JPH10322670A - Video/sound transmitting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the need for cable connection between units, to dissolve the trouble of unit arrangement and to improve the quality of a signal by providing a 'reception means for executing a prescribed reception/demodulation processing on a reception signal and the output processing means of prescribed and obtained video/sound signal in a digitally modulated state for a reception unit. SOLUTION: An antenna 6 receives a radio wave transmitted from the antenna of an analog input/transmission unit. A reception amplifier 21 executes RF signal amplification on the received radio wave and it is supplied to a frequency converter 22. The frequency converter 22 converts a frequency and a demodulator 23 executes digital demodulation. Error detection/error correction procesings by using an error correction code are executed on the demodulated digital signal by an ECC decoder 24, and the digital video signal and the digital sound signal in the state of an MPEG 2 system are obtained. A prescribed processing is executed on the digital video and the sound signal by a video code and an audio code and they are outputted to the video/sound input unit as the analog video/sound signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television monitor and a VTR (Video Tape Recorder).
r), DVD (Digital Versatile)
The present invention relates to a video / audio transmission / reception system suitable for a system having video / audio equipment such as a Disc / Digital Video Disc recorder.

[0002]

2. Description of the Related Art Television monitors, satellite tuners, VTRs, DVs,
It is common to use an AV system (audio / visual system) to which various devices that handle video signals and audio signals, such as a D recording / reproducing device, are connected. For example, as the simplest system, for example, a satellite broadcast tuner is connected to a television receiver so that satellite broadcasting can be viewed or a device such as a VTR or a DVD recording / reproducing device can be connected to the television receiver. In addition, there are those that record and reproduce video / audio.

[0003]

When a user constructs an AV system, a tuner, a VT,
Cable connection is performed by a coaxial cable, an optical cable, or the like so that transmission of a video signal and an audio signal is performed between devices such as an R and a television monitor. There are analog signal type and digital signal type as the transmission signal form of the transmitted video signal / audio signal.
The selection is made by the user according to the performance of each device (analog / digital compatible performance and connection terminal form). As is well known, transmission in the form of a digital signal results in better signal quality (that is, less signal degradation in the transmission path) than transmission in the form of an analog signal, and provides high image quality and high sound quality. It is said that video / audio output is enabled.

[0004] In any case, however, there is a problem that when a cable is used to connect the devices, the arrangement of the devices is physically limited to some extent. That is, for example, when connecting a television receiver and a satellite broadcast tuner, if the cable is short, the television receiver and the satellite broadcast tuner must be arranged close to each other. Although it is only necessary to allow the equipment layout in the user's room, long cables must be used when close proximity is difficult, and in the case of analog transmission, there is a disadvantage in terms of signal degradation as the cables become longer. It becomes something. That is, the cable connection imposes restrictions on the user in terms of device layout, signal quality such as image quality and sound quality.

On the other hand, in order to solve the problem caused by the cable connection, for example, it is conceivable to wirelessly communicate video signals and audio signals between devices. For this reason, for example, when a television receiver and a satellite broadcast tuner are connected, for example, a composite video signal and an analog audio signal received and demodulated by the satellite broadcast tuner are transmitted to the television receiver by radio waves. A method of transmitting data to a device is conceivable. However, when a video signal or an audio signal in an analog form is modulated by a transmission carrier and wirelessly transmitted, the above-described problem of device arrangement is solved, but signal deterioration in the transmission process is unavoidable, resulting in high image quality and high image quality. It was difficult to obtain sound quality output.

[0006]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a wireless and digital transmission of video signals / audio signals between devices in an AV system, for example. The purpose is to solve the problem and improve the signal quality.

For this reason, a video / audio transmission system suitable for constructing AV equipment is provided. This video /
It is assumed that the audio transmission system includes a transmission unit and a reception unit. The transmission unit performs predetermined transmission modulation processing on the input video signal and audio signal input processing means, and the predetermined digitally modulated video signal and audio signal output from the input processing means, and performs transmission. A transmission means for outputting is provided. The receiving unit receives a signal transmitted from the transmitting unit of the transmitting unit and performs a predetermined receiving and demodulating process. The receiving unit obtains a video signal and an audio signal in a predetermined digitally modulated state obtained by the receiving unit. It has output processing means.

