JPH04101587A - Video/audio system - Google Patents

Abstract

PURPOSE:To obtain a video/audio system which can record television signals in plural channels and reproduce a television signal in an arbitrary channel by alternately and continuously recording asynchronous television signals in plural channels and superimposing/recording compressed audio signals in plural channels on them, and then recording them. CONSTITUTION:First, video signals B0 and B0' in a channel 2 is written in a memory. Video signals A1 and A1' in a channel 1 are recorded on tape. Next, the video signals B0 and B0' in the channel 2 are recorded on the tape. Video signals in the channel 1 and the channel 2 alternately and continuously undergo such operation and then are recorded. On them, an audio signal is superimposed and recorded. Of an audio signal and a video signal in the superimposed and recorded television signal in an arbitrary channel out of two channels, the audio signal is elongated and reproduced during reproduction. Thus, one VTR can record, for example, a ball game and a drama at the same time.

Description

[Detailed Description of the Invention] εIndustrial Application Field] The present invention relates to a video/audio device, and particularly to a video/audio device, in which television signals of a plurality of channels are alternately superimposed on a video signal and an audio signal, and recorded on a recording medium. The present invention also relates to a video/audio device capable of reproducing a television signal of any channel among a plurality of channels recorded on the medium during reproduction.

[Prior Art] FIG. 7 shows an example of a conventional video/audio device.
It is a block diagram of TR (video tape recorder).

In the figure, a VTR, which is an example of a conventional video/audio device, includes a rotating drum (10) via a rotating head (not shown), a head amplifier (11) that amplifies a video signal read by the rotating head, and a head amplifier (11) that amplifies a video signal read by the rotating head. 11), a signal processing circuit (12) that demodulates the video signal amplified by the signal processing circuit (12), an AD conversion circuit (13) that converts the video signal, which is an analog signal demodulated by the signal processing circuit (12), into a digital signal; A memory circuit (14) that stores the output of the conversion circuit (13) and a memory circuit (1
4), a DA conversion circuit (15) that converts the output from a digital signal to an analog signal, a video output terminal (101) that outputs an analog-converted video signal, and a
A memory control circuit 06) that controls the sampling timing of each circuit of the D conversion circuit (13), memory circuit (14), and DA conversion circuit (15) or the processing timing for digital signal processing, and the sequence of the entire device. A deck sequence control circuit (17) for controlling the tape sequence control circuit (17), a special playback circuit (18) for controlling tape running when performing special playback such as stay or slow, and these deck sequence control circuits (17) and the special playback circuit. A servo circuit (one) that receives the output from the servo circuit (18) to control the rotational speed of the rotating drum (10) and the capstan motor (22), and a capstan motor drive whose operation is controlled by the output from the servo circuit (19). a circuit (20);
Similarly, it is composed of a drum motor drive circuit (2) whose operation is controlled by the output of the servo circuit (one), and a capstan motor (22) which is driven by the output of the capstan motor drive circuit (20). The rotating tram (10) is driven by the output of a tram motor drive circuit (21).

Next, the operation will be explained. A conventional VTR configured as described above operates as follows.

First, during reproduction, a reproduction operation is performed in a reproduction mode selected from among various reproduction modes by the operation panel. That is, when a tape, which is a recording medium, is input, the tape is set at a predetermined position by the deck sequence control circuit (17), and the servo circuit (19) is set under the control of the deck sequence control circuit (17).
operates, and with the output of the servo circuit (19), the capstan motor drive circuit (20) and the drum motor drive circuit (
21) is driven, thereby driving the capstan motor (
22) and the rotating drum (10) are each driven to stably rotate at a predetermined speed.

Here, the video signal read by the video head of the rotating drum (10) whose rotational speed and rotational phase are controlled by the above-mentioned mechanism is amplified by the head amplifier (11), and then converted into an FM signal by the signal processing circuit (12). demodulated into a video signal.

The video signal demodulated by this signal processing circuit (12) is output as is to the video output terminal (101) and may be used as a normal video signal by inputting it to a TV etc. A video signal, which is a signal, is once converted into a digital signal by an AD conversion circuit (13).

Furthermore, the digital video signal which is the output of the AD conversion circuit (13) is stored in a memory circuit (14) consisting of five 256 kb RAMs.
) outputs the digital video signal from the DA converter circuit (
15) to an analog signal and connect it to the video output terminal (10
1) Output an analog video signal.

