CN104079350B - Video and audio transmission device and light emitting module and light receiving module thereof - Google Patents

Abstract

An audio and video transmission device includes a power line communication module, an optical transmitting module and an optical receiving module. The optical transmitting module includes an independent frequency band signal transmitting unit. The optical receiving module includes an independent frequency band signal detection unit. The power line communication module provides data to the power line and synthesizes the power line signal into a composite power line signal. The light emitting module extracts data from the composite power line signal and drives the luminous body to emit light signals based on the data. The optical receiving module receives the optical signal and restores the optical signal and converts it into sound data or image data. When the composite power line signal meets specific conditions, the independent frequency band signal transmitting unit emits a wireless signal including a synchronization signal. The independent frequency band signal detection unit receives the synchronization signal so that the optical receiving module can communicate with the optical transmitting module in synchronization.

Description

Video and audio transmission device and its light-emitting module and light-receiving module

technical field

The present invention is related to video and audio transmission, in particular, to an audio and video transmission device capable of effectively integrating Power Line Communication (PLC) technology and Visible Light Communication (VLC) technology, and a light emitting module and a light receiving module thereof.

Background technique

Generally speaking, Power Line Communication (PLC) technology refers to the use of existing power lines to transmit data or information by means of digital signal processing. Power line communication technology uses existing low-frequency (50-60 Hz) power lines to transmit broadband network information. Compared with ADSL, which uses telephone lines, general power line communication applications use fiber optic lines or cable TV lines. The advantage of using power line communication technology is that there is no need to re-lay network lines, and the area covered by the power line is much wider than that of other carriers.

As for the visible light communication (VLC) technology, it is a wireless communication technology that uses visible light with a frequency between 400THz and 800THz (ie, a wavelength between 375nm and 780nm) as a communication medium. For example, when using ordinary fluorescent lamps for visible light communication, the transmission speed is 10kbit/sec; when using LED lamps for visible light communication, the transmission speed can reach 500Mbit/sec. The transmission distance of visible light communication can reach 1 to 2 kilometers. Its biggest feature is that it can be combined with solid-state lighting technology.

Although power line communication technology and visible light communication technology have their own advantages, however, in terms of audio and video transmission applications, especially for indoor audio and video transmission or video broadcast applications, there is still a lack of an audio and video transmission system and technology that can effectively integrate power lines. Communication technology and visible light communication technology to realize video and audio transmission. Therefore, the present invention proposes an audio-video transmission device and its light-emitting module and light-receiving module to solve the above-mentioned problems encountered in the prior art.

SUMMARY OF THE INVENTION

A specific embodiment according to the present invention is an audio and video transmission device. In this embodiment, the video and audio transmission device includes a power line communication module, a light emitting module and a light receiving module. The power line communication module is used for providing data into the power line to be combined with the power line signal to form a composite power line signal, wherein the data includes audio data or image data. The light emitting module is coupled to the power line. The light emitting module includes a power line communication unit at the transmitting end, a light-emitting driving unit, a light-emitting body, a detection unit and an independent frequency band signal emitting unit. The power line communication unit at the transmitting end is used for fetching data from the composite power line signal. The light-emitting driving unit is coupled to the power line communication unit of the transmitting end, and is used for providing a driving signal according to the data. The light-emitting body is coupled to the light-emitting driving unit, and is used for sending out light signals according to the driving signals. The independent frequency band signal transmitting unit is coupled to the detecting unit. The light receiving module includes a light receiving unit, a power line communication unit at the receiving end, an audio and video restoration unit and an independent frequency band signal detection unit. The light receiving unit is used for receiving the light signal emitted by the light-emitting body. The power line communication unit at the receiving end is coupled to the light receiving unit, and is used for restoring the light signal into data. The audio and video restoration unit is coupled to the power line communication unit of the receiving end, and is used for converting data into audio data or video data. When the detection unit detects that the composite power line signal meets a specific condition, the detection unit controls the independent frequency band signal transmission unit to send out a wireless signal including a synchronization signal. The independent frequency band signal detection unit of the light receiving module receives the synchronization signal in the wireless signal, so that the light receiving module can communicate with the light transmitting module in synchronization.

In one embodiment, the light receiving module is a portable electronic device.

In one embodiment, the light emitting module is disposed on the lamp socket or the light bulb.

