JP3518541B2 - Digital signal recording / reproducing device - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to digital signal recording.
Reproduction device , especially data compression and time axis compression
Digital signal SL for recording or reproducing digital signals
The present invention relates to a recording / playback device .

[0002]

2. Description of the Related Art Conventionally, for example, a D2 format VTR has been known as a digital signal recording / reproducing apparatus. However, in such a conventional VTR, although it is possible to record an uncompressed signal without data compression, there is no description about recording of a compressed signal and data compression of an uncompressed signal.

[0003]

The above-mentioned conventional digital VTR is characterized by high image quality and no dubbing deterioration, but no consideration has been given to a data-compressed signal.

An object of the present invention is to provide a digital signal recording / reproducing apparatus capable of recording / reproducing a compressed signal on a recording medium in a short time, and the digital signal recording / reproducing apparatus.
It expands the use of .

[0005]

[0006]

The above-mentioned object is achieved as follows. The digital signal recording / reproducing apparatus of the present invention is a data compression device for compressing an input digital signal.
Compression means, recording signal processing means for performing predetermined signal processing on the data-compressed digital signal, recording / reproducing means for recording / reproducing the signal subjected to the recording signal processing by the recording signal processing means, and the recording There rows predetermined signal processing on a signal reproduced by the reproducing means, reproducing the compressed digital signal
And a control means for controlling the data compression means, the recording signal processing means, the recording / reproducing means and the reproduction signal processing means. Wherein, in recording the digital signal entered first
Data compression to the transmission rate, N times the digital signal compressed by reproducing the compressed di <br/> digital signal at the second transmission rate is N times faster than the first transmission rate at the time of reproduction
The time axis is compressed and output is controlled. The digital signal recording / reproducing apparatus of the present invention is input after data compression.
Recording signal processing means for performing a predetermined signal processing on the compressed digital signal applied thereto, recording / reproducing means for recording / reproducing the signal subjected to the recording signal processing by the recording signal processing means, and reproducing by the recording / reproducing means. There line a predetermined signal processing on signals, and reproduced signal processing means for reproducing compressed digital signals, to data expanding the compressed digital signal reproduced
Data expansion means, the recording signal processing means, the recording / reproducing means , the reproduction signal processing means, and the data expanding means.
And a control means for controlling the stage . The control means records the compressed digital signal which is time-axis compressed N times at the time of recording and is input at the first transmission rate, and at the time of reproduction, the second transmission which is 1 / N times slower than the first transmission rate. The compressed digital signal is reproduced at a rate , data is decompressed, and output is controlled.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG. In FIG. 1, 1 is an input terminal for a standard analog video signal, 2 is an input terminal for a standard digital video signal, 3 is an input terminal for a high-speed digital video signal, 5 is a recording system mode changeover switch, and 6 is a recording system changeover signal generation circuit. ,
10 is an A / D converter, 20 is a switching circuit, 30 is a data compression circuit, 40 is a switching circuit, 50 is an error correction code addition,
Recording system signal processing circuit for performing signal processing such as recording modulation, 6
Reference numeral 0 is a servo control circuit, 70 is a cylinder, 71 is a magnetic tape, 72 and 72 'are magnetic heads, 80 is a reproduction system signal processing circuit for performing signal processing such as reproduction demodulation, error detection and error correction, and 90 is a switching circuit, 100 is a data decompression circuit, 120
Is a D / A converter, 131 is a standard analog video signal output terminal, 132 is a standard digital video signal output terminal, 1
33 is a high-speed digital video signal output terminal, 135 is a reproduction system mode changeover switch, and 136 is a reproduction system changeover signal generation circuit.

The operation of the embodiment shown in FIG. 1 will be described below. In the present embodiment, as an example, a digital magnetic recording / reproducing apparatus which has a standard speed recording mode and a high speed recording mode at the time of recording and a standard speed reproduction mode and a high speed reproduction mode at the time of reproduction will be described. The recording signal is, for example, an NTSC signal, and FIG. 2 shows the specifications of each input video signal. The standard transmission rate shown in FIG. 2 is a specification when the NTSC signal is sampled with a sampling clock of 4 fsc and quantized with 8 bits as an example.

