JP2690690B2 - Magnetic tape unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape device, and more particularly to avoiding an error caused by a magnetic tape defect and avoiding a failure of a read / write / erase head and a head drive circuit.

[0002]

2. Description of the Related Art A magnetic tape device is used for the purpose of storing and exchanging a large amount of data because the magnetic tape used can be replaced.

The conventional magnetic tape device technology is generally described in "Latest Technology of Magnetic Recording and Magnetic Tape Device for Computers in Chapter 3 of Apparatus and Equipment" published by Sogo Gijutsu Shuppan. .

This conventional magnetic tape device will be described with reference to the drawings.

FIG. 3 is a block diagram of a first embodiment of a conventional magnetic tape device.

Conventionally, the magnetic tape device has an interface transmission / reception unit 23 for transmitting / receiving commands and data to / from the magnetic tape control device 29, and a magnetic tape device for controlling read / write / tape running operations of the magnetic tape device by the commands and data. Tape controller 21c and erase / write control circuit 12c for controlling reading / writing / erasing of data
And a write drive circuit 8 that drives writing of data according to an instruction from the erase / write control circuit 12c, an erase driving circuit 7 that drives erasing of data, a write head 2 that writes data, and erasing of data. Erase head 1 and read head 3 for reading data
An automatic gain adjustment circuit 13 for adjusting the output level of the read signal, an error correction circuit 16 for error correction, a data check circuit 20 for confirming the normality of data after error correction, and a magnetic tape 24. A reel motor 25 that drives the reel motor 25, a servo drive unit 26 that drives the reel motor 25, an air system supply unit 27 that stabilizes the traveling of the magnetic tape 24, and a tape position sensor unit 28 that monitors the position of the magnetic tape 24. Composed.

Next, the operation of this conventional magnetic tape device will be described with reference to FIG.

The interface transmitter / receiver 23 receives a data write command from the magnetic tape controller 29 and transmits the command to the magnetic tape controller 21c.

The magnetic tape control section 21c instructs the air system supply section 27 to supply air and the servo drive section 26 to start the rotation of the reel motor 25, and the magnetic tape 24 starts running.

When the magnetic tape 24 starts running, data transfer from the magnetic tape control device 29 is started and sent to the erase / write control circuit 12c via the interface transmission / reception unit 23 and the magnetic tape control unit 21c to drive the write drive. The circuit 8 is operated and the write head 2 writes data to the magnetic tape 24.

The data written on the magnetic tape 24 is read by the read head 3, the output level is adjusted to an appropriate value by the automatic gain adjustment circuit 13, and the data check circuit 20 confirms that the written data is normal.

When the write data is abnormal, it is reported to the magnetic tape control unit 21c, the magnetic tape 24 is temporarily stopped from running, the reel motor 25 is rotated in the reverse direction, and the position of the head of the abnormal position is repositioned. , The same data is rewritten or the erase head 1 erases the data at the abnormal portion, and the position of the magnetic tape 24 is advanced to rewrite the same data.

When reading data, the magnetic tape controller 29 starts the running of the magnetic tape in response to a read command, the read head 3 reads the data, and the automatic gain adjustment circuit 13 sets the output level to an appropriate value to read the data. If there is an error in the data, the error correction circuit 16 automatically corrects the read data, the data check circuit 20 confirms that the data is normal, and the data passes through the magnetic tape control unit 21c and the interface transmission / reception unit 23. It is transferred to the control device 29.

On the other hand, regarding the avoidance of the error occurrence in the magnetic tape device of this type, for example, Japanese Patent Laid-Open No. 4-248167.
As shown in the magnetic tape reproducing apparatus of the publication, when two heads are provided and one head detects a dropout, it is switched to the other head and is used for the purpose of preventing dropout during data reading. ing.

Next, the known magnetic tape reproducing apparatus will be described with reference to the drawings.

FIG. 4 is a block diagram of a second embodiment of a conventional magnetic tape device.

The operation of the conventional magnetic tape device will be described with reference to FIG.

The magnetic tape 24 is run in the direction indicated by the arrow.

The data read by the read-ahead head 30 is reproduced by the read-ahead reproducing amplifier 33, and the dropout detector 34 detects whether or not there is a dropout in the data, and drops if a dropout exists. The OUT display signal is output to the switch control circuit 38.

The first data that has passed through the dropout detector 34 is input to a first input terminal (not shown) of a switch circuit 37 after being delayed by a delay circuit 35 for a predetermined time.

