JP2000123505A - Magnetic disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetic disk device capable of assuring the compatibility of data at the time of making a track density higher and capable of attaining high track density without using servo information. SOLUTION: An ID field 1 which is arranged so as to correspond to the neighborhood of the center part of a data track 3 and an ID field 2 which is arranged so as to correspond to the neighborhood of the boundary part of data tracks are provided and a recording and reproducing operation is controlled by discriminating two kinds of the ID fields. Moreover, when a magnetic head is positioned on the ID field arranged so as to correspond to the neighborhood of the boundary part of data tracks, the magnetic head is minutely moved by changing the exciting current of a stepping motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive for recording and reproducing data on a magnetic disk with a magnetic head. In particular, the present invention relates to a format of an exchangeable magnetic disk such as a flexible disk and a method of positioning a magnetic head.

[0002]

2. Description of the Related Art FIG. 17 is a block diagram showing a conventional flexible disk device described in "Latest Magnetic Recording Technology and Apparatus / Equipment" (published by Sogo Gijutsu Publishing Co., Ltd.). In FIG. 17, reference numeral 100 denotes a flexible disk device. A magnetic disk 101 and a disk cartridge 102 are set in the flexible disk device 100. The magnetic disk 101 is rotated by a spindle motor 103 controlled by a spindle motor driver 104. 105 is a magnetic head, 106 is a carriage, 107 is a stepping motor, and 108 is a stepping motor driver. Magnetic head 105
Is attached to the tip of the carriage 106,
The magnetic disk 101 moves in the radial direction by the driving force generated by the stepping motor 107. The stepping motor driver 108 controls the driving of the stepping motor 107, and generally performs driving and positioning in an open loop system.

[0003] 109 is a read / write amplifier (hereinafter R / W
Amplifying or pulsing the reproduction signal of the magnetic head 105, supplying a write current to the magnetic head 105, and the like. A control circuit 110 controls the spindle motor driver 104, the stepping motor driver 108, and the R / W amplifier 109 based on a control signal given from the flexible disk controller 111, and outputs a signal indicating the state of the flexible disk device 100 to the flexible disk. Output to the controller 111. The flexible disk controller 111 responds to a command instructed from the host system 112,
It performs transmission and reception of recording / reproduction data, modulation / demodulation of data, generation of a signal for stepping a stepping motor, generation of an ON / OFF signal of a spindle motor, generation of a head switching signal, and the like.

FIG. 18 shows a track format of a general flexible disk standardized by ISO and JIS. In FIG. 18, reference numeral 120 denotes a track;
Is a preamble, 122 is a sector, 123 is a postamble, 124 is an ID field, 125 is a gap,
26 is a data track. One track includes a preamble 121, a plurality of sectors 122, and a postamble 123. The sector 122 includes an ID field 124 in which information indicating the start and address of the sector is recorded and a data track 126 in which data is recorded. A gap 125 is provided to protect data from errors in the operation timing of the erase head, which is provided to prevent data from being unerased. ID field 124 is SYNC, AM, I
D, CRC, and the data track 126 is SYN
It is composed of C, AM, DATA, and CRC. SYNC is a code for synchronization, AM is ID or DATA
, ID indicates a cylinder, side, a code indicating a sector number and a data length of a sector, and CRC indicates an ID.
Alternatively, a code for detecting a DATA error, DATA
Is an area where user data is written.

Next, a data read / write operation in the flexible disk device will be described. When the host system 112 instructs a data read operation of an arbitrary sector or a data write operation of an arbitrary sector, the flexible disk controller 111 sends a step signal to move the magnetic head 105 to a target cylinder. . The control circuit 110 outputs the excitation switching signal based on the step signal to the stepping motor driver 108.
Output to The stepping motor driver 108 switches the excitation phase of the stepping motor 107 based on the excitation switching signal and performs step feed to move the magnetic head 105. When the movement to the target cylinder is completed, the ID field 124 is searched next. First, a SYNC search is performed, and when a SYNC is found, a synchronization operation is performed.
Thereafter, when an AM indicating the start of the ID is found, the ID is read, and it is checked whether the cylinder, side, and sector numbers match the target sector. If they match, the CRC is checked, and if no error is detected, the process moves to the data track 126. Since a gap 125 exists between the ID field 124 and the data track 126, the synchronization operation is performed again at the SYNC of the data track 126.

Thereafter, when an AM indicating the start of DATA is found, data is read or written. When reading data, the read signal detected by the magnetic head 105 is amplified and pulsed by the R / W amplifier 109, and is read as serial data by the flexible disk controller 1.
11 is output. The flexible disk controller 111 demodulates data and converts serial data to parallel data. If no error is detected by the CRC check, the data is transferred to the host system 112. When writing data, the data provided from the host system 112 is converted from parallel data to serial data by the flexible disk controller 111, further modulated, and input to the R / W amplifier 109. The R / W amplifier 109 changes the write current supplied to the magnetic head 105 based on the input signal and records data on the magnetic disk 101.

