JPS63171402A - Rotary head type recording and reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce PCM audio signal by selecting the band of the PCM audio signal higher than the band of an FM audio signal, lower than the band of a video signal, recording the signals in the order of FM audio, PCM audio and video signals so as to decrease the disturbance onto the video signal thereby allowing the coexistence with the FM audio. CONSTITUTION:The signals are recorded in the order of the FM audio signal 34, the PCM audio signal 35 and the video signal 36 by using an FM audio signal recording head 22, a PCM audio signal recording head 23 and a video signal recording head 24 having a different azimuth angle respectively. Since each frequency band is selected higher in the order of the FM audio a signal, the PCM audio signal and the video signal, the FM audio signal is recorded at the deepest part 39, then the F, audio signal is recorded and the video signal is recorded at the surface part 41. Since the signal is reproduced at the reproduction by using a head having a different azimuth angle, the signal component recorded to the other layers is attenuated by the azimuth effect. Thus, each signal is recorded by the optimum recording condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high quality audio signal recording and reproducing system compatible with current VTRs.

[Conventional technology]

Conventional devices used the so-called shallow recording method, which records the audio PCM signal after the video signal has been recorded, as described in Japanese Patent Application Laid-Open No. 145701.As a result, the video signal may deteriorate. In order to reduce the deterioration of the video signal, it was necessary to control the recording current of the audio PCM signal.

Furthermore, as devices for recording and reproducing video signals and digital signals, for example, Japanese Patent Application Laid-open Nos. 59-218606 and 59-2
As described in No. 21802, there is a method of providing a guard band on the video signal track and recording digital signals in the same area, but it does not take into account the method of deep recording of FM audio signals, and therefore it is not compatible with conventional equipment. No compatibility was found.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, the video signal deteriorates, and in order to reduce the deterioration, it is necessary to control the recording current of the audio PCM signal.

An object of the present invention is to record and reproduce PCM audio while causing less interference with video signals and coexisting with FM audio.

[Means for solving problems]

The above purpose is to increase the band of the PCM audio signal to a higher band than that of FM audio (
, lower than the video signal, and record the FM audio, PCM audio, and video signal in that order with dedicated heads for each, thereby achieving multilayer recording.

[Effect]

Recording is performed by sequentially recording an FM audio signal, a PCM audio signal, and a video signal using an FM audio signal recording head, a PCM audio signal recording head, and a video signal recording head having different azimuth angles, respectively.

Here, each signal frequency band is an FM audio signal.

The PCM audio signal and video signal are higher in this order,
Therefore, the °C1 recorded signal contains the FM audio signal secondary P in the deep layer.
A CM audio signal and a video signal are recorded on the surface layer.

During reproduction, by reproducing with heads having respective azimuth angles, signal components recorded on other layers are destroyed by the azimuth effect.

In this way, each signal can be recorded under optimal recording conditions.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

The audio signal for FM recording is input from the FM audio signal input terminal 1, subjected to FM modulation processing by the FM audio recording processing circuit 7, amplified by the FM audio signal recording amplifier 16, and sent to the FM audio signal recording/playback switch 19. input, record/playback control signal 3
Set to recording mode at 0, input to FM audio head 22,
Record on tape 26.

The audio signal for PCM recording is input from the PCM audio signal input terminal 2, converted into a digital signal by the PCM audio recording processing circuit 8, subjected to error correction code encoding processing, interleaving processing, adding a control signal, and converting it into a synchronization signal. Perform formatting processing to provide

Perform modulation. The output of the processing circuit 8 is increased by the PCM audio signal recording amplifier 20, inputted to the PCM audio signal recording/playback switch 20, set to recording mode by the control 18 30, and inputted to the PCM audio head 25K. , recorded on tape 26.

The video signal is input from the video signal input terminal 3, subjected to recording signal conversion processing by the video signal recording processing circuit 9, amplified by the video signal recording amplifier 15, and then sent to the video signal recording/playback switch 2.
1, set the recording mode using the control signal 30, input it to the video signal head 24, and record it on the tape 26.