First, the standard speed recording will be described. The standard analog video signal input from the input terminal 1 is A / D
A predetermined sampling clock (4 fs
In c), the analog signal is converted into a digital signal and input to the terminal 20a of the switching circuit 20. Where A / D
The transmission rate after conversion is 114 Mbps. On the other hand, the standard digital video signal (transmission rate 114 Mbps) is input from the input terminal 2 and sent to the terminal 20b of the switching circuit 20.

Here, the standard digital video signal is a signal obtained by digitally transmitting the standard analog video signal, and as shown in FIG. 2, the standard analog video signal is A / D.
The output after conversion and the standard digital video signal have the same transmission rate.

When the recording system mode selector switch 5 is switched according to the input signal, the recording system switching signal generating circuit 6 outputs switching signals RS1 and RS2. The switching circuit 20
Is controlled by the switching signal RS1. When the input signal is the standard analog video signal, the terminal 20a and the terminal 20c are switched so as to be connected, and when the input signal is the standard digital video signal, the terminals 20b and 20c are connected. Switch to connect.

The digital signal (transmission rate 114 Mbps) output from the terminal 20c of the switching circuit 20 is input to the data compression circuit 30 and subjected to predetermined data compression processing such as vector quantization, Hadamard transform and cosine transform. In the present embodiment, as an example, the data compression processing is performed by 1 / 11.4 times. Therefore, in the present embodiment, the digital signal is converted into a digital signal having a transmission rate of 10 Mbps by the data compression processing and then input to the terminal 40a of the switching circuit 40. Switching circuit 40
Is controlled by the switching signal RS2 output from the recording system switching signal generating circuit 6, and when the input signal is a standard analog video signal or a standard digital video signal, the terminal 4
0a and the terminal 40c are switched so as to be connected to each other, and are input to the recording system signal processing circuit 50. Recording system signal processing circuit 50
Then, the magnetic head mounted on the cylinder 70 after signal processing such as channel division, addition of error correction code, recording modulation, etc. is performed by a predetermined processing clock RCK1 corresponding to the data-compressed signal (10 Mbps). 72,
It is supplied to 72 ′ and recorded on the magnetic tape 71. The cylinder 70 and the magnetic tape 71 are controlled by the servo control circuit 60. The servo control circuit 60 controls the cylinder motor and the capstan motor in accordance with the switching signal RS2 so that the cylinder rotation speed RR1 and the tape speed RT1 are achieved, and that the cylinder motor and the capstan motor are synchronized with the input video signal.

Next, the case of high speed recording will be described.
The high-speed digital video signal input from the input terminal 3 is
It is sent to the terminal 40b of the switching circuit 40. Here, the high-speed digital video signal is a signal obtained by further compressing the digital video signal, which has been subjected to the same data compression processing as that performed by the data compression processing circuit 30, by time axis compression to increase the transmission rate.

In this embodiment, the time base compression rate is 1 as an example.
Therefore, the transmission rate of the high-speed digital video signal is 100 Mbps in this embodiment. Since the high-speed digital video signal is a signal that has already undergone data compression processing, it is not necessary to pass through the data compression circuit 30. When the recording mode changeover switch 5 is set to the high-speed digital video signal side, a corresponding changeover signal RS2 is output from the recording system changeover signal generation circuit 6 to control the changeover circuit 40 and the terminal 4
0b and the terminal 40c are switched so that the high-speed digital video signal is input to the recording system signal processing circuit 50. The recording system signal processing circuit 50 performs signal processing such as channel division, addition of error correction code, recording modulation, etc. at a predetermined processing clock RCK2 corresponding to the high speed digital video signal (100 Mbps), and then the cylinder 70 is processed. The data is supplied to the attached magnetic heads 72 and 72 ′ and recorded on the magnetic tape 71. The cylinder 70 and the magnetic tape 71 are controlled by the servo control circuit 60.
The servo control circuit 60 controls the cylinder motor and the capstan motor so that the predetermined number of cylinder circuits RR2 and the tape speed RT2 are achieved in accordance with the switching signal RS2, and in synchronization with the input video signal.

The present invention relates to the recording system signal processing circuit 50,
By the servo control circuit 60, standard speed recording and speed recording can be performed on the tape in exactly the same format, and the recording time can be greatly shortened in the high speed recording mode. Basically, the processing clock RCK at standard speed recording
1, cylinder rotation speed RR1, tape speed RT1, processing clock RCK2 at high speed recording, cylinder rotation speed RR
2. The tape speed RT2 is realized by establishing a predetermined relationship according to the recording signal processing format.

