JPH06325310A - Recording and reproducing device for digital information signal - Google Patents

Abstract

(57) [Abstract] [Purpose] Re-read the missing portion of the reproduction data from the helical track of the magnetic tape to recover the partially destroyed data. [Structure] Data is recorded on a magnetic tape 1 for each helical track (not shown), and during normal reproduction, the magnetic tape 1 runs at the same speed as during recording and is reproduced by the rotary heads 23 and 24. . The reproduced data is
The error is corrected by the inner error correction circuit 27, the outer error correction circuit 28, and the correction buffer 29. However, if there is an uncorrectable error, the magnetic tape 1 is made to run in the reverse direction at a speed less than 1/2 of the speed during normal reproduction. And the helical track in which such an error has occurred is the rotary head 23.
Alternatively, 24 is reproduced and scanned a plurality of times to re-read the error occurrence portion. Then, the reproduced data is corrected as described above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical device which, when an uncorrectable error is detected from reproduction information data on a magnetic tape, makes it possible to reread the data on the portion of the magnetic tape where the error has occurred. The present invention relates to a scan type digital information signal recording / reproducing apparatus.

[0002]

2. Description of the Related Art As a helical scan type digital information signal recording / reproducing apparatus for realizing high density recording / reproducing,
For example, those described in Japanese Patent Application Laid-Open No. 4-286751 and a magnetic tape device (MSS) for a computer are known. Since the data can be recorded / reproduced with high density by the helical system, the access time can be shortened and the number of cartridge tapes can be reduced as compared with the conventional fixed head system information signal recording / reproducing apparatus. There are advantages such as downsizing and downsizing of the cart machine that manages the cartridge tape.

[0003]

However, in the above-mentioned prior art, troubles and dropouts in the transmission system,
When a read signal is missing (read error) due to clogging of the read head, this is usually called a data read error, and the data is read again from the beginning. However, this takes a long time to read the data, and there is a problem that the access time becomes long. In particular, in a digital information recording / reproducing apparatus used as an external storage device of a computer or the like, reliability of data, speedup of data access, and shortest tape path are required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a digital information signal recording / reproducing apparatus which solves such a problem and is capable of quickly relieving a data reading error.

[0005]

In order to achieve the above object, the present invention provides a means for detecting an uncorrectable error from reproduction information data, and thereby a magnetic tape in a direction opposite to that in normal reproduction. Further, it is provided with means for traveling at a tape speed of 1/2 or less of that during normal reproduction, and means for re-reading the data in the portion in which the error has occurred on the thus traveling magnetic tape.

[0006]

The helical track, which has an uncorrectable error, is reproduced and scanned a plurality of times in the opposite direction by the rotary head.
The data is read again. This makes it possible to reread the data on the helical track without rewinding the magnetic tape to the front of the helical track.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a helical scan type digital information signal recording / reproducing apparatus according to the present invention, in which 1 is a magnetic tape, 2 is a control head,
3 is a drum rotation speed detector, 4 is a capstan rotation speed detector, 5 is a rotary drum, 6 is a drum motor, 7 is a drive amplifier, 8 is a drum speed controller, 9 is a drum phase controller, and 10 is a cap. Stan, 11 is a control track, 12 is a capstan motor, 13 is a drive amplifier, 14 is a capstan speed controller, 15 is a capstan phase controller, 16 and 17 are adders, 18 is a reference signal generator, and 19 is Servo system controller, 2
0 and 21 are input terminals, 22 is a drum rotation phase detector, 2
3, 24 are rotary heads, 25 are equalizer amplifiers, 26
Is a demodulation circuit, 27 is an inner error correction circuit, 28 is an outer error correction circuit,
Reference numeral 29 is a correction buffer, 30 is a read buffer (read buffer), 31 is an output terminal, and 32 is a switch circuit.

In FIG. 1, the rotation speed of the drum motor 6, and thus the rotation speed of the rotating drum 5 (hereinafter referred to as the drum rotation speed), is detected by the drum rotation speed detector 3, and the drum speed control is performed as rotation speed information DFG. Device 8
Is supplied to. The drum speed control device 8 detects a difference between the drum rotation speed represented by the supplied rotation speed information DFG and a predetermined target rotation speed set in advance, and a control signal corresponding to this is added as a drum speed control signal to the adder. Supply to 17.