Of course, various combinations of the number of bits for AD conversion and memory capacity can be considered, but in general, in order to reduce deterioration in image quality, 6-bit AD conversion/DA conversion and five 256kb RAMs are recommended. It is known that the frame memory method requires twice as much memory as the field memory method.

These digital processes are generally carried out by a memory control circuit (16) that performs sampling processing at a clock frequency of 14 MHz, and the memory circuit (14) has a frequency of 3000 to 4000.
It consists of a gate array consisting of gates.

Generally, during playback, the AD conversion circuit (13), memory circuit (14), DA conversion circuit (15), and memory control circuit (16) do not necessarily need to be operated, but when performing special playback such as stay or slow. This is used to recall the memory contents through the operation of the special playback circuit (18) and the memory circuit (14), thereby making it possible to easily obtain a still screen or slow screen with good quality.

That is, by storing the video signal in the field memory during field playback when the running tape is stopped or intermittently running, a high-quality still screen or slow screen can be obtained.

[Problems to be Solved by the Invention] In conventional video/audio devices, such as a conventional VTR configured as described above, only one channel of television signals can be recorded, and two channels of television signals can be recorded simultaneously. If you wanted to do that, you would need to prepare two VTRs.

Furthermore, since the memory circuit is used only for special playback such as stay or slow during playback, and does not operate during recording, there has been a desire to utilize this effectively.

The present invention was developed in view of the above-mentioned situation, and it records television signals of a plurality of unsynchronized channels alternately on a recording medium by superimposing a video signal and an audio signal, and also superimposes a video signal and an audio signal on a recording medium. It is an object of the present invention to provide a video/audio device capable of reproducing a television signal of any channel among a plurality of channels recorded on the medium.

[Means for Solving the Problems] In order to achieve the above object, one video/video related to the present invention is provided.
In order to alternately record television signals of a plurality of channels that are not synchronized, and to superimpose a video signal and an audio signal on a recording medium, the audio device inputs a television signal of a first channel. a second input circuit for inputting a second channel television signal; a video/digital conversion circuit for converting a video signal output from the second input circuit into a digital signal; a memory circuit that stores output information of the digital conversion circuit; a digital video conversion circuit that converts the output information of the memory circuit into an analog signal; and a first video signal output from the first input circuit and the digital means for sequentially and alternately recording a second video signal output from the video conversion circuit onto a recording medium in synchronization with a synchronization signal of the first video signal; and the first and second inputs. first and second audio/digital conversion circuits for converting audio signals output from the circuits into digital signals, and a first audio/digital conversion circuit for storing output information of each audio/digital conversion circuit, respectively;
a second RAM, first and second compression circuits for respectively compressing the output information of each of the RAMs, and a digital audio conversion circuit for converting the output information of each of the compression circuits into an audio signal; The first video signal and the second video signal are sequentially and alternately recorded on a recording medium.
means for superimposing and recording an audio signal that is an output of the audio conversion circuit on a video signal, and at the time of playback, any of the television signals of a plurality of channels on the recording medium recorded by the video/audio device. video signal selection means for selecting and separating a video signal of a designated channel from among the two channel video signals recorded on the recording medium; a memory circuit for storing the video signal selected and separated by the selection means; and a memory circuit for selecting and separating the audio signal of a designated channel from among the two channels of audio signals recorded on the recording medium.
an audio signal selection means to be separated; an audio-to-digital conversion circuit for converting the audio signal selected and separated by the audio signal selection means into a digital signal; and a RAM for storing output information of the audio-to-digital conversion circuit; It has an expansion circuit that expands the output information of the RAM, and a digital-audio conversion circuit that converts the output of the expansion circuit from a digital signal to an audio signal, and the video signal selected and separated by the video signal selection means is An audio/digital conversion circuit for digitally converting an audio signal recorded on a recording medium, characterized in that the memory circuit for storing also serves as a memory circuit for storing output information of the video/digital conversion circuit used during recording. The RAM is characterized in that it also serves as a RAM for storing output information of an audio/digital conversion circuit that digitally converts an audio signal input from an input circuit.

[Function] Therefore, according to the video/audio device of the present invention, during recording, television signals of a plurality of channels with different synchronization are alternately and consecutively recorded, and on top of that,
Compressed audio signals of a plurality of channels are superimposed and recorded on a recording medium, and when played back, an audio signal and a video of a television signal of any channel among the plurality of channels superimposed on the medium are recorded. The signal can be expanded and played back in the case of an audio signal.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a video/audio device according to the present invention.

