JPH07222099A - Digital video signal recording device - Google Patents

Abstract

PURPOSE:To provide the digital video signal recording and reproducing device capable of handling recording and reproduction of digital video signals of three kinds of modes being a high definition mode, a 1-channel standard mode and a 2-channel standard mode. CONSTITUTION:The device recording a digital video signal by using N-sets (N is a natural number being 2 or over) of heads 1-4 arranged close to each other is provided with 1st-Nth input means 17, 61 receiving N-kinds of 1st-Nth digital video signals, a synchronization means 60 implementing synchronization or synthesis of the received N-kinds of 1st-Nth digital video signals and an input selection means 62 selecting the 1st digital video signal received from the 1st input means 17 or an output signal from the synchronization means 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to recording a digital video signal, and more particularly to a digital video signal recording apparatus suitable for recording two kinds of digital video signals, a standard video signal and a high definition video signal. It is a thing.

[0002]

2. Description of the Related Art HDTV (High Definition Televisi)
When digitally recording and reproducing a high-definition video signal such as an on) system, a high recording density is required because of the large amount of recorded data. A conventional magnetic recording / reproducing apparatus for recording / reproducing high-definition digital video signals is disclosed in Japanese Patent Laid-Open No. 3-268591. This enables high-density recording by simultaneously performing 2-channel recording / reproduction using two sets of four heads facing each other.

[0003]

Using the above device,
When recording a standard video signal with a transmission rate of 1/2 in high definition mode, the rotational speed of the rotary head and the tape feed speed are halved, or the rotational speed of the rotary head and the tape feed speed are changed. Instead, a method of using only two of the four heads can be considered.

However, if the rotational speed of the rotary head and the tape feed speed are halved, the recording frequency on the tape is also 1.
In view of the frequency characteristics of the head, it becomes difficult to record / reproduce with the same head.

Further, in the method of using only two heads without changing the tape feeding speed, the recording time is halved, and half of the tape is unused. In this case, although it is conceivable to record another standard video signal at the same time, the conventional apparatus does not consider recording a 2-channel video signal.

Further, both methods are different from the track pattern in the recording apparatus dedicated to the standard video signal in which one set of heads records one channel. It becomes impossible to achieve compatibility.

It is an object of the present invention to provide a digital video signal recording apparatus capable of recording two kinds of digital video signals of a high definition mode and a standard mode. Further, it is possible to simultaneously record the standard video signals of two channels.

[0008]

SUMMARY OF THE INVENTION The above-described object is to provide an N-type first device in an apparatus for recording a digital video signal by N sets of heads (N is a natural number of 2 or more) that are close to each other.
-First to N-th input means for inputting the N-th digital video signal, and synchronization means for synchronizing or synthesizing the input N kinds of the first-Nth digital video signals
An input selection means is provided for selecting either the first digital video signal input from the first input means or the output signal of the synchronization means, and the first input means has a first transmission rate. A digital video recording signal is input, the input selection means selects the first digital video recording signal, the recording medium is fed at a first feed speed, and the first set of digital video recording is performed using the N sets of heads. A first mode for recording a signal and the first input means inputs a second digital video recording signal having a second transmission rate which is 1 / N of the first transmission rate, and the input selecting means. Is the second
The digital video recording signal is selected, the recording medium is fed at a second feeding speed which is 1 / N of the first feeding speed, and the second digital video recording signal is produced by using N heads close to each other. The second mode for recording
The Nth input means inputs the third to N + 2th digital video recording signals each having the second transmission rate, and the input selection means selects the output signal of the synchronization means,
This can be achieved by feeding the recording medium at the first feeding speed and providing the third mode in which the Nth to N + 2th digital video recording signals are recorded using the N sets of heads.

[0009]

In the second mode, since only N heads that are close to each other are used and recording is performed with the tape feeding speed being half of that in the first mode, it is not necessary to change the rotational speed of the rotary head. The recording frequencies can be made equal in the first mode and the second mode. Further, since the tape feeding speed is halved, the recording time becomes twice as long as that in the first mode, and the tape usage rate can be improved. Further, since the track pattern is the same as the track pattern in the recording device dedicated to the standard video signal for performing 1-channel recording with one set of heads, compatibility can be maintained.

