JPH07311901A - Magnetic tape unit - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to a magnetic tape device, and realizes cost reduction of the magnetic head assembly without increasing the number of effective tracks of the magnetic head assembly with respect to the increase in the number of tracks of the magnetic tape. The purpose is to do. A magnetic head assembly 16 including a plurality of head chips 28 and 29 each having a recording element / reproducing element, a head moving mechanism (such as a microstep motor 22) for moving the magnetic head assembly, and a nonvolatile memory 8A. , MPU6, etc. are provided, and the non-volatile memory stores information on defective elements that do not satisfy predetermined characteristics, information on elements used for normal recording / reproduction, and movement information of the magnetic head assembly when a defective element exists. The MPU 6 judges the defective element from this information, and moves the magnetic head assembly so that recording / reproducing can be performed with the normal element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head assembly having a plurality of recording elements for performing recording and reproduction on each track (multitrack) of a magnetic tape, and a reproducing element, and the magnetic head assembly. Is provided with a head moving mechanism for moving the magnetic tape in the track width direction of the magnetic tape, and the magnetic head assembly is moved in the track width direction of the magnetic tape to cause the magnetic tape to run in the forward direction and the reverse direction. For trucks,
The present invention relates to a recordable / reproducible magnetic tape device.

In recent years, in a magnetic tape device, due to a demand for improvement of recording density on a magnetic tape, the recording density is
Increasingly denser. Along with this, the mainstream of magnetic heads is shifting to thin film magnetic heads, and it is necessary to achieve narrower tracks.

[0003]

2. Description of the Related Art Conventionally, a magnetic head assembly provided in a magnetic tape device is provided with the same number of recording elements or reproducing elements as the number of tracks (multitracks) of a magnetic tape as a recording medium. However, the number of recording elements and the number of reproducing elements in the magnetic head assembly are also increasing in response to the increase in recording density, particularly the increase in the number of tracks due to the decrease in track width.

The magnetic head assembly has at least two head chips in the running direction of the magnetic tape, and the head chips have recording elements, reproducing elements for the number of tracks of the magnetic tape in the track width direction. Or both elements are formed.

The above-mentioned head chip is a recording element, a reproducing element, and the elements extracted from these elements on a ferrite substrate such as Mn-Zn ferrite or Ni-Zn ferrite, or a substrate such as AL ₂ O ₃ TiC (Altic). The terminal portion is formed by a thin film process technique such as sputtering, vapor deposition, plating, and processed into a predetermined shape.

[0006]

SUMMARY OF THE INVENTION The above-mentioned conventional device has the following problems. (1): 1 as the number of tracks on the magnetic tape increases
The number of recording elements and reproducing elements included in one head chip increases. Then, as the number of recording elements and reproducing elements of one head chip increases, the number of defective elements that do not satisfy the predetermined characteristics increases due to variations in manufacturing and the like.

(2): Even if one recording / reproducing element in the head chip is defective, the head chip becomes defective, so that the number of elements formed on one head chip, that is, , As the number of tracks increases,
The manufacturing yield of head chips deteriorates. As a result, the cost of the magnetic head assembly is increased.

The present invention solves such a conventional problem and realizes cost reduction of the magnetic head assembly without increasing the number of effective tracks of the magnetic head assembly with respect to the increase in the number of tracks of the magnetic tape. The purpose is to do.

Further, according to the present invention, even if the recording element / reproducing element of the head chip has a defective element and the number of tracks on the magnetic tape increases, it is possible to sufficiently cope with the recording / reproducing on the magnetic tape. The purpose is to

[0010]

FIG. 1 is a diagram for explaining the principle of the present invention. In FIG. 1, 6 is an MPU (microprocessor), 8A is a non-volatile memory, 15 is a microstep motor drive circuit, and 16 is a magnetic field. Head assembly, 22
Is a micro step motor, 28 and 29 are head chips, and 36 is a magnetic tape.

In order to solve the above problems, the present invention provides a magnetic tape device for each track of the magnetic tape 36.
A plurality of head chips 28, 29 for recording / reproducing
And a head moving mechanism (microstep motor 22, etc.) for moving the magnetic head assembly 16 in the track width direction (Y / −Y) of the magnetic tape 36, and the microstep motor 2
A microstepping motor drive circuit 15 for driving 2;
The nonvolatile memory 8A, the MPU 6 and the like are provided.

The head chips 28 and 29 are respectively provided with the magnetic tape 36 in the track width direction (Y /
-Y), recording elements and reproducing elements are alternately arranged, and with respect to the running direction (X / -X) of the magnetic tape 36,
The recording element and the reproducing element are arranged adjacent to each other as a set of elements.

Further, the nonvolatile memory 8A has a defective head table storing positional information of defective elements which do not satisfy predetermined characteristics, and recording / reproducing element positions (normal recording) corresponding to each track of the magnetic tape. / Head position information table storing the position information of the element used for reproduction and the movement information of the magnetic head assembly when there is a defective element is stored in advance.

[0014]

The operation of the present invention based on the above construction will be described with reference to FIG. When the host issues a command to instruct recording / reproduction, the magnetic tape controller (MTC) issues an instruction to the MPU 6 according to the content of the command. M
The PU 6 drives the magnetic head assembly 16 according to an instruction from the magnetic tape controller (MTC) to record / reproduce data on / from the magnetic tape 36.

At the time of recording / reproducing, first, the MPU 6
Refers to the defective head table of the non-volatile memory 8A, and refers to a recording element normally used for recording / reproducing of a magnetic tape.
It is determined whether the reproducing element is defective. As a result, if the element is not defective, the recording / recording is performed as it is by the normally used element.
Play.

However, if the corresponding recording element / reproducing element is a defective element, the MPU 6 refers to the head movement information table of the non-volatile memory 8A, and when the element is defective, the position of the element to be used instead, Direction of movement of the magnetic head,
Obtain information on the amount of movement.

When the element is defective, the MPU 6 sends the microstep motor drive circuit 15 instruction data corresponding to the obtained moving direction and moving amount of the magnetic head. The micro-step motor drive circuit 15 sends a drive pulse to the micro-step motor 22 based on the instruction data to drive the micro-step motor 22 so that the magnetic head assembly 16 moves in the track width direction (Y /-) of the magnetic tape. Y). In this way, the recording element / reproducing element is positioned on a predetermined track of the magnetic tape and recording / reproducing is performed.

At the time of recording / reproducing, recording / reproducing is simultaneously performed on a plurality of tracks by one tape running. For example, when the magnetic tape has 72 tracks, 18 tracks are simultaneously recorded / reproduced, and the X direction is -X.
72 times by running the magnetic tape twice in each direction.
Records / plays back tracks.

As described above, the magnetic head assembly is moved in the track width direction (Y / -Y) of the magnetic tape and the magnetic tape is run in the forward direction (X) and the reverse direction (-X). Recording / reproducing can be performed on all tracks of the magnetic tape.

In this way, even if the defective element exists in the head chip, the information of the defective element is stored in advance,
By moving the magnetic head assembly based on this information, it is possible to always perform recording / reproduction using an element that is not a defective element (normal element).

Therefore, even if there is a defective element in the head chip of the magnetic head assembly, it can be used, so that the cost of the magnetic head assembly can be reduced.

Further, even if there is a defective element in the recording element / reproducing element of the head chip and the number of tracks on the magnetic tape increases, it is possible to sufficiently cope with recording / reproducing on the magnetic tape.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 27 are views showing an embodiment of the present invention. In FIGS. 2 to 27, the same parts as those in FIG. 1 are designated by the same reference numerals.

Further, 3 is a magnetic tape unit (MTU), 4
Is a magnetic tape controller (MTC), 5 is a data control unit, 7 is a RAM (Random Access Memory), and 8 is an E
EPROM (Electrically Erasable Programmable)
Read Only Memory), 9 and 12 are recording signal drive circuits,
Reference numerals 10 and 13 are reproduction signal amplifier circuits, 11 is a reproduction signal drive circuit, 14 is an envelope detector, 19 is a write head,
20 is a read head, 21 is a servo head, 22 is a micro step motor, 23 is an encoder, 25 is a mounting frame, 26 is a head base, 27 is a head frame, 31
Is a connector fixing plate, 32 is a connector, 33 is a cleaner,
34 and 35 are roller guides, 40 is a servo track, 4
1 is a mounting plate, 42 is a magnetic head, 43 is a linear bearing, 44 is a support shaft, 45 is a rotation stop mechanism, 46 is a rotation shaft,
Reference numeral 47 is a gear mechanism, and 49 to 54 are head chips.