[0007]

As described above, in the conventional flexible disk drive, since the positioning of the magnetic head is performed by the open loop control by the stepping motor, the relative position between the magnetic head and the data track is slightly increased. There has been a problem that the displacement always occurs.
(Generally, the relative displacement between the magnetic head and the data track is called off-track.) The factors that cause off-track include the feed accuracy of the stepping motor, expansion and contraction caused by eccentricity and temperature and humidity of the flexible disk, and head mounting. There are position adjustment errors, vibrations and shocks applied from outside the device. Flexible disk devices are designed with tolerance distribution so that data compatibility is guaranteed even if off-track occurs due to these factors. Also,
An erase head is provided to prevent old data from being left when off-track and re-written. Therefore, in order to increase the track density by the open loop control method using the stepping motor, it is necessary to more strictly control the accuracy and adjustment accuracy of the mechanism, which is not practical. In addition, there is a problem that the structure of the magnetic head is complicated because an erase head is required.

As a method for solving the above problem, servo information is recorded in advance at the beginning of each sector, the off-track amount is detected from the servo information, and the magnetic head is positioned and controlled by closed-loop control to obtain a high track. There are ways to achieve densification. However, since an area for recording servo information is required, there is a problem that the data area is reduced correspondingly and the format efficiency is deteriorated. Further, there is a problem that a circuit required for detecting the off-track amount from the servo information increases the circuit scale.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the data compatibility at the time of a high track density can be achieved without more strict management of the accuracy of the mechanism and the adjustment accuracy. It is an object of the present invention to obtain a magnetic disk device that can guarantee the above. It is another object of the present invention to increase the track density of a magnetic disk drive without using servo information at the beginning of each sector.

[0010]

A magnetic disk drive according to the present invention comprises a writer for writing data with a predetermined write width and a reproducer for reproducing data with a reproduction width smaller than the write width. A plurality of data tracks to which data is to be written by the writing unit are formed concentrically, and an on-track is arranged at the head of each sector of the data track so as to correspond to the vicinity of the center of the data track. A first ID comprising a code identifying the track
A second ID field comprising a field and a code for identifying an off-track located adjacent to the first ID so as to correspond to the vicinity of the boundary of the data track. When a plurality of recorded magnetic disks and the code for identifying the on-track are correctly read, writing of data to the data track or reading of data recorded on the data track is permitted. It was done.

Further, a magnetic disk drive according to the present invention has a magnetic head including a writer for writing data with a predetermined write width and a reproducer for reproducing data with a reproduction width smaller than the write width. A plurality of data tracks to which data is written by the writing section are formed concentrically, and are on-tracks arranged at the head of each sector of the data track so as to correspond to the vicinity of the center of the data track. A first ID field including a code for identifying the data track, and a code for identifying an off-track arranged adjacent to the first ID field so as to correspond to a vicinity of a boundary of the data track. And the code for identifying the on-track is correctly read from the magnetic disk in which a plurality of second ID fields including And control means for permitting the writing of data to the data tracks when put out, a memory for predetermined capacity storing reproduced data, and which includes a discriminating means for detecting an error of the reproduced data.

Further, according to the magnetic disk drive of the present invention, the recording width of the first ID field and the second I
The recording width of the D field is made equal.

Also, the magnetic disk drive according to the present invention is a stepping motor for moving the magnetic head, means for switching an excitation phase of the stepping motor, and means for changing an exciting current to a coil of the stepping motor. And a magnetic head positioning control means for controlling an exciting current value to the coil so that the magnetic head moves slightly when the code for identifying the on-track cannot be read correctly. .

In the magnetic disk drive according to the present invention, codes for identifying off-tracks of the second ID field on both sides of the first ID field have different values.

Further, according to the magnetic disk drive of the present invention, there are provided a code for identifying an on-track of the first ID field, which is recorded in a plurality of concentric circles, and the second ID field.
Are different from each other in the value of the code for identifying the off-track in the ID field.

Further, in the magnetic disk drive according to the present invention, the magnetic head positioning control means further includes an excitation current value storage means for storing an excitation current value of the coil of the stepping motor. If the magnetic head is positioned based on the exciting current information read from the exciting current value storage means and the code for identifying on-track cannot be read correctly, the drive current value is increased by a predetermined amount until the code can be read correctly. The exciting current information stored in the exciting current value storage means is updated while changing the exciting current information.

Also, in the magnetic disk drive according to the present invention, the magnetic disk has an area in which a burst pattern of two or more phases is recorded, and a circuit for detecting an amplitude value of a reproduction signal of the burst pattern; An arithmetic unit for calculating the amount of eccentricity of the magnetic disk from the amplitude value, and an eccentricity amount storage means for storing the operation result of the arithmetic unit, the eccentricity information read from the eccentricity amount storage means at the time of data recording and reproduction. The magnetic head is positioned based on this.