The drum rotation phase detector 22 detects rotation phase information TP indicating the rotation phase of the rotating drum 5,
It is supplied to the drum phase control device 9. The drum phase control device 9 detects the phase difference between the drum phase reference signal REF supplied from the reference signal generator 18 and the phase represented by the rotation phase information TP, and the control signal corresponding to this is detected as the drum phase control signal. Is supplied to the adder 17. The adder 17 adds the drum speed control signal and the drum phase control signal and supplies them to the drive amplifier 7 as a control signal for the drum motor 6.

By such control, the rotary drum 5 rotates at a constant rotational speed and in a predetermined phase relationship with the drum phase reference signal.

The capstan rotation speed detector 4 detects the rotation speed of the capstan motor 12, outputs rotation speed information CFG indicating this, and supplies it to the capstan speed controller 14. In the capstan speed control device 14,
The servo system controller 19 supplies the rotation speed instruction information SPD indicating the target rotation speed of the magnetic tape 1, and the target rotation speed of the capstan motor 12 is obtained from the rotation speed instruction information SPD. A speed difference signal from the target rotation speed of the capstan motor 12 is obtained from the information CFG and supplied to the adder 16 as a capstan speed control signal.

A control signal is recorded in advance on a control track 11 formed in the longitudinal direction of the magnetic tape 1 during recording, and the control signal CTL is reproduced by the control head 2. This control signal CTL is supplied to the capstan phase control device 15, the phase difference from the capstan phase control reference signal supplied from the reference signal generator 18 is detected, and a capstan phase control signal corresponding to this is generated. It This capstan phase control signal is sent to the adder 1 via the switch circuit 32.
6 is supplied.

The adder 16 adds the capstan speed control signal and the capstan phase control signal, and the drive amplifier 13 serves as a control signal for the capstan motor 12.
Supply to.

By such control, the capstan motor 1
Reference numeral 2 denotes the target rotation speed instructed by the rotation speed instruction information SPD from the servo system controller 19 and rotates in a predetermined phase relationship with the reproduced control signal CTL.

The magnetic tape 1 is wound around the outer periphery of the rotary drum 5 in a spiral shape over approximately 180 °, and is held by a capstan 10 which is rotationally driven by a capstan motor 12 and a pinch roller (not shown). As the capstan motor 12 rotates, the capstan motor 12 travels at a speed corresponding to the rotation speed of the capstan motor 12. Here, the target rotation speed represented by the rotation speed instruction information SPD output from the servo system controller 19 is in accordance with the operation mode designated by the user, whereby the capstan motor 12 is selected.
The number of rotations of the magnetic tape 1 and thus the running speed of the magnetic tape 1 can be changed according to the operation mode.

From the servo system controller 19,
Further, the capstan rotation direction instruction signal REV is supplied to the drive amplifier 13, whereby the capstan motor is driven.
The rotation direction of the magnetic tape 1 is set, and the running direction of the magnetic tape 1 is set.

On the rotary drum 5, there are two 180 ° opposites.
Two rotary heads 23 and 24 are attached, and on the magnetic tape 1, oblique tracks (hereinafter referred to as helical tracks), in which information data is recorded, are sequentially formed (not shown). Then, during normal reproduction in which the magnetic tape 1 travels at the same speed as during recording, the rotary heads 23, 24 are controlled by the above-described control of the drum motor 6 and the capstan motor 12 without causing tracking misalignment. The tracks are alternately scanned to reproduce the recorded information data.

The reproduction information data from the rotary heads 23 and 24 is sufficiently amplified and equalized by the equalizer amplifier 25, demodulated by the demodulation circuit 26, and then the inner error.
Error correction processing is performed by the correction circuit 27, the outer error correction circuit 28, and the correction buffer 29. Here, this error correction will be described.

In recording and reproducing signals using a magnetic tape,
Occurrence of loss of read signal (read error) is inevitable. When recording / reproducing a digital signal as in this embodiment, there are three types of read errors: a random error, a burst error, and an error caused by a transmission system trouble. The random error is an error which occurs naturally with an average of about 1 in 100,000 pieces of data. The burst error is a dropout of a reproduction signal caused by dropout or clogging of the rotary head. An error caused by a trouble in the transmission system is a partial destruction of the reproduction data due to a trouble of a circuit connected after the output terminal 31 of the reproduction information data in FIG. The error caused by such a transmission system trouble cannot be corrected because it is the data destruction after the error correction processing in this embodiment.