In one embodiment, the wireless signal sent by the independent frequency band signal transmitting unit is infrared light, polarized light or radio frequency.

In one embodiment, the specific condition is that the composite power line signal conforms to current zero-cross triggering.

In one embodiment, the power line communication module receives data from the video and audio source through the network.

In one embodiment, the light-emitting body is a visible light-emitting diode.

Another specific embodiment according to the present invention is a light emitting module. In this embodiment, the light emitting module is applied to the transmission of image or sound data. The light emission module includes a power line communication unit, a light-emitting drive unit, a light-emitting body, a detection unit and an independent frequency band signal emission unit. The power line communication unit is coupled to the power line for obtaining data from the composite power line signal transmitted by the power line, wherein the data includes image data or sound data. The light-emitting driving unit is coupled to the power line communication unit for providing driving signals according to data. The light-emitting body is coupled to the light-emitting driving unit, and is used for sending out light signals according to the driving signals. The detection unit is used for detecting whether the composite power line signal meets a specific condition. The independent frequency band signal transmission unit is coupled to the detection unit, when the detection unit detects that the composite power line signal meets a specific condition, the independent frequency band signal transmission unit sends out a wireless signal including a synchronization signal to the optical receiving module, so that the optical receiving module and the optical transmitting module are connected. synchronization between communications.

Another specific embodiment according to the present invention is a light receiving module. In this embodiment, the light receiving module is used for image or sound transmission. The light receiving module includes a light receiving unit, a power line communication unit, an audio and video restoration unit and an independent frequency band signal detection unit. The light receiving unit is used for receiving the light signal emitted by the light-emitting body. The power line communication unit is coupled to the light receiving unit for extracting data from the optical signal. The audio and video restoration unit is coupled to the power line communication unit, and is used for restoring data to video data or sound data. The independent frequency band signal detection unit is used for receiving the synchronization signal in the wireless signal sent by the light transmitting module, so as to synchronize the communication between the light receiving module and the light transmitting module. Among them, the wireless signal including the synchronization signal is sent by the light emitting module when certain conditions are met.

Compared with the prior art, the video and audio transmission device and its light emitting module and light receiving module according to the present invention can effectively integrate the power line communication technology and the visible light communication technology for video and audio transmission, and have the following advantages and effects:

(1) It can be applied to the transmission of indoor audio and video, especially for personal audio and video tours in exhibition venues or museums, indoor video broadcasting, simultaneous translation in multi-language lecture halls, and high-confidence conference rooms.

(2) It is only necessary to use a general power line communication chipset and visible light communication technology to realize the transmission of indoor audio and video, and the cost is relatively low.

(3) In order to synchronize the data sent by the light-emitting module and the data received by the light-receiving module, the audio and video transmission device of the present invention provides the light with an analog current zero-phase sequence trigger signal through another independent frequency band signal (such as low-cost infrared ray). A receiving module, so that the communication between the light receiving module and the light transmitting module can be synchronized.

(4) The light receiving module of the present invention can be installed on a mobile communication device (such as a smart phone or a wireless earphone) according to actual needs, which not only increases the flexibility of use but also facilitates the use of the user.

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

Description of drawings

FIG. 1A is a functional block diagram illustrating an embodiment of the light emitting module TX coupled to the power line PL.

FIG. 1B is a functional block diagram illustrating another embodiment of the light emitting module TX coupled to the power line PL.

FIG. 2 is a functional block diagram illustrating an embodiment of the light receiving module RX.

FIG. 3 is a schematic diagram illustrating an embodiment of the video and audio transmission apparatus of the present invention.

FIG. 4 is a schematic diagram illustrating a detailed circuit structure of an embodiment of the light emitting module TX. FIG. 5 is a schematic diagram illustrating a detailed circuit structure of an embodiment of the light receiving module RX.