The heads adjacent to each other have different azimuth angles and are mounted with a step. For this reason, in the second mode, it is impossible to use the heads that face each other. Therefore, only the heads that are close to each other are used and the other heads are not used.

In the third mode, by providing N kinds of digital video signal input means and performing the same recording method as in the first mode, for example, N kinds of NTSC video signals can be simultaneously recorded. Becomes

[0012]

FIG. 1 shows an embodiment in which the present invention is applied to a digital video recording apparatus. 1-4 are magnetic tapes 6
A head for recording a digital video signal on the top, 5 is a rotating cylinder, 7 is a capstan for controlling the feeding speed of the magnetic tape 6, 8 is a servo circuit for controlling the operation of the rotating cylinder 5 and the capstan 7, and 9-10 are A switch for selecting the heads 1 to 4, 11 a head switching control circuit for controlling the switches 9 to 10, 12 a storage circuit for temporarily storing input data, and 13 to 14 encoding for adding an error correction code. Reference numeral 15 to 16 are recording circuits for performing modulation processing such as addition of tracking servo signals, 17 is a first digital signal input terminal for inputting a compressed high-definition digital video signal or standard digital signal signal, and 18 is A mode signal input terminal for inputting a mode signal for selecting the high definition mode or the standard mode, 61 is a second digital signal input terminal, 60 A synchronizing circuit 62 for synchronizing the first SD signal 101 input from the digital signal input terminal 17 and the second SD signal 160 input from the second digital signal input terminal 61, and 62 to the storage circuit 12. As an input signal, the signal 101 input from the first digital signal input terminal or the signal 161 output by the synchronization circuit 60
This is a switch for selecting. Also, 100 is the head 1,
It is a track identification signal indicating which of the two or the heads 3 and 4 is scanning the tape 6.

First, the operation in the high-definition mode for recording a high-definition video signal (referred to as HD signal) of the HDTV system or the like will be described.

In the high-definition mode, since the amount of data to be recorded is large, high density recording is possible by performing 2-channel recording in which two heads simultaneously record.
For this reason, the encoding circuit and the recording circuit each have two channels.
It has a system.

The compressed HD signal 101 is input from the first digital signal input terminal 17, and the switch 62 inputs the HD signal 1
By selecting 01, the data is stored in the memory circuit 12.
As shown in FIG. 3A, when a signal of one frame is recorded, in the next one frame, 1/2 of the stored HD signal is recorded.
Amount of data to the encoding circuit A13 (timing of 102), and the remaining 1/2 data is to the encoding circuit B14 (1
(Timing 03) to add an error correction code. After that, the recording circuit A15 (timing of 104) and the recording circuit B16 (timing of 105) perform processing such as addition of a signal for tracking servo, and the heads 1, 2 through the switches 9 and 10, respectively.
It is sent to the heads 3 and 4 and recorded on the magnetic tape 6. The rotary cylinder 5 is controlled by the servo circuit 8 to 900 rpm.
It rotates at 0 rotations and records one frame of HD signal over 20 tracks. In FIG. 3, Anm indicates data recorded by the head 1 or 3 on the nth frame and mth track, and Bnm indicates data recorded by the head 2 or 4 on the nth frame and mth track, respectively.

The switch 9 selects a when the track identification signal 100 is L and b when the track identification signal 100 is L, and the switch 10 selects c when the track identification signal 100 is L and d when the track identification signal 100 is H. And operates according to the head switching control circuit.

