JPH0312811A - Error recovery system - Google Patents

Abstract

PURPOSE:To surely move a magnetic head to a targeted track by detecting the center position of the targeted track, stopping a magnetic tape, rewinding the magnetic tape, moving the magnetic head to the center position of the targeted track and reading data again when the error of a read signal generates. CONSTITUTION:When the error of the read signal from the magnetic head 11 occurs, the magnetic tape 19 is caused to travel as it is, and the magnetic head 11 is moved while the center position of the target track is detected from the read signal from the magnetic tape 11. Then, the magnetic tape 19 is stopped. Then, the magnetic tape 19 is rewound and the magnetic head 11 is moved to the center position of the target track, and the magnetic head 11 reads data again. When the error of the read signal depending on an off-track state generates, a probability for loading the magnetic head 11 on the target track is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an error recovery method in a data backup tape recorder or the like.

[Conventional technology]

Conventionally, in data backup tape recorders, a magnetic head writes and reads data on 9 tracks, 15 tracks, or 18 tracks on a magnetic tape. and a reading section in which a winding is wound around a core having a reading gap wider than a writing gap are used, which are integrally arranged in the running direction of the magnetic tape for one channel.

During a data writing operation, a reference signal is written in the central track of the magnetic tape, which serves as a reference, by the writing section of the magnetic head, and then data is written in this track and other tracks in a fixed order. In data reading, when a magnetic tape is inserted, a reference signal is first read from the magnetic tape by the reading unit of the magnetic head, and based on this reference signal, an arbitrary target track on the magnetic tape is sought, and the magnetic head reads from this target track. )" 11 to read the data. When an error occurs in the data from this reading section, the magnetic tape is stopped immediately, and then the magnetic tape is rewound and moved a certain distance to the magnetic /\no1. The magnetic spatula 1 is then moved to the "-" side or downward and then run again to read the data again using the reading section for the magnetic spatula 1.

Recently, a data backup tape recorder has been proposed in which data is written and read on a magnetic tape using a magnetic spatula 1 at a high density of 26 tracks. In this tape recorder, as shown in FIG.
1 is an erasing part in which a winding is wound around a core having an erasing gap 12, and two writing parts in which two windings are wound around each core having two writing gaps; 3a and 13b;
Two reading sections each having a winding wound around each core having reading gaps 14a and 14b are integrally provided. An input section having old input gaps 13a arranged in a line in the forward running direction of the magnetic tape and a reading section having an eJl pickup gap l/l a are the If input section and the reading section of the lower channel. 31), which are arranged in a line in the reverse running direction of the magnetic tape.
The reading part having the knee cutting part and the reading gap +4b constitutes the reading part and the reading part of the second channel, and the reading part and the reading part for these two channels are 7::The reading part and the reading part 1" for these two channels. The magnetic tapes are arranged at a predetermined pitch in a direction perpendicular to the running direction of the magnetic tape.

The width of the write core is 178μm)1, and the width of the read core is 267μm compared to the conventional width.
It is considerably narrower than the M.

This data backup tape recorder is 61 yen.
II()1'(lle(Hjn Of
1'ape), IEOT (End Of Tape), P
, 1l(lEar]y Warnjng), LP(Lo
A magnetic tape 19 is used that covers each of the marks 15 to 18 (ad Poi, nt). Marks 15 to 18 are holes drilled in the magnetic tape 11, and there are magnetic holes in the center of each of the north and lower parts of the magnetic tape j9, which are divided into two in the upper direction perpendicular to the running direction. They are arranged parallel to the running force direction of the tape 19. BOT15. EOT] 6 are provided at both ends of the magnetic tape 19, and IE], 7. LP
11 is located at the center of the upper part of the magnetic tape 19, and BOTI5. It is provided a certain distance inside from r40T16. This data backup tape recorder runs the magnetic tape 19 in the right direction during data writing operation, and operates the writing section 71j of the lower channel of the magnetic head 11, which has a writing gap 13a, to write the upper side of the magnetic tape 19. B in the center of the section
After writing a reference signal of a specific frequency fo to the reference signal area 20 inside the OT] 5, data is written to the data area 10. Next, this data backup tape recorder runs the magnetic tape 19 to the left and operates the writing unit having the gap 13b for inserting the upper channel in the magnetic tape 11 to write the lower part of the magnetic tape 19. A specific frequency f' is placed in the reference signal area 1 or 21 inside the central BOT 15.