Further, in the magnetic disk drive according to the present invention, the eccentricity of the magnetic disk is calculated from the amplitude value of the reproduction signal of the burst pattern obtained from the writing section.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a diagram showing a sector format of a magnetic disk device according to Embodiment 1 of the present invention. Although not shown in FIG. 1, one track is composed of a preamble, a plurality of sectors, and a postamble similarly to a known flexible disk. In FIG. 1, 1 is a first ID field, 2
Is a second ID field, 3 is a data track, and 4 is a guard band. The first ID field 1 is located at a position corresponding to the center of the data track 3, and the second ID field 2 is located at a position corresponding to the boundary of the data track 3, that is, a position corresponding to the guard band 4. Are located. First ID field 1 and second I
D field 2 is SYNC, AM, ID, POS, CR
C, and data track 3 includes SYNC, AM, D
It consists of ATA and CRC. SYNC is a code for performing synchronization, AM is a mark indicating the start of ID or DATA, ID is a code indicating cylinder, side, sector number and data length of sector, and POS is a first ID field 1 and a second ID field. A code for identifying the ID field 2, CRC is a code for detecting an ID and POS or DATA error, and DATA is an area in which user data is written. In this embodiment, it is assumed that 00 (hexadecimal) is recorded in the POS of the first ID field 1 and FF (hexadecimal) is recorded in the POS of the second ID field 2. Further, it is assumed that the same ID as the first ID field 1 on the outer peripheral side is recorded in the ID of the second ID field 2. The guard band 4 is a non-recording area between data tracks.

FIG. 2 is a block diagram showing a magnetic disk drive according to the first embodiment of the present invention. 2, reference numeral 10 denotes a magnetic disk drive, 11 denotes a magnetic head, 12 denotes a stepping motor driver, 13 denotes a control circuit, 14 denotes a magnetic disk controller, and a magnetic disk 101 and a disk cartridge 102 are set in the magnetic disk drive 10. Is done. The magnetic disk 101 has a spindle motor 103 controlled by a spindle motor driver 104.
Is driven to rotate. The magnetic head 11 is attached to the leading end of the carriage 106, moves in the radial direction of the magnetic disk 101 by the driving force generated by the stepping motor 107, and the stepping motor driver 12 controls the driving of the stepping motor 107. is there.

The control circuit 13 controls the spindle motor driver 104, the stepping motor driver 12, and the R / W amplifier 109 based on a control signal given from the magnetic disk controller 14, and outputs a signal indicating the state of the magnetic disk device 10. Output to the magnetic disk controller 14. The magnetic disk controller 14 transmits / receives recording / reproduction data, modulates / demodulates data, generates a signal for stepping a stepping motor, generates an ON / OFF signal for a spindle motor, For example, it generates a switching signal. Reference numeral 109 denotes a read / write amplifier (hereinafter, referred to as an R / W amplifier), which amplifies and pulses a reproduction signal of the magnetic head 11, supplies a write current to the magnetic head 11, and the like.

FIG. 3 is a partial block diagram of the magnetic disk controller 14 according to the first embodiment of the present invention. In FIG. 3, 20 is a state machine, 21 is a PLL circuit, 22
Is an AM detection circuit, 23 is a demodulation circuit, 24 is a serial / parallel conversion circuit, 25 is a CRC check circuit, 26 is I
D comparison circuit, 27 is a POS identification circuit, 28 is a data transfer circuit, 29 is a parallel / serial conversion circuit, 30 is a CR
The C generation circuit 31 is a modulation circuit.

Next, the data read / write operation of the magnetic disk drive of the present invention will be described. First, when the host system 112 instructs a read operation of data in an arbitrary sector or a write operation of data in an arbitrary sector, the magnetic disk controller 14 sends a step signal to move the magnetic head 11 to a target cylinder. Send out. The control circuit 13 outputs an excitation switching signal to the stepping motor driver 12 based on the step signal. The stepping motor driver 12 switches the excitation phase of the stepping motor 107 based on the excitation switching signal and performs step feed to move the magnetic head 11.

The state machine 20 controls the operation timing of each circuit. When the movement of the magnetic head 11 is completed, first, the PLL circuit 21 is activated. PLL circuit 21
Is input with serial data amplified and pulsed by the R / W amplifier 109. PLL circuit 21 is SYNC
Is searched, and when a SYNC is found, a synchronization operation is performed, and the completion of synchronization is notified to the state machine 20. Next, the state machine 20 activates the AM detection circuit 22. When the AM is found, the AM detection circuit 22 notifies the state machine 20 that the AM has been found and the type of the found AM. Further, the AM detection circuit 22 has a serial /
The parallel conversion circuit 24 outputs a signal indicating a data break when serial data is converted into parallel data. If the found AM indicates the start of the ID,
The state machine 20 activates the ID comparison circuit 26. I
The D comparison circuit 26 reads the read ID and the host system 11
It is checked whether the IDs specified from 2 match. When a signal indicating that the IDs match is input from the ID comparison circuit 26, the state machine 20 activates the POS identification circuit 27. The POS identification circuit reads the read PO
This circuit identifies whether the code of S indicates the first ID field 1 or the second ID field 2. The read code is 00, and the magnetic head 11 is stored in the first ID field 1.
State machine 20 recognizes that
Checks whether a signal indicating an error is output from the CRC check circuit 25, and if no error has occurred, shifts to data track processing. On the other hand, if the read POS code is FF and it is known that the magnetic head 11 is located in the second ID field 2, the state machine 20 reads normal data with a large off-track amount of the magnetic head, It is determined that writing cannot be performed, and the data read / write operation is interrupted.

