WO2008075608A1

WO2008075608A1 - Transmission system, transmission device, reception device, signal transmission method, and program

Info

Publication number: WO2008075608A1
Application number: PCT/JP2007/074005
Authority: WO
Inventors: Shuya Kishimoto; Kenichi Maruhashi
Original assignee: Nec Corporation
Priority date: 2006-12-20
Filing date: 2007-12-13
Publication date: 2008-06-26

Abstract

[PROBLEMS] To provide a video transmission method capable of suppressing disturbance of a video and an audio even if one of communication paths is disconnected in a transmission system for transmitting a video signal and an audio signal via a plurality of communication paths and a system for realizing the method. [MEANS FOR SOLVING PROBLEM] A transmission signal generation unit (2) divides a video signal an output signal from an output device (1) by a predetermined amount of information. The divided signals are distributed and transmitted to a plurality of transmission units (3). The transmitted signals are received by a plurality of reception units (4). Synchronization of the signals are detected by a reception signal processing unit (5) so that a video signal is generated from all the signals for which synchronization has been detected. When synchronization is not detected for at least one input signal, a video signal is generated with a drop frame and outputted to a display device (6).

Description

Specification

Transmission system, transmission device, reception device, signal transmission method and program

The present invention relates to a technique for transmitting high-definition video via a plurality of communication paths, and to a technique for reducing disturbance between video and audio even when at least one communication path is interrupted. Background art

[0002] In recent years, with the rapid spread of large-screen displays capable of displaying high-definition video and the start of terrestrial digital broadcasting, it has become possible to easily view high-definition video even at home. In order to enjoy high-definition video, devices such as tuners and DVD players are required. Considering the user's degree of freedom, it is desirable not to install the functions of these devices on the display, but to combine the display and these devices in various ways. However, in this case, the devices must be connected with cables, which causes a problem that damages the aesthetics of the room.

[0003] Therefore, there is a growing need for devices that transmit high-definition video using wireless transmission technology. A device that transmits high-definition video compressed with a high compression ratio using conventional wireless LAN technology has been developed. There are also problems such as interference with radio waves used by other devices, and transmission quality is not always maintained. /!

[0004] Furthermore, encoding / decoding circuits for compression are required, which causes an increase in cost, and circuit and software upgrades are required to adapt to the compression technology that advances day by day. .

[0005] As a method for solving these problems, transmission systems using millimeter waves have been developed. For example, Non-Patent Document 1 describes a device for transmitting video using 60 GHz band radio waves. The transmission speed of this device is 1.5 Gbps, and it is possible to transmit high-definition video without compression. In addition, millimeter waves have the advantage that free space loss is large, and because there is almost no diffraction due to its strong straightness, there is almost no interference with radio waves from other devices. /!

[0006] On the other hand, a millimeter wave with strong straightness has an obstacle such as a person between the transmitter and the receiver. If it exists, there is a problem that radio waves are blocked and communication is interrupted. In order to solve such problems, if two receivers 2 are used for one transmitter, and one receiver cannot receive a signal due to shielding, as in the device shown in FIG. Switch to the other receiver and receive a signal! /

[0007] However, in wireless communication, not limited to millimeter waves, communication quality deteriorates due to multipath caused by reflected waves from a building wall or the like, and the bit error rate of a received signal increases. In order to improve this, there are a method of requesting retransmission to the transmitting side and a method of adding an error correction code to the data string. In non-compressed video transmission, there is no delay, and error correction is used from a retransmission request. However, if an error correction code is added to the data string, the amount of transmission data increases, which causes problems such as an increase in the occupied bandwidth of the signal and a reduction in transmission distance.

[0008] Therefore, a method of dividing transmission data into two or more communication channels, for example, a plurality of communication channels having different frequencies, and communicating in parallel can be considered. This method makes it possible to perform high-capacity and highly reliable communication as a whole system without having to increase the amount of transmission data per communication path.

Non-Patent Document 1: 25tn IEEE Gallium Arsenide Integrated Circuit (GaAs IC; Symposium, Annual Technical Digest 2003. Pages 85-88, Nov. 2003

Disclosure of the invention

Problems to be solved by the invention

[0009] Even in the case of using parallel communication as described above, if a person enters at least one communication path, the radio wave is blocked, transmission data is lost, and the image is disturbed.

[0010] To solve this problem, when the configuration as shown in FIG. 16 is applied to each communication path, the number of receivers is more than twice that of the transmitter, leading to an increase in system cost.

[0011] Therefore, the problem to be solved by the present invention is to solve the above problems, and provide a technique for transmitting high-definition video and audio using a small number of transmitters and receivers. It is to be.

Means for solving the problem [0012] A first invention for solving the above-described problems is

A transmission system,

A transmission signal generation unit that divides the image signal based on a predetermined condition;

A plurality of transmission units for allocating and transmitting the divided image signals;

A plurality of receiving units for receiving the transmitted image signals;

A received signal processing unit for displaying a synchronized image signal among the received image signals;

It is characterized by having.

[0013] A second invention for solving the above-described problem is the above-described first invention,

The transmission signal generation unit divides the image signal for each frame.

[0014] A third invention for solving the above-described problem is the above-described first invention,

The transmission signal generation unit divides the image signal for each scanning line.

[0015] A fourth invention for solving the above-mentioned problems is any one of the first to third inventions described above.