In this embodiment, the above random error and burst error can be corrected, and for this purpose, a parity code for error detection and correction is added to the record information data in advance. The solution of the operation using this parity code is to perform the inverse operation at the time of reproduction to correct the error. As the error correcting means, for example, a parity code is doubly generated (inner code, outer code) in different time axis directions. Then, at the time of reproduction, inner error correction is performed by the inner error correction circuit 27 and the correction buffer 29 by using the inner code, and a small error (random error) is corrected by this, and the outer code is used. Out-error correction is performed by the outer error correction circuit 28 and the correction buffer 29, and the remaining error is corrected by this.

The error-corrected information data is temporarily stored in the read buffer 30 and output from the output terminal 31.

Next, the most important point of this embodiment,
The function (readback function) of running the magnetic tape 1 in the reverse direction and performing the same operation as the normal reproduction will be described.

Among the above data errors, an error caused by a transmission system trouble and an error which cannot be corrected by the outer error correction circuit 28 need to be reread. One of the most efficient re-reading methods is to run the magnetic tape 1 in the reverse direction from the end of the position on the magnetic tape 1 where the data is missing during reproduction, thereby retrieving the information data at this position. There is a so-called readback function for rereading the data. The features of the readback function will be described below.

As a method of reading an area where data is missing on the magnetic tape, a method of running the magnetic tape in the forward direction and reading the area again can be considered. However, considering the rewinding time and the running direction switching time of the magnetic tape, it is possible to quickly read and rescue the missing information data by running the magnetic tape in the opposite direction and rereading. Further, the system controller for controlling the current digital information signal recording / reproducing apparatus by the fixed head type magnetic tape system corresponds to the readback command, and the novel helical scan system digital information signal according to the present invention. There is also an advantage that it can be directly applied to a recording / reproducing apparatus.

Next, the read back operation in the helical scan type digital information signal recording / reproducing apparatus will be described.

In this embodiment, during readback, the magnetic tape is run in the reverse direction at a tape running speed less than half the tape running speed during normal reproduction and without tracking control. Try to play the data. In normal reproduction by a helical scan type digital information signal recording / reproducing apparatus, tracking control is performed so that a rotary head faithfully traces a helical track on a magnetic tape. At the time of the read back in this embodiment, the control is simplified and the response time is shortened, so that the magnetic tape is run in the reverse direction without performing the tracking control to perform the re-reading. There is.

FIG. 2 does not show the scanning locus and reproduction data on the magnetic tape 1 at the time of readback without tracking control.

Now, the rotary head 23 on the rotary drum 5 is the A head, and the rotary head 24 having a different azimuth angle from the A head.
2A, the helical tracks A1, A2, A3, ... Are by the A head, and the helical tracks B0, B1, B2, B3 ,. In addition, each helical track is
As shown in (b), it is assumed that information data 1, 2, 3, ... Are recorded.

Here, assuming that the helical track A2 is the target track for readback, when the magnetic tape 1 is read back at a tape running speed of, for example, 1/4 that of the normal reproduction, the magnetic tape 1 is run. , A head performs reproduction scanning in the order of scanning loci 40d, 40c, 40b, 40a. That is, the helical track A2 is reproduced and scanned four times. According to this, in the scanning locus 40d,
As shown in FIG. 2 (f), the latter ¼ portion of the latter half of the helical track A2, and the scanning locus 40c, as shown in FIG. 2 (e), the former ¼ portion of the latter half of the helical track A2. In the scanning locus 40b, as shown in FIG.
As shown in FIG. 2B, the first quarter of the first half of the helical track A2 is reproduced in the first quarter of the first half of the helical track A2 as shown in FIG. 2B. The recorded information data on the helical track A2 is divided into four and reproduced.

Here, in the reproduction signal for each reproduction scan shown in FIGS. 2C to 2F, in addition to the reproduction information data from the helical track A2, the other helical tracks A3 and A1 by the A head. Informational data from is also included. Since the A and B heads have different azimuths, no signal is reproduced when the scanning loci 40a to 40d hit the helical tracks B0, B1, B2 and B3 by the B head.

From the reproduction signal in each reproduction scan as described above,
In FIG. 1, information data from the helical track A2 is extracted, combined and stored in a correction buffer 29 composed of a semiconductor memory or the like. As a result, the information data recorded on the helical track A2 is restored.