Next, the operation when the magnetic head 11 is located in the first ID field 1 and the processing shifts to data track processing will be described. When reading data, the state machine 20 sequentially activates the PLL circuit 21 and the AM detection circuit 22 to perform SYNC search, synchronization, and AM search. When the AM indicating the start of DATA is found, the read user data is read. The data transfer circuit 28 is instructed to transfer the data to the host system 112. If an error is detected by the CRC code at the end of the data track, the host system 112 is notified that a CRC error has occurred. When writing data, the state machine 20 instructs the data transfer circuit 28 to transfer user data provided from the host system 112 to the parallel / serial conversion circuit 29. The user data is converted into serial data by a parallel / serial conversion circuit 29, a CRC code is added by a CRC generation circuit 30, modulated by a modulation circuit 31, and output to the R / W amplifier 109.

In order to clarify the effect of the present invention, an overwrite operation of a data track in an off-track state will be described.

FIG. 4 is a diagram showing the relationship between the read gap, the write gap, and the track pitch of the magnetic head 11 of the present invention. In FIG. 4, reference numeral 35 denotes a read gap which is a reproducing portion formed on the magnetic head 11, and 36 denotes a write gap which is a writing portion. The read gap 35 and the write gap 36 are formed apart from each other by a predetermined distance.
The read head 35 traces the track in advance. The width of the read gap 35 is smaller than the width of the write gap 36.

FIG. 5 is a diagram showing how data tracks are rewritten in the off-track state. As described above, data is written when the first ID field 1 can be read correctly. Accordingly, the positions of the read gap 35 and the write gap 36 when the magnetic head 11 performs the data writing with the maximum off-track toward the data track N-1 are as shown in FIG. Here, for simplicity of description, it is assumed that when the read gap 35 completely traces the first ID field 1, the data can be correctly read. (Actually, lead gap 3
There are cases where 5 can be read correctly even if it slightly protrudes. The cause of off-track is AC disturbance such as eccentricity of the disk or expansion and contraction due to temperature and humidity. Therefore, the amount of off-track may increase during data writing. In the worst case,
The rewritten data track N is as shown in FIG. In FIG. 5, the data track N in which 37 is rewritten
And 38 is a past data track N remaining without being overwritten. To ensure data compatibility,
Even in such a case, the data on the data track N or the data track N-1 must be correctly read.

FIG. 6 is a diagram showing a state in which the data track N is read. In FIG. 6, reference numeral 39 denotes the magnetic head 11.
Is the trajectory of the read gap 35 when the maximum off-track occurs toward the data track N + 1 and the amount of off-track increases due to AC disturbance during data reading. The trajectory 39 of the read gap 35 completely traces the rewritten data track N, so that data can be read correctly.

FIG. 7 is a diagram showing how data track N-1 is read. In FIG. 7, reference numeral 40 denotes a locus of the read gap 35 when the magnetic head 11 is off-tracked to the data track N side at the maximum and the off-track amount increases due to AC disturbance during data reading. The trajectory 40 of the read gap 35 completely traces the data track N-1, and data can be read correctly.

The above-mentioned FIGS. 6 and 7 will be examined mathematically. FIG. 6 shows a case where data written off-track in one direction is read off-track in the reverse direction.
The read width of the read gap 35 is R, the write gap 36 is
Assuming that the recording width of the first ID field 1 is W, the width of the first ID field 1 is B, and the off-track amount generated by AC disturbance during data track writing or reading is d, rewriting is performed from the track center of the track N in FIG. The distance L1 between the input data and the boundary between the past data is W / 2− (B / 2−R / 2).
+ D). The distance L2 from the track center of the track N to the end of the path of the read gap 35 is B / 2 + d. If L1 is larger than L2, the data can be read correctly. In this case, the condition that must be satisfied is W / 2> BR / 2 + 2d (Equation 1).

On the other hand, FIG. 7 shows a case where data of an adjacent track is written close to the track, and off-track data is read out so as to approach the data. The distance L3 from the track center of the track N in FIG. 7 to the boundary between the rewritten data track N and the data track N−1 is W / 2 + (B /
2-R / 2 + d). The distance L4 from the track center of the track N to the end of the path of the read gap 35 is T−B / 2−d, where T is the track pitch. L
4 is larger than L3, the data can be read correctly. In this case, the condition that must be satisfied is T-B
> W / 2−R / 2 + 2d (Equation 2). Therefore,
Even when the track density is increased, the data is always guaranteed by setting the width of the first ID field or the gap width of the head so as to satisfy Expressions 1 and 2.

As described above, since the magnetic disk drive of the present invention controls the recording / reproducing operation by identifying two types of ID fields, even if the track density is increased, the data is written off-track. Fatal errors such as sometimes destroying data on adjacent tracks can be avoided, and data can always be guaranteed. Further, since this effect can be achieved without the erase head, the structure of the head can be simplified.

The effect of ensuring data compatibility when the read / write operation is performed by reading the first ID field correctly has been described above. In the following, the magnetic head is positioned in the second ID field. Will be described. In the present invention, a micro-step driving means for changing the exciting current of the stepping motor is provided so that the magnetic head can be minutely moved to a position where the first ID field can be read.