During playback, the signal recorded on the tape 26 is transferred to the head 2.
2, 23, and 24, the head output is input to the head switchers 19, 20, and 21, and the control signal 30 sets the reproduction mode to the FM audio compensation amplifier 16.
- The PCM sound signal is inputted to the reproducing device 17 and the video signal reproducing amplifier 18 for increasing. The amplified outputs of the amplifiers 16, 17 and 18 are sent to the FM audio reproduction processing circuit 10. P
The CM audio processing circuit 11 and the video signal processing circuit 12 perform playback processing, and the processing circuits in, 11 and 1
2 outputs are respectively FM audio signal output terminal 4 and PCM
It is output from the audio signal output terminal 5 and the video signal output terminal 6.

Here, the recording processing circuits 7, 8 and 9. The control signals 28, 29 of the reproduction processing circuits 10, 11, and 12, the switching control signal 50, etc. are connected to a control signal group 27 generated and output by the control signal generation circuit 32. Furthermore, the generation circuit 32 causes the system control circuit 31 to
The circuit 31 is generated and controlled based on the control signal 53.

Here, for example, the FM audio signal system and video signal system have the same configuration as the conventional fJVH8 system H:-FI VTR. Additionally, PCM audio recording or playback processing circuits 8 and 11
is a processing circuit configuration equivalent to CD'PDAT.

Figure 2 shows the FM audio head 22°PC of cylinder 25.
M audio head 23, video head 24, FM audio recording signal 34. FIG. 3 is a recording pattern diagram of a PCM audio recording signal 35 and a video recording signal 36 in the thickness direction of the magnetic tape 26. FIG. The magnetic tape 26 is a base film 3
8 and a magnetic body portion 67.

For recording, first, the FM audio recording signal 34 is recorded by the FM audio head 22. The FM audio recording signal 34 is a signal with a carrier wave of 13 MHz and t7 MH, respectively, and a frequency deviation of about 150 KH, and is recorded deep into the magnetic material. Next, a PCM audio recording signal 35 is recorded by the PCM audio head 23.

The PCM audio recording signal 35 has a carrier wave higher in frequency than the carrier wave frequency of the FM audio recording signal 34, for example, from 2 to 5.5 MH.
, is a PSK modulated signal with a Nyquist band of 15MH21, and the depth of the FM audio recording signal (recorded portion 39 is left and rewritten).

Next, a video recording signal 36 is recorded by the video signal head 24. The video recording signal is recorded leaving a deeply recorded portion 40 of the PCM audio signal.

With the above recording method, the FM audio recording signal 34, the PCM audio recording signal 35, and the video recording signal 66 are recorded in the deep portion 39. Recording can be performed in a five-layer structure such as the intermediate layer portion 40 and the surface layer portion 41.

Here, by increasing the frequency of the luminance signal portion of the video signal, there is an effect of reducing erasure of the PCM audio signal by the video signal.

Here, the PCM audio signal is erased by the video signal. Next, the FM audio signal is erased by the PCM audio signal and the video signal, but since it is erased by the PCM audio signal first and the PCM audio signal has more components at lower frequencies than the video signal, the FM audio signal Most of the signal is erased by the PCM audio signal.

In this case, the video signal frequency is assumed to be 4 MH, and compared to the case where the FM audio signal is erased at the same frequency, the carrier wave of the PCM audio signal is 2.5 MH2 to 3 MH2.
Although the cancellation of the M audio signal deteriorates by 5 to 5 dB, sufficient performance as an FM audio signal can be obtained.

Further, although the video signal can be recorded independently of the above signal, interference due to crosstalk may pose a problem.

Here, the FM audio recording signal level, PCM audio recording signal level, and video recording signal level are each set to, for example, an optimum recording current (ORC) K. In other embodiments, the PCM audio recording signal level may be set such that the playback output of the FM audio recording signal is
The video recording signal level is set to an optimum value in consideration of the playback output of the PCM audio recording signal.

