JPH0644503A - Magnetic recording/reproducing device for video signal and audio signal - Google Patents

Abstract

PURPOSE:To provide a video movie for recording/reproducing the video and digital audio signals maintaining a compatibility with a VHS-C system as before. CONSTITUTION:At the video movie of this system, the digital audio signal of a format different from that of a previous hi-fi audio signal is simuiltaneously recorded. By this system, the audio signal of one field period is information- compressed by using, for example, the high performance coding system of a DCT, MPEG 2, etc., the high performance coding system is operated by about 0.1 times and its frequency is multiplexed with the existing hi-fi audio signal. Even when a reproduction is operated at the video movie of this system, by using this recording system, a series of videos and audio signals having no time differences are reproduced. By this constitution, recording patterns recorded by existing VHS and VHS-C are formed and even at the time of reproducing, a reproducing time difference between the video and audio is eliminated.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a NTSC system, a PAL system, a SECAM system, a color video signal such as EDTV, an audio signal such as a stereo audio signal or a bilingual audio signal, and a magnetic recording medium such as a magnetic tape. The present invention relates to a magnetic recording / reproducing apparatus for video signals and audio signals, such as a video tape recorder for recording and reproducing.

[0002]

2. Description of the Related Art Conventionally, in a home video tape recorder (hereinafter referred to as VTR) represented by the VHS system, a color video signal records and reproduces a frequency-modulated luminance signal and a low-frequency-converted carrier color signal. The so-called color under system is adopted, and as the high-fidelity audio signal, a so-called deep recording method is adopted in which the audio signal is frequency-modulated and pre-recorded before the video signal.

For example, Journal of Television Society, 1978.
Vol. 32, No. 10, pp. 876-881, Yuma Shiraishi, "VHS System VTR" and Journal of Television Society, 1983, Vol. 37, No. 12, 1009-1013, 1 page Shuzo Machi, "VHS Hi-Fi VTR", and further about camera-integrated Hi-Fi system video camera, National Technical Report, 1988, Vol. 34, No. 6, p.
Page, Noriyuki Abe et al., “HiFi S-VHS C Movie NV-M50”.

[0004]

However, conventionally, a rotary cylinder having a diameter of 62 mm has been used in the VHS system, which is a typical VTR for home use. As the VHS system spreads in the market, a video camera with a built-in camera,
So-called video movies have been miniaturized. Currently, most of VHS video movies are so-called VHS-of about 47 mm, which is three quarters of 62 mm in diameter.
The C method is adopted. Also in this VHS-C system, miniaturization and high functionality have been advanced so that it is more convenient to carry, and the development phase has advanced to the point where further innovative miniaturization is impossible. In other words, if the cylinder diameter remains the same as before, there is a limit to further downsizing of the device, and in particular, there is a big problem that the video movie does not become smaller.

In view of the above problems, the present invention can record and reproduce a color video signal and an audio signal compatible with the conventional VHS system, and further, when reproducing a video movie of this system, the It is intended to provide an ultra-small video movie capable of reproducing a continuous digital audio signal.

[0006]

In order to solve the above problems, a new digital audio signal is recorded at the same time in a frequency band different from that of a hi-fi audio signal, and the new digital audio signal is an audio signal for one field period. About 0.1
This is a configuration in which high-efficiency coding is performed twice and frequency multiplexing is performed with the audio signal within the vertical synchronizing signal period of the video signal.

[0007]

With the above-described structure, the present invention can be applied to an ultra-small video movie for recording and reproducing a video signal and an audio signal while maintaining compatibility with the conventional VHS system and VHS-C system.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of essential parts in an embodiment of the present invention.