The head 2 is attached to the rotary cylinder 5 with a step corresponding to one track pitch with respect to the head 1, and has different azimuth angles. Further, the head 3 and the head 4 have the same relationship. For this reason,
As shown in FIG. 2A, the track 20 is moved by the head 1.
However, the track 21 is simultaneously recorded by the head 2.
Further, the rotation speed of the tape 6 is changed by the capstan 7 so that the rotary cylinder 5 is rotated by 180 ° and the data is recorded on the track 22 and the track 23 at the timing when the head 3 and the head 4 scan the magnetic tape 6. Is controlled. The feed speed at this time is V. When the rotary cylinder 5 is further rotated by 180 °, the head 1 and the head 2 scan the tracks 24 and 25, so that recording can be performed using the head 1 and the head 2 again.

The video signal is recorded in the center of each track (middle side of the solid line), and audio, sub-code, etc. are recorded outside this.

With the above operation, high density recording of digital high definition video signals can be performed.

On the other hand, when recording a standard video signal such as NTSC, the transmission rate of the digital standard video signal (referred to as SD signal) input from the digital signal input terminal 17 is 1/2 of the HD signal, This SD in the device of Figure 1
The following three methods can be considered as a method of recording a signal.

(1) Number of revolutions of the rotary cylinder 5 = 9000/2 = 4500 revolutions Feed speed of the tape 6 = V / 2 2 channel recording (2) Number of revolutions of the rotary cylinder 5 = 9000 revolutions Feed speed of the tape 6 = V 1-channel recording (3) Number of rotations of rotating cylinder 5 = 9000 rotations Feed rate of tape 6 = V / 2 2-channel recording Of the above (1), the recording frequency on the tape 6 is also 1 /
2, which is extremely difficult when the frequency characteristics of the head are taken into consideration. In the case of (2), the recording time is halved, and the tape usage efficiency deteriorates.

Further, since the recording pattern is different from the track pattern in the recording device dedicated to the standard video signal for recording one channel with one set of heads, it becomes impossible to achieve compatibility.

Therefore, the method (3) is considered to be the best. In this case, heads 1 and 3 (or heads 2 and 4)
Since they have the same azimuth, one channel recording cannot be performed by these two heads. When the feeding speed of the tape 6 is V / 2, it is impossible to record with the heads 1 and 4 (or the heads 2 and 3) due to the mounting step of the head. Therefore, recording must be performed using the heads 1 and 2 (or the heads 3 and 4).

FIG. 2B shows a recording track pattern when an SD signal is recorded by using the head 1 and the head 2.

The head 1 tracks the track 26 and the head 2
The track 27 is recorded by. When the rotating cylinder 5 rotates 180 ° and the heads 1 and 2 finish scanning the tape 6, the head 3 moves the track 27 and the head 4 moves.
Scans track 28. Therefore, it is necessary to stop the recording current so that the heads 3 and 4 not used for recording do not record. Since the feeding speed of the tape 6 is V / 2, when the head 1 is further rotated 180 °, the head 1 moves to the track 2
8 is the timing when the head 2 scans the track 29, and recording can be performed again.

The recording timing at this time is shown in FIG. The switch 62 uses the signal 101 as in the high definition mode.
Is selected. Track identification signal 1 in standard mode
Only when 00 is H, the storage circuit 12 causes the encoding circuit A1
3 and the encoding circuit B14 read the SD signals 102 and 103. The recording circuit A15 and the recording circuit B105 perform processing only when the track identification signal 100 is L,
The switch 9 is always selecting a and the switch 10 is always selecting c so that the recording current does not flow through the head 3 and the head 4.

By the above operation, the SD signal can be recorded by the device for recording the HD signal only by changing the timing without adding a special circuit.

Further, since the recording pattern is the same as the track pattern in the recording device dedicated to the standard video signal for recording one channel with one set of heads, compatibility can be maintained, and the tape recorded in the standard mode of this device. Can be reproduced by a reproduction device dedicated to the standard video signal.

When recording is performed using the head 3 and the head 4, the operation for the polarity of the track identification signal 100 may be reversed.

Although not particularly shown, a mode identification signal for identifying the high definition mode or the standard mode may be recorded in some cases and is used for mode identification in the reproducing apparatus.