Here, the azimuth angles of the video signal recording and reproducing head, the FM audio signal recording and reproducing head, and the PCM audio signal recording and reproducing head are, for example, the same as those of the FM audio signal recording and reproducing head.
The head for recording and reproducing audio signals has an upper 6° azimuth and ±30° azimuth, respectively, and the azimuth angle is the same as the Vt (S type VTR standard), and the azimuth angle of the PCM audio signal recording and reproducing head is larger than ±6° and ±30°. smaller value or ±3
The value shall be greater than 0° and less than ±90°. For example ±
18° again L++ sun'1lXI? Juice, );
483--F;& .

FIG. 3 is a frequency spectrum diagram of the recorded signal. Figure 3 (α) shows the FM audio recording signal 34, which is a two-channel F
M modulated signals 42 and 43. Here, for example, the signal 4
2 is the carrier frequency t5ME-12. The signal 43 has a carrier frequency of 17 MH. FIG. 3(b) shows the PCM audio recording signal 35, and the signal 44 is a signal subjected to offset four-phase differential phase shift keying (0-QDPSK). FIG. 3 <a> is a video signal 36, which is composed of a chromaticity signal 45 and a luminance signal 46 that have been subjected to low frequency conversion.

By sequentially recording three types of signals with frequency spectra as shown in FIG. 5, starting with a signal mainly consisting of lower frequency components, each recorded signal has an area in the depth direction of the magnetic layer that is not erased. In this process, the FM audio signal is recorded to a deep depth based on the wavelength vs. recording signal depth, wavelength vs. optimum recording current value, wavelength vs. recording rad gap, etc., and then the PCM
The audio signal is rewritten leaving the deep part of the FM audio signal,
Next, the video signal is rewritten leaving a part of the PCM audio signal.

During reproduction, the PCM audio signal is accompanied by a loss corresponding to the spacing loss due to the video signal layer, and the FM audio signal is associated with a spacing loss due to the video signal and PCM audio signal layer.

However, in this case, the same loss is caused by the FM audio signal and the PCM
They are arranged in the order of the audio signals so as to have less influence.

FIG. 4 is a diagram of the track pattern on the tape 26.

The video signal is recorded on the surface layer 41 with a track pitch and a track width f. This video signal recording head width 49 is shown. Here, in the case of override, for example, the head width is made wider than the track pitch f, as shown by the broken line.

The PCM audio signal is stored in the intermediate layer section 40 with a track width (α+b+
c). This PCM audio signal recording head width 4
8 is shown.

The FM audio signal has a track width (C+d+θ) in the deep layer 59.
). This FM audio signal recording head width 47 is shown.

Here, the FM audio signal is recorded in the center of the video signal track, for example, in the SP odd mode of a VH8 VTR.

The head is arranged so that the PCM audio signal is recorded even in areas where the FM audio signal is not recorded.

Further, by setting the head width to 5 so that a portion of the FM audio signal is not erased, a good reproduction output of the FM audio signal can be obtained.

The so-called tllFt V H5 that records FM audio signals
Regarding VTR track width and track pattern, etc., for example, "H1FiVH8VTR0 System Development";
Kuniaki Miura et al.: Institute of Electronics and Communication Engineers, Technical Report MR83-20:
Published on pages 16 and 22 of October 18, 1983.

Here, the track width of the FM audio signal is VH8 system VT
In R, &-! in NTSC SP mode. ,,minimum 2
0μm, maximum 58μm, minimum 16μm in the same EP mode
m, maximum is 19.3 μm. Next, in the CCIR method, the minimum thickness is 16 μm and the maximum thickness is 49 μm. Here, the FM audio signal track! By setting - to a value narrower than the maximum value, an area where no FM audio signal is recorded can be formed.

Furthermore, by setting the track width of the PCM audio signal to a value narrower than the track pitch of the video signal and separating it from the center of the track, an area can be formed in which the FM audio signal is not erased by the PCM audio signal.

FIG. 5 shows an example of a track pattern on a tape, in which the FM audio signal track width (c+d+e) is narrower than the video signal track pitch f, and includes an area where the FM audio signal track and video signal track do not overlap. Like PC
The arrangement is such that M audio signal tracks are formed.

Here, V and V- respectively indicate a positive azimuth track and a negative azimuth track of the video signal.