The transmission signal generation unit includes an encoding unit that encodes the divided image signal.

[0016] A fifth invention for solving the above-mentioned problems is any one of the first to third inventions described above.

The transmission signal generation unit includes an encoding unit, and divides the image signal encoded by the encoding unit.

[0017] A sixth invention for solving the above-mentioned problems is any one of the first to fifth inventions described above.

The transmission signal generation unit has a memory for holding the divided image signal, and the number of memories is more than twice the number of the transmission units.

[0018] A seventh invention for solving the above-described problems is the above-described sixth invention,

The transmission speed of the image signal input to the memory is different from the transmission speed of the image signal output from the memory.

[0019] An eighth invention for solving the above-mentioned problems is A transmission device for a transmission system that transmits and displays an image signal,

A plurality of transmitters for allocating and transmitting the divided image signals;

It is characterized by having.

[0020] A ninth invention for solving the above-mentioned problems is the above-mentioned eighth invention,

[0021] A tenth invention for solving the above-mentioned problems is the above-mentioned eighth invention,

[0022] An eleventh invention for solving the above-described problems is any one of the eighth to tenth inventions,

[0023] A twelfth invention for solving the above-described problems is any one of the eighth to tenth inventions,

[0024] A thirteenth invention for solving the above-described problems is any one of the eighth to twelfth inventions,

[0025] A fourteenth invention for solving the above-described problem is the above-described thirteenth invention,

[0026] The fifteenth invention for solving the above-mentioned problems is

A receiving device of a transmission system for transmitting and displaying an image signal,

A plurality of receiving units for receiving image signals divided based on a predetermined condition; a received signal processing unit for displaying a synchronized image signal among the received image signals; It is characterized by having.

[0027] A sixteenth invention for solving the above-described problems is the fifteenth invention, in which

The divided image signal is divided into frames! /, For each frame.

[0028] A seventeenth invention for solving the above-mentioned problems is the above-mentioned sixteenth invention,

The divided image signal is divided for each scanning line! /.

[0029] An eighteenth invention for solving the above-described problems is

A signal transmission method comprising:

A division step of dividing the image signal into predetermined information amounts;

A transmission step of allocating the divided image signals and transmitting them from a plurality of transmission units; a reception step of receiving the transmitted image signals by a plurality of reception units; and among the received image signals, synchronized And a display step for displaying an image signal.

[0030] In a nineteenth aspect of the invention for solving the above-described problem, in the eighteenth aspect of the invention,

In the dividing step, the image signal is divided for each frame.

[0031] A twentieth aspect of the invention for solving the above-described problems is the eighteenth aspect of the invention,

In the dividing step, the image signal is divided for each scanning line.

[0032] A twenty-first invention for solving the above-mentioned problems is any one of the eighteenth to twentieth inventions,

The dividing step includes an encoding step for encoding the divided image signal.

[0033] According to a twenty-second invention for solving the above-mentioned problem, in any one of the eighteenth to twentieth inventions,

The dividing step divides the encoded image signal.

[0034] The twenty-third invention for solving the above-mentioned problems is

A transmission system program, the program comprising: a transmission signal generation unit that divides the transmission system based on a predetermined condition;

A plurality of receiving units for receiving the transmitted image signals; Of the received image signals, a received signal processing unit for displaying a synchronized image signal

It is made to function as.

[0035] A twenty-fourth invention for solving the above-described problems is

A program for a transmission device in a transmission system for transmitting and displaying an image signal

, The program sends the transmitting device,

A transmission signal generation unit that divides the image signal based on a predetermined condition and allocates the divided image signal to a plurality of transmission units;

It is characterized by functioning.

[0036] A twenty-fifth invention for solving the above-described problems is

A program for a receiving apparatus in a transmission system for transmitting and displaying an image signal.

, The program is for the receiving device,

A received signal processing unit that displays an image signal from a receiving unit that has received a synchronized image signal among image signals divided based on a predetermined condition;

It is characterized by functioning.

[0037] The present invention divides a video signal input from a plurality of transmission units having different radio frequency or polarization and an output device into a predetermined amount of information, and the information is input from the output device. A transmission signal generation unit that generates a transmission information in which an audio signal and a synchronization signal are inserted, and outputs the transmission information to the plurality of transmission units; a plurality of reception units having different radio frequency or polarization; A reception signal processing unit is provided for synthesizing transmission signals obtained from radio signals received by the reception unit and generating video signals and audio signals.

[0038] The transmission signal generation unit according to the present invention is divided into a synchronization detection unit that detects vertical or horizontal synchronization with respect to an input video signal, a plurality of buffer memories that hold the video signal, and a predetermined amount of information. A signal conversion unit that converts the received video signal into a transmission signal, and the predetermined amount of information is set to one frame or one scanning line, and is distributed to a plurality of transmission units for each frame or each scanning line. And features.

[0039] In the present invention, the reception signal processing unit includes a plurality of synchronization detection units that detect synchronization of transmission signals input from the plurality of reception units, and converts the transmission signals into audio signals and video signals. A signal converter and multiple buffer memories that hold video signals. Video signals and audio signals are generated from at least one transmission signal for which synchronization has been detected, and all synchronization detectors synchronize. If no signal is detected, the last output video is output and the sound is muted.