Further, when recording the SD signal, if the tape 6 is fed at V and the recording is performed on 2 channels, the SD signal is SD.
Since the data amount of the signal is 1/2 of the data amount of the HD signal, it is possible to record another SD signal.
The apparatus of FIG. 1 is a recording apparatus capable of simultaneously recording two types of SD signals. Digital signal input terminal 17
The transmission rates of the signals input from the first digital signal input terminal 61 and the second digital signal input terminal 61 are 1/2 of the HD signal, and the signal 161 output from the synchronizing circuit 60 has the same transmission rate as the HD signal.

As the recording track pattern in this case,
The following three types will be described with reference to FIGS. In the figure, No1 is the first SD signal and No2 is
Represents the second SD signal.

(1) Heads 1 and 2: No1, heads 3 and 4: No2 (FIG. 4) (2) Heads 1 and 3: No2, heads 2 and 4: No2
(Fig. 6) (3) Switching between No1 and No2 in frame units
(FIG. 8) In (1), as shown in FIG. 5, the second SD signal is processed in the half period during which no operation is performed, and the switches 9 and 10 operate in the same manner as in the high definition mode. ,
When the track identification signal 100 is H, the second SD signal is recorded by using the heads 3 and 4. Since this method has a strong compatibility with the normal standard mode, it is an easy method for processing SD signals.

(2) is the first SD as shown in FIG.
The signal is processed by the encoding circuit A13 and the recording circuit A15,
Recording is performed by using the head 1 and the head 3 via the switch 9, and the second SD signal is recorded in the encoding circuit B14 and the recording circuit B.
Processing is performed in step 16 and recording is performed using the head 2 and the head 4 via the switch 10. This method is advantageous for a system centered on an HD signal because the SD signal channel and the recording channel coincide with each other.

In (3), as shown in FIG. 9, the first SD signal for two frames is time-compressed and recorded in one frame, and the second SD signal for two frames is recorded in the next one frame. Record. Since this method processes each SD signal in units of frames, it is suitable for performing processing such as frame interpolation in the reproducing apparatus.

Although not shown, if the channel discrimination signal of the SD signal is recorded at the same time as the mode discrimination signal, it can be used for channel discrimination in the reproducing apparatus.

In recording the two types of SD signals described above, it is assumed that the transmission rates of the two SD signals are exactly the same and are synchronized, but in the case of completely different SD signals, synchronization is not always required. It is not always done.

Therefore, the synchronizing circuit 60 uses the two types of SD.
It is necessary to synchronize the signals so that both signals are recorded exactly.

10 and 11 show examples of the synchronizing circuit 60.

In FIG. 10, 80 and 82 are RAMs for temporarily storing input signals, 85 and 86 are frame head signal input terminals, and 81 and 83 are frame synchronization signal generation circuits for generating frame synchronization signals from the input frame head signals. ,
Reference numerals 85 and 86 are switches for selecting the signal output from the RAM or the frame synchronization signal, and 87 is a switch for selecting the first SD signal or the second SD signal.

Simultaneously with each SD signal, the frame head signals 180 and 181 synchronized with each SD signal are input terminal 8
By inputting from Nos. 5 and 86, the position of the beginning of the frame of each signal can be known. Therefore, the frame synchronization signal generation circuits 81 and 83 generate a frame and a synchronization signal, and the switches 85 and 86 insert the frames into each SD signal for recording. Therefore, since the head of the frame can be known by detecting the frame synchronization signal with the reproducing apparatus, it is possible to record the SD signal regardless of the cycle of the rotary cylinder 5 while holding the frame cycle of the SD signal. .

Further, in the example of FIG. 11, RAMs 80 and 82
By storing the data on the tape 6 after storing it for several frames after increasing the capacity thereof, it is possible to absorb the asynchronousness of the two types of SD signals. In the figure, 90, 91
Is a read control circuit that generates read addresses of the RAMs 80 and 82, and 92 is an address abnormality detection circuit that monitors the read addresses of both.

For example, when the transmission rates of the two types of SD signals are different by 0.01%, the difference in the data amount is about 10 frames in recording for 1 hour, so if there is a capacity of about 10 frames, Asynchronous can be absorbed.