After writing the reference signal, data is written in the data area t1. Next, the data backup tape recorder runs the magnetic tape 19 to the right in one direction/＼constantly, and writes the magnetic tape 19 in the writing section having the writing cap J:l a of the lower channel in the magnetic/＼Fl]. r30T in the upper part]
After writing the reference signal of the specific frequency f1 to the reference signal area 22 inside the −5, the data area 14
, 2 - blacken the data, run the magnetic tape 19 in the left direction 7N, and operate the write unit with the writing gear 131 in the upper channel of the magnetic tape 11) under the magnetic tape 19. B in the side part
After writing a reference signal with a specific frequency f°1 into the reference signal area 23 inside O7'15, data is written into data areas 1 and 3. Similarly, the data backup tape recorder runs the magnetic tape I9 alternately to the right and to the left while moving the magnetic head 11 to the reference signal areas 24, 25, . ...31 and data area t'l, l;5. ...t 1. ], and while the magnetic tape 19 is running alternately in the right and left directions, the upper and lower parts of the magnetic tape 19 are recorded by the magnetic head 11. Data area L] 2, t, ]
3,...1.Data 1 on 2/1? Finally, the magnetic tape 19 is run rightward to write a reference signal and data of a specific frequency f'□ into the reference signal area 32 and data area t25. In addition, the data hack-up tape recorder has data read operation 11.
．． 1'', the magnetic head 11 is moved in a direction perpendicular to the running force direction of the magnetic tape 19 to seek from 1'' mark i to the rack (the track in which the data to be read is written);
Magnetic spatula I from the data area of this target track: ]
Read gap I in I,'l fl or 1
4(a) A) Read the data by the reading section. In this case, if the f-1 mark track is on the lower part of the magnetic tape 19, the magnetic tape] 9 is run in the right direction, data is read out by the reading section having the reading cap 14a, and the data is read out from the +1 mark track or the magnetic tape. If the magnetic tape 19 is located on the side of the tape 19, the magnetic tape 9 is moved to the left and the data is read out by a reading section having a reading gap 71b.

[Problem to be solved by the invention]

2. In the data backup tape recorder, the magnetic head reads data from the rack to target 1 on the magnetic tape while the magnetic tape is running, and if an error occurs in the read signal from the magnetic head, the magnetic tape is immediately removed. After the magnetic tape is stopped, the magnetic tape is rewound, the magnetic head is moved upward or downward by a certain distance, and then the magnetic tape is run again to read the data again using the reading section of the magnetic spatula. However, when writing and reading data at a high density of 26 tracks using a magnetic head that has two channels of writing and reading sections, the width of the reading section of the magnetic head becomes narrower than the width of the writing section. Therefore, if a read signal error occurs due to an off-1-rack condition in which the magnetic head is off the target track on the magnetic tape, the magnetic head will not move even if the magnetic head is moved a certain distance upward or downward. The probability of getting on the center of the target track is very low.
Error recovery operations such as moving the magnetic head, rewinding and rereading the magnetic tape may be repeated many times, and heart errors (mechanical errors) are likely to occur.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks and provide an error recovery method that can reliably place the magnetic head on the rack at target 1 when a read signal error occurs due to the off-1-rack state in a tape recorder. shall be.

