JPS62298975A - Head positioning control method - Google Patents

Abstract

PURPOSE:To obtain a disk driving device with a small wasteful time by positioning a head device to the fine track position of a recording track which is an object based upon the positioning information to the fine track position to a servo track. CONSTITUTION:The driving voltage of a motor when a head device is positioned at the fine track position of a servo track, in case of a stepping motor, a prescribed exciting phase and the exciting voltage value are stored, while the voltage value is held, they are returned to the original recording track, and then, a fine track position is kept even to the recording track. In case of the stepping motor, the exciting phase and the exciting voltage corresponding to respective steps of the number of the step equal to an 1/2 period are stored, they are shifted to the servo track equivalent to the exciting phase in case of the original recording track, the servo information is read, positioned to the fine track position, thereafter, the head is returned to the original recording track position equivalent to the same exciting phase, and by applying the same exciting voltage, the fine track position can be realized.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to a recording head device in an information recording medium drive device that drives an information recording medium to record/reproduce information. The present invention relates to a positioning control method for a track.

[Conventional technology]

Various types of disk drives are known for recording and/or reproducing information by rotationally driving an information recording medium, for example, a disk-shaped magnetic recording medium (hereinafter referred to as a magnetic disk). However, especially for small-sized devices that require a large amount of information, disk U-axis devices, also called hard disk devices, are often used. This hard disk g2 is made by rotating a magnetic disk with a magnetic recording layer formed on the surface of a hard circular surface at a rotational speed.
Recording/reproduction is performed by floating a magnetic head above the surface of a magnetic disk.

An example of this type of disk drive is shown in FIG. In the figure, the disk drive device includes a magnetic disk 1 for recording information, a 6-metal head 2 for recording/reproducing information on and from the magnetic disk 1, and a direct drive (not shown) for rotationally driving the magnetic disk 1. Motor (hereinafter referred to as
A DD motor (abbreviated as DD motor), a head drive mechanism 4 for moving the stone head 2 to a predetermined track on the magnetic disk 1, and a magnetic disk 1, a magnetic head 2, etc. are accommodated and held in a sealed state. Base plate 5 that serves as the base of the housing
It mainly consists of a printed circuit board 6 on which a motor drive circuit, a control circuit, etc. are formed, and a frame (not shown) for attaching this printed circuit board 6 to the base plate 5.

In this magnetic disk device, the magnetic disk 1 is
Two magnetic heads 2 are provided, and since double-sided recording is performed on one magnetic disk l, one magnetic head 2 is provided on each surface, a total of four magnetic heads 2 are provided. It is attached via a support spring. The head drive mechanism 4 consists of this swing arm 8, a steel belt 9 attached to a part of the swing arm 8, a pulley 10 around which the middle part of the steel belt 9 is wound, and a stepping motor 11. The pulley 10 around which the steel belt 9 is wound is inserted into the drive shaft 12 of the stepping motor 11 and fixed, and the stepping motor 1
1, the swing arm 8 can be swung around the rotation shaft 8a.

Magnetic disk 1. Magnetic head 2. Swing arm 8. The casing that houses the steel belt 9, pulley 10, etc.
Consisting of the base plate 5 and a top cover (not shown), gaskets are used at the contact area between the base plate 5 and the top cover and at the mounting area of the stepping motor 11 to maintain airtightness, and magnetic fluid is used at the shaft of the DD motor. is filled. Further, a shutter 17 is protruded and recessed outward on the side 8b where the swing arm 8 is attached.Furthermore, on the airtight chamber Sa side of the base plate 5, a photointerrupter is installed as an outside sensor. 18 is provided, and the insertion path + of this photointerrupter 18 is
The shutter 17 is arranged so as to be loosely inserted into the interior of the shutter 8a. In this conventional example, when the magnetic head 2 reaches the position of the O track on the outer periphery, the shutter 17 blocks the optical path formed in the insertion path 18a of the photointerrupter 18.

[Problem that the invention seeks to solve]

By the way, when moving the magnetic head 2 using the striving motor 11 as described above, as density increases, it becomes difficult to position the head. In other words, in hard disk drives, the expansion coefficients of the materials inside the drive differ;・Magnetic helad 2 against the track due to 1μ degree change
There is a problem called thermal off-track in which the position of the magnetic head 2 shifts, and for this reason, in a 5.25-inch hard disk drive, for example, it is generally necessary to position the magnetic head 2 without using a servo when the magnetic head exceeds 4007 PI. becomes difficult.

One of the control methods using this servo is JP-A-57-86.
There is an invention disclosed in No. 910. This invention provides a track centerline servo $11' that can be read by a head. I
One data-masked servo sector containing t data is used to position the head from servo information once per X rotations of the magnetic disk.