FIG. 8 is a block diagram of the micro step driving means. In FIG. 8, 45 is a microcontroller, 46 is a matrix circuit, 47 is a D / A converter,
8 is a current supply circuit. Stepping motor 107
Is composed of an exciting coil 49, a rotor 50, and a stator 51. The matrix circuit 46 is a circuit for switching the excitation phase in accordance with an instruction to the microcontroller 45, the D / A converter 47 is a circuit for converting a digital current command value given from the microcontroller 45 into an analog voltage, and the current supply circuit 48 is Matrix circuit 46 and D
A predetermined current is supplied to a predetermined excitation coil 49 based on an output signal from the / A converter 47.

Next, the operation will be described. As described above, the state machine 20 is configured such that the magnetic head 11
When recognizing that it is located in the D field 2, the data read / write operation is interrupted. Thereafter, the state machine 20 outputs a micro-step instruction signal 52. The microcontroller 45 receives the microstep instruction signal 5
When 2 is input, the data to be output to the D / A converter 47 is changed, and the exciting current is unbalanced to feed the magnetic head 11 minutely. Then, the ID field is searched again to check the POS code, and
Check the position of. If it is still located on the second ID field, the exciting current is further changed.
Until the magnetic head 11 comes over the first ID field,
This operation is continued. As a method of changing data output to the D / A converter 47, a method of changing the data by a constant value, a method of changing based on a table pattern stored in a ROM or the like in the microcontroller 45, a method of calculating and setting by a function, and the like. Can be cited as a realization means. In the present embodiment, the microcontroller 45 and the D /
Although the configuration using the A converter 47 has been described, it is also possible to combine the microcontroller 45 with a logic circuit such as a counter or a decoder instead of the microcontroller 45, or to use the microcontroller 45 and the D / A converter 47. Instead, it may be configured by an analog circuit.

As described above, in the magnetic disk drive of the present invention, when the off-track amount is so large that the magnetic head is positioned on the second ID field, the exciting current of the stepping motor is changed to change the magnetic head to the second ID field. ID of 1
Since it is moved minutely on the field, data can be written and read reliably even when the track density is increased.

Embodiment 2 In the first embodiment,
When the amount of off-track is large and the first ID field cannot be read correctly, the data reading operation is interrupted. However, even if the first ID field cannot be read correctly, an AC disturbance acts in a direction to reduce off-track during data track reproduction, and data may be read correctly. Therefore, in the second embodiment, data is read regardless of the magnetic head position, the data is stored in the memory, and the data is transferred to the host system when no error is detected by the CRC check circuit.

FIG. 9 is a partial block diagram of the magnetic disk controller 14 according to the second embodiment of the present invention. In FIG. 9, reference numeral 55 denotes a memory. The second embodiment differs from the first embodiment in the data read operation. The operation will be described. SYNC search, synchronization, AM detection, ID comparison, P
The operation up to the operation of OS identification, CRC check of ID and POS is the same as that of the first embodiment. Next, the state machine 20 shifts to processing of the data track regardless of the position of the magnetic head 11. The SYNC search, synchronization, and AM search of the data track 3 are performed. When the AM indicating the start of DATA is detected, the read user data is stored in the memory 55. Then, an error is checked by the CRC at the end of the data track, and if there is no error, the user data stored in the memory 55 is transferred to the host system 112.
If there is an error, the exciting current of the stepping motor 107 is changed as in the first embodiment to change the magnetic head 11.
Is slightly moved.

As described above, the magnetic disk device of the second embodiment reads data regardless of the position of the magnetic head, stores the data in the memory, and stores the data in the host when no error is detected by the CRC check circuit. Since the data is transferred to the system, the data reading speed can be improved compared to the first embodiment.

Embodiment 3 Embodiment 3 is the first ID
This is an example in which the width of the field is equal to the width of the second ID field.

FIG. 10 is a diagram showing a sector format of the magnetic disk drive according to the third embodiment of the present invention.
In FIG. 10, reference numeral 60 denotes a first ID field, and 61 denotes a second ID field.

In a magnetic disk drive, in normal use, only data on a data track is rewritten. Other preamble, postamble, ID field,
The gap should be recorded before normal use. This recording operation is called formatting or initialization. In a flexible disk drive, formatting is performed by the flexible disk drive itself before use, or
The method is performed in a process of manufacturing a disk and supplied to a market. Formatting of a disk on which servo information is recorded, such as a large-capacity flexible disk or a hard disk, is performed by a dedicated writing device called a servo writer. In any case, at the time of formatting, it is necessary to sequentially send the magnetic head in accordance with the preamble, postamble, ID field, gap recording pitch, or servo information recording pitch. Therefore, if the recording widths of the first ID field 1 and the second ID field 2 are different as in the first embodiment, the formatting operation becomes complicated. As in the present embodiment, the first ID field 60 and the second ID field
By making the recording width of the field 61 equal, the formatting operation can be prevented from becoming complicated.

Embodiment 4 FIG. In the fourth embodiment, the first ID
POS for the second ID field on each side of the field
This is an example in which the code of is different.