[0008] In such a video / audio transmission system, the input processing means of the transmission unit converts the video signal and the audio signal input as analog signals into A / D signals, respectively.
The digital signal is converted, subjected to a predetermined digital modulation process, and supplied to a transmitting unit. Alternatively, the input processing means of the transmission unit inputs a video signal and an audio signal which have been subjected to predetermined digital modulation processing, and supplies the input video signal to the transmission means.

In such a video / audio transmission system, the output processing means of the receiving unit performs a predetermined digital demodulation process on the video signal in a predetermined digital modulation state obtained by the receiving means, Further, by performing D / A conversion processing, a video signal / audio signal as an analog signal is output. Alternatively, the output processing means of the receiving unit outputs the video signal and the audio signal which have been subjected to the predetermined digital modulation processing and obtained by the receiving means.

[0010] By transmitting a video signal and an audio signal using such a transmission system, it is no longer necessary to perform a connection in the form of an analog signal by wire as in the related art. In addition, digital transmission can also improve signal degradation during transmission.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, three examples of an embodiment of a video / audio transmission system according to the present invention will be described with reference to FIGS. FIGS. 1, 2 and 3 show a first embodiment, FIGS. 4 and 5 show a second embodiment, and FIGS. 6 and 7 show a third embodiment.
Used in the description of the embodiment. Each of the embodiments is an example in which the form of the transmission unit and the form of the reception unit as a video / audio transmission system are different. The difference in the form in this case means that the transmission unit is built in another main device or is a separate and independent device, and the video input to the transmission unit is different. The difference is whether the signal and the audio signal are in analog form or digital form. Regarding the receiving unit, the difference between whether it is built in another main device or whether it is a separate independent device, and whether the video signal and audio signal output from the receiving unit are analog Or digital form.

First, as a first embodiment, FIG. 1 shows the configuration of an AV system having the video / audio transmission system of the present embodiment. In FIG. 1, the video / audio output device 1 is a VT
The device corresponds to an R, laser disk player, BS (satellite broadcast) tuner, DVD player, or the like. That is, the video / audio output device 1 is a device positioned as a unit that outputs video / audio and audio signals to other devices in the AV system. And in this example,
The audio output device 1 includes an analog video signal Va, and L, R
It is assumed that stereo analog audio signals ALa and ARa are output.

The video / audio input device 4 is a device corresponding to, for example, a television monitor, a VTR, a DVD recorder, and the like. In other words, it is a device that is positioned as a unit that receives video / audio and audio signals from another device and performs predetermined processing in the AV system. In this example, the video / audio input device 4 outputs the analog video signal V
a, and L, R stereo analog audio signals ALa, A
It is assumed that Ra can be input.

The video / audio transmission system of the present embodiment comprises an analog input transmission unit 2 and an analog output reception unit 3. In this case, the analog input transmission unit 2 is a unit independent of the video / audio output device 1, and receives analog video signals Va and L, R stereo analog audio signals ALa,
It is assumed that ARa is a unit to be input. The analog output receiving unit 3 is a unit independent of the video / audio input device 4 and outputs an analog video signal Va and analog audio signals ALa and ARa of L and R stereo to the video / audio input device 4. Unit.

As shown in FIG. 1, a video / audio output device 1
From the analog video signal Va, the analog audio signal ALa,
ARa is output to the analog input transmission unit 2 via, for example, the cables 7, 8, and 9. The signals Va, ALa, and ARa supplied to the analog input transmission unit 2 are subjected to digital conversion, predetermined modulation processing, and the like in the analog input transmission unit 2, and are wirelessly transmitted from the antenna 5 as digital data.