[0040] According to the transmission method of the present invention, a video signal is divided into information amounts for one frame or one scanning line, transmitted from a plurality of transmission units for each frame or scanning line, and received for each received frame. Alternatively, only the signal for which synchronization is detected among the signals for each scanning line is used, and the video signal is generated by frame dropping or scanning line dropping.

The invention's effect

[0041] According to the present invention, it is possible to realize a video transmission method and a video transmission method that can suppress disturbance of video and audio even when at least one of the plurality of communication channels is blocked.

[0042] This is because the present invention employs a configuration in which a video signal from a communication path in which synchronization is detected is output with a frame drop or a scan line drop, and at least one of a plurality of wireless communication paths is used. If one path can communicate, it is possible to reduce the disturbance between video and audio, and to reduce the problem of radio wave shielding.

Brief Description of Drawings

FIG. 1 is a configuration diagram of a transmission system according to the present invention.

FIG. 2 is a configuration diagram of a transmission signal generation unit 2 according to the first embodiment.

FIG. 3 is a configuration diagram of a received signal processing unit 5 according to the first embodiment.

FIG. 4 is a diagram for explaining an operation of a transmission signal generation unit 2 according to the first embodiment.

FIG. 5 is a diagram for explaining the operation of the received signal processing unit 5 according to the first embodiment when communication can be performed on all communication paths.

FIG. 6 is a diagram for explaining the operation of the reception signal processing unit 5 according to the first embodiment when communication cannot be performed through at least one of a plurality of communication paths.

FIG. 7 is a diagram of transmission signal data according to the first embodiment.

FIG. 8 is a configuration diagram of another form of the transmission signal generation unit 2 according to the first embodiment.

[Fig. 9] Fig. 9 is a configuration diagram of another form of received signal processing unit 5 according to the first embodiment. 10] A diagram for explaining the operation of the transmission signal generation unit 2 according to the second embodiment. 11] A received signal according to the second embodiment when communication can be performed through a plurality of communication paths. 7 is a diagram for explaining the operation of the processing unit 5. FIG.

FIG. 12 is a diagram for explaining the operation of the received signal processing unit 5 according to the second embodiment when communication cannot be performed through at least one of a plurality of communication paths.

13] is a transmission signal data diagram according to the second embodiment.

14] A configuration diagram of the transmission signal generation unit 2 according to the third embodiment.

15] A block diagram of the received signal processing unit 5 according to the third embodiment.

FIG. 16 is a block diagram of a conventional transmission system.

Explanation of symbols

1 Output device

2 Transmit signal generator

3 Transmitter

4 Receiver

5 Received signal processor

6

7 Control unit

8 Sync detector

9 Audio buffer

10 Switching section

11 a, l ib Video buffer

12a, 12b Video buffer

13a, 13b switching part

14a, 14b Sign part

15a, 15b Signal converter

16 Speech decoder

17 Control unit 18a, 18b Sync detector

19a, 19b Signal converter

20a, 20b decoder

21 a, 21b switching part

22a, 22b Video buffer

23a, 23b Video buffer

24 Switching section

25 Audio buffer

26a, 26b Audio decoder

27 Voice switching part

28 Audio buffer

29 Sign part

30 Decryption unit

31 Transmission signal generator

32 Signal selector

33 Received signal processor

BEST MODE FOR CARRYING OUT THE INVENTION

[0045] In order to explain the characteristics of the present invention, the following is specifically described with reference to the drawings.

[0046] A first embodiment for carrying out the present invention will be described in detail with reference to the drawings.

[0047] <First embodiment>

A block diagram of the transmission system according to the present embodiment is shown in FIG.

The transmission system includes a transmission device having an output device 1, a transmission signal generation unit 2, and a plurality of transmission units 3, and a reception device having a plurality of reception units 4, a reception signal processing unit 5, and a display device 6. .

[0048] The output device 1 is a device that outputs a video signal (image signal) and an audio signal. Examples of output device 1 include a tuner and a video player that output high-definition video signals and audio signals. A video recorder, a hard disk recorder, a personal computer, a camera, and the like.

The transmission signal generator 2 divides the video signal and audio signal from the output device 1 into a plurality of predetermined information amounts and converts them into serial signals.

[0050] A plurality of transmission units 3 are provided, and a synchronization signal is added to the signal converted by the transmission signal generation unit 2 and transmitted by radio waves. Each transmitter 3 transmits using radio waves having different frequencies or polarizations.

[0051] The same number of receiving units 4 as the transmitting units 3 are provided. The receiving unit 4 is set to receive radio waves transmitted using radio waves having different frequencies or polarizations. The receiving unit 4 receives radio waves from the transmitting unit 3 respectively determined by this, This radio wave is converted into a serial signal and output to the received signal processing unit 5.

The received signal processing unit 5 converts the serial signal received by the receiving unit 4 into a video signal and an audio signal and displays them on the display device 6.

The display device 6 is a device that displays the video signal and the audio signal converted by the reception signal processing unit 5. Further, the display device 6 may incorporate the reception signal processing unit 5. As an example of the display device 6, a general display such as a large-screen plasma display or a liquid crystal display can be considered. In the following description, the display device 6 will be described using a case where an audio output unit is provided!

Here, the transmission signal generation unit 2 will be described in detail. FIG. 2 shows a configuration diagram of the transmission signal generation unit 2.