[Means to solve the problem]

To achieve the above object, the present invention provides a tape recorder in which a magnetic head writes data to and reads data from a plurality of tracks on a magnetic tape. When an error occurs in the read signal from the magnetic head during reading, the center position of the target track is detected from the read signal from the magnetic head while the magnetic tape is running as it is and the magnetic head is moved. The magnetic tape is stopped, the magnetic tape is rewound, the magnetic head is moved to the center position of the target track, and the magnetic/\rad data is read again.

〔Example〕

FIG. 2 shows a circuit configuration of an example of a data backup tape recorder to which the present invention is applied.

This data backup tape recorder uses a magnetic head to write and read data on a magnetic tape at a high density of 26 tracks, and uses the magnetic head 11 and magnetic tape 19 described above. magnetic head 1
The read signal from the reading section 33 having the reading gaps 14a, 14b at 1 is amplified by the amplifier 34, the envelope is detected by the envelope circuit 35, and the analog/digital (A/ D) Input to the converter 37. Further, the hall sensor circuit 38 detects the holes 15 to 18 in the magnetic tape moon and inputs the detection signals to the CI) U 36, and the track designation circuit C) 9 sends a rack signal to 1 indicating the track designated by the operator. Input to CPU 36. The write circuit 40 includes an erase section having an erase gap 12 and a write gap 13 according to a control signal from the CPU 36.
The stepper 4z selectively drives the writing section 41 having the drive circuit 4a and stepper 4z, which moves the magnetic head 11 in a direction perpendicular to the running direction of the magnetic tape.
:3 drives the stepper 42 in response to a control signal from the CPU 36.

The motor 44 is driven by a drive circuit 45 to run the magnetic tape 19, and the drive circuit 45 drives the motor 44 in response to a 1i1 control signal from the CPU 36. This drive circuit 45 has a tacho generator that detects the rotation of the motor 44, and outputs pulses from the tacho generator to C.
Output to PU36.

During the data write operation, the CPU 36 causes the drive circuit 45 to drive the motor 44 to run the magnetic tape 19 in the right direction, and writes the write gap 1 in the lower channel of the magnetic head 11 via the lie I circuit 40.
3a is operated to write a reference signal of a specific frequency fo into the reference signal area 20 inside the reference signal area 11OT] 5 at the center of the upper part of the magnetic tape 19, and then data is written into the data area to. Next, the CPtJ36 moves the magnetic tape 19 to the left and operates the 11 entry section having the writing gap (I) of the second side channel to apply the magnetic head 11 to the lower side of the magnetic tape I9. After a reference bracket of a specific frequency f11 is written in the reference signal area 21 inside the central BOT]5, data is written in the data area t1. Next CPU3
6 runs the magnetic tape 19 rightward to the magnetic head 1.
Lower channel writing gap 13a in 1
A reference signal with a specific frequency ■゛□ is written in the reference signal area 22 on the inner side of the magnetic tape 19 at the second side portion of the magnetic tape 19 using a writing section having a The tape] 9 is run to the left and the magnetic head 11 has a write gap 13b on the second side channel. After a specific frequency f and a reference signal are written in the area 23, data is written in the data area L3.

Similarly, the CPU 36 moves the magnetic tape 19 to the right.

1 Reference signal areas 24, 25 . ...;31 and data area t4. t5. A reference signal and data of a specific frequency f□ are written to t1.1, and the magnetic head 11 writes the -J- side of the magnetic tape 19 while running the magnetic tape 19 alternately to the right and left. Each data area t12, 1:13. ...(,2
Finally, the magnetic tape 19 is run rightward to write the reference signal and data of the specific frequency f1 into the reference signal area 32 and data area L25.