(Explanation of the First Embodiment) §1: Description of the device of the first embodiment ... See FIG. 2 FIG. 2 is a block diagram of the device of the first embodiment. Hereinafter, the apparatus (magnetic tape subsystem) of the first embodiment will be described with reference to FIG.

This device (magnetic tape subsystem) is
It is composed of a magnetic tape unit (MTU) 3 and a magnetic tape control unit (MTC) 4. The magnetic tape unit (MTU) 3 includes a data control unit 5, a recording signal drive circuit 9, a reproduction signal amplification circuit 10, a reproduction signal drive circuit 11, a recording signal drive circuit 12, a reproduction signal amplification circuit 13, and an envelope detection. The unit 14, the micro step motor drive circuit 15, the magnetic head assembly 16, the micro step motor 22, the encoder 23 and the like are provided.

Further, the data control unit 5 has an MP
A U6, a RAM 7, and an EEPROM 8 are provided, and the magnetic head assembly 16 is provided with a write head 19, a read head 20, a servo head 21, and the like. Functions and the like of the above-mentioned respective parts are as follows.

(1): The data control section 5 performs various controls when recording / reproducing (reading / writing) data on the magnetic tape. (2): The recording signal drive circuit 9 is a circuit for driving a recording signal. The recording signal drive circuit 9 sends a recording signal (data signal) to the write head 19 based on the recording signal sent from the magnetic tape controller (MTC) 4 to record the data on the magnetic tape.

(3): The reproduction signal amplifier circuit 10 amplifies the read signal (data signal) read by the read head 20. (4): The reproduction signal drive circuit 11 is the reproduction signal amplifier circuit 10
Of the output signal (data signal) is transferred to the magnetic tape controller 4.

(5): The recording signal drive circuit 12 uses the MPU 6
The servo information is recorded on the magnetic tape by driving the servo head 21 based on the servo information (recording signal) instructed by the.

(6): The reproduction signal amplifier circuit 13 amplifies the servo signal (servo information read signal) read by the servo head 21. (7): The envelope detector 14 is the reproduction signal amplifier circuit 1.
The envelope is detected from the output signal of No. 3.

(8): Microstep motor drive circuit 1
Reference numeral 5 drives the microstep motor 22 in the instructed direction (the track width direction of the magnetic tape) based on the instruction of the MPU 6.

(9): The magnetic head assembly 16 includes a write head 19, a read head 20, and a servo head 21.
Etc. are integrated (see FIG. 3 for details). (10): The microstep motor 22 is driven by the microstep motor drive circuit 15 to move the magnetic head assembly 16 in the track width direction of the magnetic tape.

(11): The encoder 23 encodes the rotation detection signal of the microstep motor 22. (12): The MPU 6 performs various controls (recording / reproducing control, etc.) in the magnetic tape unit (MTU) 3 based on an instruction from the magnetic tape control unit (MTC) 4.

For example, the MPU 6 reads out the information (information on the defective head table and the information on the head movement information table) stored in the EEPROM 8 of the data control unit 5 at the time of turning on the power source, downloads it to the RAM 7, and thereafter. , RAM 7 is used for control (described later).

(13): The RAM 7 is a memory accessed by the MPU 6 and is used by the MPU 6 for work. In addition, in the RAM 7, as described above,
The information stored in the EEPROM 8 is downloaded.

(14): In the EEPROM 8, a defective head information table and a head movement information table (which will be described later) are set in advance, and the magnetic head is inspected in these tables at the time of factory shipment. , The result data (information) is stored.

(15): The write head 19 is a head for writing data on the magnetic tape. The write head 19 is a general term for a plurality of recording elements (write elements).

(16): The read head 20 is a head for reading data from the magnetic tape. The read head 20 is a general term for a plurality of reproducing elements (read elements).

(17): The servo head 21 is a head for writing servo information (control information for performing servo control) on the magnetic tape and for reading control information from the magnetic tape. The servo head 21 is a generic term for a pair of recording elements and reproducing elements.

§2: Description of magnetic head assembly
-Refer to FIG. 3 and FIG. 4. FIG. 3 is a perspective view of the magnetic head assembly, and FIG. 4 is a sectional view taken along line MN of FIG. The magnetic head assembly will be described below with reference to FIGS. 3 and 4.

As shown in FIG. 3, on the mounting frame 25,
A head base 26 is provided so as to be movable in the Y and -Y directions shown, and a head frame 27 is fixed on the head base 26.

A magnetic head composed of a plurality of head chips 28, 29 is fixed to one side of the head frame 27, and a connector fixing plate 31 is fixed to the other side.
Is provided. Further, a connector 32 for making an electrical connection is coupled to the connector fixing plate 31.

A magnetic head comprising the head frame 27 and the head chips 28 and 29, and the connector fixing plate 3
1, the connector 32 and the like constitute the magnetic head assembly 16.

A cleaner 33 is provided adjacent to the magnetic head assembly 16, and roller guides 34, 35 for guiding the magnetic tape are provided on both sides of the magnetic head assembly 16.

The magnetic tape 36 is guided by the two roller guides 34, 35, and the head chip 28,
29, while contacting the cleaner 33, the X direction in the drawing, and-
Run in the X direction.

As shown in FIG. 4, a mounting plate 41 is provided below the head base 26. The mounting plate 41 has a microstep motor 22, a linear bearing 43, and a rotation stopping mechanism. 45 and the like are provided.

A support shaft 44 is fixed to the head base 26, and the support shaft 44 is inserted into a linear bearing 43. Inside the linear bearing 43, the Y direction and the -Y direction in the drawing are shown. It is configured to be able to move to.

On the other hand, the microstep motor 22 has
A rotary shaft 46 is provided, and a gear mechanism 47 is provided on the rotary shaft 46 and a part of the head base 26. As the gear mechanism 47, for example, a rack, a pinion mechanism, a screw gear mechanism, or the like is used.

When the rotary shaft 46 is rotated by the micro step motor 22, the head base 26 is moved (elevated) in the Y direction or -Y direction in the figure by the gear mechanism 47 according to the rotating direction. With the movement of the head base 26, the magnetic head assembly also moves (elevates) in the Y direction or the −Y direction. Therefore, the magnetic head also moves in the Y direction or the -Y direction in the figure.

For example, when the microstep motor 22 is driven, depending on the direction (+ or −) of the driving pulse of the microstep motor 22 and the number of pulses, Y,
Alternatively, the movement in the −Y direction is determined.

When the micro step motor 22 is driven, the MPU 6 moves in the moving direction of the magnetic head assembly,
And the amount of movement (track pitch in the Y / -Y direction) are determined, then, with respect to the microstep motor drive circuit 15,
Instruction data corresponding to the movement amount is sent.

The microstep motor drive circuit 15 creates the drive pulse in accordance with the instruction data from the MPU 6 and sends the drive pulse to the microstep motor 22. Thereby, the micro step motor 22
Rotates to move the magnetic head assembly.

In this case, in the MPU 6, the encoder 23
An accurate movement control of the magnetic head assembly is performed by detecting a signal (encoded from the rotation detection signal of the microstep motor 22) output from the magnetic head assembly.

§3: Description of magnetic head--see FIG. 5 FIG. 5 is an illustration of a magnetic head. The magnetic head constituting the magnetic head assembly will be described below with reference to FIG.

As shown in the figure, the magnetic head 42 is composed of two head chips 28 and 29 arranged adjacent to each other. Recording elements for recording data on the magnetic tape and reproducing elements for reproducing data from the magnetic tape are alternately arranged on the head chips 28 and 29, respectively, in the track width direction (Y / -Y) of the magnetic tape 36. 36) are arranged in each direction.

That is, the head chip 28 has recording elements W ₁ , W ₃ , W ₅ , W ₇ , W ₉ ... W ₇₁ and reproducing elements R ₂ , R ₄ , R ₆ , R ₈ , R _10. ... R ₇₂ are alternately arranged in the track width direction of the magnetic tape 36, and the head chip 29 has recording elements W ₂ , W ₄ ,
W ₆ , W ₈ , W _10, ... W ₇₂ and reproducing elements R ₁ , R ₃ ,
R ₅ , R ₇ , R ₉ ... R ₇₁ are magnetic tapes 3 respectively
6 are alternately arranged in the track width direction.

Of the recording elements and reproducing elements of the head chips 28 and 29, the running direction (X
(/ -X direction), a recording element and a reproducing element, which are arranged adjacent to each other, form a set, and writing and reading (write / read) can be performed in the same track on the magnetic tape. There is.