Therefore, in this type of servo control system, the data record 9 is shortened by the amount of servo information, so the rotation speed is slightly lowered to adjust the transfer speed. Therefore, there is a possibility that the head may become slightly unstable.

Another control method using servos is to use the innermost and outermost tracks as dedicated servo tracks. This method uses the internal diameter
meter ), OutSide Diam
This is an abbreviation of ID-OD method.

In this system, the disk device first reads the outer servo track and performs fine 2M alignment so that the head is centered on the track. The head is then moved toward the inner servo track. At this time, head drive +
The number of step pulses of the stepping motor in the b m groove is counted, and when the cough head reaches the inner servo track, the head positioning mechanism performs precise positioning so that the head is centered on the track. and,
During the precise positioning of each servo track, the positioning mechanism learns the amount of correction needed to find the center of the track. Once you know this amount of correction, you can calculate the steps required to move between the outer and inner tracks.
The information regarding the number of pulses and the amount of microstep correction required on each servo track allows the positioning JQ set to calibrate the exact position of each track.

However, with this method, the positioning mechanism has to repeat the calibration procedure every time a positioning error occurs, so if this happens frequently, a lot of time is wasted that is not directly related to recording/playback. Disc drive 8
usage efficiency decreases. Furthermore, once the -rad is on the data track, there is no guarantee that the head will be held in the correct position since there is no means to readjust it.

This invention was made in view of the problems of the prior art as described above, and its purpose is to eliminate the need to reduce the rotation speed (
To propose a head positioning control method that can read servo information at any time and position the head at an accurate track position (fine track position), providing an efficient small disk drive device with less wasted time. be.

[Failure to solve the problem]

In order to resolve the problems faced by the prior art and achieve the above object, the present invention provides a recording medium drive device that writes or reads signals to or from a recording track on an information recording medium via a head device. A method for positioning a head device with respect to a recording track is configured as follows.

First, if a stepping motor is used as a head transport motor for an information recording medium, a preset number, for example, 1 One (pair) or several (pairs) of servo information are assigned in correspondence with an internal index signal to form a servo track. At the time of writing or reading, the head WiZ is moved from the recording track to be written or read to the servo track to which servo information is attached at any time, the servo information is read out, and the read servo 1rt information is used to transfer the head device. By controlling the drive voltage supplied to the motor,
The head device is positioned at a fine track position relative to the servo track.

After that, the head device is returned to the recording track before movement, and the head device is positioned at the fine track position of the target recording track based on the positioning information for the fine track position with respect to the servo track.

[For production]

The above means works as follows.

In other words, the recording medium itself! I] The R device moves the head device from the recording track onto the servo track as necessary, and controls the head transport motor based on the servo information so that the head device comes to a fine track position on the servo track. Then, the head device is returned to the original recording track, and the head device can be positioned at the original fine track position of the recording l/rack based on the motor control information regarding the fine track position of the servo track.

Specifically, the driving voltage of the motor when the head device is located at the fine track position of the servo track, and the predetermined excitation phase and its rib 6f in the case of a stepping motor.
The voltage value is stored and returned to the original recording track with the voltage value held. Then, the fine track position is maintained with respect to the recording track as well. In the case of a stepping mode, the excitation phase and excitation voltage corresponding to each step corresponding to 1/2 period are stored in a recording means such as a RAM, and the excitation phase and excitation voltage corresponding to the excitation phase in the case of the original recording track are stored. The servo information is read out and positioned at the fine track position, and then returned to the original recording track position corresponding to the same excitation phase, and the fine track position is set by applying the same excitation voltage. realizable. Here, the number of steps is set at 1/2 cycle of the stepping motor because it can be assumed that the rotational error of the stepping motor is the same every 1/2 cycle.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

1 to 5 are for explaining the present invention in detail. FIG. 1 is a block diagram showing the first system of a disk drive device according to an embodiment, and FIG. 2 is a block diagram showing a system for recording magnetic disks. Explanatory diagram showing the writing state of tracks and servo signals, Part 3
4 is a block diagram showing an example of a servo circuit, and FIG. 5 is a bottom view of the disk drive device for explaining index detection.

Further, the disk drive device itself is the same as the conventional example shown in FIG. 6, and in the following explanation, the same reference numerals are given to components that are the same or can be considered to be the same as those of the conventional example.

In FIG. 1, the control system of the disk drive device controls the DD motor 3 that rotates the magnetic disk 1 and the stepping motor 11 that swings the swing arm 8, and sends and receives signals to and from the head amplifier 21. The drive circuit 22 is interfaced with a servo circuit 23 that processes the servo information read by the magnetic head 2 and amplified by the head amplifier 21 and sends an electric signal related to servo control to the drive circuit 22. 2
It mainly consists of a controller 25 which controls the controller 25 via a controller 41. The controller 25 and host computer 26 are connected by a bus 27, and are capable of processing signals detected by the magnetic head 2 or signals sent to the magnetic head 2.

