coupled to the modulation module 42; the modulation module 42 is coupled to the output module 44; the control module 46 is coupled to the modulation module 42, the output module 44, and the signal transmission module 48. The network signal receiving module 47 is coupled to the line module 49; the line module 49 is coupled to the output module 44 and the signal transmission module 48.

The second transmitter TX2 has the same circuit structure as the first transmitter TX1, and includes an audio and video signal receiving module 50, a modulation module 52, an output module 54, a control module 56, a network signal receiving module 57, and a signal transmission. Module 58 and hub module 59. The audio and video signal receiving module 50 is coupled to the modulation module 52; the modulation module 52 is coupled to the output module 54; the control module 56 is coupled to the modulation module 52, the output module 54, and the signal transmission module 58. The network signal receiving module 57 is coupled to the line module 59; the line module 59 is coupled to the output module 54 and the signal transmission module 58.

As described in the previous embodiment, since the CAT5 transmission line L can transmit a relatively wide bandwidth, generally at least 15 different channels having a 6M bandwidth can be transmitted, so even if the output module 44 of the first transmitter TX1 outputs The pair of intermediate frequency differential signals IF± to the transmission line L are combined by four pairs of intermediate frequency differential signals respectively corresponding to different frequency bands, and when the transmission line L transmits the pair of intermediate frequency differential signals IF± to the receiver RX These four pairs of IF differential signals do not interfere with each other.

Similarly, the output module 44 will also receive network differentials from other transmitters. The signals N1± and N2± and the control differential signal D± are transmitted to the receiver RX through the other three pairs of twisted pairs L2 to L4 in the transmission line L.

In the above manner, assuming that the transmission line L can transmit at least 15 different channels having a 6M bandwidth, the video transmission system 3 may even include 15 transmitters connected in series, but not limited thereto.

Next, please refer to FIG. 7. FIG. 7 is a schematic diagram showing the circuit structure of the receiver RX in FIG. As shown in FIG. 7, the receiver RX includes at least a receiving module 60, a demodulation module 62, and an output module 64. The complex includes a control module 66, a network signal output module 67, and a signal transmission module 68. Line assembly module 69. The receiving module 60 is coupled to the demodulation module 62; the demodulation module 62 is coupled to the output module 64; the control module 66 is coupled to the demodulation module 62; and the network signal output module 67 is coupled The line module 69 is coupled to the line module 69, the receiving module 60, the demodulation module 62, and the control module 66.

The receiving module 60 of the receiver RX coupled to the transmission line L receives a pair of intermediate frequency differential signals IF± transmitted by the first pair of twisted pairs L1 to L4 of the transmission line L, and two pairs of networks. The differential signals N1± and N2± and one pair of control differential signals D±.

When the receiving module 60 receives the pair of control differential signals D±, the receiving module 60 transmits the pair of control differential signals D± to the demodulation module 62. The demodulation module 62 can be operated by the pair of control differential signals D±, for example, demodulation of the variable frequency band, but not limited thereto. In addition, the setting of the demodulator module 62 can also be performed directly through the control module 66 of the receiver RX.

When the receiving module 60 receives the pair of intermediate frequency differential signals IF±, the receiving module 60 transmits the pair of intermediate frequency differential signals IF± to the demodulation module 62. The demodulation module 62 has a specific set frequency band. The pair of intermediate frequency differential signals IF± are four pairs of intermediate frequency differential signals respectively corresponding to four different frequency bands (first frequency band to fourth frequency band) (the pair of first intermediate frequency differential signals to the pair) The four intermediate frequency differential signals are combined. Therefore, when the demodulation module 62 receives the pair of intermediate frequency differential signals IF±, for example, if the pair of the intermediate frequency differential signals IF± The first frequency band of the first intermediate frequency differential signal corresponds to a specific set frequency band of the demodulation module 62, and the demodulation module 62 demodulates the first intermediate frequency differential signal into a video input signal VS1. And outputting the video input signal VS1 by the output module 64, for example, outputting the video input signal VS1 to the coupling and corresponding to the receiver RX Video output device (such as TV or monitor), but not limited to this.

Similarly, if the second frequency band of the pair of second intermediate frequency differential signals of the pair of intermediate frequency differential signals IF± corresponds to a specific set frequency band of the demodulation module 62, the demodulation module 62 will The pair of second intermediate frequency differential signals is demodulated into a video input signal VS2, and the output module 64 outputs the video input signal VS2. The rest and so on.

When the receiving module 60 receives the two pairs of network differential signals N1± and N2±, the receiving module 60 transmits the two pairs of network differential signals N1± and N2± to the network through the line module 69. The signal output module 67, the network signal output module 67 outputs the two pairs of network differential signals N1± and N2± to a network.