As an example, RCK1: RCK2, RR
By setting the relationship of 1: RR2 and RT1: RT2 to 1:10, 10 times higher speed recording becomes possible.

Here, the specific circuit configuration of the recording system signal processing circuit 50 for realizing standard speed recording and high speed recording, the circuit operation, the operation of the servo control circuit 60, the number of magnetic heads,
There are various possible methods of mounting, etc., which will be described later in detail by showing examples.

Next, the signal processing during reproduction will be described. In the present invention, the recording pattern on the magnetic tape is the same whether the recording mode is standard speed recording or high speed recording.

As a result, the reproduction is performed regardless of the recording mode.
Either standard speed playback or high speed playback can be selected.

First, the normal speed reproduction will be described. When the standard speed reproduction is selected by the reproduction system mode changeover switch 135, the reproduction system switching signal generation circuit 136 outputs the switching signal PS2 corresponding to the standard speed reproduction. Servo control circuit 6
0 controls the cylinder motor and the capstan motor so that the predetermined cylinder rotation speed RR1 and tape speed RT1 are obtained in accordance with the switching signal PS2. Magnetic head 7
The signal reproduced by 2, 72 ′ is input to the reproduction system signal processing circuit 80. In the reproduction system signal processing circuit 80,
After performing signal processing such as reproduction demodulation, channel synthesis, error detection, and error correction with a predetermined processing clock RCK1 according to standard speed reproduction, a reproduction signal (10 Mbps) is supplied to the terminal 90a of the switching circuit 90. The switching circuit 90 is controlled by the switching signal PS2, and is switched so that the terminal 90a and the terminal 90c are connected during the standard speed reproduction.
A reproduction signal is sent to the data expansion circuit 100. The data decompression circuit 100 restores the original signal by signal processing that is the reverse of the data compression processing at the time of recording. The data expansion rate at this time is the reverse of the data compression rate, and is 11.4 times in this embodiment. Therefore, the transmission rate returns to the original value (114 Mbps in this embodiment). The reproduced signal subjected to the data expansion processing is sent to the D / A converter 120 and the output terminal 132. The signal input to the D / A converter 120 is converted from a digital signal to an analog signal and then output terminal 1
A standard analog video signal is output from 31. On the other hand, the standard digital video signal output is output from the output terminal 132.

Next, high speed reproduction will be described. When high-speed playback is selected with the playback system mode switch 135,
The reproduction system switching signal generation circuit 136 outputs the switching signal PS2 according to the high speed reproduction. The servo control circuit 60 is
According to the switching signal PS2, a predetermined cylinder rotation speed RR
2. Cylinder motor, so that the tape speed is RT2
It controls the capstan motor. Magnetic head 72,
The signal reproduced by 72 'is input to the reproduction system signal processing circuit 80. In the reproduction system signal processing circuit 80, after performing signal processing such as reproduction demodulation, channel synthesis, error detection, error correction, and the like with a predetermined processing clock RCK2 corresponding to high speed reproduction, a reproduction signal ( 1
00 Mbps). The switching circuit 90 is controlled by the switching signal PS2, and is switched so that the terminals 90a and 90b are connected during high speed reproduction, and a high speed digital video signal is output from the output terminal 133.

The present invention enables standard speed reproduction and high speed reproduction by the servo control circuit 60 and the reproduction system signal processing circuit 80, and makes it possible to greatly reduce the reproduction time in the high speed reproduction mode. Basically, the processing clock R during standard playback
CK1, cylinder speed RR1, tape speed RT1
And the processing clock RCK2 during high-speed reproduction, the cylinder rotation speed RR2, and the tape speed RT2 have a predetermined relationship. As an example, RCK1: RCK
2, RR1: RR2, RT1: RT2 relationship is 1:10
By doing so, 10 times faster reproduction is possible.

Here, a specific circuit configuration of the reproduction system signal processing circuit 80 for realizing standard speed reproduction and high speed reproduction, circuit operation, operation of the servo control circuit 60, number of magnetic heads,
There are various possible methods of mounting, etc., which will be described later in detail by showing examples.