FIG. 3 shows the servo tracks formed on the 6-speed disk 1 and the recording tracks to which no servo information is attached. The magnetic disk 1 is made of a thin aluminum plate coated with a magnetic coating, An inhibit zone (2) in which data is not written is formed on the circumference side, and a data zone D is formed on the outer circumference side.In the data zone D, recording tracks T inside and outside the 600 trees are formed concentrically, and further, This data zone D is divided into approximately three parts, and each zone is formed with a nervo track group consisting of 94 tracks as shown in FIG. O3T, an intermediate servo track group MST, and an inner servo track group IST; each servo track group O3T, MS
T, IST is the servo zone OS in which the servo signal F is written as servo information with the position shifted by 130 degrees.
Z.

03Z2. MSZ,,MSZ,,I SZ,,I SZ
2 is formed.

FIG. 2 is an explanatory diagram of a servo track group MST formed, for example, in the middle part, and the servo track group MST has four
Book servo track MST+, MSTz,
It consists of MSTx and MST4. And each servo track MST+, MSTz, MS
Ts, MST4 correspond to the first and second internal index signals IN+, 1N2, at positions equidistant with respect to the center line C in the longitudinal (circumferential) direction,
Servo signals F are written alternately in a staggered manner at the same frequency. And this is the above servo zone MSZ+1
It corresponds to MS Zz. In this case, since the servo signal F is written with the same magnetic head 2, the servo signal F, the recording track T, and the servo track MST + ~
The track width of MSTa matches the gear G length of the magnetic head 2, and off-track occurs when the position of the gap G of the 6ffi magnetic head 2 deviates from the target recording track T.

In this embodiment, servo zones OSZ, and 0S2.
, MSZ, and MSZz, ISZ, and l5Z2 are formed with a phase shift of 180 degrees because
This takes into consideration the convergence time for correcting the position of the magnetic head 2 and the rotation time per rotation of the magnetic disk 1.

In other words, the time required for one rotation of the magnetic disk 1 is 3
Assuming 600 rpm, it is about 16.67 m5ec, and the convergence time after driving the stepping motor 11 is about 3ms e
It is c. Therefore, the phase of the servo zone is 180
For example, if the first internal index signal I
Servo zones O3Z+, MSZ, ,I corresponding to N,
The servo signal F of SZ, is read out and the position is corrected, and immediately after the correction operation converges, the servo zone 05Zz, MSZ corresponding to the second internal index signal INz is read out and corrected.
By reading out the servo signals F of z and I SZz, it is possible to detect whether or not the corrective action is appropriate. In this case, the rotation time per rotation of the magnetic disk 1 and the stepping motor 1
Since the convergence time of 1 is in the above relationship, the phase of the servo zones is shifted by 180 degrees to provide 2 servo zones per revolution, but this is because the stepping motor 1
1 or other types of drive motors depending on the convergence time of the positioning operation, the number of revolutions of the recording medium, etc. However, even if the motor type is different, it is thought that providing one or several servo zones per revolution will function satisfactorily.

In addition, in this disk drive device, the above-mentioned Noyo Nisahozu-70SZl, 03Zz, MSZ+,
MSZ! , I SZt , I SZt are formed with a phase difference of 180 degrees, so the first and second internal index signals I N+ and I Nt also have a phase difference of 180 degrees.
A phase difference of degrees is required. In order to deal with this, for example, as shown in FIG.
A magnet (hereinafter referred to as PC magnet) 4 is provided as a pulse generating means on the outer periphery of the rotor 3a of the motor 3.
0 is attached, and the magnetic change from the PG magnet 40 is applied near the outer circumference of the rotor 3a of the DD motor 3, at a position symmetrical to the rotation center of the DD motor 3. Detection means (hereinafter referred to as PG sensor) 41a, 41 such as a coil or a Hall element provided
b, and the detected pulse is detected by the first and second pulses.
Internal index signal ■N1. It is set as IN2.

Next, the reason why four servo tracks form a group will be explained.

In the stepping motor 11, the rotation angle per -step is not completely the same due to errors in the formation interval of the magnetic pole teeth, errors in the magnetization interval of the rotor, and the like.

Therefore, when a four-phase unipolar type or a two-phase bipolar type stepping motor is used, one cycle consists of a total of 8 steps: 4 steps with 1-phase excitation and 4 steps with 2-phase excitation. At this time, it is known that the rotation angle error due to the excitation (n phase) shows the same pattern every 1/2 period. If the excitation voltages are matched (it can be corrected), when the same excitation phase and excitation phases shifted by 1/2 period are excited, every fourth recording track T can be controlled by 2. !1 Conditions are the same.