In an actual application, the audio-visual transmission system 3 can include a user interface, and the user interface is coupled to the control module. The user interface can be set only at the receiver RX or the first transmitter TX1, or even any transmitter, or at the receiver RX and the transmitter at the same time for the user to perform channel selection operation, frequency band setting or The transmission of other control signals and related settings. The user interface can be a button type or a remote control type, and there is no particular limitation.

In summary, in the audio-video transmission system 3 having the audio-visual switch mode, since the first transmitter TX1 to the fourth transmitter TX4 are connected in series, the first transmitter TX1 only needs to pass through one CAT5 transmission line. At the same time, the HDMI digital audio and video signals from different audio and video sources can be output to the receiver RX at the same time, which can effectively improve the shortcomings of the complicated wiring which is caused by setting multiple transmission lines in the prior art, and the user can change the solution of the receiver RX. The output of different audio and video sources is switched in a manner of a specific set frequency band of the modulation module 62 or a frequency band of the modulation module of each transmitter. In addition, the AV transmission system 3 only needs one CAT5 transmission line to achieve the simultaneous transmission of digital audio and video signals, network signals and control signals.

Compared with the prior art, the video transmission system according to the present invention has the following advantages:

(1) Applicable to different types of audio and video transmission systems, whether it is a transmitter-to-multiple receiver video signal splitter (Splitter) type, or multiple transmitter-to-multiple receiver matrix (Matrix) Type, or a variety of transmitter-to-receiver audio and video switch (Switch) type, only through a CAT5 transmission line can transmit audio and video signals (or even transmit network signals and control signals simultaneously), can improve the prior art Need to set the cloth caused by multiple transmission lines The line is complicated and difficult to organize. In addition, traditionally, multimedia audio and video signals usually contain high-frequency video signals, and because high-frequency signals are more easily attenuated during transmission, high-frequency multimedia audio and video signals (such as HDMI or DVI signals) often exceed The bandwidth of the Category 5 transmission line (CAT5 line) is about 100 MH. Therefore, if the multimedia video signal is not processed, it is difficult to transmit over long distances through the Category 5 transmission line. However, the present invention first converts the multimedia video signal into a differential signal with a frequency less than or equal to 30 MHz by using a modulation module, for example, an intermediate frequency differential signal, which can be applied to a Category 5 transmission line for transmission.

(2) All transmitters are connected in series with each other and the respective received digital video signals are converted into intermediate frequency differential signals and then transmitted to a specific transmitter, and the specific transmitter outputs the intermediate frequency differential signals through a CAT5 transmission line. All receivers are also connected in series with each other, and a specific receiver receives the intermediate frequency differential signal transmitted by the CAT5 transmission line, and then transmits the intermediate frequency differential signal to other receivers to correspondingly demodulate into digital audio and video. Output after the signal.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed.

1‧‧‧Video transmission system

TX‧‧‧transmitter

RX1~RX4‧‧‧ Receiver

L‧‧‧ transmission line

Claims (35)