【Symbol Description】

PL: Power Line

TX, TX1~TX3: optical transmitter module

MAC: Media Access Control Circuit

10: Front-end circuit

12: DC current generation circuit

14: Voltage to Current Amplifier

15: Processor

16: Current addition circuit

17: White LED

18: Detection unit

19: Infrared LED

S _AV : Composite Power Line Signal

I _DC : DC current signal

I _AC : AC current signal

S _DR : drive signal

S _CT : Control signal

S _syn : Synchronization signal

_SW : Optical signal

RX, RX1~RX3: Optical receiving module

20: Light receiving unit

22: Front-end circuit

24: Infrared sensor

26: Detection unit

28: Processor

AVS: Video source

PLC: Power Line Communication Module

DTU: Detection Unit

IRLED: Infrared Light Emitting Diode

DCG: DC power generation circuit

BPF: Band Pass Filter

TCA: Voltage to Current Amplifier

40: Current addition circuit

42: White Light Emitting Diode

44: Front-end circuit

46: Media Access Control Circuit

MCU: Processor

PGA: Programmable Gain Amplifier

LPF: Low Pass Filter

ADC: AC-DC Converter

PHY: Physical Layer

MAC: Media Access Controller

CLK: clock unit

DAC: DC-AC Converter

PHS: Light Receiver Unit

50: Front-end circuit

IRS: Infrared Sensor

52: Media Access Control Circuit

CPU: processor

ZCD: Zero Current Detector

Detailed ways

A preferred embodiment according to the present invention is an audio and video transmission device. In this embodiment, the video and audio transmission device includes a light emitting module and a light receiving module. In fact, the light emitting module can be disposed on a lamp socket or a light bulb; the light receiving module can be any type of portable electronic device, such as a smart phone, a tablet computer or a wireless earphone, but not limited thereto.

Please refer to FIG. 1A . FIG. 1A is a functional block diagram of an embodiment of the light emitting module TX coupled to the power line PL. As shown in FIG. 1A , the light emitting module TX includes a front-end circuit 10 , a media access control circuit MAC, a DC current generating circuit 12 , a voltage-to-current amplifier 14 , a current summing circuit 16 , a processor 15 , a white LED 17 , a detection unit 18 and Infrared LED19. The front-end circuit 10 and the media access control circuit MAC constitute a power line communication unit at the transmitting end; the DC current generating circuit 12, the voltage-to-current amplifier 14 and the current summing circuit 16 constitute a light-emitting driving unit; the white light LED 17 can also be any other illuminant; The infrared LED 19 can also be any other independent frequency band signal transmitting unit that emits wireless signals (infrared, polarized light or radio frequency), which is not limited to this example.

The power line PL is respectively coupled to the front-end circuit 10 and the DC current generating circuit 12; the front-end circuit 10 is respectively coupled to the medium access control circuit MAC and the detection unit 18; the medium access control circuit MAC is respectively coupled to the voltage-to-current amplifier 14 and the processor 15 The DC current generating circuit 12 and the voltage-to-current amplifier 14 are both coupled to the current summing circuit 16; the current summing circuit 16 is coupled to the white LED17; the detection unit 18 is coupled to the infrared LED19.

In this embodiment, since the power line PL is coupled to the front-end circuit 10, the detection unit 18 and the DC current generation circuit 12, respectively, the composite power line signal _SAV transmitted by the power line PL will be transmitted to the front-end circuit 10, the detection unit 18 and the DC current. Generation circuit 12 . In one embodiment, the composite power line signal S _AV is an AC voltage signal with a specific operating frequency, which carries data belonging to a high frequency signal. The operating frequency is not limited, generally speaking, it is 60Hz. The front-end circuit 10 is used for gain filtering the composite power line signal _SAV , and then the medium access control circuit MAC extracts data from the gain filtered signal. The data includes video data or audio data. As for the DC current generating circuit 12 , the DC current signal I _DC is provided to the current adding circuit 16 according to the composite power line signal S _AV .

The voltage-to-current amplifier 14 is used to convert the data extracted by the medium access control circuit MAC into an alternating current signal I _AC and output to the current adding circuit 16 . When the current summing circuit 16 receives the direct current signal I _DC and the alternating current signal I _AC from the direct current generating circuit 12 and the voltage-to-current amplifier 14, respectively, the current summing circuit 16 couples the direct current signal I _DC and the alternating current signal I _AC It is the driving signal SDR and is output to the white _LED17 . The white light LED 17 will emit a light signal SW according to the driving signal _{S DR} . Since the driving signal _SDR is the combination of the DC current signal and the analog AC current signal, the light-emitting signal of the white LED 17 will produce a continuous combined change of increasing and decreasing light intensity with the change of the analog AC current signal.