In FIG. 1, the video/audio device of the present invention is
A tuner (31) for receiving television signals.

(32) and video intermediate frequency amplifier/video detection circuit (3
3), (34) and a video amplifier (35).

(36), synchronous separation circuits (37), (38),
Changeover switch (39) (40), (41
)(44), (49) (56), (57
), (65), signal processing circuit (42), recording amplifier (43), audio intermediate frequency amplifier/audio detection circuit (45) (46), and audio amplifier (47)
, (48) and AD conversion circuit (50), <51
), RAM (52), (5B), time axis compression circuit (54), (55), and DA conversion circuit (58)
, FM modulation circuit (59), system clock signal generation circuit (60), head amplifier (61), FM demodulation circuit (62), field selection circuit (6B), (
66) and a time axis expansion circuit (64), and the other components are the same as those shown in FIG. 7, which is a block diagram of a conventional video/audio device.

Next, the operation will be explained. First, the recording operation of the video/audio device of the present invention configured as described above will be explained.

In FIG. 1, a tuner (31) and a tuner (32) are shown.
) are receiving television signals from different channels. Here, it is assumed that the tuner (31) receives the television signal of channel 1, and the tuner (32) receives the television signal of channel 2.

The video signals received by the tuners (31) and (32) are sent to the video amplifier (35) via video intermediate frequency amplifier/video detection circuits (33) and (34), respectively.
), (36).

The output of the video amplifier (35) is
) is applied to the fixed terminal (39A), and is also output to the synchronous separation circuit (37).

In addition, the output of the other video amplifier (36) is output to the AD conversion circuit (13), and the output of the other video amplifier (36) is output to the AD conversion circuit (13).
8) is also output.

These synchronization separation circuits (37) and (38) extract the synchronization signal from the video signal amplified by the video amplifiers (35) and (36), respectively, shape the waveform of this synchronization signal, and send it to the memory control circuit (16). It is being output. This synchronization signal is used as a control signal in the memory control circuit (16), and the synchronization signal output from the synchronization separation circuit (37) is used as a reading signal.
The synchronizing signal output from 8) is used as a writing signal.

The video signal amplified by the video amplifier (35) is transferred to the changeover switch (40) via the changeover switch (39).
is input to the movable terminal (40A). On the other hand, the video signal amplified by the video amplifier (36) is transferred to the AD conversion circuit (13), the memory circuit (14), and the DA conversion circuit (1).
5) to the fixed terminal (4) of the changeover switch (40).
0B).

Therefore, the changeover switch (40) allows the channel 1 video signal output from the video amplifier (35) and the D
It can be seen that this is a switch for switching the channel 2 video signal input from the A conversion circuit (15) and subjected to digital processing. Therefore, the changeover switch (40
) from the movable terminal (40C) to channel 1 and channel 2.
video signals will be output according to the operation of the changeover switch.

The movable terminal (40C) of the changeover switch (40) is connected to the fixed terminal (41A) of the changeover switch (41), and is further connected to the fixed terminal (41A) of the changeover switch (41).
1B) is connected to a video output terminal (101), and a fixed terminal (41A) is connected to a fixed terminal (44A) of a changeover switch (44) via a signal processing circuit (42) and a recording amplifier (43). There is.

That is, during recording, the changeover switch (41
), the movable terminal (41A) and fixed terminal (41B) are connected, and the movable terminal (40) of the changeover switch (40)
The video signals of channel 1 and channel 2 output from C) are modulated into FM recording signals by a signal processing circuit (42) via a changeover switch (41), and then sent to a recording amplifier (43). output, recording amplifier (43
) amplifies the FM recording signal and selects the changeover switch (44).
) is output to the fixed terminal (44A).

The fixed terminal (44B) of the changeover switch (44) is connected to the input terminal of the head amplifier (11), and the movable terminal (44B) is connected to the input terminal of the head amplifier (11).
4C) is connected to the rotating drum (10).

Next, the above recording operation will be explained in more detail with reference to FIG. 2 showing the tape format.

As mentioned above, tuner (31) and tuner (3)
2) are receiving television signals of different channels. The outputs of the tuners (31) and (32) are respectively connected to a video intermediate frequency amplifier/video detection circuit (33),
(34), video amplifier (35), (3
6) is output. Therefore, the video amplifier (35),
The signal output from (36) is a video signal having completely different information from both the synchronization signal and the image signal.