Digital data wirelessly transmitted from the antenna 5 is received by an antenna 6 provided in the analog output receiving unit 3. The analog output receiving unit 3 demodulates the received data and converts the demodulated digital signal into an analog signal. The analog video signal Va and the analog audio signals ALa and ARa are transmitted through the cables 10, 11 and 12. It is supplied to the video / audio input device 4. Assuming that the video / audio input device 4 is a television monitor, the video / audio input device 4 uses the analog video signal V supplied from the analog output receiving unit.
a, video and audio output are executed by the analog audio signals ALa and ARa.

The analog input transmission unit 2 shown in FIG.
Will be described with reference to FIG. The analog video signal Va supplied from the video / audio output device 1 is converted into a digital signal by the A / D converter 13. A / D converter 1
The digital video signal obtained from 3 is subjected to, for example, MPEG2 information compression processing by the video encoder 15. The analog audio signals ALa and ARa supplied from the video / audio output device 1 are converted into digital signals by the A / D converter 14. The digital audio signal obtained from the A / D converter 14 is subjected to MPEG2 information compression processing by the audio encoder 16.

The digital video signal and the digital audio signal encoded in the MPEG2 format are supplied to an ECC encoder 17 where a process for adding an error correction code for wireless transmission is performed. And E
The digital signal output from the CC encoder 17 is subjected to predetermined digital modulation / multiplexing by a modulator 18 for digital data communication. Various digital modulation methods can be considered. For example, π / 4 shift DQPSK modulation and QP
SK modulation and the like can be considered, and as a multiplexing method of audio data and video data, a frequency division multiplexing method (FDM)
A), time division multiplexing (TDMA), code division multiplexing (CDMA), orthogonal frequency division multiplexing (OFDM) and the like can be adopted. The modulated signal is frequency-converted by a frequency converter 19 to be an RF signal, amplified by a transmission amplifier 20, and then transmitted from the antenna 5 by radio waves.

Next, the configuration of the analog output receiving unit 3 will be described with reference to FIG. The antenna 6 receives the radio wave transmitted from the antenna 5 of the analog input transmission unit 2 as described above.
The F signal is amplified and supplied to the frequency converter 22. Then, the frequency is converted by the frequency converter 22 and the demodulator 2
The digital demodulation is performed at 3. The demodulated digital signal is subjected to error detection and error correction processing using an error correction code by the ECC decoder 24, and a digital video signal and a digital audio signal in the form of the MPEG2 system are obtained.

The digital video signal output from the ECC decoder 24 is converted into an MP
The information that has been compressed by the EG2 method is decoded, and is further converted into an analog signal by the D / A converter 27 and output to the video / audio input device 4 as an analog video signal Va. The digital audio signal output from the ECC decoder 24 is decoded by an audio decoder 26, and is further converted to an analog signal by a D / A converter 28 and output to the video / audio input device 4 as analog audio signals ALa and ARa. You.

In this embodiment, the transmission of the video signal and the audio signal from the video / audio output device 1 to the video / audio input device 4 is executed via the analog input transmission unit 2 and the analog output reception unit 3 as described above. Therefore, there is no need to connect a cable between the video / audio output device 1 and the video / audio input device 4, which allows the video / audio output device 1 to be connected to the video / audio output device 1.
The arrangement positional relationship of the voice input device 4 is no longer limited within a range where the radio wave can reach. Further, the analog input / transmission unit 2 only needs to be equipped with an encoding / transmission circuit system, and can be configured as a small device. For example, the analog input / transmission unit 2 should be suitable for being disposed near the video / audio output device 1. it can. Therefore, there is no problem particularly in the arrangement of the video / audio output device 1 and the analog input / transmission unit 2, and short cables 7, 8, and 9 are sufficient. Signal degradation during transmission to the receiver. The same applies between the analog output receiving unit 3 and the video / audio input device 4. Further, since the wireless transmission data from the analog input transmission unit 2 to the analog output reception unit 3 is performed in a digital system, transmission with almost no signal deterioration becomes possible, and the quality of the video signal and the audio signal can be maintained.