For example, the track T of the magnetic tape 36₁To
On the other hand, the recording element W₁And reproducing element R₁Is a set of elements
It corresponds, and the track T₁Against the record element
Child W ₁Recording with the playback element R₁To be able to play with
ing.

Further, the track T of the magnetic tape 36₂Against
Then, the recording element W₂And reproducing element R ₂As a set of elements
The truck T₂Against the recording element
W₂Recording with the playback element R₂Now you can play with
There is.

The magnetic tape (recording medium) 36 has T ₁ , T
₂ , T ₃ , T _4, ... T ₇₁ , T ₇₂ , 72 tracks, one of which is used as a servo track.

Recording / reproduction of the magnetic tape 36 is performed simultaneously on a plurality of tracks by one tape running. In this example, 18 tracks are simultaneously recorded or reproduced, and all 72 tracks are recorded or reproduced by running the magnetic tape twice each in the illustrated X direction and -X direction.

§4: Description of servo head and servo track--see FIG. 6 FIG. 6 is an explanatory diagram of the servo head and servo track.
The servo head and the servo track will be described below with reference to FIG.

As described above, the track structure of the magnetic tape 36 is 72 tracks, and one of the tracks is used as a servo track. In this case, the servo head 21 is attached to the servo track 40 of the magnetic tape 36.
(Refer to Fig. 2) to write servo information
Read out.

The servo information to be written on the servo track of the magnetic tape 36 is control information necessary for servo tracking control (on-track control, etc.) for positioning the magnetic head assembly on a predetermined track on the magnetic tape, and runs the magnetic tape. The control information and the like necessary for

The servo tracking control is, for example,
Do the following: First, the track width of the servo track 40 of the magnetic tape 36 is set to the same width as the width of the servo head 21, and servo information is written to the servo track 40 (data having the same width as the width of the servo head is written).

Then, the written servo information is read out to perform servo tracking control. In this case, by the servo head 21 shown in FIG. 2, the servo information written on the servo track 40 of the magnetic tape 36 is read by the servo head 21, and the servo signal from the servo head 21 is amplified by the reproduction signal amplifier circuit 13. .

After that, the servo signal amplified by the reproduction signal amplifier circuit 13 is input to the envelope detector 14, the envelope of the servo signal is detected, and the detected envelope signal is sent to the MPU 6.

The MPU 6 detects the level of the envelope signal from the envelope detector 14, sends an instruction signal to the microstep motor drive circuit 15 in accordance with the detection result, and the microstep motor drive circuit 15 causes the microstep motor 22 to operate. Is driven to move the magnetic head assembly 16 (moves in the Y / -Y direction) to perform servo tracking control.

In this case, in FIG. 6, the servo head 2
If 1 is the position of E1 (the servo head is in the servo track), it is in the on-track state, and the servo signal output from the servo head 21 is the maximum output.

However, when track deviation of the servo head occurs, for example, when the servo head 21 comes to the position E2 (position where the servo head is displaced to the upper side), the output of the servo signal decreases. Further, when the servo head 21 reaches the E3 position (position where the servo head is displaced downward), the output of the servo signal also decreases.

Therefore, the envelope signal output from the envelope detector 14 becomes maximum at the position of E1 (on-track position), and if it deviates from this position, the output decreases.

Therefore, the output change of the servo signal is controlled by the MPU6.
Is detected, the magnetic head assembly is moved so that the output of the servo signal is maximized, and the magnetic head is on-tracked.

§5: Description of EEPROM information table example ... See FIGS. 7 and 8. FIG. 7 is a defective head table example, and FIG. 8 is a head movement information table example. Hereinafter, based on FIGS. 7 and 8, the EEP
An example of the table stored in the ROM 8 will be described.

The defective head table and the head movement information table are stored in the EEPROM 8 shown in FIG. These tables are as follows: (1): Description of defective head table ... See FIG. 7. The defective head table is a table for registering defective elements (defective recording element / defective reproducing element) of the magnetic head shown in FIG. It is sometimes stored in the EEPROM 8.

When creating this defective head table,
In advance (for example, when assembling the apparatus), the characteristics of each recording element and reproducing element that constitute the magnetic head are measured, and the element that does not obtain the predetermined characteristic is detected as a defective element. Then, the detected defective element is registered in the defective head table.

For example, in the case of the magnetic head shown in FIG.
The defective head table is as shown in FIG. In this case, the characteristics of the recording elements W _{1 to} W ₇₂ and the reproducing elements R _{1 to} R ₇₂ are measured, and good / defective (good = 0, bad = 1) is registered for each element.

As described above, the EEP is set at the time of factory shipment.
The defective head table is stored in the ROM 8. When the magnetic tape device is operated, the EEPROM 8
The recording / reproducing control is performed based on the information of the defective head table.

(2): Explanation of head movement information table
-Refer to FIG. 8. The head movement information table shown in FIG. 8 is a normal element used in place of the defective head (defective recording element / defective reproducing element) registered in the defective head table, and movement to the normal element. It is a table that stores information.
It is stored in the EPROM 8.

This head movement information table corresponds to each track of the magnetic tape, "elements normally used during recording and reproducing of the magnetic tape" (recording element, reproducing element).
There are items of "element used when the element corresponding to track of magnetic tape is defective" (recording element, reproducing element) and "moving direction / moving amount of magnetic head".

In the item of "movement direction / movement amount of magnetic head", + Y means to move by 2 track pitches in + Y direction, and -Y means to move by 2 track pitches in -Y direction. It means that. According to this example of the head movement information table, the control at the time of recording / reproducing with respect to the magnetic tape is as follows.

For example, to record / reproduce the track T ₁ ,
Normally, W ₁ and R ₁ are used, but if either _one of W ₁ and R ₁ is defective, recording / reproduction is performed using W ₃ and R ₃ . At this time, the magnetic head is moved by + Y (moved by two track pitches in the + Y direction) before recording / writing.
Play.

For recording / reproducing of the track T2, W ₂ and R ₂ are usually used. However, if either one of W ₂ and R ₂ is defective, W ₄ and R ₄ are used. Use to record / playback. At this time, recording / reproduction is performed after moving the magnetic head by + Y.

Further, normally, W ₃ and R ₃ are used for recording / reproducing of the track T ₃ , but if either of W ₃ or R ₃ is defective, W ₁ or R _{1 is used.} Use to record / play back. At this time, the magnetic head is moved by -Y before recording / reproducing.

§6: Outline of processing during recording / reproduction ...
2 to 8, the outline of processing at the time of recording / reproducing will be described below with reference to FIGS. When the power of the magnetic tape device is turned on, the MPU 6 of the data control unit 5 reads each data of the defective head table and the head movement information table stored in the EEPROM 8 and transfers them to the RAM 7. After that, the MPU 6 controls by referring to the defective head table stored in the RAM 7 and the head movement information table.

After that, when the host issues a command,
The magnetic tape controller (MTC) 4 receives the command and analyzes the contents. Then, the magnetic tape control device 4 issues an instruction to the MPU 6 of the data control unit 5 according to the content of the command.

When the command is a command for instructing recording / reproduction, the MPU 6 of the data control section 5 drives the magnetic head of the magnetic head assembly 16 in accordance with an instruction from the magnetic tape control device 4 to form a magnetic tape. On the other hand, data recording / playback is performed.

In this case, the MPU 6 refers to the defective head table of the RAM 7 to determine whether or not the element (recording element / reproducing element) normally used for recording / reproducing of the magnetic tape is defective. As a result, if the element is not defective, the element (recording element / reproducing element) normally used is used for recording / reproducing as it is.

However, if the corresponding element (recording element / reproducing element) is a defective element, the head movement information table of the RAM 7 is referred to, when an element is defective, the element to be used instead and the moving direction of the magnetic head, Information on movement amount (+ Y /-
Y) is acquired.

When the element is defective, the MPU 6 sends instruction data corresponding to the moving direction and the moving amount of the magnetic head to the microstep motor drive circuit 15. The micro-step motor drive circuit 15 sends a drive pulse to the micro-step motor 22 based on the instruction data to drive the micro-step motor 22 to move the magnetic head assembly 16.

In this way, the element for recording / reproducing on / from the magnetic tape (recording element / reproducing element) is positioned on the corresponding track of the magnetic tape, and recording / reproducing is performed. At the time of this recording / reproducing, recording / reproducing is simultaneously performed on a plurality of tracks by one tape running. In this case, 1
Eight tracks are simultaneously recorded / reproduced, and recording / reproduction of all 72 tracks is performed by running the magnetic tape twice each in the X direction and the -X direction.