For convenience of explanation, the state of this received signal is shown in tape format diagrams C and D in FIG. 2 in correspondence with the tape format. Here, An and An' shown in tape format diagrams C and D in FIG. 2 are symbols indicating the fields of the video signal of channel 1, respectively, with An indicating an odd field and An' indicating an even field. .

Similarly, Bn and Bn respectively indicate the fields of the video signal of channel 2, with Bn indicating an odd field and Bn' indicating an even field. As shown in the tape format diagram CD of FIG. 2, it can be seen that the video signal of channel 2 and the video signal of channel 2 are not synchronized.

As described above, the video/audio device of the present invention which receives different video signals for both the synchronization signal and the image signal records as follows.

That is, video signal BO of channel 2.

BOo is written into the memory circuit (14) via the AD conversion circuit (13). This is a synchronous separation circuit (38
) The memory control circuit (16) is operated based on the synchronization signal extracted by the synchronous signal. That is, the video signal amplified by the video amplifier (36) is sent to the sync separation circuit (
At step 38), the synchronization signal is extracted, and the extracted synchronization signal is applied to the memory control circuit (16) for use as a write control timing signal for the memory control circuit (16). This controls the memory control circuit (16), AD conversion circuit (13), and memory circuit (14), so
The video signal amplified by the video amplifier (35) is digitally processed by the AD conversion circuit (13), and then digitally processed by the AD conversion circuit (13).
) will be written to.

On the other hand, regarding the video signal input from channel 1,
The first input video signals AO and AO' are ignored,
The next input video signals AI, A1' are transferred to the changeover switch (39) as described above.

(40) and (41), the signal processing circuit (42)
), and the signal processing circuit (42) converts the video signal into FM
After modulating the recording signal and amplifying it with a recording amplifier (43), it is sent to the rotating drum (10) via a changeover switch (44).
) and recorded on tape in the same way as a conventional VTR (see tape format diagram B in FIG. 2).

Next, when the operation of writing the AI and Alo signals to the tape is completed, the video signals BO and BO' of channel 2, which have been previously stored in the memory circuit (14), are DA Via the conversion circuit (15), it is sent to the changeover switch (40), and then through the changeover switch (41), the signal processing circuit (12), the recording amplifier (4B), and the changeover switch (44). input into the video head of the rotating tram (10),
Record it on tape in the same way.

At this time, the call timing of the signal stored in the memory circuit (14) is based on the synchronization signal of channel 1 separated by the synchronization separation circuit (37).
) controls the memory circuit (14) and the DA conversion circuit (
15), the tape format diagram B in Figure 2 is created.
As shown in the figure, A1, AI', BO, BO' are recorded consecutively in this order.

These operations are performed alternately and continuously for the video signals of channel 1 and channel 2, as shown in the tape format diagram B in Figure 2, and the channels are displayed on the tape as shown in the tape format diagram B in Figure 2. One video signal is removed frame by frame and recorded alternately and continuously. It can be seen that the tape format recorded on this tape is the same as one in which only one channel is recorded continuously, or the contents are two channels mixed in each frame.

The above-mentioned changeover switches (39) and (41).

(44) are linked to operate the video head of the rotating drum (1o) in recording mode and playback mode, but during the above operations, the connection state is such that it operates in recording mode. It becomes.

Next, we will discuss the operation of the audio signal system.

First, an audio intermediate frequency amplifier/audio detection circuit (45),
The audio signal output from (46) is applied to audio amplifiers (47) and (48). Also,
The changeover switch (49) is a changeover switch for audio signal recording/playback mode, and is connected to the AD conversion circuit (5).
0) and (51) are RAMs (52) that convert analog signals into digital signals.

(53) temporarily stores the digital audio signal;
The time axis compression circuits (54) and (55) are RAM (5
2), the digital audio signal stored in (53) is compressed in the time axis, and the changeover switch (56)
is a changeover switch that operates only in the recording mode and is used to select the field of the video signal, the changeover switch (57) is a recording/playback mode changeover switch, and the DA conversion circuit (58) is a time axis compression circuit ( 5
4).

(55) converts the compressed digital audio signal into an analog audio signal, and the FM modulation circuits (5) perform FM modulation on the DA-converted compressed analog audio signal.
60) is for controlling the sequence of processing the audio signal, and is a system clock signal generation circuit (61).
operates based on output signals from the synchronization separation circuits (37), (38) and the memory control circuit (16).