An audio-visual transmission system includes: a transmitter, comprising: a first receiving module for receiving a first video input signal; a first modulation module coupled to the first receiving module for The first video input signal is modulated into a first pair of intermediate frequency differential signals corresponding to one of the first frequency bands; and a first output module is coupled to the first modulation module for outputting the first An intermediate frequency differential signal; a transmission line coupled to the first output module for transmitting the first pair of intermediate frequency differential signals; and a plurality of receivers, wherein one of the plurality of receivers receives the first The device includes: a second receiving module coupled to the transmission line, configured to receive the first pair of intermediate frequency differential signals, and output the first pair of intermediate frequency differential signals to one of the plurality of receivers a second demodulation module coupled to the second receiving module, the first demodulation module has a first set frequency band, and the first demodulation module receives the second The first pair of intermediate frequency differential signals of the receiving module, if the first pair of intermediate frequency differential signals are the first The segment corresponding to the first set frequency band, the first demodulation module demodulating the first pair of intermediate frequency differential signals into the first video input signal; and a second output module coupled to the first a demodulation module for outputting the first video input signal; wherein the plurality of receivers are connected in series, and the transmitter is coupled to the first receiver through the transmission line. The video transmission system of claim 1, wherein the transmission line includes four pairs of twisted pairs, wherein the transmitter transmits the first pair of intermediate frequency differentials through a first pair of twisted pairs of the transmission line. Signal to the first receiver. The video transmission system of claim 1, wherein the transmitter further comprises a network signal receiving module for receiving a network signal and transmitting the network signal to the first output module, The network signal is transmitted to the first receiver through the transmission line. The audio-visual transmission system of claim 3, wherein the transmission line includes four pairs of twisted pairs for transmitting the transmitter through the second pair of twisted pairs and the third pair of twisted pairs of the transmission line. The network signal is sent to the first receiver. The video transmission system of claim 3, wherein the first receiver comprises a network signal output module coupled to the second receiving module for receiving the network signal and outputting to the external . The video transmission system of claim 1, wherein the transmitter further comprises a control module coupled to the modulation module and the first output module for transmitting a control signal. The video transmission system of claim 6, wherein the transmission line includes four pairs of twisted pairs, wherein the transmitter transmits the control signal to the first reception through a fourth pair of twisted pairs of the transmission line. Device. The video transmission system of claim 1, wherein the first receiver comprises a signal transmission module coupled to the second receiving module for transmitting the first pair of intermediate frequency differential signals. Transfer to the second receiver. The video transmission system of claim 8, wherein the first receiver includes a control module coupled to the signal transmission module and the first demodulation module to send a control signal. . The video transmission system of claim 1, wherein the second receiver comprises: a third receiving module coupled to the first receiver for receiving the first pair of intermediate frequency differences a second demodulation module coupled to the third receiving module, the second demodulation module having a second set frequency band, the second demodulation module receiving the third receiving The first pair of intermediate frequency differential signals of the module, if the first frequency band of the first pair of intermediate frequency differential signals corresponds to the second set frequency band, the second demodulation module is configured to be in the first pair The frequency difference signal is demodulated into the first video input signal; and a third output module is coupled to the second demodulation module for receiving the first video from the second demodulation module Input a signal and output the first video input signal. The audio-visual transmission system of claim 1, further comprising: a user interface disposed on the transmitter and/or the receiver for operation or setting by a user. An audio-visual transmission system, comprising: a plurality of transmitters, wherein one of the plurality of transmitters comprises: a first receiving module for receiving a first video input signal; and a first modulation mode The first receiving module is coupled to the first video input signal to adjust to a first pair of intermediate frequency differential signals corresponding to a first frequency band; and a first output module coupled The first modulation module is configured to output a pair of synthesized intermediate frequency differential signals, wherein the pair of synthesized intermediate frequency differential signals comprise the first pair of intermediate frequency differential signals and one corresponding to a second frequency band For the intermediate frequency differential signal, the second pair of intermediate frequency differential signals are from one of the plurality of transmitters; a transmission line coupled to the first output module for transmitting the pair of composites An intermediate frequency differential signal; and a plurality of receivers, wherein the first receiver of the plurality of receivers comprises: a second receiving module coupled to the transmission line for receiving the pair of synthesized intermediate frequency differential signals And outputting the pair of synthesized intermediate frequency differential signals to the plurality of receiving One of the second receiver; a first demodulation module coupled to the second receiving module, the first demodulation module having a first set frequency band, the first demodulation module receiving the second receiving module The pair of synthesized intermediate frequency differential signals, if the first frequency band of the first pair of intermediate frequency differential signals in the pair of synthesized intermediate frequency differential signals corresponds to the first set frequency band, the first demodulation variable module Demodulating the first pair of intermediate frequency differential signals into the first video input signal; and a second output module coupled to the first demodulation module for outputting the first video input signal; The plurality of transmitters are connected in series, the plurality of receivers are connected in series, and the first transmitter is coupled to the first receiver through the transmission line. The video transmission system of claim 12, wherein the transmission line comprises four pairs of twisted pairs, wherein the first transmitter transmits the pair of synthesized intermediate frequency differences through the first pair of twisted pairs of the transmission line. The signal is sent to the first receiver. The video transmission system of claim 12, wherein the first transmitter comprises a network signal receiving module for receiving a network signal and transmitting the network signal to the first output module. Transmitting the network signal to the first receiver through the transmission line. The audio-visual transmission system of claim 14, wherein the transmission line comprises four pairs of twisted pairs for the first transmitter to pass through one of the transmission lines, the second pair of twisted pairs and a third pair of twisted pairs. The line transmits the network signal