+F and F indicate the positive azimuth track and negative azimuth track, respectively, of the FM audio signal, and P+ and P indicate the positive azimuth track and negative azimuth track, respectively, of the PCM audio signal. The track width of the PCM audio signal is α+b+c, where α and C are the overlapping areas between the PCM audio signal track and the FM audio signal track.

The above track pattern is, for example, VH3H3 system VT
Corresponds to RP odd mode, in this case f is 58 μm, (o+
The minimum value of a+e) is 20 μm.

FIG. 6 shows an example of a track pattern on a tape, including an FM audio signal track! (L+)) to be narrower than the video signal track pitch and to include an area where the FM audio signal track and the video signal track do not overlap,
The arrangement is such that a PCM audio signal track is formed.

Here, the PCM audio signal track width is g+h-H-i, the area where the PCM audio signal does not overlap with the FM audio signal is 5, and the area where the FM audio signal does not overlap with the PCM audio signal is ()°-! 1).

The above track pattern is, for example, E of a VH8 system VTR.
Corresponding to P mode, in this case k is 193 μm and (
The minimum value of L0)) is 16 μm. Le in this case is 4
It is 3 μm.

Here, in the method of increasing the luminance signal frequency band of the video signal, erasure of the FM audio signal by the video signal is reduced. Therefore, even if the track width for FM audio signals is narrowed,
FM audio signal can ensure good CMN.

Therefore, by narrowing the track width for the FM audio signal, it is possible to secure the FM audio No. 1g recording area that will not be erased by the PCM audio signal.

For example, if the luminance signal frequency band is set to about 2M [(2 high), the erasure of the FM audio signal by the video signal is about 4
aB reduce. This corresponds to, for example, about 16 times the track width, and therefore, to obtain the same output as before increasing the 2MF (2MF), the track width should be about 1/16.

According to the above method, conventional linear track recording, F
Three types of recording, M audio recording and PCM audio recording, are possible, and different signals can be recorded.

In addition, the Japan Electronics Machinery Industry Association technical standard CPZ-1os consumer PCM double condenser coder (established September 1983)
By using a method of converting the audio PCM signal based on
Simultaneous recording and reproduction of the M audio signal and the linear track audio signal becomes possible.

In the multi-layer recording described above, by using the recording/playback head for vertical recording/playback of a part of the signal, such as a PCM audio signal, and performing perpendicular recording, it is possible to obtain effective effects in terms of interference, output level, etc. .

Further, in this embodiment, a system having a recording/reproducing head for each signal has been described, but a configuration only for PCM audio signals or FM audio signals is also possible.

An apparatus for reproducing a tape recorded using the above recording method will be explained using the reproduced audio signal control circuit 50 of the embodiment shown in FIG.

First, a circuit 51 is provided to detect whether or not a PCM audio signal is recorded, and if it is recorded, the same signal 54 is reproduced and output as an audio signal output 57 from an audio signal output switching circuit 53. If the FM audio signal is not recorded, a circuit 52 is provided to detect whether or not the FM audio signal is recorded.
If recorded, the same signal 55 is reproduced and output. If not recorded, IJ near-track audio signal 5
6 is reproduced and output.

Next, an embodiment of the pond will be explained with reference to FIG.

When reproducing and outputting a PCM audio signal, a circuit 66 is provided to detect the reproduction quality of the signal 61, and if the quality falls below a predetermined quality, the FM audio signal is reproduced and output. Here, if the PCM audio signal and the FM audio signal are different signals in the identification signal detection circuit 65 which inputs the identification signal 61, switching from the PCM audio signal to the FM audio signal is blocked. The above output switching control signal is generated by the switching control circuit 62. here 64
is a control signal for switching the audio output, for example, and is generated by an output changeover switch or the like.

Here, in the playback quality detection circuit 66, for example, the PCM of FIG.
Based on the decoding result of the error detection and correction code decoding circuit of the audio signal reproduction processing circuit 11, it is determined whether the error is larger or smaller than a predetermined value.

In addition, it is also possible to determine based on the reproduced signal level, dropout, clock reproduction status in the demodulation circuit 138 in FIG. 10, which will be described later, and the like.