The audio signal recording operation of the video/audio device of the present invention configured as described above will be explained in more detail.

Audio signals of different channels received by Chu+ (31) and (32) are detected by audio intermediate frequency amplifier/audio detection circuits (45) and (46), and amplified by audio amplifiers (47) and (48). be done. Analog audio signals amplified by audio amplifiers (47) and (48) are converted into digital signals by AD conversion circuits (50) and (51), respectively.

In general, the sampling theorem, which represents a continuous analog signal by sampling it at a certain time interval, states that if sampling is performed at a frequency that is at least twice the highest frequency of the signal's spectral distribution, the original waveform can be completely reproduced. . Further, it is possible to identify an audio signal if its frequency characteristic is 10 KHz. Therefore, in this case, sampling at 20 KHz is sufficient.

Therefore, an analog audio signal having a frequency of up to 10 KHz is divided into two, for example, 8 bits, and written to the RAM (52) (53) at a sampling frequency of 20 KHz. Next, write the digital audio signal stored in the RAMC52>(53) and convert it to 10 times the frequency (
200KH2), the time axis is 1, /
This means that it has been compressed to 10.

That is, the digital signal is once stored in the RAM (52),
(53) at a predetermined speed and read it out at high speed, the time axis compression circuit (54), (5
Perform step 5). For example, the data transmission rate is 10 KHz x 8 bits - 80 kbps. Here, in order to compress the time axis to 1/10, it is necessary to read 80 kbps data at 10 times the speed. R.A.
M data is read out at a high speed of 80 kbps x 10 = 0.8 mbps, time axis compressed, and this digital signal is added to the DA converter circuit (58) via the changeover switches (56) and (57), and is converted into a time axis compressed analog signal. This signal is converted into an audio signal and is applied to the FM modulation circuit (59), modulated and amplified, passed through the mode changeover switch (65), and applied to the deep recording head of the rotating drum (10) to record the audio signal or tape. be done.

Here, the changeover switch (56) selects the time axis compression circuit (54), (55) for each frame of the audio signal.
) output signals are switched alternately. Therefore,
Audio digital time-base compressed signals of two different channels, channel 1 and channel 2, are sequentially switched and sent to the output of the changeover switch (56) for each frame.

The system clock signal generation circuit (61) performs the timing processing of the digital signal described above, and is generated based on the synchronization signal of the video signal and the burst signal of the chroma signal.

Next, the above recording operation of the audio signal will be explained in more detail with reference to FIG. 2, which shows the tape format as in the case of the video signal.

Now, as shown in the tape format diagram B in Figure 2, the video signal is divided into AlAl', AlAl',
BOBO', A3A3', 82B2°, etc., the frame information of the two channels is sequentially recorded alternately and continuously without skipping one frame at a time. On the other hand, as shown in tape format diagrams F and G in Figure 2, 2
The different audio information signals of the two channels are Ash, As
h'Asl, Asl', As2...*, BsO, B
sO' Bsl Bsl', Bs2 ----- are sent out sequentially, or there is no particular reference signal, and continuous analog signals are sent out. (Therefore, in the tape format diagrams F and G in FIG. 2, for convenience of explanation, temporal divisions for each frame are temporarily added, like the video signal).

This analog audio signal is added to each AD conversion circuit (13) and converted into an 8-bit digital signal.
Store it in each RAM (52)+, (53),
Compressed by each time axis compression circuit (54) (55),
Channels are sequentially switched by a changeover switch (56) that switches the compressed audio signal frame by frame. At this time, the audio signals recorded on the tape by the above operation are continuously recorded by switching the audio signals of two channels sequentially for each frame. E
It becomes as shown in . Therefore, the time axis compression circuit (54),
In (55), it is sufficient to compress the audio signal to 1/2, but considering the case where the number of channels is 3 or more, it is desirable to compress the audio signal to about 1/10.

This compressed digital audio signal is converted into a DA conversion circuit (5
8), convert it again to an analog audio signal, and convert it to an FM modulation circuit (59) used in the VH5 system.
M modulation is performed, and deep recording is performed using a dedicated audio signal head of a rotating drum (10) via a changeover switch (65).

In other words, the relationship between the audio signals of the two channels is
As shown in tape format diagrams F and G in FIG. 2 and tape format diagram E in FIG. 2, the data is compressed to 1/2 and further modulated for deep recording.