In this embodiment, in a helical scan type magnetic recording / reproducing apparatus for recording / reproducing each of a color video signal and a high-fidelity audio signal, 2 are provided on the circumference of a rotary cylinder having a diameter of 31 mm which is half of the conventional VHS.
Wrap a 1-inch magnetic tape about 340 degrees. Here, the rotating cylinder with a diameter of 31 mm is 1
It makes one revolution in the field period. Since about 10 degrees of the tape winding angle is a margin of the mechanical system, this cylinder can record only a signal of (330/360), that is, a period of about 91% in one field, The signal of the remaining 9% period cannot be recorded. Below, about 9
A track on which a signal of 1% period is recorded is called a main track, and a track on which a signal of the remaining 9% period is recorded is called a sub-track.

In the above configuration, the conventional VHS or VH
It is not possible to record the same temporally continuous video and audio signals as those recorded by the SC cylinder. Therefore, it is necessary to record the 9% signal with another head. As the 9% signal, a vertical synchronizing signal can be applied, and the 91% signal can be applied with other signals.

Since the vertical synchronizing signal has the same waveform repeatedly, it is possible to record the video signal with another head whose head relative height is shifted, for example. Therefore,
The video signal can be reproduced by the head cylinder mechanism system of this configuration and the conventional VHS or VHS-C head cylinder mechanism system.

However, there is a problem with high fidelity audio signals. That is, if a high-fidelity FM audio signal in the vertical synchronizing signal period is recorded by another head whose head relative height is shifted, the temporal continuity of the hi-fi FM audio signal cannot be ensured. That is, the signal recorded by the head cylinder mechanism system of this configuration is converted into the conventional VHS or VHS-
When reproduced by the head cylinder mechanism system of C, the hi-fi sound becomes a discontinuous sound signal. Therefore, it is possible to delay the audio signal in the vertical synchronizing signal period by using the memory for a time (T1) corresponding to the head relative height and record a temporally continuous high-fidelity FM audio signal. Therefore, when reproducing by the conventional VHS or VHS-C system, there is no problem in time continuity.

Next, at the time of splicing and recording which is often performed in a video movie, it is necessary to maintain continuity between the video signal and audio signal of the main track and the audio signal of the sub track.
This can be dealt with by devising the recording / reproducing timing.
That is, although the timing setting is slightly complicated, the recording of the video and audio signals by the sub head is extended by (T1) from the recording end time, and the sub head is recorded by (T1) from the recording start time. This can be achieved by delaying the recording timing of the video and audio signals. In this case, when performing joint shooting, a time interval of at least twice (T1) from the end time of recording to the start time of recording is required.

However, when a video movie of this method is reproduced, a high-fidelity audio signal whose timing is delayed by (T1) from the video signal is reproduced. To eliminate the time difference between the video and the audio, delaying the video signal and the hi-fi audio signal in the period other than the vertical synchronization signal period (T1) requires a huge memory of several tens of megabytes or more and is not practical. Therefore, when playing back a video movie of this method, there is a problem that only a linear track sound of low sound quality can be used especially in the long time mode.

Therefore, in the video movie of this system, a digital audio signal of a format different from the conventional hi-fi audio signal is recorded at the same time. In this system, the audio signal of one field period is subjected to information compression using a high efficiency encoding system such as DCT or MPEG2, and frequency-multiplexed with a conventional hi-fi audio signal.

By adopting the recording system as described above, it is possible to reproduce continuous video and audio signals with no time difference even when a video movie of this system is reproduced.

With the above structure, the conventional VHS or VHS-C
It is possible to form a recording track pattern that is exactly the same as the recording track pattern that was recorded in, which is compatible with the conventional method, and there is no difference in the reproduction time of the video and audio signals when reproducing with this method. .

A specific configuration will be described below. First, the video signal recording processing system will be described. In FIG. 1, reference numeral 1 is a first input terminal for a color video signal, from which an NTSC composite video signal is input and separated into a luminance signal Y and a carrier color signal C by a Y / C separation circuit 2. Reference numeral 3 denotes a second input terminal pair for the color video signal, from which the luminance signal Y and the carrier color signal C of the components forming the NTSC video signal are input. The Y and C signals from the Y / C separation circuit 2 and the input terminal pair 3 are switched to arbitrary input signals by the switcher circuit 4.