Further, by configuring the analog input transmitting unit 2 and the analog output receiving unit 3 as independent units, the configuration shown in FIG. 1 can be realized corresponding to various AV devices owned by the user.

Next, an AV system having a video / audio transmission system according to a second embodiment will be described with reference to FIGS. In FIG. 4, the video / audio output device 30 is positioned as a unit for outputting video / audio and audio signals to other devices in the AV system, similarly to the video / audio output device 1 of the first embodiment described above. Equipment.
However, in this example, the video / audio output device 30 has a built-in digital input / transmission unit that constitutes the video / audio transmission system of the present example.
0, the video signal and the audio signal to be output are
The digital input transmission unit is supplied in the form of digital data.

On the other hand, the video / audio input device 57 is a television monitor device or the like, like the video / audio input device 4 of the first embodiment, and has an analog video signal V.
a, and L, R stereo analog audio signals ALa, A
It is assumed that Ra can be input. In addition, video of this example /
The analog output receiving unit 53 constituting the audio transmission system has the same configuration as the analog output receiving unit 3 of the first embodiment. That is, the analog output receiving unit 53 is a unit independent of the video / audio input device 57, and outputs the analog video signal Va and the analog audio signals ALa and ARa of the L and R stereos to the video / audio input device 57. Unit.

In this example, the video / audio output device 30, which is a device such as a VTR, a laser disk player, a BS tuner, or a DVD player, is a video / audio input device 5.
7 are supplied to the digital input transmission unit 50 in the form of digital data. Then, the video signal and the audio signal are digitally modulated for wireless transmission by the digital input transmission unit 50 and transmitted and output from the antenna 51.

This transmission radio wave is received by an antenna 52 projecting from an analog output receiving unit 53, and demodulated, decoded, and converted into an analog signal in the analog output receiving unit 53. The video / audio output device 5 is converted into an analog video signal Va by the cable 54.
7 and are output to the video / audio input device 57 as analog audio ALa and ARa via the cables 55 and 56.

FIG. 5 shows a configuration example when the video / audio output device 30 is a BS tuner. In the figure, the portion surrounded by the dashed line is the built-in digital input transmission unit 50, and the other portion is a component as a normal BS tuner.

A 12 GHz band radio wave transmitted from a broadcasting satellite is received by a BS antenna (not shown) and converted into a BS-IF signal having a center frequency of 1 GHz band and a frequency bandwidth of 27 MHz by a BS converter. The signal converted into the intermediate frequency signal IF is supplied to the tuner 31 via a coaxial cable. The received signal obtained by performing the tuning process by the tuner 31 is output to a QPSK demodulation unit 32.
Are demodulated by QPSK, Viterbi-decoded by the Viterbi decoder 33, and error-corrected by the Reed-Solomon error corrector. Then, the video signal and the audio signal of the MPEG2 system are extracted from the demultiplexer 35.

MP output from the demultiplexer 35
The video signal and the audio signal of the EG2 system are supplied to the digital input transmission unit 50, and the video decoder 36,
It is supplied to the audio decoder 38. The video signal supplied to the video decoder 36 is decompressed by MPEG2 information and then output as an analog video signal Va by the D / A converter 37. Audio decoder 3
The audio signal supplied to the decoder 8 is subjected to MPEG2 decoding processing, and then output as analog audio signals ALa and ARa by the D / A converter 39. The outputs of the analog video signal Va and the analog audio signals ALa and ARa are used for connection to a television receiver or the like by a conventional cable. This is not necessary when transmitting signals by the method of the present example shown in FIG.

The MPEG2 video signal and audio signal supplied from the demultiplexer 35 to the ECC encoder 40 in the digital input transmission unit 50 are subjected to encoding for adding an error correction code. Then, digital modulation / multiplexing is performed in the modulator 41. Further, the signal converted into the RF signal in the frequency converter 42 is amplified in the transmission amplifier 43 and output wirelessly through the antenna 44.