Specifically, recording / reproduction is performed in the following order. First, the magnetic tape is run in the X direction to perform recording / reproduction on T _4n-3 tracks (n = 1 to 18), and then the magnetic tape is run in the -X direction to read T _4n-2 tracks ( n =
1 to 18), and then write the magnetic tape to X.
Direction, to record / reproduce on T _4n-1 tracks (n = 1 to 18), and finally to run the magnetic tape in the −X direction to record on T _4n tracks (n = 1 to 18). / Play.

§7: Description at the time of recording: see FIGS. 9 to 12. FIG. 9 is a process flowchart 1 at the time of recording, FIG. 10 is a process flowchart 2 at the time of recording, and FIG. 11 is a process flowchart 3 at the time of recording. 12 is a processing flowchart 4 at the time of recording. Note that S1 to S45 indicate processing steps. Further, the movement of the magnetic head assembly will be described as the movement of the magnetic head (substantially the same).

In the following processing, recording is performed on the magnetic tape in the order of track T _4n-3 → track T _4n-2 → track T _4n-1 → track T _4n (n = 1 to 18). In this case, each of them is simultaneously recorded on a plurality of tracks (18 tracks).

First, the MPU 6 of the data control unit 5
Starts recording the track T _4n-3 (n = 1 to 18) of the magnetic tape in response to an instruction from the magnetic tape controller (MTC) 4 (S1). At this time, the MPU 6 judges the quality of the recording element W _4n-3 by referring to the defective head table in the RAM 7 (S2).

As a result, if the recording element W _4n-3 is normal, the MPU 6 runs the magnetic tape in the X direction (S3),
A recording current is passed through the recording element W _4n-3 (S4). By this processing, the data is recorded on the track T _4n-3 (S5).

However, in the process of S2, the recording element W
_{When 4n-3} is defective, the MPU 6 refers to the head movement information table of the RAM 7 and alternately uses the recording element (normal element), the moving direction of the magnetic head, and the moving amount (Y /
-The information of Y) is acquired.

Then, the MPU 6 moves the magnetic head in the Y direction by two track pitches based on the acquired information (S6). Then, the magnetic tape is run in the X direction (S7), and a recording current is passed through the recording element W _4n-1 (S).
8). By this processing, the data is recorded on the track T _4n-3 (S5).

After the processing of S5 is completed, the MPU 6 stops the running of the magnetic tape (S9), and judges whether or not the head has moved during recording on the track T _4n-3 (S).
10). As a result, when the head moves, the magnetic head is moved and returned to the original position (S11).

Next, when recording is started on the track T _4n-2 (S12), the MPU 6 refers to the defective head table in the RAM 7, and the MPU 6 causes the recording element W _4n-2.
It is determined whether or not (S13).

As a result, if the recording element W _4n-2 is normal,
The magnetic tape is run in the -X direction (S14), and a recording current is passed through the recording element _W4n-2 (S15). By this process,
It is recorded on the track T _4n-2 (S16).

In the process of S13, the recording element W
_{When 4n-2} is defective, the MPU 6 refers to the head movement information table of the RAM 7 and alternately uses the recording element (normal element), the moving direction and the moving amount (Y /
-The information of Y) is acquired.

Then, the MPU 6 moves the magnetic head in the Y direction by two track pitches based on the acquired information (S18). Then, the magnetic tape is run in the -X direction (S19), and a recording current is supplied to the recording element _W4n (S).
20). By this processing, the data is recorded on the track T _4n-2 (S16).

After the processing of S16 is completed, the MPU 6 stops the running of the magnetic tape (S17), and the track T
_It is determined whether or not the head has moved during recording on _4n-2 (S21). As a result, when the magnetic head moves, the magnetic head is moved and returned to the original position (S2).
2).

Next, when recording is started on the track T _4n-1 (S23), the MPU 6 determines whether or not the recording element W _4n-1 is defective by referring to the defective head table in the RAM 7 ( S24).

As a result, if the recording element W _4n-1 is normal,
The magnetic tape is run in the X direction (S25), and the recording element W
_A recording current is passed through _4n-1 (S26). By this processing, the data is recorded on the track T _4n-1 (S27).

However, in the processing of S24, the recording element W
_{When 4n-1} is defective, the MPU 6 refers to the head movement information table of the RAM 7 and alternately uses the recording element (normal element), the moving direction of the magnetic head, and the moving amount (Y /
-The information of Y) is acquired.

Then, the MPU 6 moves the magnetic head by two track pitches in the -Y direction based on the acquired information (S29). Then, the magnetic tape is run in the X direction (S30), and a recording current is passed through the recording element W _4n-3 (S31). By this processing, it is recorded on the track T _4n-1 (S27).

After the processing of S27 is completed, the MPU 6 stops the running of the magnetic tape (S28), and the track T
_It is determined whether or not the head has moved during recording on _4n-1 (S32). As a result, if the head is moved, the magnetic head is moved to the original position (S33).

Next, when recording is started on the track T _4n (S34), the MPU 6 judges whether the recording element W _4n is good or bad by referring to the defective head table in the RAM 7 (S35). As a result, if the recording element W _4n is normal, the magnetic tape is run in the −X direction (S36), and a recording current is supplied to the recording element W _4n (S37). By this processing, the data is recorded on the track T _4n (S38).

However, in the processing of S35, the recording element W
_{When 4n} is defective, the MPU 6 refers to the head movement information table of the RAM 7 and alternately uses the recording element (normal element), the moving direction of the magnetic head, and the moving amount (Y /
-The information of Y) is acquired.

Then, the MPU 6 moves the magnetic head by two track pitches in the -Y direction based on the acquired information (S39). Then, the magnetic tape is run in the -X direction (S40), and a recording current is passed through the recording element _W4n-2 (S41). By this processing, the data is recorded on the track T _4n (S38).

After the processing of S38 is completed, the MPU 6 stops the running of the magnetic tape (S42), and the track T _4n
It is determined whether or not the head has moved during recording on (S43). As a result, when the head moves, the magnetic head is moved and returned to the original position (S44).
By the above processing, recording is performed on all tracks (72 tracks) (S45).

§8: Description of processing during reproduction ... See FIGS. 13 to 16. FIG. 13 is a processing flowchart 1 during reproduction, FIG. 14 is a processing flowchart 2 during reproduction, and FIG. 15 is a processing flowchart 3 during reproduction. FIG. 16 is a processing flowchart 4 at the time of reproduction.
Is. The process at the time of reproduction will be described below with reference to FIGS. 13 to 16.

It should be noted that S51 to S87 indicate processing steps. Further, the movement of the magnetic head assembly will be described as the movement of the magnetic head (substantially the same). In the following processing, the track T _4n-3 → track T _4n-2 → track T _4n-1 → track T _4n (n = 1 to 1) is applied to the magnetic tape.
Play in the order of 8). In this case, each is simultaneously reproduced on a plurality of tracks (18 tracks).

First, the MPU 6 of the data control unit 5
Starts reproducing the track T _4n-3 (n = 1 to 18) of the magnetic tape according to an instruction from the magnetic tape controller (MTC) 4 (S51). At this time, MPU6 is RAM7
The quality of the read element R _4n-3 is determined by referring to the defective head table in the table (S52).

As a result, if the reproducing element R _4n-3 is normal, the MPU 6 runs the magnetic tape in the X direction (S5).
3). By this processing, the track T is reproduced by the reproducing element R _4n-3.
4n-3 data is reproduced (S54).

However, in the process of S52, the reproducing element R
_{When 4n-3} is defective, the MPU 6 refers to the head movement information table of the RAM 7 and acquires information on the reproducing element to be used alternately, the moving direction of the magnetic head, and the moving amount (Y / -Y). To do.

Then, the MPU 6 moves the magnetic head in the Y direction by two track pitches based on the acquired information (S56). Then, the magnetic tape is run in the X direction (S57). By this processing, the track T _4n-3 is reproduced by the reproducing element R _4n-1 (S54).

After the processing of S54 is completed, the MPU 6 stops the running of the magnetic tape (S55), and the track T
_It is determined whether or not the head has moved during the _4n-3 reproduction (S58). As a result, when the head is moved, the magnetic head is moved and returned to the original position (S59).