The detection unit 18 is used for detecting a specific condition on the composite power line signal S _AV as a basis for signal synchronization with the light receiving module RX. Since in this embodiment, the signal corresponding to the data is carried on an AC voltage signal, the specific condition is based on the time point at which the current zero-cross of the AC voltage signal is triggered as the basis for signal synchronization. It should be noted that although the composite power line signal S _AV is a composite signal composed of a power signal and a data signal, the existence of the data signal can be regarded as noise to the detection unit 18, and therefore does not affect the zero-phase sequence triggering ( Zero-cross) time point detection; however, in another embodiment, a filter to filter out the data signal can be set before the detection unit 18 or inside the detection unit 18, which can be determined by those skilled in the art according to requirements. The setting is not a limitation for implementing the spirit of the present invention. When the detection unit 18 detects that the composite power line signal S _AV meets the specific condition (such as current zero-phase sequence triggering), the detection unit 18 outputs the control signal S _CT to the infrared LED 19 to control the infrared LED 19 to emit a wireless radio including the synchronization signal S _syn Signal. When the detection unit 18 does not detect that the composite power line signal S _AV meets a specific condition (eg, current zero-phase sequence triggering), the infrared LED 19 will not send out a wireless signal including the synchronization signal S _syn .

Please also refer to FIG. 1B , which is a functional block diagram illustrating another embodiment of the light emitting module TX coupled to the power line PL. The difference between FIG. 1B and FIG. 1A is that the detection unit 18 in FIG. 1B is disposed in the front-end circuit 10 and coupled to the infrared LED 19 , while the detection unit 18 in FIG. 1A is disposed between the front-end circuit 10 and the infrared LED 19 . But both are used to detect whether the composite power line signal S _AV conforms to the current zero-phase sequence trigger, so as to selectively control the infrared LED 19 to send out a wireless signal including the synchronization signal S _syn .

Next, please refer to FIG. 2 , which is a functional block diagram illustrating an embodiment of the light receiving module RX. As shown in FIG. 2 , the light receiving module RX includes a light receiving unit 20 , a front-end circuit 22 , an infrared sensor 24 , a detection unit 26 , a medium access control circuit MAC and a processor 28 . The front-end circuit 22 and the medium access control circuit MAC constitute the receiving-end power line communication unit. The light receiving unit 20 is coupled to the front-end circuit 22 ; the infrared sensor 24 is coupled to the detection unit 26 ; the front-end circuit 22 and the detection unit 26 are both coupled to the medium access control circuit MAC;

1A or 1B, when the white light _LED17 of the light emitting module TX sends out the light signal SW, the light receiving unit 20 of the light receiving module RX in FIG. 2 will receive the light signal _SW and transmit it to the front-end circuit 22, After the front-end circuit 22 performs gain filtering on the optical signal _SW , the medium access control circuit MAC obtains data from the gain-filtered optical signal _SW and outputs the data to the processor 28 . The processor 28 includes an audio and video restoration unit (not shown) for restoring the data to video data or audio data and then outputting the data.

When the detection unit 26 detects that the wireless signal received by the infrared sensor 24 includes the synchronization signal S _syn , the detection unit 26 outputs the synchronization signal S _syn to the processor 28 through the medium access control circuit MAC, so that the light receiving module RX The communication with the light transmitting module TX can be synchronized. Through the synchronization signal S _syn , the detection unit 26 can correctly determine the timing of receiving data.

Please refer to FIG. 3 . FIG. 3 is a schematic diagram illustrating an embodiment of the video and audio transmission apparatus of the present invention. As shown in FIG. 3 , it is assumed that the audio and video transmission device is used in an indoor environment, and the audio and video transmission device includes a power line communication module PLC, a power line PL, light transmitting modules TX1-TX3 and light receiving modules RX1-RX3. Wherein, the power line communication module PLC is coupled to the power line PL that has been installed indoors, and the power line PL is coupled to the light emitting modules TX1 to TX3 respectively disposed on different lamp sockets or bulbs.

The power line communication module PLC can receive data including audio data or video data in a wired or wireless manner from the audio and video source AVS (such as a notebook computer or audio and video player, but not limited to this) through a network or a connecting line, and send It is combined with the power line signal to form a composite power line signal S _AV , which is then loaded onto the power line PL, and the composite power line signal S _AV is transmitted to the light transmitting modules TX1 - TX3 by the power line PL, respectively.