The transmission signal is subjected to reception, demodulation, MPEG2 decoding and D / A conversion by the analog output receiving unit 53 as described above, and the analog video signal Va,
The analog audio signals ALa and ARa are supplied to the video / audio input device 57. Note that the configuration of the analog output receiving unit 53 is the same as that of the analog output receiving unit 3 of the first embodiment shown in FIG. 3, and redundant description is omitted.

In the second embodiment, similarly to the first embodiment, the effects of the arrangement of the devices and the maintenance of the signal quality can be obtained, and the digital input transmission unit 50 is of a built-in type. Therefore, the arrangement of the digital input / transmission unit 50 does not occur at all, and the video / audio output device 3 such as a cable is used.
Since signal transmission between 0 and 0 is not required, higher quality can be realized. In the case of the configuration shown in FIG.
The video signal and the audio signal extracted as the EG2 method are directly modulated for wireless transmission.
This eliminates the waste of decoding the second signal and then re-encoding and transmitting, thereby maintaining signal quality and simplifying the overall circuit configuration.

Next, a third embodiment of the present invention will be described with reference to FIGS.
An embodiment will be described. In this example, it is assumed that the digital input transmission unit 50 and the digital output reception unit 62 which are the video / audio transmission system of the present example are of a type built in a main device. That is, as shown in FIG.
A digital input transmission unit is built in the audio output device 30, and a digital output reception unit is built in the video / audio input device 61. In this case, the video / audio output device 30
Is a device such as a BS tuner, and a video signal and an audio signal to be output are wirelessly transmitted and output from an antenna 51 by a built-in digital input transmission unit 50.
The video / audio output device 30 and the digital input transmission unit 50 have the same configuration as the video / audio output device 30 and the digital input transmission unit 50 of the second embodiment, for example, the configuration of FIG. Omitted.

The radio signal transmitted from the antenna 51 is transmitted to the digital output receiving unit 6 in the video / audio input device 61.
2 is received by the antenna 60 connected to the second antenna. The video / audio input device 61 incorporating the digital output receiving unit 62 is, for example, a digital video tape recorder, a DVD, or the like.
It is preferable to use a recorder or the like, and the configuration is, for example, as shown in FIG. In FIG. 7, a portion surrounded by a dashed line indicates a digital output receiving unit 62, and other portions indicate a recording circuit system as a video tape recorder, a DVD recorder, or the like. The signal received by the antenna 60 is amplified by the reception amplifier 64, frequency-converted by the frequency converter 65, and digitally demodulated by the demodulator 66. The ECC decoder 67 performs error detection and error correction using the error correction code. As a result, for example, a video signal and an audio signal of the MPEG2 system are obtained by the digital output receiving unit 62. The video signal and the audio signal of the MPEG2 system are supplied in the form of digital data to a circuit system in the video / audio input device 61 for executing a recording operation which is an essential function. That is, an encoding process is performed by the recording encoder 68 in accordance with the format of the recording medium corresponding to the recording apparatus, and is supplied to the recording drive unit 69 as a recording signal to perform writing on the recording medium.

In the third embodiment, similar to the first embodiment, the effects of the arrangement of the devices and the preservation of the signal quality are obtained, and the digital input transmission unit 5
Since both the digital output receiving unit 62 and the digital output receiving unit 62 are of a built-in type, there is no problem in arrangement as a video / audio transmission system. Signal transmission between the video / audio output device 30 and the digital input / transmission unit 50;
As for signal transmission between the digital output receiving unit 62 and the video / audio input device 61, deterioration due to signal transmission between the video / audio output device 30 via a cable or the like can be completely eliminated.

Although three examples have been described above as embodiments, it is needless to say that various other configuration examples can be considered as the video / audio transmission system of the present invention. For example, the transmitting unit may be a digital input and an independent unit, and the receiving unit may be a digital output and an independent unit.