Next, the control operation of the capstan motor 12 during the readback operation will be described.

In FIG. 1, when the readback operation start control signal RBW is input from the input terminal 20, the servo system controller 19 supplies the drive amplifier 13 with the capstan rotation direction instruction signal REV and the capstan motor 12 reverses. Let it rotate. Next, the servo system controller 19 outputs a switch control signal CADJ, which turns off the switch circuit 32. Therefore, the phase control system of the capstan motor 12 is cut off, and only the speed control of the capstan motor 12 is performed to cause the magnetic tape 1 to run in the reverse direction. The servo system controller 19 also outputs the rotational speed instruction information SPD at the time of readback and supplies it to the capstan speed control device 14. In this case, the rotation speed instruction information SPD is 1/2 of the rotation speed of the capstan motor 12 during normal reproduction.
The following target rotation speed (here, 1/4 times) is represented, and therefore, the magnetic tape 1 runs at 1/4 times the speed during normal reproduction.

Although the tracking control need not be performed at the time of the readback and the reverse rotation control of the capstan motor 12 is performed only by the speed control, the capstan phase control is performed. It is also possible to go back and perform readback.

Next, the error correction processing will be described. In this embodiment, when the information data is recorded, the product code of the Reed-Solomon code is used as the error detection / correction code, and the different time axis direction (inner (INNER)) is used. The error detection and correction code is added to the direction and the outer direction. In normal data reproduction, the reproduced information data is subjected to inner correction and outer correction processing using the error detection and correction code to restore the original information data.

In the case of readback as well, similar error detection and correction processing is performed, but as described with reference to FIG. 2, the helical track to be read back is sequentially reproduced from the portion after the helical track. Therefore, it is necessary to restore the order of the data and then perform the error detection and correction process. An example of the error correction procedure at the time of readback including such processing will be described with reference to FIG. However, 50a is a predetermined data amount unit (1 block: here, data for 1 helical track), 50a to 50c are blocks in the recording process, and 52a to 52d are in the reproducing process. Each block is shown.

At the time of recording, the data rearrangement (shuffling) process is performed in the block 50a and the block 5
0b is generated. Next, the block 50b is divided, data is calculated for each of the divisions 51a, ..., 51b, ..., 51c to obtain an error detection and correction code (parity code P), and these are assigned to the corresponding divisions. A recording block 50c is additionally generated. The sequential blocks 50c thus formed are recorded on each helical track on the magnetic tape 1.

As described with reference to FIG. 2 and the like, at the time of readback, a low tape running speed (for example, at the time of standard recording / reproduction 1
.., 51b, ..., 51c, which is the reverse of the recording sequence, because the target helical track is repeatedly reproduced at a tape running speed of ½ or less) and without tracking control. …, 51b…, 51
The block 52a which is a is reproduced. The block 52a is divided into respective sections 51c, ..., 51b.
a is stored in the correction buffer 29 of FIG. 1 in the order of reproduction,
The inner correction process and the outer correction process are not started until the data for one block is stored therein. Here, for example, it is assumed that an error has occurred in the data "6, 7, 507" indicated by the mark x during reproduction.

When one block of data is stored in the correction buffer 29, the sections whose order of arrangement is reversed are rearranged in the normal order at the time of recording to generate the block 52b. Then, by using the parity code P,
The inner error correction (inner correction) circuit 27 performs inner error correction processing for each section 51a, ..., 51b, ..., 51c of one block 52b stored in the correction buffer 29. As a result, only the data "507" of the error data is restored and the data of the block 52c is generated. Next, the outer error
The correction circuit 28 performs the outer error correction processing of the block 52c, and the data "6, 7" which cannot be restored by the inner error correction processing is restored to obtain the block 52d of the original data array. .

Needless to say, the process from the block 52a to the block 52b is not necessary in the standard reproduction in which the tape is reproduced at the same tape traveling speed as that in the recording.

As described above, in this embodiment, the error correction means at the time of the read back is the reverse read data.
The data array is changed back to a normal array, whereby the error correction processing means performs the same processing operation as in the normal reproduction. However, the error correction means at the time of the read back is not limited to this, and for example, reverse read data may be subjected to inner error correction processing and outer error correction processing with the data array kept as it is. It may be configured.

FIG. 4 is a block diagram showing another embodiment of the digital signal recording / reproducing apparatus according to the present invention, in which 33 is a time code detecting head, 34 is a time code reader.
Reference numeral 35 is a time code memory, and the parts corresponding to those in FIG.