[0055] The transmission signal generation unit 2 includes the control unit 7, the synchronization detection unit 8, the audio buffer memory 9, the switching unit 10, the plurality of video buffer memories 11 and 12, and the same number as the transmission unit 3. Switching sections 13, the same number of encoding sections 14 as transmission sections 3, the same number of signal conversion sections 15 as transmission sections 3, and an audio encoding section 16.

[0056] The synchronization detection unit 8 detects a vertical synchronization signal and a horizontal synchronization signal of the video signal input from the output device 1, and outputs a detection signal at the detected timing.

The control unit 7 generates a control signal according to the detection signal from the synchronization detection unit 8.

The switching unit 10 outputs the video signal input from the synchronization detection unit 8 to the video buffer memories 11 and 12 in accordance with the control signal from the control unit 7. The number of buffer memories for this video Is preferably more than twice the number of transmitters 3.

The switching unit 13 selects the video buffer memory 11 or 12 according to the control signal from the control unit 7 and outputs the video signal held in the video buffer memory 11 or 12 to the encoding unit 14.

The encoding unit 14 encodes the video signal from the switching unit 13 and outputs the encoded video signal to the signal conversion unit 15.

[0061] The audio buffer memory 9 holds the audio signal input from the output device 1, and outputs the held audio signal to the audio encoding unit 16 in accordance with the control signal of the control unit 7.

[0062] The audio encoding unit 16 encodes the input audio signal and outputs the encoded audio signal to the signal conversion unit 15.

[0063] The signal conversion unit 15 generates a serial signal from the video signal encoded by the encoding unit 14, and inserts the audio signal encoded by the audio encoding unit 16 into the blank area. After that, a synchronization signal is added and output from the transmitter 3.

[0064] Next, the received signal processing unit 5 will be described in detail. FIG. 3 is a configuration diagram of the received signal processing unit 5.

The received signal processing unit 5 includes a control unit 17, the same number of synchronization detecting units 18 as the receiving unit 4, the same number of signal converting units 19 as the receiving unit 4, and the same number of decoding units as the receiving unit 4. 20, the same number of switching units 21 as the receiving unit 4, the plurality of video buffer memories 22 and 23, the switching unit 24, the video buffer memory 25, and the same number of audio decoding units as the receiving unit 26 And an audio switching unit 27 and an audio buffer memory 28.

[0066] The synchronization detection unit 18 detects synchronization with respect to the serial signal input from the reception unit 4 to which the synchronization detection unit 18 is connected. If synchronization is detected, the synchronization detection signal is output to the control unit 17 and serialized. The signal is output to the signal converter 19.

The control unit 17 generates a control signal according to the synchronization detection signal from the synchronization detection unit 18.

[0068] The signal conversion unit 19 separates the serial signal into a video signal and an audio signal in accordance with the control signal from the control unit 17, outputs the video signal to the decoding unit 20, and outputs the audio signal to the audio decoding unit 26. To do.

The decoding unit 20 decodes the video signal and outputs it to the switching unit 21. The switching unit 21 outputs a video signal to the video buffer memory 22 or 23 in accordance with a control signal from the control unit 17.

The switching unit 24 selects the video buffer memory 22 or 23 according to the control signal from the control unit 17, takes out the held video signal, and outputs it to the video buffer memory 25.

The video buffer memory 25 outputs the video signal temporarily held to the display device 6 according to the control signal from the control unit 17.

[0073] The audio switching unit 27 selects a signal for which synchronization is detected by the synchronization detection unit 18, and switches to the other when synchronization is not detected, and the audio signal decoded by the audio decoding unit 26 is detected. Is output to the audio buffer memory 28.

The audio buffer memory 28 outputs an audio signal to the display device 6 in synchronization with the video signal in accordance with the control signal from the control unit 17.

[0075] In the transmission system of the present invention, when the synchronization signal cannot be detected by at least one synchronization detection unit 18, the control unit 17 outputs the video buffer memory connected to the synchronization detection unit in which the synchronization is detected. A control signal is output to the switching unit 24 so as to select a video signal. At this time, the video signal from the receiving unit in which synchronization is not detected is lost, and is output from the switching unit 24 as a frame drop. In addition, the power of all synchronization detection units 18 is not detected, and in this case, the control unit 17 outputs the video signal held in the video buffer memory 25 as a still image and silences the video signal. Control signals are output to the buffer memory 25 and the audio buffer memory 28.

[0076] Next, the operation of the present invention will be described.

The transmission signal generation unit 2 divides the video signal and audio signal from the output device 1 into a plurality of predetermined information amounts and converts them into serial signals.

The signal converted by the transmission signal generator 2 is transmitted by the transmitter 3 using radio waves.

The receiving unit 4 receives radio waves from the respective transmitting units 3 that are determined, converts the radio waves into serial signals, and outputs the serial signals to the received signal processing unit 5.

The received signal processing unit 5 converts the serial signal received by the receiving unit 4 into a video signal and an audio signal and displays them on the display device 6. Here, the operation of the transmission signal generation unit 2 will be described.

FIG. 4 is a diagram for explaining the operation of the transmission signal generation unit 2.

FIG. 4A shows a video signal input to the switching unit 10.

[0084] B, C, D, and E in FIG. 4 are respectively transmitted from the switching unit 10 to the video buffer memory 11a and lib.

Signals Ml lai, Ml lbi, M12ai and M12bi input to 12a and 12b, respectively, are shown. These signals are video signals that the switching unit 10 distributes to the video buffer memory 11a, lib, 12a, and 12b for each frame in accordance with the control signal from the control unit 7.