The operation of the light transmitting modules TX1 - TX3 is as shown in FIG. 1A or FIG. 1B , respectively receiving the composite power line signal _{S AV} from the power line PL and outputting different optical signals SW . When the light transmitting modules TX1-TX3 detect that the composite power line signal S _AV meets a specific condition (eg current zero-phase sequence triggering), the light transmitting modules TX1-TX3 will send out wireless signals including the synchronization signal S _syn .

It is assumed that different users are wearing (or carrying) the optical receiving modules RX1 to RX3 and stand within the signal transmission range of the optical transmitting modules TX1 to TX3, that is, the optical receiving module RX1 is located near the light transmitting module TX1, and the optical receiving module RX2 The light transmitting module TX2 is located near the bottom and the light receiving module RX3 is located near the light transmitting module TX3. The operation of the light-receiving modules RX1-RX3 is as shown in FIG. 2, respectively, receiving different optical signals SW from the light-emitting modules TX1- _TX3 and restoring them to the original sound data or image data, and then outputting them for wearing respectively. Each user of (or carrying) the light receiving modules RX1 to RX3 listens to the audio data or watches the video data.

Therefore, assuming that the composite power line signal S _AV transmitted by the power line PL to each of the light emitting modules TX1 ˜ TX3 has different audio data or video data, then each user standing under the different light emitting modules TX1 ˜ TX3 can listen to them respectively. to a different sound or to see a different image.

For example, in the exhibition hall, it is assumed that different visitors wear wireless guide headsets (light receiving modules) RX1 to RX3, as shown in Figure 3, when the visitor wearing the wireless guide headset RX1 walks to the light emission When the module is below the module TX1, the wireless navigation headset RX1 will receive the optical signal sent by the optical transmission module TX1, and restore the voice introduction data about the exhibits located under the optical transmission module TX1 from the optical signal, so as to play it to the audience. Visitors listen. Similarly, when a visitor wearing the wireless guide headset RX2 walks under the light emitting module TX2, the wireless guide headset RX2 will receive the optical signal sent by the light emitting module TX2, and restore the information from the light signal. The audio introduction data of the exhibits located under the light emitting module TX2 is played for the visitors to listen to; when the visitor wearing the wireless guide headset RX3 walks under the light emitting module TX3, the wireless guide headset RX3 will receive to the optical signal sent by the light emitting module TX3, and restore the voice introduction data about the exhibits located under the light emitting module TX3 from the optical signal, so as to play it for the visitors to listen to.

Of course, once the visitor wearing the wireless guide headset RX3 walks from the light emitting module TX3 to the light emitting module TX2, since the wireless guide headset RX3 is located within the signal transmission range of the light emitting module TX2 at this time, Therefore, the wireless guide headset RX3 will be changed to receive the optical signal sent by the optical transmitting module TX2, and restore the voice introduction data about the exhibits located under the optical transmitting module TX2 from the optical signal, so as to be played to the visitors. . The rest of the cases can be deduced by analogy, and will not be repeated here.

Please refer to FIG. 4 . FIG. 4 is a schematic diagram illustrating a detailed circuit structure of an embodiment of the light emitting module TX. As shown in FIG. 4 , the light emitting module TX includes a detection unit DTU, an infrared light-emitting diode IRLED, a DC power generation circuit DCG, a band-pass filter BPF, a voltage-to-current amplifier TCA, a current adding circuit 40, a white light-emitting diode 42, and a front-end circuit. 44. A medium access control circuit 46 and a processor MCU. The front-end circuit 44 includes a programmable gain amplifier PGA and a low-pass filter LPF; the media access control circuit 46 includes an AC-DC converter ADC, a physical layer PHY, a media access controller MAC, a clock unit CLK and a DC-DC converter. AC Converter DAC.

In this embodiment, the composite power line signal S _AV transmitted by the power line PL will be respectively transmitted to the detection unit DTU, the DC power generation circuit DCG and the band pass filter BPF; the detection unit DTU is coupled to the infrared light emitting diode IRLED; the band pass filter The device BPF is coupled to the front-end circuit 44, which includes a programmable gain amplifier PGA and a low-pass filter LPF. In this embodiment, the band-pass filter BPF is coupled to the programmable gain amplifier PGA, the programmable gain amplifier PGA is coupled to the low-pass filter LPF; the low-pass filter LPF is coupled to the AC-DC converter ADC; The device ADC is coupled to the physical layer PHY; the physical layer PHY is coupled to the media access controller MAC and the clock unit CLK; the media access controller MAC is coupled to the clock unit CLK and the processor MCU; the DC-AC converter DAC is coupled to Between the physical layer PHY and the voltage-to-current amplifier TCA; the DC power generation circuit DCG and the voltage-to-current amplifier TCA are both coupled to the current summing circuit 40 ; the current summing circuit 40 is coupled to the white light emitting diode 42 and is emitted by the white light emitting diode 42 Optical signal S _W . When the detection unit DTU detects that the composite power line signal S _AV meets certain conditions (eg current zero-phase sequence triggering), the detection unit DTU controls the infrared light-emitting diode IRLED to emit a wireless signal including the synchronization signal S _syn .