In the figure, a time code indicating the absolute address of the magnetic tape 1 for each block is arranged on a track parallel to the control track 11 in the longitudinal direction of the magnetic tape 1.
Is recorded. At the time of data reproduction, the time code detection head 33 also reproduces this time code each time one block of data is reproduced, and is read by the time code reader 34 and supplied to the servo system controller 19 and the time code memory 35. To be done. When no uncorrectable error occurs in the data during the reproduction of the data, the time code reader 34 only supplies the time code to the time code memory 35.
When an error occurs in the data and the outer error correction circuit 28 finds that the error cannot be corrected, the outer error correction circuit 28 stores the time code output from the time code reader 34 in the time code memory 35. Let Therefore, the time code memory 35 stores the time code indicating the final position of the block (helical track) on the magnetic tape 1 in which the error has occurred.

Here, when there is a block in which an uncorrectable error occurs during normal reproduction, the block is immediately read back, and all necessary blocks (blocks for one file) on the magnetic tape 1 are read. In some cases, readback is performed after reproduction. FIG. 5 shows the former case, and FIG. 6 shows the latter case.

First, the operation in the case of FIG. 5 will be described. The data of each block is recorded in the order of blocks 0, 1, 2, ... On the magnetic tape 1, and during normal reproduction, it is the same as during recording. Block 0, 1, at tape running speed
Data is reproduced in the order of 2, ... If an uncorrectable data error is detected in the block 2 during such normal reproduction, the outer error correction circuit 28 generates an error signal ERR. Due to this error signal ERR, the time code memory 3 is then stored in the time code memory 35.
The time code output from No. 4 is stored, and at the same time, the error signal ERR is supplied to the servo system controller 19 as a readback operation start signal RBW.

Therefore, the servo system controller 19
When this read-back operation start signal RBW is received, all the data in the block 2 are reproduced, and then, as described above, the magnetic tape 1 is in the direction opposite to the normal reproduction and in the normal reproduction. The tape is run at a tape running speed of ½ or less, the time code is read from the time code memory 35, and compared with the time code reproduced by the time code detection head 33 and read by the time code reader 34. Then, when they match or close to each other, the servo system controller 19 starts the readback operation of the block 2 as described above.

By the way, when data is reproduced from a file consisting of a plurality of blocks from the magnetic tape 1 in this way, readback is carried out every time an uncorrectable error is detected from the block. It is costly and inefficient. To solve this problem, there is a method shown in FIG.

That is, in FIG. 4 and FIG. 6, it is assumed that the file consisting of blocks 0, 1, 2, 3, 4, and 5 is now data-reproduced, and blocks 1 and 3 cannot be corrected during normal reproduction. If an error occurs, the outer error correction circuit 28 generates an error signal ERR each time the error occurs, and the time code memory 35 stores the time code for each data reproduction end of these blocks 1 and 3, as described above. .

When the reproduction of the data of one file is completed, a readback operation start signal RBW is input from the input terminal 20. As a result, the servo system controller 19
Reads the last stored time code from the time code memory 35 (in this case, the time code of block 3) and compares it with the time code from the time code reader 34 until the end of the block 3 reaches the magnetic tape. 1 is rewound and the above-described readback operation of block 3 is performed. When the read back operation of block 3 is completed, the servo system controller 19 causes the time code stored in the time code memory 35 to be the penultimate time code (in this case, the time code of block 1).
Is read and the time code from the time code reader 34 is compared, and the magnetic tape 1 is rewound to the vicinity of the end of the block 1 to perform the above-described read back operation of the block 1.

There are 3 blocks in which an uncorrectable error occurs.
Even in the case of more than one, readback is performed in order from the subsequent block in the same manner.

[0051]

As described above, according to the present invention,
When a data reading error occurs, the part in which the error occurs is read again by reversing the tape running direction.
There is no need to rewind the magnetic tape before the part where it occurs, rereading can be performed quickly with the shortest tape path, and the required time can be shortened. Also, the tape running speed at that time is Since it is one-half or less,
Even if the running direction of the magnetic tape is reversed, it is possible to reproduce the data in the portion where the error has occurred. Therefore, the prompt relief of the read error can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a digital information signal recording / reproducing apparatus according to the present invention.