If there is a transmission rate difference that exceeds the capacity of the RAMs 80 and 82, the difference between the addresses generated by the read control circuit 90 and the read control circuit 91 exceeds a certain value. Can be detected. At this time, the SD with the faster transmission rate
Asynchronization can be absorbed by using a method such as recording one frame of a signal continuously for two frames.

FIG. 12 is a block diagram of a digital video reproducing apparatus for reproducing the tape recorded by the digital video recording apparatus of the present invention.

In the figure, 42 to 43 are heads 1 to 4.
A switch for selecting, a demodulation circuit for demodulating the reproduced signal reproduced, 46-47 for an error correction circuit for correcting an error in the demodulated data, a storage circuit for temporarily storing the corrected data, and a reference numeral 49. A mode discrimination circuit that discriminates between the high-definition mode and the standard mode by discriminating the mode identification signal,
Reference numeral 50 is a servo signal detection circuit that detects a tracking servo signal included in the reproduction signal. Also, 40 is a playback HD
A digital signal output terminal for outputting a signal or a reproduction SD signal, 41 is a mode signal output terminal for outputting the discriminated mode, and 90 is a channel selection signal input terminal. At the time of reproduction, the feeding speed of the tape 6 is set to V in the high definition mode. When the signal recorded on the tape 6 is the HD signal, the mode identification signal is also reproduced and it can be easily determined that the high definition mode is set. Therefore, the reproduction is continued in the high definition mode. When the signal recorded on the tape 6 is the SD signal, the recording track pattern is different from that of the HD signal. However, if the heads 1 to 4 scan the portion on which the mode identification signal is recorded, the reproduction is performed. Therefore, it is possible to determine that the standard mode is set. Therefore, the reproduction may be continued by setting the feeding speed of the tape 6 to V / 2.

In the high definition mode, since the track pattern is as shown in FIG.
The servo circuit 8 controls the rotary cylinder 5 and the capstan 7 so that the heads 1, 2, 3, and 4 scan the heads 2 and 23, respectively. At this time, the tracking servo signals added by the recording circuits 15 to 16 in the recording apparatus are detected by the servo signal detection circuit 50, and the tracks 20 to
23 are identified. As in the case of recording, when the track identification signal 100 is L, the switch 42 selects a and the switch 43 selects c, and when the track identification signal 100 is H, the switch 42 selects b and the switch 43 selects d. The head switching control circuit 11 works. Head 1 and head 3
The reproduced signal 144 reproduced in (1) is demodulated by the demodulation circuit A44, the error is corrected by the error correction circuit A46, and the signal is sent to the storage circuit 48. The reproduction signal 145 reproduced by the head 2 and the head 4 is demodulated by the demodulation circuit B45, the error is corrected by the error correction circuit B47, and the signal is sent to the storage circuit 48. Further, the HD signal 1 input from the digital signal output terminal 40 and the digital signal input terminal 17 of the recording apparatus
01 is read out from the storage circuit 48 in the same order as 01, subjected to processing such as expansion, and an HDTV video signal is obtained.

In the standard mode, since the track pattern is as shown in FIG. 2B, the head switching control circuit 11 operates so that the switch 42 always selects a and the switch 43 always selects c. Further, the servo signal detection circuit 50 and the servo circuit 8 work so that the head 1 scans the track 26 and the head 2 scans the track 27. The reproduction signal 144 reproduced by the head 1 is demodulated by the demodulation circuit A44 when the track identification signal 100 is L, then the error is corrected by the error correction circuit A46 and sent to the storage circuit 48. Similarly head 2
The reproduction signal 145 reproduced by the track identification signal 10
When 0 is L, the signal is demodulated by the demodulation circuit B45, after which the error is corrected by the error correction circuit B47 and sent to the storage circuit 48. Further, the SD signal 1 input from the digital signal output terminal 40 and the digital signal input terminal 17 of the recording apparatus
01 is read out from the storage circuit 48 in the same order and subjected to processing such as decompression to obtain, for example, an NTSC video signal.