[0037]

As described above, according to the video / audio transmission system of the present invention, the input processing means for the input video signal and audio signal, and the video in a predetermined digitally modulated state output from the input processing means. For signals and audio signals,
A transmission unit having a transmission unit for performing a predetermined transmission modulation process and transmitting and outputting, a reception unit for receiving a signal transmitted from the transmission unit of the transmission unit and performing a predetermined reception demodulation process, and a reception unit. And a receiving unit having output processing means for video and audio signals in a predetermined digitally modulated state. By using such a video / audio transmission system for transmitting video signals and audio signals between the devices constituting the AV system, there is no need to connect cables between the devices, and it is possible to eliminate restrictions on the respective arrangement positions. There is an effect that can be. This allows the user to use a television receiver, tuner, VT
Devices such as R can be arranged freely. Further, since wireless transmission between the transmission unit and the reception unit uses a digital communication form, there is an effect that a high quality signal can be maintained with almost no signal deterioration. Further, by being unitized, it is possible to generally support various AV devices as a single device, and on the other hand, it can be easily realized as a built-in type of main device.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an AV system having a video / audio transmission system according to a first embodiment of the present invention.

FIG. 2 is a block diagram of an analog input transmission unit according to the first embodiment.

FIG. 3 is a block diagram of an analog output receiving unit according to the first embodiment.

FIG. 4 is a schematic diagram of an AV system having a video / audio transmission system according to a second embodiment of the present invention.

FIG. 5 is a block diagram illustrating an example in which a video / audio output device according to the second embodiment is a BS tuner.

FIG. 6 is a schematic diagram of an AV system having a video / audio transmission system according to a third embodiment of the present invention.

FIG. 7 is a block diagram illustrating a video / audio input device according to a third embodiment.

[Explanation of symbols]

1, 30 video / audio output device 2 analog input transmission unit 3 analog output reception unit 4 video /
Voice input device 5, 6, 44, 51, 52, 60 Antenna 7, 8, 9, 10, 11, 12 Cable 1
3,14 A / D converter 15,16 MPEG2 1
7, 40 ECC encoding 18, 41 Modulator 1
9, 22, 42, 65 Frequency converters 20, 21, 4
3, 64 Transmission amplifier 23, 66 Demodulator 24, 67
ECC decoding 25, 26 MPEG2 video decoding 27, 28, 37, 39 D / A converter 31 Tuner 50 Digital input transmitting unit 62 Digital output receiving unit

Claims (5)

[Claims] 1. A video / audio transmission system comprising a transmission unit and a reception unit, wherein the transmission unit is an input processing unit for inputting a video signal and an audio signal, and is output from the input processing unit. A transmitting unit that performs a predetermined transmission modulation process on the video signal and the audio signal in a predetermined digitally modulated state, and transmits and outputs the transmission signal, wherein the reception unit transmits the signal transmitted from the transmission unit of the transmission unit. Receiving means for receiving and receiving a predetermined demodulation process; and output processing means for outputting a video signal and an audio signal in a predetermined digitally modulated state obtained by the receiving means. Voice transmission system. 2. An input processing means of the transmission unit converts a video signal and an audio signal input as analog signals into digital signals, performs predetermined digital modulation processing, and supplies the digital signals to the transmission means. The video / audio transmission system according to claim 1, wherein: 3. The transmission unit according to claim 1, wherein the input processing unit of the transmission unit inputs a video signal and an audio signal that have been subjected to predetermined digital modulation processing, and supplies the input video signal to the transmission unit. Video / audio transmission system. 4. An output processing unit of the receiving unit performs a predetermined digital demodulation process on the video signal in a predetermined digital modulation state obtained by the receiving unit, and further converts the video signal into an analog signal. The video / audio transmission system according to claim 1, wherein the video / audio transmission system outputs a signal. 5. The apparatus according to claim 1, wherein the output processing means of the receiving unit outputs the video signal and the audio signal which have been subjected to a predetermined digital modulation process and obtained by the receiving means. Video / audio transmission system.