FIG. 9 shows an example of the configuration of a selection control circuit for a PCM audio signal, an FM audio signal, and a linear track audio signal. FIG. 9(α) shows the configuration of the recording system selection control circuit. 67, 68 and 69 are PCM, FM# and linear track audio signal input terminals;
1 and 72 are output signals to the PCM, FM and linear track audio signal processing circuits, for example, the output signal 70
, 71 are connected to the input terminals 2 and 1 in FIG. Reference numeral 74 is an audio signal selection control signal for the recording system, which controls, for example, the output signal to the audio signal processing circuit, and records signals from different signal input terminals 67, 68, and 69, or selects one of Make selections such as recording the signal from the input terminal. Reference numeral 75 denotes selection information, which is added, for example, as a display or identification signal to an identification signal in a PCM signal, such as the ID code area in FIG. 11.

FIG. 9(b) shows the configuration of the reproduction system selection control circuit.

76, 77 and 78 are output signals of the PCM, FM and near track audio signal processing circuits, respectively; for example, the output signals 76, 77 are connected to the output terminal 5.4 in FIG. 82 and 83 are the audio signal output selection circuit 8 and its control signal. 79, 80 and 81 are PCM
, FM and linear track audio signal output terminals.

FIG. 10 shows the configuration of an embodiment in which a PCM audio signal recording and reproducing processing circuit is integrated.

During recording, from PCM audio signal input terminal 2.

Two R channels of analog signals are input.

The input signal is amplified to a predetermined level by an amplifier circuit 102, band-limited by a filter 103, and then sampled by a sample hold circuit 104. The sampled input signal is sent to the switching circuit 105.
The signals are sequentially input to the A/D converter 106 and converted into PCM signals. The PCM signal converted by the A/D converter 106 is written to the RAM 115 through the line 114. Then, the address of the RAM 115 is controlled by the address generation circuits 117 to 119 and the address switching circuit 116, and is written in accordance with a predetermined format. Arrangement of PCM signals and addition of error correction codes are performed.Addition of error correction codes is performed using the error correction circuit 120.After arrangement of PCM signals and addition of error correction codes, each data is The data are sequentially read out from the RAM 115.

At this time, the read address generation circuit 119 calculates that the number of audio signal samples in one field counted by the in-field sample number counting circuit 93 is the difference between the write address and the read address extracted by the address difference extraction circuit 90. Based on the signal determined by the determination circuit 91, the number of samples is controlled to be the number of samples set by the in-field sample number setting circuit 92. The signals read from the RA Mlls are converted into serial signals by the juxtaposition exchange circuit 123. Then, when the number of audio signals in one field is small, a control signal generation circuit 124 and a switching circuit 125 based on signals from the in-field sample number counting circuit output 94 and the timing generation circuit 121 generate signals other than the audio signal following the audio signal. The modulation circuit 15 modulates the predetermined data by adding a control signal such as a signal, a code for determining whether it is an audio signal or not, and a synchronization signal.
Modulated by 6. and PCM audio signal recording amplifier 1
14, the signal is amplified to a predetermined level and recorded on the magnetic tape 25 by, for example, a PCM audio rotary head 23. Further, the timing generation circuit 121 is a circuit that generates a timing signal for controlling the entire system using a clock generated by the oscillation circuit 122K, a head switching signal 145 from the video circuit 142, a synchronization signal, and the like.

During reproduction, the signal reproduced by the PCM audio head 23 is amplified to a predetermined level by the PCM audio reproduction amplifier 17, and the waveform equalization circuit 137 performs waveform equalization. The waveform-equalized signal is demodulated by the demodulation circuit 138, and the digital signal is sent to the synchronization detection circuit 128.
Detection of the synchronizing signal and conversion to a parallel signal by the serial-to-parallel conversion circuit 127 are performed. The detected synchronization signal is used as a reference for data reproduction. The signal determination circuit 144 determines whether the data converted into a parallel signal is an audio signal or a signal other than an audio signal, and only the audio signal is sent to the Rmu υ
噌1ζ F Gl □ times 1 vkekiichikuzu, 4 gigantic 1shi 噜斡代会EN, (r(,h data is also stored in the RAM 115, and data rearrangement and error correction by the error correction circuit 120 are performed. Then, it is input to the D/A converter 112 through the pass line 114, and is sequentially converted into one analog word.
A sample and hold circuit 111 performs resampling for each channel. The analog signal resampled in each channel is outputted from the PCM audio signal output terminal 5 through the filter 110 and the amplifier circuit 109.