Since the track pattern shown in FIG. 2 (b) is the same as the track pattern recorded by the recording device dedicated to the standard video signal, the tape recorded by the recording device dedicated to the standard video signal is recorded on this device. It is also possible to play with.

When reproducing a tape on which two types of SD signals are recorded, since the track pattern is the same as that on the tape recorded in the high definition mode, it is determined whether the high definition mode or the 2-channel standard mode is used. , Mode discrimination circuit 4
It can be determined only by 9. In the 2-channel standard mode, the tape feed speed is set to V as in the high definition mode, and reproduction is performed. Further, the memory selection circuit 4 inputs the channel selection signal from the channel selection signal input terminal 90 and outputs the predetermined SD signal from the digital signal output terminal according to the above-described methods (1) to (3).
Control 2

When the track identification signal 100 is H, the head 2 scans the track 27 and the head 4 scans 28, but these have different azimuth angles at the time of recording, and the reproduction output due to azimuth loss. descend. For this reason, since the tracking servo signal is not reproduced during this period, normal servo cannot be applied. Therefore, the operation of the servo circuit 8 is stopped and the state when the track identification signal 100 is L is maintained. It is necessary to operate the rotary cylinder 5 and the capstan 7 by means of this. In the above description, the ratio of the transmission rates of HD signal and SD signal is 2: 1.
However, in general, when N: 1, N channel recording is performed using 2N heads in the high-definition mode, and the tape feeding speed is set to V / N in the standard mode.
Further, in the same manner, it is possible to record and reproduce N kinds of SD signals at the same time.

Further, although two encoding circuits and two recording circuits are provided, it is also possible to provide only one system and perform time division processing on signals for two channels.

[0053]

According to the present invention, in an apparatus for recording a high-definition digital video signal such as HDTV, a standard digital video signal such as NTSC is recorded with a recording time twice as long as that when recording a high-definition digital video signal. It is possible to achieve compatibility with the recording track pattern of the recording / reproducing device dedicated to the standard digital video signal.

Further, standard digital video signals of a plurality of channels can be synchronized with each other and simultaneously recorded.

[Brief description of drawings]

FIG. 1 is a block diagram showing a recording apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a recording track pattern in the recording apparatus of FIG.

FIG. 3 is an explanatory diagram showing a recording timing relationship in the recording apparatus of FIG.

4 is an explanatory diagram showing an example of a recording track pattern in the recording apparatus of FIG.

5 is an explanatory diagram showing an example of a recording timing relationship in the recording apparatus of FIG.

6 is an explanatory diagram showing an example of a recording track pattern in the recording apparatus of FIG.

FIG. 7 is an explanatory diagram showing an example of a recording timing relationship in the recording apparatus of FIG.

8 is an explanatory diagram showing an example of a recording track pattern in the recording apparatus of FIG.

9 is an explanatory diagram showing an example of a recording timing relationship in the recording apparatus of FIG.

10 is a block diagram showing an example of a synchronizing circuit in the recording apparatus of FIG.

11 is a block diagram showing another example of the synchronizing circuit in the recording apparatus of FIG.

FIG. 12 is a block diagram showing a reproducing device for reproducing a tape recorded by the recording device of the present invention.

[Explanation of symbols]

 1 to 4 ... Head, 5 ... Rotating cylinder, 8 ... Servo circuit, 9-10 ... Switch, 11 ... Head switching control circuit, 12 ... Storage circuit, 13-14 ... Encoding circuit, 15-16 ... Recording circuit, 17 ... 1st digital signal input terminal, 18 ... Mode signal input terminal, 60 ... Synchronizing circuit, 61 ... 2nd digital signal input terminal, 80 ... RAM1, 81 ... Frame synchronizing signal generating circuit 1, 82 ... RAM2, 83 ... Frame synchronization signal generation circuit 2, 90 to 91 ... Read control circuit, 92 ... Address abnormality detection circuit.