[0085] F, G, H, and I in FIG. 4 are the image notch memories 11a, l ib, 12a, 12b, force, and the signal Ml lao that is manually input to the switch 咅 ^ 13a and switch 咅 13b. Ml lbo, M12ao and M12bo are shown respectively. When the storage of the video signal for one frame in the video buffer memory is completed, the switching unit 13 selects the buffer memory and reads the video signal from the video buffer memory after spending two frames. At this time, the data transmission speed of the signals Ml lao, Ml lbo, M12ao, and M12 bo is ½ of the transmission speed of the video signal output from the output device 1.

[0086] J and K in FIG. 4 indicate video signals S13ao and S13bo output from the switching unit 13a and the switching unit 13b, respectively. Since data transfer from the video buffer memory takes 2 frames, the switching unit 13 switches the video buffer memory every 2 frame times. Further, the switching unit 13a, the force and other data S13ao, and the data S13bo from the switching unit 13b are output with a shift of one frame time.

FIG. 5 shows signals TX1 and TX2 output from the signal converter 15a and the signal converter 15b, respectively. V2n and ν2η + 1 in Fig. 5 indicate the video signals of the 2ηth and 2η + 1 frames, and Α2η and Α2η + 1 represent the 2ηth and 2η + 1 frames. Each audio signal is shown. The signal converter 15 inserts two frames of audio signals into the blank area for one frame of video signals to generate TX1 and と 2. Data TX1 or ΤΧ2 includes a video signal skipped by one frame, whereas an audio signal includes all frames.

FIG. 6 is a diagram for explaining the operation of the received signal processing unit 5, and shows all synchronization detection units.

FIG. 18 is a diagram when synchronization is detected at 18; [0089] A and B in FIG. 6 indicate video signals S21ai and S2 lbi input to the switching units 21a and 21b, respectively.

[0090] C, D, E, and F in FIG. 6 are transferred from the switching unit 21a and the switching unit 21b to the video buffer memory 22a.

The video signals M22ai, M22bi, M23ai, and M23bi that are manually operated by 22b, 23a, and 23b are shown. The switching unit 21a and the switching unit 21b switch the video buffer memory for each video signal for one frame in accordance with the control signal from the control unit 17, and output the video signal.

[0091] G, H, and IiJ in FIG. 6 indicate video signal memories 22a, 22b, 23a, 23b, power, and video signals M22ao, M22bo, M23ao, and M23bo that are output to switch 24. ! / The video signal selected by the switch 24 is once held in the video buffer memory 25 and is output to the display device 6 in accordance with a control signal from the control unit 17.

K in FIG. 6 represents a video signal output from the video buffer memory 25 to the display device 6, and reproduces the video signal output from the output device 1.

[0093] FIG. 7 is a diagram for explaining the operation of the received signal processing unit 5 when the synchronization is not detected by the synchronization detecting unit 18a, and when it is detected.

Each of A and B in FIG. 7 indicates video signals S21ai and S2 lbi input to the switching units 21a and 21b. In A of FIG. 7, since the synchronization detection unit 18a could not detect synchronization, it indicates that no video signal is input to the switching unit 21a! /.

[0095] Each of C, D, E, and F in FIG. 7 represents the video signals M22ai, M22bi, and M23ai that are manually input from the switching unit 21a and the switching unit 21b to the video buffer memories 22a, 22b, 23a, and 23b. And M2 3bi. C and D in FIG. 7 indicate that no video signal is input to the video buffer memories 22a and 23a because no video signal is input to the switching unit 21a. E and F in FIG. 7 indicate that the video signals M22bi and M23bi from the switching unit 21b are input to the buffer memory because the video signal is input to the switching unit 21b.

[0096] Each of G, H, and IiJ in FIG. 7 indicates the video signal memories M22ao, M22bo, M23ao, and M23bo that are output to the video nother memories 22a, 22b, 23a, 23b, and the power. Yes. G and H in FIG. 7 indicate that M22ao and M23ao are not output because no video signal is held in the video buffer memories 22a and 23a. The video signal selected by the switching unit 24 is once held in the video buffer memory 25 and sent to the display device 6. Is output.

In FIG. 7, K represents a video signal output from the video buffer memory 25 to the display device 6. Since the video signals M22ao and M23ao are not output, the video signal stored in the video buffer memory 25 is output continuously for two frames. For this reason, the video signal is output with the frame dropped, but the audio signal is played back normally.

On the other hand, when synchronization is not detected by all the synchronization detectors 18, the video signal stored in the video buffer memory 25 is output as a still image, and the sound is muted.

[0099] In the above description, the video signal and the audio signal are transmitted. However, the present invention can be applied to only the video signal.

[0100] The configuration of the transmission system in this case is almost the same as the configuration of the above embodiment, but the audio buffer memory 9 and audio encoding unit 16 of the transmission signal generation unit 2, and the reception signal processing unit 5 The audio decoding unit 26, the audio switching unit 27, and the audio buffer memory 28 are not configured. FIG. 8 is a configuration diagram of the transmission signal generation unit 2 when only the video signal is transmitted, and FIG. 9 is a configuration diagram of the reception signal processing unit 5.