FIG. 11 is a diagram showing a format of an ID field according to the fourth embodiment. In FIG. 11, the first ID field is shaded. The first I
00 is recorded in the POS of the D field, and FF and 55 are recorded alternately in the POS of the second ID field.

The magnetic disk drive of the first embodiment is configured such that when the off-track amount is large and the magnetic head is located in the second ID field, the magnetic head is moved slightly by changing the exciting current of the stepping motor. It had been. In the first embodiment, from the POS of the ID field to F
By reading F, it can be recognized that the magnetic head is off-track. However, since it is impossible to recognize which side is off-tracking, an operation of trial and error necessarily occurs in setting the exciting current value. In the present embodiment, for example, when data is read from or written to the track N, FF is read when the track is off-track to the track N−1, and 55 is read when the track is off-track to the track N + 1. Therefore, it is possible to recognize to which side the magnetic head should be moved, and it is possible to shorten the time until the positioning of the magnetic head is completed.

Embodiment 5 In the fifth embodiment, the first I
This is an example in which the POS codes of the D field and the second ID field are all different values.

FIG. 12 is a diagram showing a format of an ID field according to the fifth embodiment. In FIG. 12, a hatched portion is a first ID field. POS values are different by one in adjacent first ID fields, and POS values are recorded so as to be equal in the same track. By doing so, it is possible to know on which track the magnetic head is located from the read POS value. Therefore, it is possible to substitute the cylinder number information recorded in the ID of the ID field with this,
It is possible to omit the cylinder number code of D.

Embodiment 6 FIG. The sixth embodiment is an example in which means for storing the exciting current value of the stepping motor is provided to improve the time required for completing the positioning of the magnetic head.

FIG. 13 is a block diagram of the micro step driving means according to the sixth embodiment of the present invention. In FIG. 13, reference numeral 66 denotes an exciting current value memory, which is constituted by a RAM in the microcontroller 45 or the like. The microcontroller 45 receives a sector number signal 65 from the state machine 20 in addition to the microstep instruction signal 52. The number of sectors in one track is N, and the exciting current value memory can store N kinds of exciting current values correspondingly.

The operation will be described. First, the positioning of the magnetic head and the reading and writing of data are performed according to the operation procedure described in the first embodiment. At this time, the state machine 20 outputs the sector number included in the read ID to the microcontroller 45 as a sector number signal 65. The microcontroller 45 stores the exciting current value at that time in the exciting current value memory 66 corresponding to the input sector number signal 65. This operation is performed by the host system 11
2 may be executed not only when data is accessed, but also in an initial state such as when power is turned on. Next, when an access to a data track having the same sector number is instructed, the microcontroller 45 performs a magnetic head positioning operation based on the exciting current value stored in the exciting current value memory 66. If the first ID field cannot be read correctly at this time, the exciting current of the stepping motor is changed to change the magnetic head to the first I field.
It is slightly moved to a position where the D field can be read correctly. Then, the contents of the exciting current value memory 66 are replaced with the exciting current value at the time of completing the minute movement. In the present embodiment, in positioning to the same sector, the positioning operation is first performed based on the excitation current value at the time of the previous positioning, so that the operation by trial and error is reduced, and until the positioning of the magnetic head is completed. Time can be reduced.

Embodiment 7 In the seventh embodiment, a burst pattern for learning eccentricity is recorded in a specific area of a magnetic disk, and the magnetic head is positioned based on eccentricity information calculated from the burst pattern. This is an example of improvement.

FIG. 14 is a diagram showing a configuration of a magnetic disk according to the seventh embodiment of the present invention. In this embodiment, a reference track 70 on which an A burst 71 and a B burst 72 for learning the amount of eccentricity of the magnetic disk are recorded.
Are recorded near the outer periphery of the magnetic disk 101. The location where the reference track 70 is provided need not be limited to the outer circumference, but may be provided on the inner circumference side. The recording width of the A burst 71 and the B burst 72 is the same as that of the read gap 35, and the recording is performed alternately with the phases shifted in the radial direction as shown in FIG.

FIG. 15 is a block diagram showing a configuration of a magnetic disk drive according to Embodiment 7 of the present invention. In FIG. 15, reference numeral 73 denotes a position signal generation circuit, and 74 denotes an A / D converter. The position signal generation circuit 73 is a circuit for detecting the amplitude of the A burst 71 and the B burst 72. The detected amplitude value is converted into a digital value by the A / D converter 74 and is taken into the microcontroller 45.

The operation of the eccentricity learning will be described. The learning of the eccentricity is executed in an initial state at the time of turning on the power or at regular intervals. First, the magnetic head 11 is mounted on the reference track 7.
It is sent to the position where 0 is provided. This feed operation
This is performed by the two-phase excitation drive of the stepping motor 107. Two-phase excitation stable point of stepping motor 107 and A burst 7
Since there is a possibility that the radial position where 1 and the B burst 72 contact each other is offset, the offset is corrected first. The offset is corrected by integrating the amplitude data of the A burst 71 and the B burst 72 sequentially taken in by the microcontroller 45, and changing the exciting current of the stepping motor 107 so that the values become substantially the same. This is performed by a minute movement. When the offset correction is completed, the microcontroller 45 stores the amplitude data of the A burst 71 and the B burst 72 for one round or several rounds with the magnetic head 11 stopped, and calculates the eccentricity by calculating the data. Calculate and store.