FIG. 11 shows an example of the data block configuration of the signal format output from the switching circuit 125 of FIG. 10. An identification code (or ID code) indicating the type and form of the signal is added to the PCM audio signal (or digital data) and parity for error detection/correction, and a parity for error detection for the code and block address is generated. will be added.

FIG. 12 shows a specific example of the modulation circuit 136. This embodiment is a 0-QDPSK modulation circuit. In Figure 12,
150 is a digital data (DATA) input terminal, 1
51 is an input terminal of a clock (DCK) that is bit synchronized with the digital data, and 152 is an input terminal for converting the input digital data into 2-bit parallel data (X-DATA, Y-DATA).
DATA) converting circuit, 153α, 1531)
154 is a differential encoding circuit that encodes the sign change of each parallel data converted to 2 bits, in other words, the phase change of the modulated wave has information, and 154 encodes one data by 1/
Delay circuit delayed by 2 data periods, 155α, 155b
157 is a balanced modulator that modulates a carrier wave with a waveform-shaped digital signal;
is a carrier wave oscillator, and 158 is a 9 to obtain an orthogonal carrier wave.
0 degree phase shifter, 159 is adder and 160 is 0-QDPS
This is the K signal output terminal. FIG. 13 shows this modulation circuit 136.
FIG. Like this 〇-QDP
In the SK method, X-DATA and Y converted into 2-bit parallel
-Amplitude fluctuations are suppressed by shifting DATA by 1/2 parallel data period. As a result, the recorded spectrum does not expand even with the nonlinearity of magnetic recording (therefore, there is almost no interference with the video signal).

FIG. 14 is a configuration diagram showing a specific example of the 0-QDPSK demodulation circuit 168. In the same figure, 161 is the reproduced 0
-QDPSK signal input terminal, 162α.

162b is a phase detector that detects the phase of the reference carrier signal regenerated by the carrier regeneration circuit 163 and the input modulated wave signal;
64 is a 90-degree phase shifter, 165α and 165b are phase detectors 162α and 162b, LPFs that remove unnecessary harmonic components generated in the phase detectors 162α and 162b are phase detectors, and 166α and 166b are comparison units that determine whether the detected signal is positive or negative and convert it into a digital signal. vessel, 16
7α, 167b are latch circuits that strobe the digital signals from the comparators 166α, 166b at the timing of the clock reproduced by the clock reproduction circuit 168;
9 is an inverter circuit, 170α, 170b is a differential decoding circuit that decodes the data string encoded on the modulator side into the original data string, 171 is a circuit that converts 2-pit parallel data into the original serial data, 172 is an output terminal for demodulated data, and 173 is an output terminal for a reproduced clock synchronized with the demodulated data in pits. FIG. 15 shows operating waveforms of each of these parts. In this way, by synchronously detecting the input modulated wave with the regenerated reference carrier wave and data strobe the detected signal with the regenerated clock, I-DATA and Q-DA
TA is obtained, and X-DATA and Y-DATA are obtained by differentially decoding K.

By converting these parallel data into serial data, final demodulated data is obtained.

Figure 16 shows the O-Q of a signal with a transmission rate of 2.5 Mbps.
It is a DPSK modulation signal frequency spectrum diagram. The figure shows a carrier wave frequency (fO・) of approximately 2. In the case of OMHg&, a carrier frequency of 2.5 or ao MHz has a similar spectrum. Here, the carrier frequency is 3.0M
H, the carrier frequency of the FM audio signal is f=, and the band of the 0-QDPSK modulated signal frequency spectrum is
Becomes outside the area. This leads to crosstalk problems and 0-Q
This has the effect of reducing erasure of the FM audio signal due to the DPSK-modulated PCM audio signal.