The output Y of the switcher circuit 4 is subjected to linear or non-linear emphasis by the emphasis circuit 5 and then FM-modulated by the FM modulation circuit 6. Further, the output C of the switcher circuit 4 is input to the low frequency conversion circuit 7, and F
After the frequency is converted to a frequency lower than that of the M-modulated Y signal, it is added to the FM-modulated Y signal in the first adding circuit 8.

By the way, the Y signal output of the switcher circuit 4 reaches the vertical synchronizing signal separating circuit 9, and the separated vertical synchronizing signal is inputted to the switcher circuit 10 and the switcher circuit 23. In the switcher circuit 10, a switching signal that is at a high level only during the vertical synchronization period and is at a low level during the other periods is created from the input vertical synchronization signal, and the switching signal is used to select the switcher output as follows.

That is, when the switching signal is low level, the signal is supplied to the recording amplifier 11a, and when the switching signal is high level, the signal is supplied to the recording amplifier 11b through the delay circuit 12. The signal delay time of the delay circuit 12 is set such that the recording track by the recording amplifier 11a and the recording track by the recording amplifier 11b on the magnetic tape have the same azimuth and are continuous VHS system video recording signals. .

Next, the audio signal recording processing system will be described. In FIG. 1, reference numeral 13 is an input terminal for a stereo audio signal, and a buffer circuit 14 produces two systems of stereo audio signals. One of them is emphasized by the emphasis circuit 15, and the carrier frequency is about 1.3 to 1.7M.
From the FM modulation circuit 16 that performs FM modulation at Hz to the second addition circuit 17. The other one system is input to the A / D conversion circuit 18, converts the audio signal R / L channel into a digital audio signal, and outputs the digital audio signal to the serial signal conversion circuit 19.

The output signal from the A / D conversion circuit 18 is converted into a serial digital signal (digital signal of one channel) of each R / L channel in the serial signal conversion circuit 19, and the high efficiency encoding circuit is provided. 20 is transmitted. The serial digital signal converted by the serial signal conversion circuit 19 is subjected to information compression with a compression rate of about 9% in the high efficiency encoding circuit 20, and is transmitted to the error correction encoding circuit 21. Here, the high-efficiency encoding circuit 20 is, for example, D
It can be easily realized by using CT or MPEG2,
Details are published in "Systematic Image Coding" by Miyahara.

The output signal from the high efficiency encoding circuit 20 is
In the error correction coding circuit 21, an error correction parity bit is added and transmitted to the modulation coding circuit 22. Here, the error correction coding circuit 21 can be easily realized by using, for example, Reed-Solomon product coding,
Details are published in "Code theory" by Imai. The output signal of the error correction coding circuit 21 is converted into a modulation code of, for example, a four-phase PSK system having a carrier frequency of about 3.0 MHz in the modulation coding circuit 22, and the second addition circuit 1
To 7.

In the second adder circuit 17, the FM modulator circuit 1
The frequency-multiplexed output signal from 6 and the output signal from the modulation and coding circuit 22. At this time, the frequency-multiplexed period is a vertical synchronization signal period. Adder circuit 17
Is output to the switcher circuit 23. In the switcher circuit 23, a switching signal that is at a high level only during the vertical synchronization period and is at a low level during the other periods is created from the input vertical synchronization signal, and the switching signal is used to select the switcher output as follows.

That is, when the switching signal is low level, the signal is supplied to the recording amplifier 25a, and when the switching signal is high level, the signal is supplied to the recording amplifier 25b through the delay circuit 24. The signal delay time of the delay circuit 24 is the same as the recording amplifier 25 on the magnetic tape 28.
The continuous VHS FM with the same azimuth on the recording track by a and the recording track by the recording amplifier 25b.
It is set to be a voice recording signal.

By the way, in FIG. 1, reference numeral 26 denotes a rotary cylinder, and the rotary cylinder 26 is driven by a rotary cylinder drive circuit 27 to indicate an arrow A for each field of the color video signal.
Rotate once in the direction. 28 is about 340 in the rotating cylinder 26
The magnetic tape 29 is wound around once to change the recording track width by the two magnetic heads.
The magnetic tape 28 is moved in the direction of arrow B by a tape feeding speed varying device that changes the feeding speed of the magnetic tape 28 into a plurality of modes.