Here, a description will be given of whether a video signal that changes every frame or an audio signal that is compressed to 1/2 is recorded on a tape with reference to FIGS. 3 to 6 showing the superimposed recording method of the present invention.

First, as shown in the modulation signal waveform A for surface recording in Figure 3, the luminance signal of the video signal is modulated by the FM carrier wave modulation, the chroma signal is modulated by the low frequency conversion direct recording method, and the video head (V
In the H5 method, recording is performed at an azimuth angle of ±6). On the other hand, the audio signal (Fig. 2 tape format diagram E)
F at the frequency shown in modulation signal waveform B of deep recording in the figure.
It is M-modulated and recorded by an audio head (azimuth angle 30 in the VH5 system).

When this situation is viewed from the cross section of the tape, it becomes as shown in the cross section of the tape shown in FIG. Also, when viewed from the magnetic surface, it looks like Figure 6, and one track is written and recorded in the thickness direction with two heads: once for the audio signal, once for the video signal, and twice for the dialogue. become.

Next, the operation during playback will be explained. The video signal is as follows.

The video signal read out from the rotating drum (10) is sent to the head amplifier (11) via the changeover switch (44).
) and input to the signal processing circuit (12), or demodulation is performed in the signal processing circuit (12). The output of the signal processing circuit (12) is the field selection circuit (66)
is input.

The field selection circuit (66) selects any one frame of the alternately recorded video signals of the two channels. The video signal selected by the field selection circuit (66) is sent to the AD conversion circuit (13) and is also applied to the fixed terminal (:39B) of the changeover switch (39). Therefore, this changeover switch (39) is used to switch the video head (not shown) of the rotating drum (10) in recording mode or playback mode, and its movable terminal (39C ) is the changeover switch (40
) is connected to the fixed terminal (40A).

Next, for the audio signal, the rotating drum (10)
The FM audio signal read out is input to the head amplifier (61) via the changeover switch (65). The head amplifier (61) amplifies the read audio signal and sends it to the FM modulation circuit (62). F
The M demodulation circuit (62) demodulates the FM audio signal, and the field selection circuit (63) selects any frame of the alternately recorded audio signals of the two channels. Since the audio signal selected by the field selection circuit (63) has been compressed on the time axis, the compressed audio signal is expanded in the time axis expansion circuit (64).

In the above embodiment, the case of two channels of television signals has been explained, but it can be easily inferred that recording can be performed in the same manner even in the case of three or more channels.

However, as a matter of course, the frame or field resolution for a video signal deteriorates depending on the number of channels.

Also, can the memory circuit (14) be a field memory or a frame memory? When recording and reproducing operations in units of frames as shown in Figure 2, a frame memory is always required. You will need twice as much RAM.

RAM (
52) and (53) in which the clock frequencies for writing and reading are changed, but the present invention is not limited to this method; for example, a bit conversion method may be used.

Furthermore, a QPSK modulation method may be adopted as the audio signal modulation method. At this time, the DA conversion circuit (58)
becomes unnecessary.

Note that the functions in the special playback field of the conventional video/audio device shown in FIG. 7 are not directly related to the present invention, and therefore their explanation has been omitted. t2 is V equipped with field memory.
Regarding TR, the video/audio device of the present invention can be implemented without increasing costs.

Regarding superimposed recording, in one embodiment of the present invention, a two-layer method of deep recording and surface recording has been described. This is a method for reducing mutual interference between video signals and audio signals, and performance is particularly important. If not required, it is also possible to adopt a superimposition method in which audio signals are mixed on one set of rotating video heads.

Further, in the block diagram shown in FIG. 1, the memory circuit (14) and the RAM (52), (53) are integrated;
Further, it is also easily possible to integrate the time axis compression circuits (54) and (55).