[0101] The signal conversion unit 15 of the transmission signal generation unit 2 generates a serial signal from the video signal encoded by the encoding unit 14, adds a synchronization signal, and outputs the serial signal to the transmission unit 3. In the first embodiment, the signal output from the signal conversion unit 15 is obtained by inserting an audio signal for 2 frames into a blank area with respect to a video signal for 1 frame. In, it becomes only a video signal.

[0102] When the synchronization signal cannot be detected by at least one synchronization detection unit 18, the control unit 17 of the reception signal processing unit 5 receives video from the video buffer memory connected to the synchronization detection unit in which synchronization is detected. A control signal is output to the switching unit 24 so as to select a signal. At this time, the video signal from the receiving unit in which synchronization is not detected is lost, and is output from the switching unit 24 as a frame drop. Therefore, the video signal output from the video buffer memory 25 to the display device 6 outputs the video signal held in the video buffer memory 25 continuously for two frames. Further, the control unit 17 outputs the video signal held in the video buffer memory 25 as a still image when all the synchronization detection units 18 have not detected synchronization.

[0103] As described above, by using the transmission system of the present invention, it is possible to reduce the number of communication paths. In both cases, even when one communication path is interrupted, disturbance of images and sounds can be suppressed.

The configuration diagram of the transmission system according to the present embodiment is the same as that in FIG. 1, and the circuit configurations of the transmission signal generation unit 2 and the reception signal processing unit 5 are the same as those in FIG. 2 and FIG. Therefore, the same components as those in the above embodiment are given the same reference numerals, and detailed descriptions thereof are omitted.

FIG. 10 shows an operation of the transmission signal generation unit 2 of the transmission system according to the present embodiment.

Yes

FIG. 10A shows a video signal input to the switching unit 10.

[0107] B, C, D, and E in FIG. 10 are respectively the video signals Ml lai, Ml lbi, and M12ai that are manually input from the switching unit 10 to the video buffer memories 11a, lib, 12a, and 12b. M12bi is shown. Each of these signals indicates a video signal input to the buffer memory by the switching unit 10 switching the buffer memory for each scanning line in accordance with the control signal from the control unit 7.

[0108] F, G, H, and I in Fig. 10 are the video signals Ml lao and Ml that are manpowered by the nota memory 1 la, 1 lb, 12a, 12b, and the switch 、 13a, 13b, respectively. lbo, M12ao, and M12bo are shown.

[0109] When the video signal of the odd-numbered scan line or even-numbered scan line for one frame is stored in the video buffer memory, the switching unit 13a selects the video buffer memory for which the storage has been completed, To output the video signal. At this time, the transmission speed of the signals Mllao, Mlbo, M12ao, and M12bo is half the transmission speed of the video signal input from the output device 1.

Each of J and K in FIG. 10 indicates video signals S 13ao and S 13bo output from the switching unit 13a and the switching unit 13b. Since the data transfer from the video buffer memory takes 1 frame time, the switching unit 13 avoids switching the video buffer memory every frame time and outputs M13ao and M13bo.

FIG. 11 shows signals TX1 and TX2 output from the signal converter 15a and the signal converter 15b, respectively. Each of Vn, o and Vn, e in FIG. 11 indicates an odd-numbered scan line video signal and an even-numbered scan line video signal of the nth frame, and An represents the nth frame. The audio signal is shown. The signal conversion unit 15 generates TX1 and TX2 by inserting audio data for one frame into the blank area of the video data for odd-numbered scanning line video data or even-numbered scanning line video data for one frame.

FIG. 12 is a diagram for explaining the operation of the reception signal processing unit 5, and is a diagram when synchronization is detected by all the synchronization detection units 18.

[0113] Each of A and B in FIG. 12 represents the video signals S21ai and S input to the switching units 21a and 21b.

21bi.

[0114] Each of C, D, E, and F in FIG. 12 represents the video signals M22ai, M22bi, and M23ai that are manually input from the switching unit 21a and the switching unit 21b to the video buffer memory 22a, 22b, 23a, and 23b. And M 23bi. The switching unit 21a and the switching unit 21b switch the video buffer memory for each frame time in accordance with the control signal from the control unit 17, and output the video buffer memory.

[0115] Each of G, H, I, and J in FIG. 12 indicates video signals M22ao, M22bo, M23ao, and M23bo output from the video buffer memory 23 to the switching unit 24! /. When the storage of the video signal in the video buffer memory 23 is completed, the switching unit 24 selects two buffer memories that have completed the storage of the video signal according to the control signal from the control unit 17, and the two memories are stored for each scanning line. The video signal is output to the video buffer memory 25.

[0116] K in FIG. 12 represents a video signal output from the video buffer memory 25 to the display device 6, and reproduces the video signal output from the output device 1.

FIG. 13 is a diagram for explaining the operation of the reception signal processing unit 5 when the synchronization detection unit 18a cannot detect synchronization.

[0118] FIGS. 13A and 13B show video signals S21ai and S2 lbi input to the switching units 21a and 21b, respectively. In FIG. 13A, since synchronization is not detected by the synchronization detection unit 18a, the video signal is input to the switching unit 21a.

[0119] C, D, E, and F in FIG. 13 are the video signals M22ai, M22bi, and M23ai that are manually input from the switching unit 21a and the switching unit 21b to the video buffer memory 22a, 22b, 23a, and 23b, respectively. And M 23bi. C and D in FIG. 13 indicate that no signal is input to the video buffer memories 22a and 23a because no video signal is input to the switching unit 21a. Figure 1 E and F in 3 indicate video signals M22bi and M23bi input from the switching unit 21b to the video buffer memory 24.