Further, reference numerals 30, 31, 32 and 33 denote combi-type magnetic head pairs, each having a different azimuth angle. One combi-type magnetic head pair is composed of two magnetic heads having the same track width and opposite azimuths. Each of the four magnetic head pairs obliquely scans the magnetic tape 28 wound around the rotating cylinder 26 at an angle of about 340 degrees. This VTR is a so-called helical scan VTR.

The FM audio output from the recording amplifier 25a is passed through a conventionally known rotary transformer (RT), and a magnetic head pair 30 is arranged on the circumference of the rotary cylinder 26.
Then, the first signal recording track is formed on the magnetic tape 28. Further, the multiplexed signal output of the FM sound and the digital sound of the recording amplifier 25b is similarly performed by the magnetic head pair 3 as well.
1 to form a second signal recording track on the magnetic tape 28 on an extension of the first signal recording track. The video output of the recording amplifier 11a is also the same as that of the magnetic head pair 3
2 to form a third signal recording track on the magnetic tape 28. Similarly, the output of the recording amplifier 11b is also guided to the magnetic head pair 33 and forms a fourth signal recording track on the extension line of the third signal recording track on the magnetic tape 28. Here, the third and fourth video signal recording tracks respectively record the first and second audio signal recording tracks in an overlapping manner, and the audio signals are recorded by a so-called deep recording method.

FIG. 2 shows an example of a recording track pattern of this recording method. The magnetic head pair 30 has azimuth angles of (+30 degrees) and (-30 degrees), and the magnetic head pair 31 has azimuth angles of (+30 degrees) and (-30 degrees). Further, the azimuth angle of the magnetic head pair 32 is (−6 degrees) and (+6 degrees), and the azimuth angle of the magnetic head pair 33 is also (−6 degrees) and (+6 degrees).
Degree).

As for the magnetic heads used for recording / reproducing, one of the magnetic head pairs is alternately used for each field, and the adjacent tracks have a reverse azimuth relationship with each other. The magnetic head 55 in FIG. 2 is one of the magnetic head pairs 30, and the azimuth angle is (+30
The magnetic head 56 is one of the magnetic head pairs 32, and the azimuth angle is (-6 degrees).

In the tracks T1 (-30) and T1 (+30) in FIG. 2, the head used for recording differs depending on the recording timing. That is, recording is performed by the magnetic head pair 30 during the period other than the vertical synchronization signal period (period TC in FIG. 2), and recording by the magnetic head pair 31 in the vertical synchronization signal period (period TB in FIG. 2).

The authors examined the feasibility of this recording / reproducing system. In the VHS VTR, the recording track widths of the third and fourth video signals are 19.3 μm, and the recording track widths of the first and second audio signals are also 19.3 μm.
μm, and the mechanism of the magnetic head, the rotary cylinder, etc. is adjusted so that the third and fourth recording tracks completely overlap the first and second recording tracks. Signals of 1.3 MHz and 1.7 MHz are recorded on the first recording track. The second recording track has 1.3 MHz and 1.7 MHz and a weak level of 3.0 for some periods.
Record the MHz signal. The video signal is recorded on the third recording track. The vertical synchronizing signal of the video signal is recorded on the fourth recording track.

Since the video signal, the 1.3 MHz FM audio signal and the 1.7 MHz FM audio signal can be reproduced from the prior art, there is no problem. Since the 3.0 MHz digital audio signal is also a digital signal, the CN ratio required for reproduction may be smaller. Here, the CN ratio is the ratio of C to N when the noise measurement band is 3 kHz, the reproduction output of the carrier signal is C, and the average value of the noise level at a frequency 100 kHz Hz above and below the carrier signal is N. Define in. For a 3.0 MHz digital audio signal, the CN ratio necessary for reproduction can be secured even if the recording level is low.
And, interference such as cross modulation distortion on the FM audio signal of 1.7 MHz can be almost ignored. Therefore, this method can be sufficiently realized.