In addition, during data reading operation, the CPU 36 causes the drive circuit 43 to drive the stepper 42 according to the data of the target 1 to rack positions in the memory in response to the 1-rack signal from the track designation circuit 21, thereby moving the magnetic head 11 onto the magnetic tape. ] 9 in a direction perpendicular to the running direction to seek the target track in which data to be read is written, and from the data area of the 4th track 1 to rack 14, there is a read gap 148 or 14b in the magnetic head 11. The readout unit reads data, and the readout signal is taken in via the amplifier 34 and the envelope circuit 35.
The A/D converter 37 performs A/+1 conversion and processing. In this case, if the target track is on the lower part of the magnetic tape 19, the magnetic tape 19 is moved to the right and the data is read by the reading unit having the reading gap 14a, so that the target track is on the upper part of the magnetic tape 19. If the magnetic λ tape 19 is located in the area, the magnetic λ tape 19 is moved to the left to cause the reading unit having the reading gap 14b to read the data.

The CPU 36 inputs the read signal from the reading section of the magnetic head 11 to the amplifier 34. 2. The read signal is taken in through the envelope circuit 35 and an error check is performed on the read signal.
When an error occurs in the read signal, the OP tJ 36 positions the magnetic head 11 by causing the drive circuit 43 to drive the stepper 42 while the drive circuit 45 continues to drive the motor 44 . In positioning the magnetic head 11, the CPU 36 sequentially performs 16 microsteps 0 to 15 as shown in FIG. 4 one step at a time until there is no error in the read signal. First, microstep O is executed to perform on-track seek to position the magnetic head 11 at the center position of the 11-mark track on the magnetic tape 19. In this micro step 0, the C, PU 36 causes the drive circuit 4:3 to drive the stepper 42 to move the magnetic eight 1-11 across the target track TR and move the magnetic head 11.
The read signal from the reading section of the amplifier 34. The point between points A and B (1/2
), the center position of the target track TR on the magnetic tape 19 is detected. and CPU36
By causing the drive circuit 43 to drive the stepper 42, the magnetic head]1 is moved to the center position of its target 1-rack'[R. Next, the CPtJ 36 causes the drive circuit 45 to stop the motor 44 to stop the magnetic tape 19, causes the drive circuit 45 to drive the motor 44, and rewinds the magnetic tape 19 by a predetermined amount.
The reading section of the magnetic head 11 is caused to read the data again while running in the same direction as when reading the previous data. The tape controller 1-roller 46 is the magnetic head 1.
The read signal from the reading unit 1 is sent to the amplifier 34. VFO
47, the read signal is checked for errors, and if there is an error in the read signal, the next microstep is executed. CI) U36 performs the same operation as the microstep O to remove the magnetic helad 11.
is moved to the center position of the [''] track rR, and the magnetic tape 19 is stopped by causing the drive circuit 45 to stop the motor 44. Next, the CPU 36 drives the drive circuit 45
After rewinding the magnetic tape 19 by a predetermined amount by driving the motor 44, the reading section of the magnetic head 11 is caused to read data again while running the magnetic tape 19 in the same direction as when reading the previous data. The tape controllers 1 to 0-46 take in read signals from the readout section of the magnetic head 11 via the amplifier 34 and VFO 47, and perform error checking on the read signals.

5 If there is an error in the read signal during this error check,
I) Execute the next microstep 2 on the TJ 36, that is, the CPU 36 causes the drive circuit 43 to drive the stepper 42 to move the magnetic head J1 to the magnetic tape 19.
If it is a magnetic tape with 9 tracks, it is moved upward by 25 .mu.n, and if it is a magnetic tape with 19, 15, 18 or 26 tracks, it is moved upward by 12.5 .mu.I. Next, the CPU 36 causes the drive circuit 45 to stop the motor 44 to stop the magnetic tape 19, causes the drive circuit 45 to drive the motor 44 to rewind the magnetic tape 19 by a predetermined amount, and then moves the magnetic tape 19 to the previous position. The reading section of the magnetic head 11 is caused to read data again while traveling in the same direction as when reading data. and tapecon 1
The ~〇-ra 46 takes in the read signal from the reading section of the magnetic helad 11 via the amplifier: 34° VFO 46 and performs an error check for the read signal equal to 1-''j, and similarly checks for errors in the read signal. Each stage of microsteps 3 to 15, stopping and rewinding of the magnetic tape 19, re-reading operation, and error checking are repeated until all are exhausted.