Next, when the reproduction of the track T _4n-2 is started (S60), the MPU 6 refers to the defective head table in the RAM 7 to judge the quality of the reproducing element R _4n-2 (S61). As a result, if the reproducing element _R4n-2 is normal, the magnetic tape is run in the -X direction (S62).
By this processing, the track T _4n-2 is reproduced by the reproducing element R _4n-2 (S63).

In the process of S61, the reproducing element R
_{If 4n-2} is defective, the MPU 6 refers to the head movement information table of the RAM 7 and acquires information on the reproducing element to be used alternately, the moving direction of the magnetic head, and the moving amount (Y / −Y). .

Then, the MPU 6 moves the magnetic head in the Y direction by two track pitches based on the acquired information (S64). Then, the magnetic tape is run in the -X direction (S65). By this processing, the data of the track T _4n-2 is reproduced by the reproducing element R _4n (S63).

After the processing of S63 is completed, the MPU 6 stops the running of the magnetic tape (S66), and judges whether or not the head has moved during the reproduction of the track T _4n-2 (S6).
7). As a result, when the head is moved, the magnetic head is moved and returned to the original position (S68).

Next, when the reproduction of the track T _4n-1 is started (S69), the MPU 6 refers to the defective head table in the RAM 7 to judge the quality of the reproducing element R _4n-1 (S70).

As a result, if the reproducing element R _4n-1 is normal,
The magnetic tape is run in the X direction (S71). By this processing, the track T _4n-1 is reproduced by the reproducing element R _4n-1 (S72).

However, in the processing of S70, the reproducing element R
_{When 4n-1} is defective, the MPU 6 refers to the head movement information table of the RAM 7 and acquires the information of the reproducing element to be used alternately, the moving direction of the magnetic head, and the moving amount (Y / -Y). To do.

Then, the MPU 6 moves the magnetic head in the -Y direction by two track pitches based on the acquired information (S74), and runs the magnetic tape in the X direction (S).
75). By this processing, the track T is reproduced by the reproducing element R _4n-3.
4n-1 data is reproduced (S72).

After the processing of S72 is completed, the MPU 6 stops the running of the magnetic tape (S73), and the track T
_It is determined whether or not the head has moved during _4n-1 reproduction (S76). As a result, when the head moves, the magnetic head is returned to the original position (S77).

Next, when the reproduction of the track T _4n is started (S78), the MPU 6 refers to the defective head table in the RAM 7 to judge the quality of the reproducing element R _4n (S79). As a result, if the reproducing element _R4n is normal, the magnetic tape is run in the -X direction (S80). By this processing, the data of the track T _4n is reproduced by the reproducing element R _4n (S81).

However, in the processing of S79, the reproducing element R
_{When 4n} is defective, the MPU 6 refers to the head movement information table of the RAM 7 and acquires the reproducing element to be used alternately, the moving direction of the magnetic head, and the moving amount (Y / −Y).

Then, the MPU 6 moves the magnetic head in the -Y direction by two track pitches based on the acquired information (S83), and runs the magnetic tape in the -X direction (S84). By this processing, the data of the track T _4n is reproduced by the reproducing element R _4n-2 (S81).

After the processing of S81 is completed, the MPU 6 is controlled to stop the running of the magnetic tape (S82), and it is determined whether or not the head has moved during the reproduction of the track T _4n (S85). As a result, when the head is moved, the magnetic head is moved and returned to the original position (S8).
6). Through the above processing, all tracks (72 tracks)
Is reproduced (S87).

(Explanation of Embodiment 2) FIGS. 17 to 27 are views showing Embodiment 2 of the present invention.
Second Embodiment A second embodiment will be described based on 7. The device configuration of the first embodiment shown in FIGS. 2, 3 and 4 and the servo head and the servo track configuration shown in FIG. 6 are the same as those of the second embodiment. Description will be made with reference to each drawing.

§1: Description of magnetic head example 1 ... FIG.
Reference FIG. 17 is an explanatory diagram 1 of the magnetic head according to the second embodiment. Less than,
A magnetic head example 1 will be described with reference to FIG.

The magnetic head 42 shown in FIG. 17 is composed of three head chips 49, 50 and 51. Each of the head chip 49 and the head chip 51 is composed of only reproducing elements (R _{1 to} R ₇₂ ) (72 reproducing elements). The head chip 50 is composed of only the recording elements (W _{1 to} W ₇₂ ) (72 recording elements).

That is, the magnetic head 42 has a structure in which head chips 50 composed of only 72 recording elements are sandwiched and head chips 49 and 51 composed of only 72 reproducing elements are arranged on both sides of the head chip 50. Has become.

Also in this case, the magnetic tape 36 has T ₁
There are 72 tracks consisting of ~ T ₇₂ . The recording element and the reproducing element correspond to each track.

Even when the magnetic head having the above-mentioned configuration is used, recording / reproducing on / from the magnetic tape 36 is performed simultaneously by a single tape running in the same manner as in the first embodiment. In the case of this magnetic head, 18 tracks are simultaneously recorded or reproduced, and a total of 72 tracks are recorded / reproduced by running the magnetic tape twice each in the X direction and the -X direction.

Specifically, the recording on the magnetic tape 36 is
It is performed in the following order by the recording element of the head chip 50.
First, the recording on the track T _4n-3 (n = 1 to 18) is performed by X
Recording is performed when the magnetic tape is run in the negative direction, then recording on track T _4n-2 (n = 1 to 18) is performed when the magnetic tape is run in the -X direction, and then track T
Recording to _4n-1 (n = 1 to 18) is performed when the magnetic tape is run in the X direction, and then the track _T4n (n = 1 to 1)
Recording on 18) is performed when the magnetic tape is run in the -X direction, thereby recording on all tracks.

When reproducing from the magnetic tape 36,
Do in the following order: First, track T _4n-3(N = 1 to 1
The reproduction of 8) is performed by the head chip 51 with a magnetic tape in the X direction.
The track T, and then the truck T_4n-2(N =
1-18) in the -X direction with the head chip 49.
This is done when the magnetic tape is run, then track T_4n
-1Playback of (n = 1 to 18) is performed with the head chip 51 by X
Direction when running the magnetic tape in the direction
Ku T_4nPlayback of (n = 1 to 18) is performed by the head chip 49.
Then, what to do when running the magnetic tape in the -X direction
To play all tracks.

§2: Description of magnetic head example 2 ... FIG.
Reference FIG. 18 is an explanatory diagram 2 of the magnetic head according to the second embodiment. Less than,
A magnetic head example 2 will be described with reference to FIG.

The magnetic head 42 shown in FIG. 18 is composed of three head chips 52, 53 and 54. The head chip 52 and the head chip 54 are each composed of only recording elements (W _{1 to} W ₇₂ ) (72 recording elements). The head chip 53 is composed of only the reproducing elements (R _{1 to} R ₇₂ ) (72 recording elements).

That is, the magnetic head 42 has a structure in which head chips 53 composed of only 72 reproducing elements are sandwiched, and head chips 52 and 54 composed of only 72 recording elements are arranged on both sides of the head chip 53. Has become.

Also in this case, the magnetic tape 36 has T ₁
There are 72 tracks consisting of ~ T ₇₂ . The recording element and the reproducing element correspond to each track.

Also in this case, in the same manner as in the above-mentioned example, recording / reproducing on / from a magnetic tape simultaneously records / reproduces a plurality of tracks by one tape running, and records 2 in the X direction / -X direction respectively. Recording of all tracks by running tape once
Play.

Specifically, recording on the magnetic tape is performed in the following order. First, recording on the track T _4n-3 (n = 1 to 18) is performed when the magnetic tape is run in the X direction by the recording element of the head chip 52, and then the track T _4n-3.
Recording to _4n-2 (n = 1 to 18) is performed by the head chip 54
Then, when the magnetic tape is run in the -X direction, recording on the track _T4n-1 (n = 1 to 18) is performed by the head chip 52 when the magnetic tape is run in the X direction. Then, recording on the track T _4n (n = 1 to 18) is performed when the magnetic tape is run in the −X direction by the head chip 54, thereby recording on all tracks.

When reproducing from the magnetic tape 36,
The reproducing operation of the head chip 53 is performed in the following order.
First, the reproduction of the track T _4n-3 (n = 1 to 18) is performed when the magnetic tape is run in the X direction, and then the reproduction of the track T _4n-2 (n = 1 to 18) is − This is performed when the magnetic tape is run in the X direction, and then the track T _4n-1 (n =
By reproducing the magnetic tape in the X direction, the reproduction of tracks T _4n (n = 1 to 18) is performed when the magnetic tape is moved in the X direction. , Play all tracks.