FIG. 3 shows an example of frequency arrangement of this recording method. FIG. 3A shows a case where the present invention is applied to a conventional VHS system VTR. The dotted line signals recorded by the magnetic heads with azimuth angles of (+30 degrees) and (-30 degrees) are FM audio signals at 1.3 MHz and 1.7 MHz and digital signals recorded at a weak level near 3.0 MHz. It is an audio signal. The solid line signals recorded by the magnetic heads with azimuth angles of (-6 degrees) and (+6 degrees) are
A low-frequency conversion carrier color signal having a carrier at 0.629 kHz and an FM luminance signal at 1 to 6 MHz.

FIG. 3B shows a case where the present invention is applied to a conventional SVHS type VTR. Azimuth angle is (+3
The signal of the dotted line recorded by the magnetic head of (0 degree) and (-30 degree) is F of 1.3 MHz and 1.7 MHz vicinity.
It is an M audio signal and a digital audio signal recorded at a weak level around 3.0 MHz. Azimuth angle is (-6
The solid line signals recorded by the (.degree.) And (+ 6.degree.) Magnetic heads are a low-frequency conversion carrier color signal having a carrier at 0.629 kHz and an FM luminance signal of 1 to 10 MHz.

By the way, in FIG. 1, at the time of reproduction, the reproduction output of the magnetic head pair 30 is amplified by the reproduction head amplifier 48 through RT. Similarly, the outputs of the magnetic head pairs 32 and 33 are also amplified by the reproducing head amplifiers 34 and 35, respectively.

The output of the head amplifier 35 reaches the BPF 42, where only the FM luminance signal is extracted and the delay circuit 4
3 and the FM demodulation circuit 3 via the switcher circuit 37.
Up to 8. After being demodulated to a baseband signal by the FM demodulation circuit 38, it is deemphasized by the deemphasis circuit 39. The output of the de-emphasis circuit 39 is sent to the vertical sync signal separation circuit 44 or separates the vertical sync signal to control the switching timing of the switcher 37.
That is, the output of the switcher 37 is the output of the delay circuit 43 during the vertical synchronization period and the output of the BPF 36 during the period other than the vertical synchronization period. BPF 36 and BP
The output of F42 is a frequency-modulated luminance signal, and the delay circuit 43 is used to secure a video signal that is temporally continuous than the video signal outputs of the BPF 36 and BPF 42.

The output of the head amplifier 34 is the BPF.
At 40, the carrier color signal that has been low-pass converted here is extracted and converted to the frequency of the original NTSC signal by the frequency conversion circuit 41.

The reproduced luminance signal Y which is the output of the de-emphasis circuit 39 and the reproduced carrier color signal C which is the output of the frequency conversion circuit 41 are added by the third adding circuit 45 and output from the output terminal 46. Also, the reproduction luminance signal Y output from the de-emphasis circuit 39 and the frequency conversion circuit 41.
The reproduced carrier color signal C, which is the output of the above, is output from the output terminal pair 47 as a component color video signal.

The output of the head amplifier 48 reaches the BPF 49, where the digital audio signal waveform is extracted and transmitted to the demodulation circuit 50. The output signal from the BPF 49 is
In the demodulation circuit 50, the digital voice signal is detected from the digital voice signal waveform extracted by the BPF 49 and transmitted to the error correction code decoding circuit 51. The output signal from the demodulation circuit 50 is an error correction code decoding circuit 51.
In (1), the code error is corrected and then transmitted to the high efficiency code decoding circuit 52. The output signal from the error correction code decoding circuit 51 is supplied to the high efficiency code decoding circuit 52,
It is expanded and transmitted to the parallel signal conversion circuit 53.