Each of G, H, I, and J in FIG. 13 represents video signals M22ao, M22bo, M23ao, and M23bo that are output from the video buffer memory 23 to the switching unit 24. G and H in FIG. 13 indicate that video signals M22ao and M23ao are not output because synchronization was not detected by the synchronization detector 18a. IiJ in FIG. 13 indicates a signal output from the video buffer memory 22b and 23b. The switching unit 24 switches between the video buffer memories 22b and 23b connected to the synchronization detection unit 18b where synchronization is detected according to the control signal from the control unit 17 for each frame time. The signal is output to the video buffer memory 25. At this time, the video signal output to the display device 6 is displayed in the same manner as the interlace. However, since all audio signals are transmitted, the audio is played without interruption.

[0122] By using the transmission system as described above, even when at least one of the plurality of communication paths is interrupted, the video signals for the even-numbered scan lines or odd-numbered scan lines of all frames. Therefore, the video is played back smoothly.

[0123] In the above description, the case where the video signal and the audio signal are transmitted has been described. However, as in the first embodiment, the configuration may be such that only the video signal is transmitted.

[0124] <Third embodiment>

The configuration diagram of the transmission system according to this embodiment is the same as FIG. Therefore, the same components as those in the above embodiment are given the same reference numerals, and detailed description thereof is omitted.

FIG. 14 is a configuration diagram of the transmission signal generation unit 2.

The transmission signal generation unit 2 includes a control unit 7, a synchronization detection unit 8, a coding unit 29, an audio buffer memory 9, a switching unit 10, a video buffer memory 11 and 12, a switching unit 13, and a signal conversion unit 15. And a voice encoding unit 16.

[0127] The synchronization detector 8 is synchronized with the vertical synchronization signal and the horizontal synchronization signal of the video signal input from the output device 1. The detection signal is output to the control unit 7 and the video signal is output to the encoding unit 29 at the detected timing.

[0128] The control unit 7 generates a control signal according to the detection signal.

The switching unit 10 inputs the encoded video signal input from the encoding unit 29 to the video buffer memories 11 and 12 in accordance with the control signal from the control unit 7.

The switching unit 13 selects the video buffer memory 11 or 12 in accordance with the control signal from the control unit 7, and inputs the video signal held in the video buffer memory 11 or 12 to the signal conversion unit 15.

The audio buffer memory 9 holds the audio signal input from the output device 1 and outputs it to the audio encoding unit 16 according to the control signal from the control unit 7. The encoded audio signal is input to the signal conversion unit 15.

[0132] The signal converter 15 generates a serial signal from the video signal, and inserts the encoded audio signal into the blank area. After that, a synchronization signal is added and output to the transmitter 3.

FIG. 15 shows a configuration diagram of the received signal processing unit 5.

The received signal processing unit 5 includes a control unit 17, a synchronization detection unit 18, a signal conversion unit 19, a switching unit 21, a video buffer memory 22, 23, a switching unit 24, a decoding unit 30, and a video buffer memory 25. And an audio decoding unit 26, an audio switching unit 27, and an audio buffer memory 28.

[0135] The synchronization detection unit 18 detects synchronization with the serial signal input from the reception unit 4, and when synchronization is detected, outputs the synchronization detection signal to the control unit 17 and converts the serial signal into the signal conversion unit. Output to 19.

The signal changing unit 19 separates the serial signal into a video signal and an audio signal according to the control signal from the control unit 17, outputs the video signal to the switching unit 21, and the audio signal is sent to the audio decoding unit 26. Output.

The switching unit 21 outputs to the video buffer memory 21 or 22 in accordance with the control signal from the control unit 17.

The switching unit 24 selects the video buffer memory 21 or 22 according to the control signal from the control unit 17, extracts the video signal held in the video buffer memory 21 or 22, and outputs it to the decoding unit 30. To do. The decoding unit 30 decodes the input video signal, and the decoded video signal is temporarily held in the video buffer memory 25 and output to the display device 6.

[0140] The audio decoding unit 26 combines the audio signal, and the decoded audio signal is sent to the audio switching unit 27 and then output to the audio buffer memory 28.

[0141] The voice switching unit 27 selects a signal for which synchronization is detected by the synchronization detection unit 18, and switches to the other when synchronization is no longer detected.

[0142] The audio buffer memory 28 outputs the audio signal to the display device 6 in synchronization with the video signal in accordance with the control signal from the control unit 17. If the synchronization signal cannot be detected by at least one synchronization detection unit 18, a control signal is output from the control unit 17 to the switching unit 24, and from the video buffer memory connected to the synchronization detection unit where the synchronization is detected. Select the video signal. At this time, since it is only the video signal from the received signal in which the synchronization is detected, it is output from the switching unit 24 as a frame drop. In addition, when the synchronization is not detected by all the synchronization detection units 18, the control unit 17 outputs a control signal to the video buffer memory 25 and the audio buffer memory 28, and outputs the control signal to the video buffer memory 25. The stored video signal is output as a still image and muted.

[0143] Since the operations of the transmission signal generation unit 2 and the reception signal processing unit 5 according to the present embodiment are the same as those of the first embodiment, the description thereof is omitted.