[Effects of the Invention] As explained above, according to the video/audio device of the present invention, during recording, television signals of a plurality of channels with different synchronization are alternately and consecutively recorded; The audio signals of channels are superimposed and recorded on a recording medium, and at the time of playback, the audio signal and video signal of a television signal of any channel among the plurality of channels superimposed and recorded on the medium are recorded as audio signals. Since it is constructed so that it can be expanded and played back, it has the advantage that it is possible to simultaneously record, for example, baseball and a drama broadcast at the same time on one VTR.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a video/audio device showing an embodiment of the present invention, and FIG. 2 is a block diagram of a video/audio device of the present invention, which is used to explain the recording method of the video/audio device of the present invention. 3 is a diagram of the format of the recorded tape; FIG. 3 is a modulation signal waveform diagram of surface recording showing the modulation method of the video/audio device of the present invention; and FIG. 4 is a diagram of the modulation signal waveform of surface recording showing the modulation method of the video/audio device of the present invention. FIG. 5 is a cross-sectional view of the tape recorded by the video/audio device of the present invention, FIG. 6 is a tape surface diagram of the tape recorded by the video/audio device of the present invention, and FIG. The figure is a block diagram of a VTR (video tape recorder), which is an example of a conventional video/audio device. In the figure, (10) is a rotating drum, (11) is a head amplifier, (12) is a signal processing circuit, (13) is an AD conversion circuit, (14) is a memory circuit, (15) is a DA conversion circuit, (16) is a ) is the memory control circuit, (17) is the deck sequence control circuit, (18) is the special playback circuit, (1
9) is a sabot circuit, (20) is a capstan motor drive circuit, (21) is a drum motor drive circuit, (22) is a capstan motor, (31) and (32) are a tuner,
(33) (34) is a video intermediate frequency amplifier/video detection circuit, (35) and (36) are video amplifiers, (
37), (38) are synchronous separation circuits, (39), (40)
, (41), (44), (49). (56), (57), (65) are changeover switches, (42) is a signal processing circuit, (43) is a recording amplifier, (45) is an audio intermediate frequency amplifier/audio detection circuit (4
7), (48) is an audio amplifier, (50),
(51) is an AD conversion circuit, (52). (53) is RAM, (54) and (55) are time axis compression circuits, (58) are DA conversion circuits, (5) are FM modulation circuits, (60) are system clock signal generation circuits, (6
]) is an audio amplifier. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (4)

[Claims] (1) A video/audio device capable of simultaneously recording television signals of multiple channels on the same medium, comprising a first input circuit that inputs the television signal of the first channel, and a television signal of the second channel. a second input circuit that inputs the video signal, a video digital conversion circuit that converts the video signal output from the second input circuit into a digital signal, and a memory circuit that stores output information of the video digital conversion circuit. , a digital video conversion circuit that converts output information of the memory circuit into an analog signal; a first video signal output from the first input circuit and a second video output from the digital video conversion circuit. means for sequentially and alternately recording the signals on a recording medium in synchronization with a synchronization signal of the first video signal; and converting the audio signals output from the first and second input circuits into digital signals, respectively. first and second audio-to-digital conversion circuits for conversion, and a first for storing output information of each of the audio-to-digital conversion circuits;
a second RAM, first and second compression circuits for respectively compressing the output information of each of the RAMs, and a digital audio conversion circuit for converting the output information of each of the compression circuits into an audio signal; The first video signal and the second video signal are sequentially and alternately recorded on a recording medium.
1. A video/audio device comprising means for superimposing an audio signal output from an audio conversion circuit onto a video signal and recording the same. (2) A video/audio device that reproduces video signals and audio signals of a plurality of channels on a recording medium recorded by the video/audio device according to claim (1), wherein the video and audio signals recorded on the recording medium are a video signal selection means for selecting and separating a video signal of a designated channel from video signals of a plurality of channels; a memory circuit for storing the video signal selected and separated by the video signal selection means; on the recording medium; an audio signal selection means for selecting and separating an audio signal of a designated channel from among audio signals of a plurality of channels recorded on the audio signal; and an audio signal selection means for converting the audio signal selected and separated by the audio signal selection means into a digital signal. - A digital conversion circuit, a RAM that stores output information of the audio/digital conversion circuit, an expansion circuit that expands the output information of the RAM, and a digital audio that converts the output of the expansion circuit from a digital signal to an audio signal. A video/audio device having a conversion circuit. (3) The video/audio device according to claim (2), wherein the video/digital conversion circuit according to claim (1) is used as a memory circuit for storing the video signals selected and separated by the video signal selection means. A video/audio device characterized in that it also serves as a memory circuit for storing output information. (4) The video/audio device according to claim (2), wherein the RAM stores output information of an audio/digital conversion circuit that digitally converts an audio signal recorded on a recording medium; R for storing output information of the audio/digital conversion circuit that digitally converts the audio signal input from the input circuit, as described above.
A video/audio device characterized in that it also serves as AM.