Normally, for a magnetic tape track,
Recording / reproducing is performed by the corresponding element of the magnetic head. When the element is defective, the magnetic head assembly (magnetic head) is moved to normally perform recording / reproducing by the element.

§3: Description of Defective Head Table In the second embodiment as well, the defective head table (not shown) is stored in the EEPROM 8 shown in FIG.
These tables are as follows:

The defective head table of the second embodiment is similar to that of the defective head table of the first embodiment shown in FIG.
19 is a table for registering defective elements of the magnetic head shown in FIG. 8 or defective elements of the magnetic head shown in FIG.
It is stored in the EEPROM 8 at the time of factory shipment.

When creating this defective head table,
In advance (for example, when assembling the apparatus), the characteristics of each recording element and reproducing element that compose the magnetic head are measured, and an element that has deteriorated in characteristics and cannot be used is detected as a defective element. Then, the detected defective element is registered in the defective head table.

For example, in the case of the magnetic head shown in FIG. 17, the reproducing elements R _{1 to} R _{72 of} the head chip 49, the recording elements W _{1 to} W ₇₂ of the head chip 50, and the head chip 51.
The characteristics of the reproducing elements R _{1 to} R ₇₂ are measured, and good / defective (good = 0, bad = 1) is registered for each element.

In the case of the magnetic head shown in FIG. 18,
The characteristics of each of the recording elements W _{1 to} W ₇₂ of the head chip 52, the reproducing elements R _{1 to} R _{72 of} the head chip 53, and the recording elements W _{1 to} W ₇₂ of the head chip 54 were measured, and each element was evaluated as good. / Defective (good = 0, bad = 1) is registered.

As described above, at the time of factory shipment, the EEP
The defective head table is stored in the ROM 8. When the magnetic tape device is operated, the EEPROM 8
The read / write control is performed based on the information of the defective head table of.

§4: Description of example head movement information table
.. see FIG. 19 FIG. 19 is a diagram showing an example of the head movement information table.
Hereinafter, an example of the head movement information table will be described with reference to FIG.

The head movement information table shown in FIG. 19 is a normal element to be used instead of the defective element (defective recording element / defective reproducing element) registered in the defective head table, and movement information to the normal element. Is stored in the EEPROM 8 together with the defective head table at the time of factory shipment.

This head movement information table corresponds to each track T ₁ , T ₂ , T _3, ... Of the magnetic tape.
"Elements normally used for recording and reproducing magnetic tape"
(Recording element, reproducing element) and "element used when the element corresponding to the track of the magnetic tape is defective" (recording element, reproducing element).

Then, in the item "element used when the element corresponding to the track of the magnetic tape is defective",
Each moving element and movement information (movement direction, movement amount) are stored. As the movement information, “+ Y
Direction / 1 track pitch "," -Y direction / 1 track pitch "," + Y direction / 2 track pitch "," -Y direction / 2 track pitch "," + Y direction / 3 track pitch "," -Y direction / There are three track pitches.

§5: Outline of processing during recording / reproduction Hereinafter, an outline of processing during recording / reproduction will be described. Note that FIGS. 2, 3, and 4 are the same in the second embodiment, and therefore the description will be made with reference to these drawings.

When the power supply of the magnetic tape device is turned on, the MPU 6 of the data control unit 5 reads out the respective data of the defective head table and the head movement information table (see FIG. 19) stored in the EEPROM 8 and RA
Transfer to M7. After that, the MPU 6 controls by referring to the defective head table stored in the RAM 7 and the head movement information table.

After that, when the host issues a command,
The magnetic tape controller (MTC) 4 receives the command and analyzes the contents. Then, the magnetic tape control device 4 issues an instruction to the MPU 6 of the data control unit 5 according to the content of the command.

In the MPU 6 of the data control unit 5,
In response to an instruction from the magnetic tape controller 4, the magnetic head is driven to record / record data on / from the magnetic tape 36.
Play.

In this case, the MP of the data control unit 5
In U6, the defective head table of the RAM 7 is referred to and an element (recording element / recording element /
It is determined whether or not the reproducing element) is defective. As a result, if the element is normal, the element normally used (recording element / reproducing element)
Recording / playback is performed as it is.

However, if the corresponding element is a defective head, the MPU 6 refers to the head movement information table of the RAM 7, and when the element is defective, the element to be used instead and information on the moving direction and moving amount of the magnetic head. Get (Y / -Y).

When the element is defective, the MPU 6 sends the instruction data corresponding to the moving direction and the moving amount of the magnetic head to the microstep motor drive circuit 15 based on the acquired information.

The microstep motor drive circuit 15 sends a drive pulse to the microstep motor 22 based on the instruction data to drive the microstep motor 22 to move the magnetic head assembly 16. In this way, the element for recording / reproducing on the magnetic tape (recording element / reproducing element) is positioned on the corresponding track of the magnetic tape, and recording / reproducing is performed.

At the time of recording / reproducing, recording / reproducing is simultaneously performed on a plurality of tracks by one tape running. In this case, 18 tracks are recorded / reproduced simultaneously and X
Recording / reproduction of all tracks (72 tracks) is performed by running the magnetic tape twice each in the negative direction and in the -X direction.

§6: Description of processing at the time of recording ... FIGS.
See FIG. 20. FIG. 20 is a process flowchart 1 for recording, FIG. 21 is a process flowchart 2 for recording, FIG. 22 is a process flowchart 3 for recording, and FIG. 23 is a process flowchart 4 for recording.
Is. Hereinafter, the processing at the time of recording will be described with reference to FIGS. It should be noted that S100 to S139 indicate processing steps. In the following description, the movement of the magnetic head assembly will be described as movement of the magnetic head (substantially the same).

In the following process, recording is performed on the magnetic tape in the order of track T _4n-3 → track T _4n-2 → track T _4n-1 → track T _4n (n = 1 to 18). In this case, each of them is simultaneously recorded on a plurality of tracks (18 tracks).

First, the MPU 6 of the data control unit 5
Starts recording on the track T _4n-3 (n = 1 to 18) of the magnetic tape in response to an instruction from the magnetic tape controller (MTC) 4 (S100). At this time, MPU6 is RA
By referring to the defective head table in M7, it is judged whether the recording element W _4n-3 (n = 1 to 18) is defective or not (S1).
01).

As a result, if the recording element W _4n-3 is normal, the MPU 6 runs the magnetic tape in the X direction (S10).
5) A recording current is passed through the recording element W _4n-3 (S106).
By this processing, the data is recorded on the track T _4n-3 (S11).
6).

If the recording element W _4n-3 is defective in the processing of S101, the MPU 6 refers to the defective head table in the RAM 7 to determine whether the recording element W _4n-2 (n =
The quality of 1 to 18) is determined (S102).

As a result, if the recording element W _4n-2 is normal,
The MPU 6 refers to the head movement information table in the RAM 7 and acquires information on the movement direction and movement amount of the magnetic head, thereby moving the magnetic head in the Y direction by one track pitch (S107).

Then, the MPU 6 runs the magnetic tape in the X direction (S108), and the recording element W _4n-2 (n = 1 to 1).
A recording current is applied to 8) (S109). By this process,
It is recorded on the track T _4n-3 (S116).

When the recording element W _4n-2 is defective in the process of S102, the MPU 6 refers to the head movement information table in the RAM 7 and refers to the recording element W _4n-1 (n = 1 to 1).
The quality of 8) is determined (S103).

As a result, if the recording element W _4n-1 is normal,
The MPU 6 refers to the head movement information table in the RAM 7 and obtains information on the movement direction and movement amount of the magnetic head to move the magnetic head in the Y direction by two track pitches (S110).

Then, the magnetic tape is run in the X direction (S111), and a recording current is passed through the recording element W _4n-1 (S1).
12). By this processing, the track T _4n-3 (n = 1 to 1)
It is recorded in 8) (S116).

When the recording element W _4n-1 is defective in the processing of S103, the MPU 6 refers to the head movement information table in the RAM 7 and refers to the recording element W _4n (n = 1 to 18).
It is determined whether or not (S104).

As a result, if the recording element W _4n is normal, M
The PU 6 refers to the head movement information table in the RAM 7 and acquires information on the movement direction and movement amount of the magnetic head, thereby moving the magnetic head in the Y direction by 3 track pitches (S113).

Then, the magnetic tape is run in the X direction (S114), and a recording current is supplied to the recording element W _4n (S11).
5). By this processing, the data is recorded on the track T _4n-3 (S116).