to the first receiver. The video transmission system of claim 14, wherein the first receiver comprises a network signal output module coupled to the second receiving module for receiving the network signal and outputting to the external . The video transmission system of claim 12, wherein the first transmitter further includes a control module coupled to the modulation module and the first output module for transmitting A control signal. The audio-visual transmission system of claim 17, wherein the transmission line includes four pairs of twisted pairs, wherein the first transmitter transmits the control signal to the fourth pair of twisted pairs through the transmission line to the first a receiver. The video transmission system of claim 12, wherein the first receiver comprises a signal transmission module coupled to the second receiving module for transmitting the pair of synthesized intermediate frequency differential signals. To the second receiver. The video transmission system of claim 19, wherein the first receiver comprises a control module coupled to the signal transmission module and the first demodulation module to send a control signal. . The video transmission system of claim 12, wherein the second receiver comprises: a third receiving module coupled to the first receiver for receiving the pair of synthesized intermediate frequency differential signals; The second demodulation module is coupled to the third receiving module, the second demodulation module has a second set frequency band, and the second demodulation module receives the third receiving module For synthesizing the intermediate frequency differential signal, if the first frequency band of the first pair of intermediate frequency differential signals in the pair of synthesized intermediate frequency differential signals corresponds to the second set frequency band, the second demodulation module will Demodulating the first pair of intermediate frequency differential signals into the first video input signal; and a third output module coupled to the second demodulation module for using the second demodulation module Receiving the first video input signal and outputting the first video input signal. The video transmission system of claim 12, wherein the first transmitter includes a signal transmission module coupled to the second transmitter and the first output module for receiving The second pair of intermediate frequency differential signals of the two transmitters are transmitted to the first Output module. The video transmission system of claim 12, wherein the second transmitter comprises: a fourth receiving module for receiving a second video input signal; and a second modulation module coupled to the a fourth receiving module, configured to adjust the second video input signal to the second pair of intermediate frequency differential signals corresponding to the second frequency band; and a fourth output module coupled to the second modulation The module and the first transmitter are configured to output the second pair of intermediate frequency differential signals to the first transmitter. The video transmission system of claim 12, further comprising: a user interface disposed on the transmitter and/or the receiver for operation or setting by a user. An audio-visual transmission system, comprising: a plurality of transmitters, wherein one of the plurality of transmitters comprises: a first receiving module for receiving a first video input signal; and a first modulation mode The first receiving module is coupled to the first video input signal to adjust to a first pair of intermediate frequency differential signals corresponding to a first frequency band; and a first output module coupled The first modulation module is configured to output a pair of synthesized intermediate frequency differential signals, wherein the pair of synthesized intermediate frequency differential signals comprise the first pair of intermediate frequency differential signals and one corresponding to a second frequency band For the intermediate frequency differential signal, the second pair of intermediate frequency differential signals are from one of the plurality of transmitters; a transmission line coupled to the first output module for transmitting the pair of composites An intermediate frequency differential signal; and a receiver comprising: a second receiving module coupled to the transmission line for receiving the pair of synthesized intermediate frequency differential signals; a first demodulation module coupled to the second receiving module, the first demodulation module Having a first set frequency band, the first demodulation module receives the pair of synthesized intermediate frequency differential signals from the second receiving module, and if the pair of synthesized intermediate frequency differential signals, the first pair of intermediate frequencies The first frequency band of the differential signal corresponds to the first set frequency band, and the first demodulation module demodulates the first pair of intermediate frequency differential signals into the first video input signal; and a second output The module is coupled to the first demodulation module for outputting the first video input signal; wherein the plurality of transmitters are connected in series, and the first transmitter is coupled to the receiving through the transmission line Device. The video transmission system of claim 25, wherein the transmission line includes four pairs of twisted pairs, wherein the first transmitter transmits the pair of synthesized intermediate frequency differences through the first pair of twisted pairs of the transmission line. The signal is sent to the receiver. The video transmission system of claim 25, wherein the first transmitter comprises a network signal receiving module for receiving a network signal and transmitting the network signal to the first output module. Transmitting the network signal to the receiver through the transmission line. The video transmission system of claim 27, wherein the transmission line includes four pairs of twisted pairs for the first transmitter to pass through one of the transmission lines, the second pair of twisted pairs and a third pair of twisted pairs. The line transmits the network signal to the receiver. The video transmission system of claim 27, wherein the receiver further comprises a network signal output module coupled to the second receiving module for receiving the network signal and outputting to the outside. The video transmission system of claim 25, wherein the first transmitter further comprises a control module coupled to the modulation module and the first output module to send a control signal. The video transmission system of claim 30, wherein the transmission line includes four pairs of twisted pairs, wherein the first transmitter transmits the control signal to the receiving through a fourth pair of twisted pairs of the transmission line. Device. The video transmission system of claim 25, wherein the receiver further comprises a control module coupled to the first demodulation module for transmitting a control signal. The video transmission system of claim 25, wherein the first transmitter includes a signal transmission module coupled to the second transmitter and the first output module for receiving The second pair of intermediate frequency differential signals of the two transmitters are transmitted to the first output module. The video transmission system of claim 25, wherein the second transmitter comprises: a third receiving module for receiving a second video input signal; and a second modulation module coupled to the a third receiving module, configured to adjust the second video input signal to the second pair of intermediate frequency differential signals corresponding to the second frequency band; and a third output module coupled to the second modulation The module and the first transmitter are configured to output the second pair of intermediate frequency differential signals to the first transmitter. The audio-visual transmission system of claim 25, comprising: a user interface disposed on the transmitter and/or the receiver for operation or setting by a user.