The output signal from the high-efficiency code decoding circuit 52 is converted into a 2-channel signal (R / L channel signal) in the parallel signal conversion circuit 53 and transmitted to the D / A conversion circuit 54. . The D / A conversion circuit 54 converts the input 2-channel digital audio signal into an analog audio signal and transmits it to the output terminal pair 55. Then, an analog R / L audio signal is output from the output terminal pair 55.

Even if the tape recorded by the VTR of the present invention is reproduced by the conventional VHS system or SVHS system VTR,
Since the signals are recorded even in the conventional system using the hi-fi sound, there is no problem in the reproduction of the color video signal and the hi-fi sound signal. Further, in the present embodiment, the BPF 49 extracts and reproduces the digital audio signal. However, when reproducing the high-fidelity audio signal, the signal obtained by delaying the output of the magnetic head 30 and the output signal of the magnetic head 31 are used. A switch circuit for smoothly switching between the vertical synchronizing signal period and the outside of the vertical synchronizing signal period for output is provided, a BPF for extracting the FM voice band from the output of the switching circuit, a demodulation circuit for FM demodulation, and a de-emphasis. A de-emphasis circuit for processing may be provided.

In this embodiment, the case where the high efficiency coding circuit is used as the processing unit of the digital audio signal has been described. However, by controlling the number of quantization bits in the A / D conversion circuit section. Needless to say, it is possible to use the high efficiency coding circuit. Further, although the case where the serial signal conversion circuit is inserted between the A / D conversion circuit and the high-efficiency encoding circuit has been described in the present embodiment, the serial signal conversion circuit includes the high-efficiency encoding circuit and the error correction code encoding. It goes without saying that there is a case where it is inserted between the circuits or a case where the serial signal conversion circuit is inserted between the error correction code coding circuit and the modulation coding circuit.

Further, in the present embodiment, the serial signal conversion circuit is used to convert the signals of the two channels of the R / L channels into one channel and perform the signal processing. It is needless to say that it can be realized even if the quadrature modulation method is used in the modulation coding circuit by processing up to the coding circuit. In addition, although the configuration of the recording / reproducing apparatus has been described in the present embodiment, it goes without saying that the recording apparatus can be configured by making only the recording unit independent.

[0046]

According to the present invention, the recording track pattern is exactly the same as the recording track pattern recorded by the conventional VHS or VHS-C, though it is a very small video movie for recording and reproducing a color video signal and a hi-fi audio signal. -A pattern can be formed. Therefore, the color image signal and the hi-fi audio signal can be compatible with the conventional system. Moreover, even in the reproduction by this method itself,
There is no difference in playback time between video and audio signals. further,
In the VTR of the present invention, the magnetic tape is placed on the rotating cylinder in approximately 34
By wrapping it around 0 degrees, the cylinder diameter can be reduced to half that of the conventional model, making it possible to miniaturize the device and easily support movies with a built-in camera.

[Brief description of drawings]

FIG. 1 is a block diagram of essential parts in an embodiment of the present invention.

FIG. 2 is a recording track pattern diagram in one embodiment of the present invention.

FIG. 3 is a diagram for explaining frequency allocation of recording signals in the embodiment of the present invention.

[Explanation of symbols]

 1 composite color video signal input terminal 2 Y / C separation circuit 3 component color video signal input terminal 4 switcher circuit 5 emphasis circuit 6 FM modulation circuit 7 low frequency conversion circuit 8 adder circuit 9 vertical sync signal separation circuit 10 switcher circuit 11 Recording amplifier 12 Delay circuit 13 Stereo audio signal input terminal 14 Buffer circuit 15 Emphasis circuit 16 FM modulation circuit 17 Adder circuit 18 A / D conversion circuit 19 Serial signal conversion circuit 20 High efficiency coding circuit 21 Error correction coding circuit 22 Modulation code Circuit 23 switcher circuit 24 delay circuit 25 recording amplifier 26 rotating cylinder 27 rotating cylinder drive circuit 28 magnetic tape 29 tape feed speed varying device 30, 31, 31, 33 magnetic head 34 reproducing head amplifier 35 reproducing head amplifier 3 6 BPF 37 Switcher circuit 38 FM demodulation circuit 39 De-emphasis circuit 40 BPF 41 Frequency conversion circuit 42 BPF 43 Delay circuit 44 Vertical sync signal separation circuit 45 Adder circuit 47 Stereo audio signal output terminal 48 Playback head amplifier 49 BPF 50 Demodulation circuit 51 Error Correction code decoding circuit 52 High efficiency coding decoding circuit 53 Parallel signal conversion circuit 54 D / A conversion circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiro Takeuchi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (9)