As described above, according to the recording method of the present invention, an FM audio signal based on the existing VH8 method can be recorded simultaneously with a PCM audio signal, so even when a tape recorded using the recording method is played back by a device that does not have a PCM audio signal playback system. , the FM audio signal can be reproduced.

Furthermore, a device capable of reproducing FM audio signals can play back a tape on which only FM audio signals are recorded without PCM audio signals, and the FM audio signals can be played back. Compatibility with audio signals is obtained.

Further, in a device capable of recording a PCM audio signal and an FM audio signal, it is also possible to record only one of the two signals.

It also has a mode in which the PCM audio signal, FM audio signal and linear track audio signal are each recorded as the same audio signal, and a mode in which they are each recorded as different signals,
By providing the erroneous selection circuit and the signal input/output terminal, it is possible, for example, to make both PCM and FM audio signals independent, and to record and reproduce 4-channel audio signals.

These mode identifications can be included in the identification signal in the PCM audio signal recording data.

〔Effect of the invention〕

According to the present invention, an audio signal is deep recorded using FM modulation with the same specifications as the existing VH8 system VTR, the next KPCM audio signal is PSK modulated and recorded on top of the FM audio signal, and then the video signal is recorded on top of the FM audio signal. Since each signal can be recorded and reproduced by each head, it is possible to record and reproduce KPCM audio signals while maintaining compatibility with existing FM audio signal recording systems.

[Brief explanation of the drawing]

Fig. 1 is a circuit configuration diagram of an embodiment of the present invention, Fig. 2 is a tape pattern diagram of multilayer recording of the present invention, Fig. 3 is a frequency spectrum diagram of each signal, and Fig. 4 is a tape pattern of a multilayer recording track. 5 is a diagram showing one embodiment of the tape track pattern, and FIG. 6 is a diagram showing another embodiment of the tape track pattern. Fig. 7 is a block diagram of one embodiment of the audio output signal selection circuit, Fig. 8 is a block diagram of another embodiment of the audio output signal selection circuit, and Fig. 9 is a block diagram of another embodiment of the audio output signal selection circuit. 10 is a block diagram of a specific example of a PCM audio signal recording/reproducing processing circuit; FIG. 11 is a block diagram of a data block;
FIG. 12 is a circuit diagram of a specific embodiment of a 0-QDPSK modulation circuit. Figure 13 is a waveform diagram of each part of the circuit in Figure 12, and Figure 14 is a waveform diagram of each part of the circuit in Figure 12.
- A circuit diagram of a specific embodiment of the QDPSK demodulation circuit, and FIG. 15 is a waveform diagram of each part of the circuit of FIG. 14. FIG. 16 is a frequency spectrum diagram of a 0-QDPSK modulated signal. 2... PCM audio signal input terminal, 8... PCM audio signal recording processing circuit, 23... PCM audio signal head. 11... PCM audio signal reproduction processing circuit. Representative Patent Attorney Masaru Ogawa Yuna 2 Figure Thea 3 Figure Awamaki → Figure 4 Figure 5 6 Figure 7 Ward 5oy-x Voice Imoichi! Figure 8 Figure q (mountain) (b) Figure to 17 Figure 613 Figure easy! 5 Figure atyq*ka and I pregnancy are also out of the way! 6 figure 00kHz

Claims (1)

[Claims] 1. A video tape recorder that records a video signal and an audio signal on a video track, which includes a circuit for FM modulating the audio signal, an A/D converter for converting the audio signal into a digital signal, and A digital processing circuit that receives the output of an A/D converter as an input, a digital modulation circuit that modulates the output of the digital processing circuit, the video signal recording/reproducing head, and the FM modulated audio signal recording/reproducing head. , the digitized audio signal recording/reproducing head is provided, and the audio signal is frequency multiplexed and recorded outside the occupied band of the modulated luminance signal and the modulated chromaticity signal of the video signal, or between the occupied bands of both. A rotary head type recording and reproducing device characterized by a reproducing function. 2. As a recording/reproducing head according to claim 1, a rotary head type recording characterized in that a video head, an FM audio head, and a digital audio head have different azimuth angles and perform multiplex recording. playback device.