The data read by the read-back head 32 is reproduced by the read-back reproduction amplifier 36, and the second input terminal (not shown) of the switch circuit 37 is used as the second data.
Is input to

The switch circuit 37 is the switch control circuit 3
Controlled by 8, the first data is output during normal reading, and if there is a dropout, the second data is selected and output.

[0023]

In the above-described conventional magnetic tape device, an error is detected by reading after writing, and if there is an error, the tape position is returned before the error portion after temporarily stopping. After rewriting or erasing a certain distance, the position where the error occurred is shifted and rewriting is performed to avoid the error portion.

Therefore, it takes time to reposition / rewrite, and when dropouts occur in a plurality of tracks at the same time, the written data cannot be detected when the tape position is returned and the position by the repositioning process cannot be guaranteed. Therefore, there is a problem in that the writing process must be stopped and must be performed from the beginning, which takes time.

Further, in the conventional magnetic tape device, when a failure occurs in the write head 2 used for writing / reading, the read head 3, and the write driving circuit 8, the writing / reading process is not performed by rewriting. There was a problem that it took a long time to process because it had to be stopped and the magnetic tape device had to be maintained.

On the other hand, in Japanese Patent Publication No. 4-248167, by providing two reading heads,
Although the dropout location is avoided, it has no effect because there is no function to recover data when there is an irrecoverable defect on the tape. There was a problem that you couldn't avoid the dropout.

[0027]

A magnetic tape device according to the present invention includes a first write drive circuit and a write head for writing normal data on a magnetic tape, and a write operation by the first write drive circuit and the write head. A first erase head for erasing data on the written magnetic tape; a first read head for reading data on the magnetic tape written by the first write drive circuit and the write head; In a magnetic tape device provided with a check means for checking data read by a read head, a dropout due to a magnetic tape defect in writing of normal data on a magnetic tape by a first write drive circuit and a write head is detected. For writing test data for writing on the magnetic tape with a second write drive circuit and write head. With a second read head for reading rare were test data, detection means for detecting a drop-out by test data Tsu read, and a second erase head to erase the detected dropout portion It is characterized by that.

The magnetic tape device of the present invention comprises a first write driving circuit and a first head means composed of a write head, a first erase head and a first read head, a second write driving circuit and a write. A second head means composed of a head, a second erase head and a second read head, a head failure detecting means for detecting a failure of the first head means, and a first head means by the head failure detecting means. A switching means for switching between the first head means and the second head means when a failure is detected ,
The second head means detects the failure of the first head means.
Write / read after repositioning to the specified location
It is characterized by continuing processing .

The magnetic tape device of the present invention is an interface transmission / reception unit for transmitting and receiving commands and data to and from the magnetic tape control device, and a magnetic tape for controlling read / write / tape running operations of the magnetic tape device by the commands and data. A control unit, an erase / write control circuit that controls reading / writing / erasing of data, a first write driving circuit that drives writing of data according to an instruction of the erase / write control circuit, and an instruction of the erase / write control circuit A first erase drive circuit that drives data erasure by a first write head, a first write head that writes data by a first write drive circuit, and a first erase that erases data by a first erase drive circuit. Read with the head, the first read head that reads the data, and the first read head. An automatic gain adjustment circuit that adjusts the output level of the signal, an error correction circuit that corrects the error of the signal whose level has been adjusted by the automatic gain adjustment circuit, and a data check circuit that confirms the normality of the data after the error correction. A reel motor for running the magnetic tape, a servo drive unit for driving the reel motor according to an instruction from the magnetic tape control unit, an air system supply unit for stabilizing the running of the magnetic tape according to an instruction from the magnetic tape control unit, and a magnetic tape A tape position sensor that monitors the position of the magnetic tape according to instructions from the controller, a write control circuit that controls writing of test data during writing according to instructions from the magnetic tape controller, and dropout detection for instructions from the write control circuit. Of the test data from the test data generation circuit that generates the test data of A second light driving circuit for driving the lump can, and a second write head for writing the test data by the second light driving circuit,
A second erase drive circuit that drives erase of test data according to an instruction from the erase / write control circuit, a second erase head that erases test data by the second erase drive circuit, and a second erase data reading test data. In the read head and the signal read by the second read head, a dropout determination circuit that determines a signal below a certain level as a dropout, and a dropout signal determined by the dropout determination circuit in the same track A dropout signal that exceeds a certain period of time is determined to be a dropout.A dropout time count circuit determines the dropout signal that occurs simultaneously on multiple tracks among the dropout signals determined by the dropout determination circuit. Dropout track counting circuit It is characterized by comprising an error control circuit for erasing the test data of the abnormal section by reporting the detected anomalies portion by the out time count circuit and drop-out track counting circuit on the magnetic tape control unit erase head.