[Claims] 1. A device for recording / reproducing each of a color video signal and an audio signal input to a magnetic recording medium, wherein a rotary cylinder around which the magnetic recording medium is wound about 340 degrees is used as one of the color video signals. A rotary cylinder drive circuit that rotates once for each field, a conversion circuit that converts the input color video signal into a luminance signal and a carrier color signal, and a first frequency modulation of the luminance signal that is the output of the conversion circuit. A frequency modulation circuit, a low frequency conversion circuit for low frequency converting the carrier color signal output from the conversion circuit, and a first addition circuit for adding the low frequency converted carrier color signal and the frequency modulated luminance signal. A buffer circuit for converting one set of input audio signals into two sets of audio signals; a second frequency modulation circuit for frequency-modulating the first set of audio signals of the buffer circuit; An A / D conversion circuit for digitally converting the second set of audio signals of the buffer circuit, a modulation coding circuit for performing modulation coding on the output signal from the A / D conversion circuit, and the second frequency. A second adder circuit for adding an output signal of the modulation circuit and an output signal of the modulation encoding circuit; a first magnetic head pair for recording and reproducing the output of the first adder circuit on the magnetic recording medium; And a second magnetic head pair for recording and reproducing the output of the second adder circuit on the magnetic recording medium, the second magnetic head pair being used for a period other than the vertical synchronization period of the input video signal. The track width of each magnetic head and the above-mentioned track are recorded so that the video signal other than the substantially vertical synchronizing signal is post-recorded by the first magnetic head pair so as to overlap the track on which the audio signal is pre-written and recorded. And the relative positional relationship is set on the cylinder, and the first
A vertical sync signal of a video signal is recorded on an extension line of a track recorded by the head pair by the third magnetic head pair, and a vertical sync signal period of the video signal is extended on the extension line of the track recorded by the second head pair. And the audio signal is recorded by the fourth magnetic head pair, and a continuous audio signal is obtained from one of the audio signals recorded by the fourth magnetic head pair and the second magnetic head pair. Signal magnetic recording / reproducing device. 2. An apparatus for recording / reproducing each of an input color video signal and audio signal on a magnetic recording medium, wherein a rotary cylinder around which the magnetic recording medium is wound about 340 degrees is used as one of the color video signals. A rotary cylinder drive circuit that rotates once for each field, a conversion circuit that converts the input color video signal into a luminance signal and a carrier color signal, and a first frequency modulation of the luminance signal that is the output of the conversion circuit. A frequency modulation circuit, a low frequency conversion circuit for low frequency converting the carrier color signal output from the conversion circuit, and a first addition circuit for adding the low frequency converted carrier color signal and the frequency modulated luminance signal. A buffer circuit for converting one set of input audio signals into two sets of audio signals; a second frequency modulation circuit for frequency-modulating the first set of audio signals of the buffer circuit; An A / D conversion circuit for digitally converting the second set of audio signals of the buffer circuit, a modulation coding circuit for performing modulation coding on the output signal from the A / D conversion circuit, and the second frequency. A second adder circuit for adding an output signal of the modulation circuit and an output signal of the modulation encoding circuit; a first magnetic head pair for recording and reproducing the output of the first adder circuit on the magnetic recording medium; And a second magnetic head pair that records and reproduces the output of the second adder circuit on the magnetic recording medium, and the audio signal in a period other than the vertical synchronization period of the input video signal roughly by the second magnetic head pair. On the rotary cylinder and the track width of each head, so that the video signal other than the substantially vertical synchronizing signal is post-written and recorded by the first magnetic head pair so as to overlap the pre-written and recorded track. A relative positional relationship is set, and a vertical synchronizing signal of a video signal is recorded by a third magnetic head pair on an extension line of the track recorded by the first head pair, and by the second head pair. An audio signal in an approximately vertical synchronizing signal period of a video signal is recorded on an extension line of a recorded track by a fourth magnetic head pair, and one audio signal recorded by the fourth magnetic head pair and the second magnetic head pair. In order to obtain a more continuous audio signal and change the recording track width by the two magnetic heads,