In this embodiment, a burst pattern for learning eccentricity is recorded in a specific area of the magnetic disk, and the magnetic head is positioned based on eccentricity information calculated from the burst pattern. There is an effect that the positioning completion time of the head can be shortened.

Embodiment 8 FIG. The eighth embodiment is a modification of the seventh embodiment.

FIG. 16 is a diagram showing a configuration of a magnetic disk according to the eighth embodiment of the present invention. A burst 7 of this embodiment
The 5 and B bursts 76 are recorded with the same width as the write gap 36. At the time of eccentricity learning, the signal detected from the write gap 36 is amplified by the R / W amplifier 109, the position signal generation circuit 73 detects the amplitude value,
The digital converter 74 converts the digital value into a digital value and takes it into the microcontroller 45. The detection range of the amount of eccentricity that can be detected from the burst signal is limited by the recording width of the burst signal and the gap width of the head that reproduces the burst signal. Therefore, when the eccentricity is large, the eccentricity may not be sufficiently learned in the seventh embodiment. In this embodiment, the amplitude of the burst signal is detected in the write gap 36 having a wide gap width, so that accurate learning can be performed even when the eccentricity is large.

[0059]

As described above, according to the magnetic disk drive of the present invention, the ID field arranged near the center of the data track and the ID field arranged near the boundary of the data track. Since the recording / reproducing operation is controlled by identifying the data, even when the track density is increased, it is possible to avoid a fatal error such as destroying the data of an adjacent track when writing off-track. This has the effect of ensuring data compatibility. Further, since this effect can be achieved without the erase head, there is an effect that the configuration of the head can be simplified.

The data read operation is performed regardless of the position of the magnetic head, the read data is stored in the memory, and the data is transferred to the host system when no error is detected by the CRC check circuit. Therefore, there is an effect that the data reading speed can be improved.

Further, since the recording width of the ID field arranged near the center of the data track and the ID field arranged near the boundary of the data track are made equal, the recording width of the formatting is made equal. There is an effect that the operation can be prevented from becoming complicated.

When the off-track amount is so large that the magnetic head is located above the ID field arranged near the boundary of the data track, the exciting current of the stepping motor is changed to change the magnetic head. Since the data track is slightly moved on the ID field arranged so as to correspond to the vicinity of the center of the data track, data can be written or read without fail even when the track density is increased.

The ID field arranged near the center of the data track and the I field arranged near the boundary of the data track on both sides of the ID field are arranged.
Since the identification code of the D field is different,
The off-track direction can be detected, and the time required for completing the positioning of the magnetic head can be shortened.

Further, since the identification codes of the ID field arranged near the center of the data track and the ID field arranged near the boundary of the data track are all different values, The cylinder number information recorded in the ID of the ID field can be substituted for the identification code, and the cylinder number code of the ID can be omitted.

Further, a memory for storing the exciting current value of the coil of the stepping motor is provided, the magnetic head is positioned based on the exciting current information read from the memory at the time of data recording and reproduction, and the exciting current information is updated. Therefore, there is an effect that the positioning completion time of the magnetic head can be shortened.

Further, since a burst pattern for learning eccentricity is recorded in a specific area of the magnetic disk and the magnetic head is positioned based on eccentricity information calculated from the burst pattern, the magnetic head is positioned. There is an effect that the completion time can be reduced.

Further, at the time of eccentricity learning, since the amplitude of the burst signal is detected by the write head having a wide gap width, there is an effect that accurate learning can be performed even when the amount of eccentricity is large.

[Brief description of the drawings]

FIG. 1 is a diagram showing a sector format of a magnetic disk device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a magnetic disk drive according to the first embodiment of the present invention.

FIG. 3 is a partial block diagram of the magnetic disk controller according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between a read gap, a write gap, and a track pitch of the magnetic head of the present invention.

FIG. 5 is a diagram illustrating a data track write operation according to the first embodiment of the present invention.

FIG. 6 is a diagram illustrating a data track read operation according to the first embodiment of the present invention.

FIG. 7 is a diagram illustrating a data track read operation according to the first embodiment of the present invention.

FIG. 8 is a block diagram of a micro step driving unit according to the first embodiment of the present invention.

FIG. 9 is a partial block diagram of a magnetic disk controller according to a second embodiment of the present invention.

FIG. 10 is a diagram showing a sector format of a magnetic disk device according to a third embodiment of the present invention.

FIG. 11 is a diagram showing a format of an ID field according to the fourth embodiment of the present invention.

FIG. 12 is a diagram showing a format of an ID field according to the fifth embodiment of the present invention.

FIG. 13 is a block diagram of a micro step driving unit according to a sixth embodiment of the present invention.

FIG. 14 is a diagram showing a configuration of a magnetic disk according to a seventh embodiment of the present invention.

FIG. 15 is a block diagram showing a magnetic disk drive according to a seventh embodiment of the present invention.

FIG. 16 is a diagram showing a configuration of a magnetic disk according to an eighth embodiment of the present invention.