If the magnetic tape j9 is a 9-track magnetic tape as shown in FIG. Straddle"2 side, 50μm11 below, 75μm1straddle above, 75μm below, ]OOμm"2 side, 1
00 μm below, ] 25 /J, Ill-
L side, 125 μm lower side, ]50 μm upper side, 15
Lower side with 0μmn, upper side by 175μm, 175μm
the magnetic tape 19 is moved downward by 1.
If the magnetic tape is a 51- rack, an 18+ rack, or a 26-track magnetic tape, the drive circuit 43 drives the stepper/12 to move the magnetic head 11 to the 12-track.
゜5μm11 below, 25μI11 above, 25μ
In only lower side, 37.57z m only' second side, 37.5
7zm below, 50μm only"-4 side, 50μIll
Lower side, 62.5μm1 upper side, 62.5μ) 11
on the lower side, 75μIl on the side, 75μ+n on the lower side, 87゜5μIl+ on the upper side, 87.5μn1 on the T side.
: Move each side. Tailor 0 Con 1 - Roller 4
6: If there is no error in the read signal in the second error check, stop the microstep, stop and rewind the magnetic tape 19, read the data, and perform an error check.Also, even if microstep 15 is executed, there is no error in the read signal. If there is, it is determined that there is a hard error.

In this example, when an error occurs in the read signal from the magnetic head 11, the magnetic tape 19 is run as it is and the magnetic head 11 is moved while the magnetic tape 19 is being moved.
After detecting the center position of the target track from the read signal from the magnetic tape 19, the magnetic tape 11 is stopped.
At the same time, the magnetic head 11 is moved to the center position of the target track, and the magnetic head 11 re-reads the data, thereby performing error recovery. The probability that the target truck will be placed on the target truck becomes extremely high, and the number of repetitions of error recovery operations and hard errors are reduced. Furthermore, since the 16 microsteps O to 15 are sequentially executed during error recovery, it is highly possible to avoid data errors caused by pinholes or the like on the magnetic tape 19.

〔Effect of the invention〕

As described above, according to the present invention, in a tape recorder in which a magnetic head writes data to and reads data from a plurality of tracks on a magnetic tape, the magnetic head reads data from a target track on the magnetic tape while the magnetic tape is running. When an error occurs in the read signal from the magnetic head, the center position of the target track is detected from the read signal from the magnetic head while the magnetic tape is running as it is and the magnetic head is moved. The tape is stopped, the magnetic tape is rewound, the magnetic head is moved to the center position of the target track, and the data is re-read by the magnetic head, so when an error in the read signal occurs due to an off-track state. The magnetic head can be reliably placed on the target track.

[Brief explanation of drawings]

Fig. 1 is a flowchart showing the present invention, Fig. 2 90 is a block diagram showing the circuit configuration of an example of a tape recorder for data backup to which the invention is applied, and Fig. 3 is a processing flow of the CPU in the tape recorder. Flowchart 1, which shows a part of the process, FIG. 4 is a diagram showing microsteps in the same tape recorder, FIGS. 5(a) and (b) are diagrams for explaining the error recovery operation of the same tape recorder, and FIG. The figure is a plan view showing an example of a magnetic tape, and FIG. 7 is a front view showing an example of a magnetic head. 33... Reading unit, 36... CPU, 42...
Stepper, 44...motor. moat

Claims (1)

[Claims] In a tape recorder in which a magnetic head writes and reads data on a magnetic tape in multiple tracks, the magnetic head reads data from a target track on the magnetic tape while the magnetic tape is running, and the data is read from the magnetic head. When a signal error occurs, the magnetic tape is continued to run, the magnetic head is moved, and the center position of the target track is detected from the read signal from the magnetic head, and then the magnetic tape is stopped and the magnetic tape is wound. The error recovery method is characterized in that the magnetic head is moved to the center position of the target track, and the data is reread by the magnetic head.