The magnetic tape device of the present invention is an interface transmission / reception unit for transmitting and receiving commands and data to and from the magnetic tape control device, and a magnetic tape for controlling read / write / tape running operations of the magnetic tape device according to the commands and data. A control unit, an erase / write control circuit that controls reading / writing / erasing of data, a first write driving circuit that drives writing of data according to an instruction of the erase / write control circuit, and an instruction of the erase / write control circuit A first erase drive circuit that drives data erasure by a first write head, a first write head that writes data by a first write drive circuit, and a first erase that erases data by a first erase drive circuit. The head, the first read head that reads the data, and the output level of the read signal An automatic gain adjustment circuit that performs bell adjustment, an error correction circuit that performs error correction on the signal that has been level-adjusted by the automatic gain adjustment circuit, a data check circuit that confirms the normality of data after error correction, and a magnetic tape A reel motor to run, a servo drive unit to drive the reel motor according to an instruction from the magnetic tape control unit, an air system supply unit to stabilize the running of the magnetic tape according to an instruction from the magnetic tape control unit, and an instruction from the magnetic tape control unit. The tape position sensor that monitors the position of the magnetic tape, and erase /
A second write drive circuit that drives writing of test data for dropout detection according to an instruction from the write control circuit; a second erase drive circuit that drives erasing of test data according to an instruction from the erase / write control circuit; A second write head that writes test data by a second write drive circuit, a second erase head that erases test data by a second erase drive circuit, and a second read head that reads test data. When a failure occurs in the first write drive circuit, the first erase drive circuit, the first write head, the first erase head, and the first read head, the second write drive circuit and the second erase The drive circuit and the second write head and the second erase head and the second read head And a head switching circuit for obtaining, prior to
The second write head and the second erase head
And the second read head to the first write drive.
Drive circuit and the first erase drive circuit and the first erase drive circuit
A first write head and the first erase head and
Saikurai a position fine said first read head is detected malfunction
It is characterized and this <br/> to continue writing and reading process after location with.

[0031]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a first embodiment of a magnetic tape device according to the present invention.

The magnetic tape device shown in this embodiment is shown in FIG.
The magnetic tape controller 2 of the conventional magnetic tape device shown in FIG.
1c and erase / write control circuit 12c are replaced by a magnetic tape controller 21a and erase / write control circuit 12a.
A write head 5 for writing test data, a write drive circuit 10 for driving the write head 5, a test data generation circuit 14 for generating test data, and a write control circuit 17 for controlling writing of test data at the time of writing. , A read head 6 that reads test data, a dropout determination circuit 15 that determines a signal below a certain level, and a dropout time counting circuit 18 that determines a dropout that exceeds a certain time on the same track.
And a dropout track count circuit 19 for determining dropouts simultaneously occurring in a plurality of tracks, an abnormal portion detected by the dropout time count circuit 18 and the dropout track count circuit 19 and reported to the magnetic tape controller 21a. An error control circuit 22 for erasing the test data in the abnormal portion by the head 4
Has been added.

Next, the operation of the first embodiment will be described with reference to FIG.

The erase head 4, write head 5 and read head 6 are arranged in front of the tape running direction with respect to the erase head 1, write head 2 and read head 3 for writing / reading, and the magnetic tape controller 21a is arranged.
The write control circuit 17 instructs the test data generation circuit 14 to start writing the test data by the write command from the.

The test data generation circuit 14 generates test data, and the write drive circuit 10 and the write head 5 are included.
Then, the test data is written to the magnetic tape 24 without a block interval (IBG).

The written test data is read by the read head 6, and when the output level in the dropout determination circuit 15 is below a certain value, the dropout time count circuit 18 and the dropout track count circuit 19 dropout in the same track. , If the simultaneous dropout on multiple tracks exceeds a certain value,
The error control circuit 22 detects this and reports it to the magnetic tape controller 21a.

The error control circuit 22 erases the test data of the abnormal portion by the erase head 4 through the erase drive circuit 9.

Upon detection of the abnormal portion, the magnetic tape controller 21a restarts the data writing process from the erase end position of the abnormal portion.

Next, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a block diagram of a second embodiment of the magnetic tape device according to the present invention.