After the processing of S116 is finished, the MPU 6 stops the running of the magnetic tape (S117), and the track T
_It is determined whether or not the head has moved when the data is recorded in _4n-3 (S118). As a result, if there is head movement, the magnetic head is moved to return to the original position (S11).
9).

Next, the track T _4n-2 (n =
Recording is started from 1 to 18) (S120). At this time, MP
U6 determines the quality of the recording element W _4n-2 (n = 1 to 18) by referring to the defective head table in the RAM 7 (S121).

As a result, if the recording element W _4n-2 is normal, the MPU 6 runs the magnetic tape in the -X direction (S1).
25). Then, a recording current is passed through the recording element W _4n-2 (S
126). By this processing, the data is recorded on the track T _4n-2 (S136).

If the recording element W _4n-2 is defective in the processing of S121, the MPU 6 refers to the defective head table in the RAM 7 to determine the recording element W _4n-3 (n =
The quality of 1 to 18) is determined (S122).

As a result, the recording element W _4n-3 (n = 1 to 1)
If 8) is normal, the MPU 6 refers to the head movement information table in the RAM 7 and obtains information on the moving direction and the moving amount of the magnetic head to move the magnetic head by one track pitch in the -Y direction. (S127).

Then, the MPU 6 runs the magnetic tape in the -X direction (S128), and passes a recording current to the recording element W _4n-3 (S129). By this process, the track T _4n-2
It is recorded in (n = 1 to 18) (S136).

If the recording element W _4n-3 is defective in the process of S122, the MPU 6 refers to the head movement information table in the RAM 7 and refers to the recording element W _4n-1 (n = 1 to 1).
The quality of 8) is determined (S123).

As a result, if the recording element W _4n-1 is normal,
The MPU 6 refers to the head movement information table in the RAM 7 and obtains information on the movement direction and movement amount of the magnetic head to move the magnetic head in the Y direction by one track pitch (S130).

Then, the magnetic tape is run in the -X direction (S131), and a recording current is passed through the recording element W _4n-1 (S1).
32). By this processing, the track T _4n-2 (n = 1 to 1)
It is recorded in 8) (S136).

When the recording element W _4n-1 is defective in the processing of S123, the MPU 6 refers to the head movement information table in the RAM 7 and refers to the recording element W _4n (n = 1 to 18).
It is determined whether or not (S124).

As a result, if the recording element W _4n is normal, M
The PU 6 refers to the head movement information table in the RAM 7 and obtains information on the movement direction and movement amount of the magnetic head to move the magnetic head in the Y direction by two track pitches (S133).

Then, the magnetic tape is run in the -X direction (S134), and a recording current is passed through the recording element _W4n (S13).
5). By this processing, the track T _4n-2 (n = 1 to 1)
It is recorded in 8) (S136).

After the processing of S136 is completed, the MPU 6 stops the running of the magnetic tape (S137), and the track T
When recording on _4n-2 , it is determined whether or not the head has moved (S138). As a result, if there is head movement, the magnetic head is moved to return to the original position (S13).
9).

In the same manner, recording is performed on all the tracks by recording on the tracks T _4n-1 and T _4n . §7: Description of processing during playback ... See FIGS. 24 to 27. FIG. 24 is a processing flowchart 1 during playback, FIG. 25 is a processing flowchart 2 during playback, FIG. 26 is a processing flowchart 3 during playback, and FIG. 27 is playback. Process Flowchart 4
Is.

The processing at the time of reproduction will be described below with reference to FIGS. 24 to 27. Note that S150 to S184 indicate processing steps. In the following description, the movement of the magnetic head assembly will be described as movement of the magnetic head (substantially the same).

In the following processing, the magnetic tape is reproduced in the order of track T _4n-3 → track T _4n-2 → track T _4n-1 → track T _4n (n = 1 to 18). In this case, each is simultaneously reproduced on a plurality of tracks (18 tracks).

First, the MPU 6 of the data control unit 5
Starts reproducing the track T _4n-3 (n = 1 to 18) of the magnetic tape according to an instruction from the magnetic tape controller (MTC) 4 (S150). At this time, MPU6 is RAM
By referring to the defective head table in 7, it is judged whether the reproducing element R _4n-3 (n = 1 to 18) is good or bad (S15).
1).

As a result, if the reproducing element R _4n-3 is normal, the MPU 6 runs the magnetic tape in the X direction (S15).
5). By this processing, the track T is reproduced by the reproducing element R _4n-3.
4n-3 is reproduced (S162).

When the reproducing element R _4n-3 is defective in the processing of S151, the MPU 6 refers to the defective head table in the RAM 7 to reproduce the reproducing element R _4n-2 (n =
The quality of 1 to 18) is determined (S152).

As a result, if the reproducing element R _4n-2 is normal,
The MPU 6 refers to the head movement information table in the RAM 7 and acquires information on the movement direction and movement amount of the magnetic head to move the magnetic head in the Y direction by one track pitch (S156).

Then, the MPU 6 runs the magnetic tape in the X direction (S157). By this processing, the track T _4n-3 is reproduced by the reproducing element R _4n-2 (S162). When the reproducing element R _4n-2 is defective in the process of S152, the MPU 6 refers to the head movement information table in the RAM 7 and judges the quality of the reproducing element R _4n-1 (n = 1 to 18). Yes (S153).

As a result, if the reproducing element R _4n-1 is normal,
The MPU 6 refers to the head movement information table in the RAM 7 and acquires information on the movement direction and movement amount of the magnetic head to move the magnetic head in the Y direction by two track pitches (S158).

Then, the magnetic tape is run in the X direction (S159). By this processing, the track T _4n-3 is reproduced by the reproducing element R _4n-1 (S162). When the reproducing element R _4n-1 is defective in the process of S153, the MPU 6 refers to the head movement information table in the RAM 7 to judge the quality of the reproducing element R _4n (n = 1 to 18) ( S15
4).

As a result, if the reproducing element R _4n is normal, M
The PU 6 refers to the head movement information table in the RAM 7 to obtain information on the moving direction and the moving amount of the magnetic head, thereby moving the magnetic head in the Y direction by 3 track pitches (S160).

Then, the magnetic tape is run in the X direction (S161). By this processing, the track T _4n-3 is reproduced by the reproducing element R _4n (S162). After the processing of S162 is completed, the MPU 6 stops the running of the magnetic tape (S
163), it is determined whether or not the head has moved when the track T _4n-3 is reproduced (S164). As a result, if the head is moved, the magnetic head is moved to return to the original position (S165).

Next, the track T _4n-2 (n =
1 to 18) are started to be reproduced (S169). At this time, MP
The U6 determines whether the reproducing element R _4n-2 (n = 1 to 18) is defective by referring to the defective head table in the RAM 7 (S170).

As a result, if the reproducing element R _4n-2 is normal, the MPU 6 runs the magnetic tape in the -X direction (S1).
74). By this processing, the track T is reproduced by the reproducing element R _4n-2.
4n-2 is reproduced (S181).

When the reproducing element R _4n-2 is defective in the processing of S170, the MPU 6 refers to the defective head table in the RAM 7 to reproduce the reproducing element R _4n-3 (n =
The quality of 1 to 18) is determined (S171).

As a result, if the reproducing element R _4n-3 is normal,
The MPU 6 refers to the head movement information table in the RAM 7 and obtains information on the movement direction and movement amount of the magnetic head to move the magnetic head in the -Y direction by one track pitch (S175).

Then, the MPU 6 runs the magnetic tape in the -X direction (S176). By this processing, the track T _4n-2 is reproduced by the reproducing element R _4n-3 (S181).
When the reproducing element R _4n-3 is defective in the process of S171, the MPU 6 refers to the head movement information table in the RAM 7 to judge the quality of the reproducing element R _4n-1 (n = 1 to 18). Yes (S172).

As a result, if the reproducing element R _4n-1 is normal,
The MPU 6 refers to the head movement information table in the RAM 7 and obtains information on the movement direction and movement amount of the magnetic head to move the magnetic head in the Y direction by one track pitch (S177).

Then, the magnetic tape is run in the -X direction (S178). By this processing, the track T _4n-2 is reproduced by the reproducing element R _4n-1 (S181). S172
When the reproducing element R _4n-1 is defective in the process of MPU6, the MPU6
Refers to the head movement information table in the RAM 7 to judge the quality of the reproducing element R _4n (n = 1 to 18) (S17).
3).

As a result, if the reproducing element R _4n is normal, M
The PU 6 refers to the head movement information table in the RAM 7 and acquires information on the movement direction and movement amount of the magnetic head, thereby moving the magnetic head in the Y direction by two track pitches (S179).