Next, a second embodiment will be described with reference to FIG. The second embodiment has substantially the same components as the first embodiment, but the position of the switching circuit 40 is different, and the switching circuit 90 is different.
Is eliminated, and the number of switching circuits 45 is newly increased.

First, standard speed recording and reproduction will be described. During standard speed recording, the switching circuit 45 switches so that the terminals 45a and 45c are connected, and the switching circuit 40 switches so that the terminals 40a and 40c are connected. The other circuit operation is exactly the same as the circuit operation of the first embodiment, and the explanation is omitted. During normal speed reproduction, only the switching circuit 90 is eliminated, and the circuit operation is otherwise the same as that of the first embodiment, and the description thereof is omitted.

On the other hand, high-speed recording and high-speed reproduction are different in that a high-speed digital video signal is transmitted in a recording format. That is, the input / output high-speed digital video signal is transmitted in the form of being subjected to signal processing such as addition of an error correction code and modulation performed by the recording system signal processing circuit 50. Therefore, at the time of high speed recording, the data is recorded on the tape as it is through the switching circuit 40 without passing through the recording system signal processing circuit 50. During high-speed reproduction, the reproduction system signal processing circuit 80 performs reproduction signal processing such as error detection and error correction, and then inputs the signal to the terminal 45b of the switching circuit 45. The switching circuit 45 is controlled by PS2 output from the reproduction system switching signal generation circuit 136, and switches at the time of high speed reproduction so that the terminals 45b and 45c of the switching circuit 45 are connected, and the reproduction signal is a recording system signal. It is sent to the processing circuit 50. The recording signal processing circuit 50 performs recording signal processing such as addition of error correction code and recording modulation to form a recording format, and then outputs a high-speed digital video signal from the output terminal 133.

In the example described above, both high-speed recording and high-speed reproduction are shown at 10 times speed. However, the present invention is not limited to 10 times speed, and the same applies to any n times speed recording and reproduction. Can be applied.

In this embodiment, an example in which all the modes of standard speed recording, high speed recording, standard speed reproduction and high speed reproduction are combined has been described, but it is not always necessary to have all the modes, and the modes required depending on the purpose of use are described. An example with only one is also conceivable.

Next, an example of the circuit configuration, circuit operation, tape speed, etc. of the recording system signal processing circuit 50, the servo control circuit 60, and the reproduction system signal processing circuit 80 after the data compression process of FIG. 1 will be described with reference to FIGS. A detailed description will be given by using 6.

In FIG. 4, 201 is a synchronization detection circuit, 2
Reference numeral 04 is a recording modulation circuit, 205 is a cylinder servo control circuit, 206 is a capstan servo (tape speed) control circuit, 207 is a reproduction reference signal generation circuit, 210 is a demodulation circuit, 211 is a cylinder, 212 is a pair of recording heads, Two
13 is a pair of reproducing heads, 214 is a capstan for controlling the tape speed, 215 is a magnetic tape, 216 is a delivery reel, and 217 is a take-up reel. Further, FIG. 5 is a diagram showing the timing of the input / output signals of the present embodiment.
51 is a compressed image signal which is an input signal, and 252 is 2
51 is a diagram schematically showing a sync signal 51, a standard speed reproduction signal 255 as an output signal, and a reproduction synchronization signal 256.

The present embodiment is an example in which the tape speed during recording and the number of cylinder revolutions are each n times the speed during standard speed reproduction, thereby realizing n times speed recording. The compressed video signal and sync signal which are the input signals of this circuit are as shown in FIG.
At the time of reproducing one screen at standard speed (16.7 ms in the case of NTSC signal), it is composed of n screen information 251 and n sync pulses 252 synchronized with this. Sync pulse 252
Is separated from the compressed video signal by the synchronization detection circuit 201 in FIG. 4, but if the compression circuit is provided in the previous stage, the control signal in the previous stage may be used. This image information is converted into a predetermined recording format by the recording modulation circuit 204 and recorded on the magnetic tape 215 by the recording head 212. At this time, the synchronization signals of the cylinder servo control circuit 205 and the capstan servo control circuit 206 are shown in FIG.
As in the case of 1, by multiplying by n times according to the n times speed video signal, and by increasing the number of rotations of the cylinder 211 and the feeding speed of the magnetic tape 215 by n times, the same format as in the case of the normal speed recording is recorded on the tape. It becomes possible to record. At the time of reproduction, the sync reference signals of the cylinder servo control circuit 205 and the capstan servo control circuit 206 are supplied from the reproduction reference signal generation circuit 207, the cylinder speed and the tape speed are returned to normal speed, and the signal read from the reproduction head 213 is reproduced. The demodulation circuit 210 demodulates and outputs. Further, in this circuit, the input video signal and sync signal are input at the normal speed, that is, n.
The normal speed recording is possible as it is by setting = 1 × speed. Further, by multiplying the frequency of the output signal from the reproduction reference signal generator by n times, n times speed reproduction is also possible.