FIG. 2 is a diagram showing a reproduction track and a reproduction signal of a helical track in readback reproduction in the embodiment shown in FIG.

FIG. 3 is a diagram showing a recording process and an error correction process at the time of readback in the embodiment shown in FIG.

FIG. 4 is a block diagram showing another embodiment of a digital information signal recording / reproducing apparatus according to the present invention.

FIG. 5 is a diagram for explaining one specific example of the readback start timing in the embodiment shown in FIG.

FIG. 6 is a diagram for explaining another specific example of the readback start timing in the embodiment shown in FIG.

[Explanation of symbols]

 1 magnetic tape 2 control head 3 drum rotation speed detector 4 capstan rotation speed detector 5 rotating drum 6 drum motor 8 drum speed controller 9 drum phase controller 11 control track 12 capstan motor 14 capstan speed Controller 15 Capstan phase controller 18 Reference signal generator 19 Servo system controller 20 Input terminal of readback operation start signal RBW 21 Input terminal of read operation start control signal RD 22 Drum rotation phase detector 23 , 24 rotary head 26 demodulation circuit 27 inner error correction circuit 28 outer error correction circuit 29 correction buffer 30 read buffer 33 time code reproducing head 34 time code reader 35 time code memory

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiro Aizawa, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa, Ltd.Inside the Hitachi Media Visual Media Research Center (72) Inventor Toshihiro Koyama 2880, Odawara, Kanagawa Hitachi, Ltd. Factory Storage Systems Division

Claims (8)

[Claims] 1. A helical scan type digital information signal recording / reproducing apparatus for recording and reproducing information data on a helical track on a magnetic tape by a rotary head. Means for detecting an uncorrectable error of the magnetic tape, and the magnetic tape in a direction opposite to that during normal reproduction and at a lower speed than during normal reproduction, according to the detection result of the first means. It is characterized by comprising: a second means for moving the magnetic tape; and a third means for re-reading the data of the portion of the magnetic tape running the second means in which the uncorrectable error is detected. Digital information signal recording / reproducing device. 2. The magnetic recording medium according to claim 1, wherein when the first means detects the uncorrectable error during normal reproduction of a helical track, the magnetic tape is recorded after the reproduction of the helical track is completed. A digital information signal recording / reproducing apparatus, characterized in that the magnetic tape is run in a direction opposite to that in normal reproduction and at a lower speed than in normal reproduction. 3. The magnetic tape according to claim 1, wherein address information indicating a sequential position is recorded on the magnetic tape, the fourth means for reproducing the address signal, and the fourth means during normal reproduction of a helical track. When the first means detects the uncorrectable error, the fifth means stores the address signal reproduced by the fourth means at that time, and the fourth means while rewinding the magnetic tape. Means for comparing the address information reproduced from the magnetic tape with the address information stored in the fifth means, and the second means is usually provided in the vicinity where the address information matches. A digital information signal recording / reproducing apparatus, characterized in that the magnetic tape is run in a direction opposite to that during reproduction and at a lower speed than during normal reproduction. 4. The method according to claim 3, wherein the sixth means starts operation each time the normal reproduction of the helical track on which the uncorrectable error is detected by the second means on the magnetic tape is completed. Characteristic digital information signal recording / reproducing apparatus. 5. The method according to claim 3, wherein after the normal reproduction of all of the helical tracks requiring data reproduction on the magnetic tape is completed,
Means for starting operation of the digital information signal recording / reproducing apparatus. 6. The helical track according to claim 1, 2, 3, 4 or 5, wherein the rotary head is the helical track in which the uncorrectable error on the magnetic tape is detected by the second and third means. Each time reproduction scanning is performed, the data is divided from the subsequent portion to the previous portion and read again, and the read-back sequential division is rearranged to provide the original data arrangement. 7. A digital information signal recording / reproducing apparatus which performs error correction on the re-read data processed by the means of 7. 7. The reproduction data of the helical track according to claim 1, 2, 3, 4, 5 or 6, at the time of the normal reproduction, an error correction is performed on the reproduction data of the helical track each time the reproduction of the helical track is completed. A digital information signal recording / reproducing apparatus, wherein the first means detects an uncorrectable error fog. 8. The method according to claim 1, 2, 3, 4, 5, 6 or 7.
In the digital information signal recording / reproducing apparatus, the correction code for performing the error correction processing in the time axis direction which is different for each section is added to the recording information data.