Then, the magnetic tape is run in the -X direction (S180). By this processing, the track T _4n-2 is reproduced by the reproducing element R _4n (S181). After the processing of S181 is completed, the MPU 6 stops the running of the magnetic tape (S182), and judges whether or not the head has moved when reproducing the track T _4n-2 (S183). as a result,
If the head has moved, the magnetic head is moved to return to the original position (S184).

In the same manner, all the tracks are reproduced by reproducing the tracks T _4n-1 and T _4n . (Other Embodiments) Although the embodiments have been described above, the present invention can be implemented as follows.

(1): Instead of the EEPROM of the above-mentioned embodiment, another non-volatile memory can be used. (2): The information stored in the EEPROM of the above-described embodiment is not limited to the time of factory shipment, but may be stored after the factory shipment, for example.

(3): The moving mechanism of the magnetic head assembly is not limited to the mechanism shown in FIG. 4, but another similar mechanism may be used. (4): If the number of recording elements and reproducing elements provided on the head chip is the same as or more than the number of tracks on the magnetic tape, it can be used.

[0219]

As described above, the present invention has the following effects. (1): It is measured whether or not the recording element and the reproducing element provided in each head chip satisfy predetermined characteristics, and the information about the defective element is stored in advance in the nonvolatile memory based on the measurement result. .

When performing recording / reproducing on a predetermined track of the magnetic tape, it is determined whether or not the element to be used is a defective element by referring to the information in the non-volatile memory. If the element is defective, Move the magnetic head assembly,
Recording / reproducing is performed using another normal element.

Therefore, even if there is a defective element in the head chip, recording / reproduction can always be performed by the normal element. Further, even if the number of tracks on the magnetic tape increases, it is possible to sufficiently cope with recording / reproduction on the magnetic tape.

(2): Recorded on a predetermined track of the magnetic tape /
When reproducing, by referring to the information in the non-volatile memory and moving the magnetic head assembly, recording / reproducing can be performed without using a defective element.

Therefore, even if a defective element is present in the head chip, the head chip can be used, so that the cost of the head chip becomes low. That is, the cost of the magnetic head assembly can be reduced.

(3): In the case of manufacturing a high density magnetic head, as the number of recording elements / reproducing elements in one head chip increases, an element which does not satisfy predetermined characteristics due to variations in manufacturing or the like. The number increases.

However, according to the present invention, even if there is a defective element, the information relating to the defective element is stored in the non-volatile memory, and the magnetic head assembly is moved for recording / recording based on this information. Play.

Therefore, even a head chip having a defective element can be used, the manufacturing yield of the head chip is improved, and the magnetic head assembly can be manufactured at low cost. (4): The number of elements of the head chip is increased, and even if there are defective elements that do not satisfy the predetermined characteristics, they can be used, so that it is possible to sufficiently cope with the narrowing of the track of the magnetic tape.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a device configuration diagram of a first embodiment.

FIG. 3 is a perspective view of a magnetic head assembly according to the first embodiment.

FIG. 4 is a sectional view taken along line MN in FIG.

FIG. 5 is an explanatory diagram of a magnetic head according to the first embodiment.

FIG. 6 is an explanatory diagram of a servo head and a servo track in the first embodiment.

FIG. 7 is an example of a defective head table in the first embodiment.

FIG. 8 is a diagram showing an example of a head movement information table in the first embodiment.

FIG. 9 is a processing flowchart 1 at the time of recording in the first embodiment.

FIG. 10 is a processing flowchart 2 at the time of recording in the first embodiment.

FIG. 11 is a processing flowchart 3 at the time of recording in the first embodiment.

FIG. 12 is a processing flowchart 4 at the time of recording in the first embodiment.

FIG. 13 is a processing flowchart 1 at the time of reproduction in the first embodiment.

FIG. 14 is a processing flowchart 2 at the time of reproduction in the first embodiment.

FIG. 15 is a processing flowchart 3 at the time of reproduction in the first embodiment.

FIG. 16 is a processing flowchart 4 at the time of reproduction in the first embodiment.

FIG. 17 is an explanatory diagram 1 of the magnetic head according to the second embodiment.

FIG. 18 is an explanatory diagram 2 of the magnetic head according to the second embodiment.

FIG. 19 is an example of a head movement information table in the second embodiment.

FIG. 20 is a processing flowchart 1 at the time of recording in the second embodiment.

FIG. 21 is a processing flowchart 2 at the time of recording in the second embodiment.

FIG. 22 is a processing flowchart 3 at the time of recording in the second embodiment.

FIG. 23 is a processing flowchart 4 at the time of recording in the second embodiment.

FIG. 24 is a processing flowchart 1 at the time of reproduction in the second embodiment.

FIG. 25 is a processing flowchart 2 at the time of reproduction in the second embodiment.

FIG. 26 is a processing flowchart 3 at the time of reproduction in the second embodiment.

FIG. 27 is a processing flowchart 4 at the time of reproduction in the second embodiment.

[Explanation of symbols]

 6 MPU (microprocessor) 8A Non-volatile memory 15 Micro step motor drive circuit 16 Magnetic head assembly 22 Micro step motor 28, 29 Head chip 36 Magnetic tape

Claims (5)

[Claims] 1. A magnetic head assembly (16) having a plurality of recording elements for performing recording / reproducing with respect to each track of a magnetic tape (36) and a reproducing element, and the magnetic head assembly (16). A head moving mechanism for moving the magnetic tape in the track width direction (Y / −Y) of the magnetic tape, and moving the magnetic head assembly in the track width direction of the magnetic tape to move the magnetic tape in the forward direction (X), and In a magnetic tape device capable of recording / reproducing on all tracks of a magnetic tape by traveling in the reverse direction (-X), among a plurality of recording elements and reproducing elements provided in the magnetic head assembly (16). , Recording / reproducing information to / from a non-volatile memory (8A) and a magnetic tape (36) in which information regarding defective elements that do not satisfy predetermined characteristics is stored in advance. When performing, by referring to the information on the defective element of the non-volatile memory (8A), it is determined whether the recording / reproducing element corresponding to the recording / reproducing target track on the magnetic tape is a defective element or not. And a head for moving the magnetic head assembly so that a non-defective element (normal element) is positioned at a corresponding track position on the magnetic tape. A magnetic tape device comprising head moving mechanism control means for driving and controlling a moving mechanism. 2. The non-volatile memory (8A) includes position information of defective elements which do not satisfy predetermined characteristics, and recording element / reproducing element positions (corresponding to normal recording / reproducing) corresponding to respective tracks of the magnetic tape. Information on the position of the element to be used) and head movement information (movement direction and movement amount) for moving the magnetic head assembly when the recording element / reproducing element is defective are stored in advance, and the magnetic head assembly ( The magnetic tape device according to claim 1, wherein the head moving mechanism control means drives and controls the head moving mechanism by referring to the information in the non-volatile memory (8A) when moving the head moving mechanism (16). 3. The magnetic head assembly (16) is provided with two adjacent head chips (28, 29), and each of the head chips (28, 29) has a track of a magnetic tape (36). Recording elements and reproducing elements are alternately arranged in the width direction (Y / -Y), and in the running direction (X / -X) of the magnetic tape (36),
2. The magnetic tape device according to claim 1, wherein the recording element and the reproducing element are arranged adjacent to each other as a set of elements. 4. The magnetic head assembly (16) includes three head chips (49, 50,
51), the central head chip (5
0), a plurality of recording elements are arranged in the track width (Y / -Y) direction of the magnetic tape, and head chips (49, 51) on both sides are respectively arranged in the track width direction (Y /-) of the magnetic tape. A plurality of reproducing elements are arranged in Y), and with respect to the traveling direction (X / -X) of the magnetic tape (36),
2. The magnetic tape device according to claim 1, wherein the recording element and the reproducing element are arranged adjacent to each other as a set of elements. 5. The magnetic head assembly (16) includes three head chips (52, 53, 53) adjacent to each other.
54), and the central head chip (5
3), a plurality of reproducing elements are arranged in the track width (Y / -Y) direction of the magnetic tape, and the head chips (52, 54) on both sides are respectively arranged in the track width direction (Y / -Y) of the magnetic tape. A plurality of recording elements are arranged in Y), and with respect to the running direction (X / -X) of the magnetic tape (36),
2. The magnetic tape device according to claim 1, wherein the recording element and the reproducing element are arranged adjacent to each other as a set of elements.