Another embodiment will be described with reference to FIG. In FIG. 6, 201 is a synchronization detection circuit, 202 is a synchronization signal frequency dividing circuit, 203 is a memory for temporarily storing information,
Reference numeral 204 is a recording modulation circuit, 205 is a cylinder servo control circuit, 206 is a capstan servo (tape speed) control circuit, 207 is a reproduction reference signal generation circuit, 208 reproduction reference signal frequency dividing circuit, and 209 is a memory for temporarily recording a reproduction signal. ,
210 is a demodulation circuit, 211 is a cylinder, 212 is m pairs of recording heads, 213 is m pairs of reproducing heads, 214 is a capstan for controlling the tape speed, 215 is a magnetic tape,
216 is a delivery reel and 217 is a take-up reel.

FIG. 7 is a diagram showing the timing of the input / output signals of this embodiment. 251 is a compressed image signal which is an input signal, 252 is a sync signal of 251 and 253.
FIG. 3 is a diagram showing an outline of an output signal of the recording signal temporary storage memory 203, 254 is a synchronization signal divided by m, 255 is a standard speed reproduction signal which is an output signal, and 256 is a reproduction synchronization signal.

The present embodiment is an example in which m pairs of heads are used to simultaneously record m screen magnetic signals on m tracks to realize high-speed recording while suppressing an increase in cylinder rotation speed. For reproduction, m pairs of reproducing heads are used. In this figure, the case where two screens of information are simultaneously recorded on two tracks by using two pairs of heads is shown, but the case of using three or more pairs of heads is also possible. As shown in FIG. 7, the compressed video signal and sync signal, which are the input signals of this circuit, are the time for reproducing one screen at the standard speed (1 for NTSC signals).
(6.7 ms), information 251 of an n × m screen and (n × m) sync pulses 252 generated thereby.
The (n × m) times time-compressed video signal is temporarily stored in each address of the memory 203 having a storage capacity of m screens, and from there, information of each screen is displayed as shown in FIG. 7-253. Are converted into parallel signals for each and sent to the recording modulation circuit 204 in parallel. The recording signal output from the recording modulation circuit 204 is input in parallel to the m recording heads 212 and recorded on the magnetic tape 215. At this time, the recording speed per head is n times the normal speed.

Therefore, the cylinder servo control circuit 205
A reference signal (FIGS. 7-254) divided by m is input to. On the other hand, in order to write n × m tracks in the time of one screen, the tape needs to advance at a speed n × m times as fast as the normal speed recording. Therefore, the capstan control circuit 2
A reference signal of n × m speed (FIG. 7-252) is input to 06. At this time, since the inclination of the recording head locus on the tape changes depending on the ratio of the tape speed and the cylinder speed, the inclination of the tape and the cylinder is designed according to m unlike the case of the embodiment of FIG. There is a need to. By designing in this way, recording is performed on the tape in exactly the same format as when recording at normal speed. At the time of reproduction, the synchronizing signals of the cylinder servo control circuit 205 and the capstan servo control circuit 206 are reproduced as the reproduction reference signal generation circuit 2.
07, the cylinder speed and the tape speed are returned to normal speed, and the signals read in parallel from the reproducing head 213 are demodulated by the demodulation circuit 210 and output. However, in the present embodiment, since the m heads read simultaneously, the cylinder rotation speed is 1 / m times the speed in the case of FIG. Further, in the present embodiment, it is also possible to use a pair of reproducing heads to simplify the reproducing circuit.

However, in this case, since only one track is reproduced at one time, it is necessary to set the cylinder rotation speed to n times that in the above embodiment. In this case, since the inclination of the track of the reproducing head on the tape depends on the number of cylinder rotations, it is necessary to adjust the tracking by using a movable head as the reproducing head.