The magnetic tape device shown in this embodiment is shown in FIG.
The magnetic tape controller 2 of the conventional magnetic tape device shown in FIG.
1c and erase / write control circuit 12c are replaced by a magnetic tape controller 21b and erase / write control circuit 12b.
The write head 5, the write drive circuit 10, the read head 6, the erase head 4, the erase drive circuit 9, the write head 2 for writing and reading data, the write drive circuit 8, the read head 3, and the erase When a failure occurs in the head 1 and the erase drive circuit 7, the write head 5 for dropout detection and the write drive circuit 1
0, a read head 6, an erase head 4, and a head switching circuit 11 for switching to the erase driving circuit 9 are added.

Next, the operation of the second embodiment will be described with reference to FIG.

When an abnormal output is detected by the data check circuit 20 during the writing / reading process, the head
Alternatively, it is determined that the head drive circuit system has failed, and it is reported to the magnetic tape controller 21b.

The magnetic tape control section 21b instructs the head switching circuit 11 to switch the head, and performs write / read / erase of normal data, a write head 2, a write drive circuit 8, a read head 3, an erase head 1, and an erase. The drive circuit 7 is switched to the write head 5, the write drive circuit 10, the read head 6, the erase head 4, and the erase drive circuit 9, and the writing / reading process is continued after repositioning to the position where the abnormality is detected. .

[0046]

As described above, the magnetic tape device of the present invention is provided with the dropout determination circuit, the dropout time counting circuit, and the dropout track counting circuit in the conventional magnetic tape device, and the data writing / reading process is performed. In addition to the head unit for detecting the dropout, by pre-checking the quality of the magnetic tape before the data writing / reading process by the dropout detecting head unit, the repositioning process due to the data defect is not necessary, and the writing process There is an effect that the processing time can be shortened without stopping.

Further, in the magnetic tape device of the present invention, when the head switching circuit detects a failure in the circuit for performing normal data write / read processing, the head tape switching circuit switches to the circuit for dropout detection. It is possible to continue the processing and shorten the processing time.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of a magnetic tape device according to the present invention.

FIG. 2 is a block diagram of a second embodiment of the magnetic tape device according to the present invention.

FIG. 3 is a block diagram of a first embodiment of a conventional magnetic tape device.

FIG. 4 is a block diagram of a second embodiment of a conventional magnetic tape device.

[Explanation of symbols]

 1 erase head 2 write head 3 read head 4 erase head 5 write head 6 read head 7 erase drive circuit 8 write drive circuit 9 erase drive circuit 10 write drive circuit 11 head switching circuit 12a, 12b, 12c erase / write control circuit 13 automatic Gain adjustment circuit 14 Test data generation circuit 15 Dropout determination circuit 16 Error correction circuit 17 Write control circuit 18 Dropout time counting circuit 19 Dropout track counting circuit 20 Data check circuit 21a, 21b, 21c Magnetic tape control circuit 22 Error control circuit 23 Interface Transmitter / Receiver 24 Magnetic Tape 25 Reel Motor 26 Servo Drive Circuit 27 Air System Supply 28 Tape Position Sensor 29 Magnetic Tape Controller 30 Prefetch De 31 lookbehind recording head 32 head 33 lookahead reproduction amplifier 34 dropout detector 35 delay circuit 36 postreading reproducing amplifier 37 switch circuit 38 a switch control circuit

Claims (4)