A magnetic recording / reproducing apparatus for video signals and audio signals, comprising a tape feeding speed varying device for changing the feeding speed of the magnetic recording medium to a plurality of modes. 3. The magnetic recording medium on which video signals and audio signals are recorded by the first magnetic head pair, the second magnetic head pair, the third magnetic head pair, and the fourth magnetic head pair, A magnetic head for reproducing a video signal on a rotary cylinder that rotates one half every one field of the color video signal when wound around a rotary cylinder that rotates one half every one field of the color video signal. 2. The video signal and the audio signal are recorded so that the video signal and the audio signal of approximately one field time length can be continuously reproduced by the magnetic head for reproducing the audio signal.
Alternatively, the magnetic recording / reproducing apparatus for the video signal and the audio signal described in 2. 4. The video signal recorded by the first magnetic head pair is a video signal substantially outside the vertical synchronizing signal period of the video signal.
A magnetic recording and reproducing apparatus for the described video signal and audio signal. 5. A high efficiency coding circuit is further provided between the A / D conversion circuit and the modulation coding circuit, and high efficiency coding is performed on a digital voice signal. Item 1. A magnetic recording and reproducing apparatus for video and audio signals according to Item 1 or 2. 6. An error correction coding circuit is further provided between the high efficiency coding circuit and the modulation coding circuit, and error correction coding is performed on the digital voice signal. Item 5. A magnetic recording and reproducing apparatus for video signals and audio signals according to Item 5. 7. A serial signal conversion circuit for converting an R / L channel into one channel is further provided between the A / D conversion circuit and the high efficiency coding circuit.
A magnetic recording and reproducing apparatus for the described video signal and audio signal. 8. The audio signal recorded by the second magnetic head pair is generally an audio signal other than the vertical synchronizing signal period of the video signal, and the audio signal recorded by the fourth magnetic head pair is generally the above-mentioned. 3. A magnetic recording / reproducing apparatus for a video signal and an audio signal according to claim 1, which is an audio signal within a vertical synchronizing signal period of the video signal and an audio signal digitally compressed. 9. A rotary cylinder drive circuit for rotating a rotary cylinder, on which a magnetic tape is wound about 340 degrees, once for each field of a color video signal, and a carrier color signal and a frequency for which the low frequency conversion of the color video signal has been performed. First recording of the added signal of the modulated luminance signal on the magnetic tape
Of the magnetic head, the frequency-modulated voice signal modulated at the first frequency, and the digital-converted voice signal that has been digitally converted so as to have a frequency band different from the first frequency A second magnetic head for recording on the magnetic tape, a third magnetic head for recording a vertical synchronization signal of the color video signal on the magnetic tape, and the added audio signal in a vertical synchronization signal period of the color video signal. A fourth magnetic head for recording on the magnetic tape, wherein the second magnetic head overlaps a track in which the audio signal is prewritten and recorded in a period other than the vertical synchronizing period of the color video signal. The track width of each magnetic head and the relative rotation in the rotary cylinder are set so that the video signals other than the vertical synchronizing signal are post-recorded by the first magnetic head. A positional relationship is set, and a vertical synchronizing signal of the color video signal is recorded on an extension line of the track recorded by the first head by the third magnetic head, and by the fourth magnetic head. The second
A magnetic recording apparatus for recording an audio signal in a vertical synchronizing signal period on an extension line of a track recorded by the magnetic head of.