[0037]

As described above, according to the present invention,
Digital signal recording / reproduction capable of high-speed recording or high-speed reproduction
It is possible to realize a raw device and shorten the recording time or playback time.
The effect is that it can be achieved .

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing specifications of a recording signal.

FIG. 3 is a block diagram showing a second embodiment.

FIG. 4 is a block diagram illustrating in detail the circuit configuration of the embodiment shown in FIG.

5 is a signal waveform diagram for explaining the operation of the embodiment shown in FIG.

FIG. 6 is another block diagram showing the circuit configuration of the embodiment shown in FIG.

FIG. 7 is a signal waveform diagram for explaining the operation of the embodiment shown in FIG.

[Explanation of symbols]

1, 2, 3, ... Input terminals, 10 ... A / D converter, 30 ... a data compression circuit, 50 ... Recording system signal processing circuit, 60 ... Servo control circuit, 80 ... Reproduction system signal processing circuit, 100 ... Data expansion circuit, 120 ... A / D converter, 131, 132, 133 ... Output terminals.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keizo Nishimura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Home Appliance Research Laboratory, Hitachi, Ltd. (72) Inventor Yuzumi Wataya 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Household Appliances Research Laboratory, Hitachi, Ltd. (72) Inventor Akira Shibata, 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Household Appliances Research Laboratory, Hitachi, Ltd. (56) Reference JP-A-2-101664 (JP, A) Kai 63-29376 (JP, A) JP 64-73560 (JP, A) JP 3-242877 (JP, A) JP 61-152180 (JP, A) (58) Fields investigated (58) Int.Cl. ⁷ , DB name) H04N 5/76-5/956 G11B 20/10-20/12

Claims (6)

(57) [Claims] 1. Data compression of an input digital signal
A data compression means, a recording signal processing means for performing a predetermined signal processing on the compressed digital signal compressed by the data, and a recording / reproducing means for recording / reproducing the signal processed by the recording signal processing means on a recording medium. the recording had <br/> rows predetermined signal processing on the reproduced signal by the reproducing means, and reproduced signal processing means for reproducing the compressed digital signal, the data compression means, said recording signal processing means, said reproducing means and a control means for controlling the reproduction signal processing means, the control means, at the time of recording data compressing the digital signal input to the first transmission rate, wherein during reproduction the first transmission rate A digital signal compressed by reproducing the compressed digital signal at a second transmission rate which is N times faster.
A digital signal recording / reproducing apparatus, wherein the digital signal recording / reproducing apparatus is controlled so as to compress the time signal N times and output the compressed signal. 2. The recording signal processing means adds an error correction signal to the recording signal or performs signal processing of recording modulation,
2. The digital signal recording / reproducing apparatus according to claim 1, wherein the reproduction signal processing means performs reproduction / demodulation or signal processing for error detection and error correction. 3. The digital signal recording / reproducing apparatus according to claim 1, wherein the input digital signal is a signal obtained by digitally converting an analog signal. 4. A compression digitizer which is data-compressed and inputted.
A recording signal processing means for performing predetermined signal processing on Le signal, and reproducing means for recording and reproducing said recording signal processing means in a recording signal processing signal recording medium on, the signal reproduced by said reproducing means There <br/> lines to predetermined signal processing, and reproduction signal processing means for reproducing the compressed digital signal, the data for data expanding the compressed digital signal reproduced
It has a decompressing means and a control means for controlling the recording signal processing means, the recording / reproducing means , the reproduction signal processing means and the data decompressing means, and the control means is time-time compressed N times during recording. 1
The input compressed digital signal is recorded at a transmission rate of, and the compressed digital signal is reproduced at a second transmission rate which is 1 / N times slower than the first transmission rate at the time of reproduction.
Then, the digital signal recording / reproducing apparatus is characterized by controlling so as to decompress and output the data . 5. The recording signal processing means adds an error correction signal to the recording signal or performs signal processing of recording modulation,
The digital signal recording / reproducing apparatus according to claim 4, wherein the reproduction signal processing means performs reproduction / demodulation or signal processing of error detection and error correction. 6. A digital signal recording / reproducing apparatus according to claim 4 or 5, wherein the data expanded digital signal is converted into an analog signal and output.