FIG. 17 is a block diagram showing a conventional flexible disk device.

FIG. 18 is a diagram showing a track format of a conventional flexible disk device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 first ID field 2 second ID field 3 data track 4 guard band 10 magnetic disk device 11 magnetic head 12 stepping motor driver 13 control circuit 14 magnetic disk controller 20 state machine 21 PLL circuit 22 AM detection circuit 23 demodulation circuit 24 Serial / parallel conversion circuit 25 CRC check circuit 26 ID comparison circuit 27 POS identification circuit 28 Data transfer circuit 29 Parallel / serial conversion circuit 30 CRC generation circuit 31 Modulation circuit 35 Read gap 36 Write gap 37 Rewritten data track N 38 Past data track N 39 left without overwriting Read track of read gap 40 Track of read gap 45 Microcontroller 46 Matrix circuit 47 D / A conversion Device 48 Current supply circuit 49 Excitation coil 50 Rotor 51 Stator 52 Microstep indication signal 55 Memory 60 First ID field 61 Second ID field 65 Sector number signal 66 Excitation current value memory 70 Reference track 71 A burst 72 B burst 73 Position signal generation circuit 74 A / D converter 75 A burst 76 B burst 100 Flexible disk drive 101 Magnetic disk 102 Disk cartridge 103 Spindle motor 104 Spindle motor driver 105 Magnetic head 106 Carriage 107 Stepping motor 108 Stepping motor driver 109 R / W amplifier 110 Control Circuit 111 Flexible Disk Controller 112 Host System 120 Track 121 Pre Tumble 122 sector 123 postamble 124 ID field 125 gap 126 data tracks.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D096 AA04 BB01 CC02 DD01 DD02 EE02 EE06 EE13 EE18 FF01 FF05 GG01 HH14 HH19 KK01 KK02

Claims (9)

[Claims] A magnetic head having a writing unit for writing data with a predetermined writing width, a reproducing unit for reproducing data with a reproduction width smaller than the writing width; A plurality of data tracks to be written are formed concentrically, and include a code for identifying an on-track arranged at the head of each sector of the data track so as to correspond to the vicinity of the center of the data track. 1 and the first I field so as to correspond to the vicinity of the boundary of the data track.
A magnetic disk having a plurality of concentrically recorded second ID fields including a code for identifying an off-track arranged adjacent to the D field; and a code for identifying the on-track. A magnetic disk drive, further comprising control means for permitting the writing of data to the data track or the reading of data recorded on the data track when the data can be read correctly. 2. A magnetic head having a writing section for writing data with a predetermined writing width, a reproducing section for reproducing data with a reproduction width smaller than the writing width, and a data writing section using the writing section. A plurality of data tracks to be written are formed concentrically,
A first I code comprising a code for identifying an on-track disposed at the beginning of each sector of the data track so as to correspond to the vicinity of the center of the data track;
A second ID field comprising a D field and a code for identifying an off-track arranged adjacent to the first ID field so as to correspond to the vicinity of the boundary of the data track; A plurality of magnetic disks, control means for permitting writing of data to the data track when the code for identifying the track is correctly read, and storage of the reproduced data in a predetermined capacity. A magnetic disk drive comprising: a memory for performing the operation; and a determination unit for detecting an error in the reproduced data. 3. The magnetic disk drive according to claim 1, wherein the recording width of the first ID field is equal to the recording width of the second ID field. 4. An on-track system comprising: a stepping motor for moving the magnetic head; means for switching an exciting phase of the stepping motor; and means for changing an exciting current to a coil of the stepping motor. 3. A magnetic head positioning control means for controlling an exciting current value to a coil so that a magnetic head is slightly moved when a code for identifying the magnetic head cannot be read correctly. The magnetic disk device according to the above. 5. The magnetic disk drive according to claim 4, wherein codes for identifying off-tracks of the second ID field on both sides of the first ID field have different values. 6. A method according to claim 1, wherein a plurality of concentric circles are recorded.
5. The magnetic disk drive according to claim 4, wherein the code for identifying the on-track of the ID field and the code for identifying the off-track of the second ID field all have different values. 7. The magnetic head positioning control means further includes an excitation current value storage means for storing an excitation current value of a coil of the stepping motor, and reads out from the excitation current value storage means when recording or reproducing data. When the magnetic head is positioned based on the exciting current information and the code for identifying the on-track cannot be read correctly, the drive current value is changed by a predetermined amount until the code can be read correctly, and the exciting current value is stored. 5. The magnetic disk drive according to claim 4, wherein the exciting current information stored in the means is updated. 8. The magnetic disk has an area in which a burst pattern of two or more phases is recorded, a circuit for detecting an amplitude value of a reproduction signal of the burst pattern, and an eccentric amount of the magnetic disk based on the amplitude value. And an eccentric amount storage means for storing the operation result of the arithmetic unit, and when recording and reproducing data, positioning the magnetic head based on the eccentricity information read from the eccentric amount storage means. 5. The magnetic disk drive according to claim 4, wherein: 9. The magnetic disk drive according to claim 8, wherein an eccentric amount of the magnetic disk is calculated from an amplitude value of a reproduction signal of a burst pattern obtained from the writing section.