Please refer to FIG. 5 , which is a schematic diagram illustrating a detailed circuit structure of an embodiment of the light receiving module RX. As shown in FIG. 5 , the light receiving module RX includes a light receiving unit PHS, a band pass filter BPF, a front-end circuit 50 , an infrared sensor IRS, a medium access control circuit 52 and a processor CPU. The front-end circuit 50 includes a programmable gain amplifier PGA, a low-pass filter LPF and a zero current detector ZCD; the media access control circuit 52 includes an AC-DC converter ADC, a physical layer PHY, a media access controller MAC, a time Pulse unit CLK and DC-AC converter DAC.

In this embodiment, the wireless signal including the synchronization signal S _syn emitted by the infrared light emitting diode IRLED in FIG. 4 is received by the infrared sensor IRS in FIG. 5 ; the light signal S emitted by the white light emitting diode 42 in FIG. 4 _W is received by the light receiving unit PHS in FIG. 5 . The light receiving unit PHS is coupled to the band-pass filter BPF; the band-pass filter BPF is coupled to the programmable gain amplifier PGA; the programmable gain amplifier PGA is coupled to the low-pass filter LPF; the low-pass filter LPF is coupled to the AC-DC converter ADC; AC-DC converter ADC coupled to physical layer PHY; physical layer PHY coupled to media access controller MAC and clock unit CLK; media access controller MAC coupled to clock unit CLK and processor MCU; DC-AC The converter DAC is coupled to the physical layer PHY; the zero current detector ZCD is coupled to the infrared sensor IRS. When the zero current detector ZCD detects that the infrared sensor IRS receives the wireless signal including the synchronization signal S _syn from the infrared light emitting diode IRLED in FIG. 4 , the zero current detector ZCD outputs a control signal to the physical layer PHY to control the light The clock unit CLK of the receiving module RX can be synchronized with the light transmitting module TX.

Compared with the prior art, the video and audio transmission device and its light emitting module and light receiving module according to the present invention can effectively integrate the power line communication technology and the visible light communication technology for video and audio transmission, and have the following advantages and effects:

(1) It can be applied to the transmission of indoor audio and video, especially for personal audio and video tours in exhibition venues or museums, indoor video broadcasting, simultaneous translation in multi-language lecture halls, and high-confidence conference rooms.

(2) It is only necessary to use a general power line communication chipset and visible light communication technology to realize the transmission of indoor audio and video, and the cost is relatively low.

(3) Since the power line communication chipset requires a current zero-phase sequence trigger (zero-cross) signal, the audio-video transmission device of the present invention simulates the current zero-phase sequence trigger signal through another independent frequency band signal (such as low-cost infrared rays), so that the The communication between the light receiving module and the light transmitting module can be synchronized.

(4) The light receiving module of the present invention can be installed on a mobile communication device (such as a smart phone or a wireless earphone) according to actual needs, which not only increases the flexibility of use but also facilitates the use of the user.

Through the detailed description of the preferred embodiments above, it is hoped that the features and spirit of the present invention can be described more clearly, rather than limiting the scope of the present invention by the preferred embodiments disclosed above. On the contrary, the intention is to cover various modifications and equivalent arrangements within the scope of the appended claims.