Claims (7)

[Claims] 1. An apparatus for recording a digital video signal by N sets of heads (N is a natural number of 2 or more) close to each other, wherein first to first N kinds of first to Nth digital video signals are inputted. N input means, synchronization means for synchronizing or synthesizing the input N kinds of first to Nth digital video signals, and the first digital video signal input from the first input means Input selection means for selecting whether the output signal of the synchronization means is provided, the first input means inputs a first digital video recording signal having a first transmission rate, and the input selection means has the first A digital video recording signal is selected, the recording medium is fed at a first feeding speed, and the N sets of heads are used for the first feeding.
A first mode for recording a digital video recording signal, and the first input means inputs a second digital video recording signal having a second transmission rate which is 1 / N of the first transmission rate, The input selection means selects the second digital video recording signal, feeds the recording medium at a second feeding speed which is 1 / N of the first feeding speed, and makes the N close to each other.
A second mode for recording the second digital video recording signal by using a plurality of heads, and the third to N + 2th digital video images in which the first to Nth input means respectively have the second transmission rate. A recording signal is input, the input selecting means selects the output signal of the synchronizing means, the recording medium is fed at a first feeding speed, and the Nth to N + 2th digital images are fed using the N sets of heads. A digital video signal recording apparatus having a third mode for recording a recording signal. 2. A storage unit for storing an output signal of the input selection unit, and N for adding error correction parity to 1 / N of the signal stored in the storage unit. Whether the encoding means, the N modulating means for modulating the signal to which the parity is added by the N encoding means, and the output signals of the N modulating means are sent to any of the N sets of heads. In the first and third modes, the head selecting means sends the output signal of the modulating means to the head when the head contacts a recording medium, In the second mode, the head selecting means selects only one of the heads of each set and sends the output signal of the modulating means, and does not perform recording when an unselected head contacts the recording medium. When Digital video signal recording apparatus that. 3. The I according to claim 1, wherein in the third mode, I is a natural number of 3 to N + 2, and the Ith digital video recording signal is output by two heads of the Ith group facing each other. A digital video signal recording device characterized by performing recording respectively. 4. The method according to claim 1, wherein in the third mode, at least the third to N + 2.
Storage means for storing the digital video recording signal of N frames for N frames, and the N stored in the storage means in the section of the Jth frame (J is a natural number less than or equal to N) every N frames.
The J + 2th digital video signal for frames
A digital video signal recording device characterized by recording with a pair of heads. 5. The synchronization means according to claim 1, wherein the synchronization means includes N synchronization storage means for respectively storing the third to N + 2 digital video recording signals input from the input means, and the third synchronization storage means. To N + 2 digital video recording signals, N frame input means for inputting the third to N + 2 frame signals each indicating a frame period, and the third to N + 2 input from the N frame input means. Frame synchronization signal generation means for generating a frame synchronization signal from the frame signal, N synchronization selection means for selecting the synchronization storage means or the frame synchronization signal generation means, and the N synchronizations. Synthesis selecting means for selecting any of the N output signals of the converting means, and inserting the frame synchronization signal into the third to N + 2th digital video recording signals, respectively. A digital video signal recording device, characterized by inputting and synthesizing the N kinds of third to N + 2 digital video recording signals. 6. The synchronizing means according to claim 1, wherein the synchronizing means includes N synchronizing storage means for storing at least one frame of each of the third to N + 2 digital video recording signals input from the input means. ,
A synthesis selection means for selecting any one of the N synchronization storage means is provided, and the synthesis selection means outputs the third to N + 2 digital video recording signals in the same frame period. Digital video signal recorder. 7. A constant value according to claim 6, wherein N reading detection means for detecting the number of signals output from the N synchronization storage means, and N reading detection means. Asynchronous detection means for controlling the synchronized storage means so as to output the signal of the same frame a plurality of times is provided for the synchronized storage means which is output earlier, and when the third mode is set, a non-synchronized detection means is provided. A digital video signal recording device characterized in that a digital video signal having a high transmission rate is synchronized by continuously recording signals of the same frame.