[0144] In the above description, the case where the video signal and the audio signal are transmitted has been described. However, as in the first embodiment, the configuration may be such that only the video signal is transmitted.

[0145] As described above, by using the transmission system according to the present embodiment, it is possible to suppress disturbance of images and sounds even when at least one of the plurality of communication paths is blocked. At the same time, the number of decoding units can be reduced, and the circuit scale can be reduced.

It should be noted that each component of the present invention described above can also be realized by a force computer program that can also be configured by hardware, as is apparent from the above description. In this case, functions and operations similar to those of the above-described embodiment are realized by a processor that operates according to a program stored in the program memory. Note that only a part of the functions of the above-described embodiment can be realized by a computer program.

[0147] This application is based on Japanese Patent Application No. 2006-342576 filed on Dec. 20, 2006. Claim priority and incorporate all of its disclosure here.

Claims

The scope of the claims

[1] A transmission system,

A plurality of receiving units for receiving the transmitted image signals;

A transmission system comprising:

2. The transmission system according to claim 1, wherein the transmission signal generation unit divides the image signal for each frame.

[3] The transmission system according to claim 1, wherein the transmission signal generation unit divides the image signal for each scanning line.

[4] The transmission system according to any one of claims 1 to 3, wherein the transmission signal generation unit includes an encoding unit that encodes the divided image signal.

[5] The transmission signal generation unit according to any one of claims 1 to 3, wherein the transmission signal generation unit includes an encoding unit, and divides the image signal encoded by the encoding unit. Transmission system.

[6] The transmission signal generation unit includes a memory that holds the divided image signals, and the number of the memories is at least twice the number of the transmission units. 6. The transmission system according to claim 5 of claim 5.

7. The transmission system according to claim 6, wherein a transmission speed of the image signal input to the memory is different from a transmission speed of the image signal output from the memory.

[8] A transmission device for a transmission system that transmits and displays an image signal,

A transmission device comprising:

9. The transmission apparatus according to claim 8, wherein the transmission signal generation unit divides the image signal for each frame.

[10] The transmission device according to claim 8, wherein the transmission signal generation unit divides the image signal for each scanning line.

[11] The transmission device according to any one of claims 8 to 10, wherein the transmission signal generation unit includes an encoding unit that encodes the divided image signal.

[12] The transmission signal generation unit according to any one of claims 8 to 10, wherein the transmission signal generation unit includes an encoding unit, and divides the image signal encoded by the encoding unit. Transmitter

[13] The transmission signal generation unit includes a memory that holds the divided image signal, and the number of memories is at least twice the number of the transmission units. The transmission device according to claim 12.

14. The transmission apparatus according to claim 13, wherein a transmission speed of the image signal input to the memory is different from a transmission speed of the image signal output from the memory.

[15] A transmission system receiver for transmitting and displaying an image signal,

A plurality of receiving units for receiving image signals divided based on a predetermined condition; a received signal processing unit for displaying a synchronized image signal among the received image signals;

A receiving apparatus comprising:

16. The receiving apparatus according to claim 15, wherein the divided image signal is divided for each frame.

17. The divided image signal is divided for each scanning line.

6. The receiving device according to 6.

[18] A signal transmission method comprising:

A transmission step of allocating the divided image signals and transmitting from a plurality of transmission units; a reception step of receiving the transmitted image signals by a plurality of reception units; and among the received image signals, synchronized A signal transmission method comprising: a display step for displaying an image signal.

[19] In the request, the dividing step divides the image signal for each frame. 19. The signal transmission method according to claim 18.

20. The signal transmission method according to claim 18, wherein the dividing step divides the image signal for each scanning line.

21. The signal transmission method according to claim 18, wherein the dividing step includes an encoding step for encoding the divided image signal.

22. The division step according to claim 1, wherein the coded image signal is divided.

21. The signal transmission method according to any one of claims 8 to 20.

[23] A transmission system program, the program comprising: a transmission signal generation unit that divides the transmission system based on a predetermined condition;

A plurality of receiving units for receiving the transmitted image signals;

Of the received image signals, a received signal processing unit for displaying a synchronized image signal

A program characterized by functioning as

[24] A program for a transmission device in a transmission system for transmitting and displaying an image signal, the program comprising:

A program characterized by making it function.

[25] A program for a receiving device in a transmission system for transmitting and displaying an image signal, the program comprising:

And a receiving device characterized in that the receiving device functions.

[26] A transmission system,

Multiple transmitters with different radio frequency or polarization,

A transmission signal generation unit that divides an input video signal into a predetermined amount of information and inserts an audio signal corresponding to the divided video signal to generate a transmission signal; A plurality of transmission units for transmitting the transmission signal, wherein the frequency or polarization of the radio wave is different from each other;

A plurality of receivers for receiving radio signals, wherein the radio waves have different frequencies or polarizations;

A reception signal processing unit that extracts a video signal and an audio signal from the received transmission signal and outputs the video signal and an audio signal corresponding to the video signal;

A power transmission system comprising:

A signal transmission method comprising:

Divide the video signal into the amount of information for one frame or one scanning line,

A synchronization signal is inserted into the video signal divided for each frame or each scanning line and transmitted from a plurality of transmission units,

Of the transmitted video signals, only the video signals for which synchronization has been detected are used, and the video signals are generated with dropped frames or dropped scan lines.

A signal transmission method characterized by the above.