(57) [Claims] 1. A first write drive circuit and write head for writing normal data on a magnetic tape, and erasing data written on the magnetic tape by the first write drive circuit and write head. A first erase head, a first read head for reading data written on the magnetic tape written by the first write drive circuit and the write head, and data read by the first read head are checked. In a magnetic tape device provided with a check means, a test data for detecting a dropout due to a magnetic tape defect is written before normal data is written on the magnetic tape by the first write drive circuit and a write head. Second write drive circuit and write head for writing, and test written on the magnetic tape A second read head for reading the data, further comprising detecting means for detecting a drop-out by said Tsu read test data, and a second erase head to erase the detected dropout portion Magnetic tape device characterized by. 2. A first head unit comprising the first write drive circuit and write head, the first erase head and the first read head, and the second write drive circuit and write head. A second head unit composed of the second erase head and the second read head, a head failure detection unit for detecting a failure of the first head unit, and the first unit by the head failure detection unit. Switching means for switching between the first head means and the second head means when the head means is detected to be defective, and the second head means is connected to the first head means.
The head was repositioned at the position where the failure was detected.
The magnetic tape device according to claim 1 , wherein the post-writing / reading process is continued . 3. An interface transmission / reception unit for transmitting and receiving commands and data to and from a magnetic tape controller, said commands,
A magnetic tape control unit that controls the reading / writing / tape running operation of the magnetic tape device according to the data, and an erase / control unit that controls the reading / writing / erasing of the data.
A write control circuit, a first write drive circuit that drives writing of data according to an instruction from the erase / write control circuit, and a first erase drive circuit that drives erasing of the data according to an instruction from the erase / write control circuit When,
A first write head that writes the data by the first write drive circuit, a first erase head that erases the data by the first erase drive circuit, and a first that reads the data. Read head, an automatic gain adjustment circuit that adjusts the level of the output level of the signal read by the first read head, and an error correction circuit that performs error correction on the signal whose level is adjusted by the automatic gain adjustment circuit. A data check circuit for confirming the normality of the data after the error correction, a reel motor for running the magnetic tape, and a servo drive unit for driving the reel motor according to an instruction from the magnetic tape control unit.
An air system supply unit that stabilizes the running of the magnetic tape according to an instruction from the magnetic tape control unit, a tape position sensor unit that monitors the position of the magnetic tape according to an instruction from the magnetic tape control unit, and a magnetic tape control unit. A write control circuit that controls writing of test data at the time of writing by an instruction, a test data generation circuit that generates test data for dropout detection by an instruction of the write control circuit, and a test data from the test data generation circuit. A second write drive circuit for driving writing, a second write head for writing the test data by the second write driving circuit, and driving for erasing the test data according to an instruction from the erase / write control circuit. A second erase drive circuit, and the test by the second erase drive circuit A second erase head that erases data, a second read head that reads the test data, and a dropout that determines a signal below a certain level among the signals read by the second read head as a dropout The dropout time counting circuit that determines a dropout signal that exceeds a certain time in the same track among the dropout signals that are judged by the dropout judgment circuit as a dropout, and the dropout judgment circuit. A dropout track count circuit that determines a dropout signal that occurs simultaneously in a plurality of tracks among the determined dropout signals as a dropout, and the dropout time count circuit and the dropout track count circuit detect the dropout signal. The abnormal part is Magnetic tape apparatus characterized by comprising an error control circuit for erasing the test data of the abnormal portion by reporting to the controller the erase head. 4. An interface transmission / reception unit for transmitting and receiving commands and data to and from a magnetic tape controller, the commands,
A magnetic tape control unit that controls the reading / writing / tape running operation of the magnetic tape device according to the data, and an erase / control unit that controls the reading / writing / erasing of the data.
A write control circuit, a first write drive circuit that drives writing of data according to an instruction from the erase / write control circuit, and a first erase drive circuit that drives erasing of the data according to an instruction from the erase / write control circuit When,
A first write head that writes the data by the first write drive circuit, a first erase head that erases the data by the first erase drive circuit, and a first that reads the data. Read head, an automatic gain adjustment circuit that adjusts the output level of the read signal, an error correction circuit that performs error correction of the signal whose level is adjusted by the automatic gain adjustment circuit, and the data after the error correction. Data check circuit for confirming normality of the magnetic tape, a reel motor for running the magnetic tape, a servo drive unit for driving the reel motor according to an instruction from the magnetic tape control unit, and a magnetic drive unit according to an instruction from the magnetic tape control unit. The position of the magnetic tape is monitored by an instruction of the air supply unit that stabilizes the running of the tape and the magnetic tape control unit. A tape position sensor unit, a second write drive circuit that drives writing of test data for dropout detection according to instructions of the erase / write control circuit, and erase of the test data according to instructions of the erase / write control circuit. A second erase drive circuit for driving; a second write head for writing the test data by the second write drive circuit; and a second write head for erasing the test data by the second erase drive circuit. An erase head, a second read head for reading the test data, the first write drive circuit, the first erase drive circuit, the first write head, the first erase head, and the first erase head. When a failure occurs in one read head, the second write drive circuit and the second write drive circuit And a head switching circuit for switching the over's drive circuit and said second write head and the second erase head and said second read head, said second write head and
The second erase head and the second lead head.
To the first write drive circuit and the first erase circuit.
Drive circuit, the first write head, and
The first erase head and the first read head are
Write after repositioning to the position where the failure is detected
A magnetic tape device characterized by continuing reading processing .