Claims (14)

1. A video and audio transmission device, comprising: a power line communication module for providing a data to a power line to synthesize a power line signal into a composite power line signal, wherein the data includes a sound data or an image data; A light emitting module, coupled to the power line, includes: a transmitting-end power line communication unit for fetching the data from the composite power line signal; a light-emitting driving unit, coupled to the transmitting power line communication unit, for providing a driving signal according to the data; a light-emitting body, coupled to the light-emitting driving unit, for sending out a light signal according to the driving signal; a detection unit; and an independent frequency band signal transmission unit, coupled to the detection unit; and A light receiving module, including: a light-receiving unit for receiving the light signal sent by the light-emitting body; a power line communication unit at the receiving end, coupled to the light receiving unit, for restoring the light signal to the data; an audio and video restoration unit, coupled to the power line communication unit at the receiving end, for converting the data into the audio data or the video data; and an independent frequency band signal detection unit; Wherein, when the detection unit detects that the composite power line signal meets a specific condition, the detection unit controls the independent frequency band signal transmitting unit to send out a wireless signal including a synchronization signal, and the independent frequency band signal detection unit of the light receiving module receives The synchronization signal in the wireless signal enables communication synchronization between the light receiving module and the light transmitting module, wherein the specific condition is that the composite power line signal conforms to current zero-phase sequence triggering. 2 . The video and audio transmission device of claim 1 , wherein the light receiving module is a portable electronic device. 3 . 3 . The audio-video transmission device of claim 1 , wherein the light emitting module is disposed on a lamp socket or a light bulb. 4 . 4 . The video and audio transmission device of claim 1 , wherein the wireless signal sent by the independent frequency band signal transmitting unit is an infrared ray, a polarized light, or a radio frequency. 5 . 5 . The video and audio transmission device of claim 1 , wherein the power line communication module receives the data from an audio and video source end through a network. 6 . 6 . The video and audio transmission device of claim 1 , wherein the light-emitting body is a visible light-emitting diode. 7 . 7. A light emitting module, applied to the transmission of image or sound data, the light emitting module comprising: a power line communication unit, coupled to a power line, for obtaining a data from a composite power line signal transmitted by the power line, wherein the data includes an image data or a sound data; a light-emitting driving unit, coupled to the power line communication unit, for providing a driving signal according to the data; a light-emitting body, coupled to the light-emitting driving unit, for sending out a light signal according to the driving signal; a detection unit for detecting whether the composite power line signal meets a specific condition; and an independent frequency band signal transmission unit, coupled to the detection unit, when the detection unit detects that the composite power line signal meets the specific condition, the independent frequency band signal transmission unit transmits a wireless signal including a synchronization signal to an optical receiving module, In order to synchronize the communication between the light receiving module and the light transmitting module, the specific condition is that the composite power line signal conforms to current zero-phase sequence triggering. 8 . The light emitting module of claim 7 , wherein the detection unit is coupled to the power line or disposed in the power line communication unit. 9 . 9. The light emitting module of claim 7, wherein the power line communication unit further comprises: a front-end circuit for gain filtering the composite power line signal; and A medium access control circuit, coupled to the front-end circuit, is used for extracting the data from the composite power line signal after gain filtering. 10. The light emitting module of claim 9, wherein the light-emitting driving unit comprises: a DC power generating circuit, coupled to the power line, for providing a DC current signal; a voltage-to-current amplifying circuit, coupled to the medium access control circuit, for converting the data taken out by the medium access control circuit into an alternating current signal and outputting it; and A current adding circuit is coupled between the DC power generating circuit and the light-emitting body, and is used for coupling the DC current signal and the AC current signal to form the driving signal. 11 . The light transmitting module of claim 7 , wherein the wireless signal sent by the independent frequency band signal transmitting unit is an infrared light, a polarized light or a radio frequency. 12 . 12. A light receiving module, applied to the transmission of images or sounds, the light receiving module comprising: a light-receiving unit for receiving a light signal sent by a light-emitting body; a power line communication unit, coupled to the light receiving unit, for extracting a data from the light signal; an audio and video restoration unit, coupled to the power line communication unit, for restoring the data to an image data or a sound data; and an independent frequency band signal detection unit for receiving a synchronization signal in a wireless signal sent by an optical transmitter module, so as to synchronize the communication between the optical receiver module and the optical transmitter module; Wherein, the wireless signal including the synchronization signal is sent by the light emitting module when a specific condition is met, and the specific condition is that a composite power line signal conforms to current zero-phase sequence triggering. 13. The light receiving module of claim 12, wherein the power line communication unit further comprises: a front-end circuit, coupled to the light receiving unit, for performing gain filtering on the light signal; and A medium access control circuit, coupled to the front-end circuit, is used for obtaining the data from the gain filtered optical signal. 14. The light receiving module of claim 12, wherein it is a portable electronic device.