The outer circumference of the servo track group MST shown in Figure 2 and the circumference 1! The track located at i11 is the guard track GT, and the guard track GT and the servo truck M
Tracks other than the servo signal T forming section of S T l'' M S T 4 are dummy tracks DT, and these may not be used as data areas. Note that the symbol E I N shown in FIG. Counting starts when the first index signal IN is detected as an index signal, and when a preset count number is detected, the external index signal IN is sent to the host computer 26 side. This external index signal EIN is used in step 2 as a finger for writing to or reading from the recording track T of the data track T.

Next, let us explain the operation of the disk drive device configured as described above.

There will be a relatively large temperature difference between the disc drive and the drive when it is not used. Immediately after inserting the disk drive, First, the magnetic head 2 force scans the surface of the disk once, and stores the electrical uniformity of the wJ magnetic phase of the stepping motor 11 corresponding to each recording track T in the RAM of the drive circuit 22.
Create a RAM table.

A positioning correction method that takes temperature rise into account is stored in advance in the microcomputer, and recording/reproduction is normally performed according to the servo algorithm stored in this microcomputer. That is, when a predetermined excitation phase is excited according to the above RAM table and recording/reproduction is performed on a desired recording track T, a servo command is sent from the microcomputer to the drive circuit 22 according to the above preset servo algorithm. When a command is issued, the magnetic head 2 is moved to the recording track T of the servo zone MST closest to the recording track T (or Ts), for example, where it is currently located.

(T,) and the same excitation (servo track corresponding to the ■ phase,
For example, it is located at MST+ in FIG.

In this case, if the recording track is at the T, (Ti) position, then the servo track is at the M S T z position.
If Ti (Tt) position, then MST3 position, T, (Ts)
If it is a position, it will be located at the MST position. In this embodiment, one of the stepping motors 11
In this example, the cycle is set to 8 steps, so four servo tracks are provided for one servo zone corresponding to the number of steps per 1/2 cycle of the stepping motor 11. It goes without saying that the number of servo tracks may vary depending on the control method and the number of servo tracks.

Now, when the same 1iil] magnetic phase is excited with the same voltage value and the gap G of the magnetic head 2 is at the position A in FIG. 2 and the servo signal F is read, the first read servo signal level is There will be a difference in the servo signal level read later. Therefore, the signal is discriminated by the sample/hold circuits 28 and 29 of the servo circuit 23 as shown in FIG. 4, and the signal level is compared by the comparison circuit 30.

Then, the servo amplifier 31 sets a voltage value to be applied to the excitation phase of the stepping motor 11 according to the comparison value, and the stepping motor 11 is controlled via the drive circuit 22. As a result, the gap G of the magnetic head 2 moves to a symmetrical position with respect to the center line O, as shown as position B in FIG. 2, and converges, thereby defining a fine track position with respect to the servo track MST.

Immediately after the movement of the magnetic head 2 converges, for the above-mentioned reason, the servo signal F of the second servo zone MSZ is read out, and it is determined from this second servo zone MSZ whether or not the above movement is appropriate. do. That is, if the output from the comparison circuit 30 in the second servo zone M S Z z is below a preset level, the above-mentioned moving state is maintained as it is, and if it is below the preset level, the stepping motor 11 is started again. A similar position control is performed by driving the magnetic head 2 to position the magnetic head 2 at a proper track position, that is, a fine track position.

Then, the voltage value applied to the excitation phase of the stepping motor 11 when located at the fine track position is superimposed on the RAM of the drive circuit 22, and the magnetic head 2 is
Returning to the original recording track T3 position while checking the M table, the gear G position with respect to the recording track T1 is defined by the voltage values stored in the R4 to M. As a result, a fine track is also realized for the recording track T.

The RAM table is updated at any time in response to temperature rises or over time, so that the magnetic helad 2 is always controlled based on the latest position data. During recording/reproduction, the head position is not only corrected (e) according to the servo algorithm, but also the controller 2
The head position is determined in the same manner as described above using the control of the head 5 and the host computer 26, so that recording/reproduction is always performed in the best condition.

In addition, in the above embodiment, the servo track group O3T
, MST, and IST are provided in three locations, but these servo track groups OS T, MST, and IST are
(It is selected as appropriate depending on the diameter and track density of the n-air disk 1. Also, the servo algorithm can be modified in various ways depending on the design concept, and it goes without saying that the above embodiment is only one example. do not have.

In addition, when setting the servo tracks above, in order to determine the servo track position, the servo track group O3T on the outer periphery is positioned at the outermost periphery, and the servo track OS
It is useful to match Tl to the zero track.

Furthermore, in the above embodiment, the stepping motor 1
1 is shown, but it is also possible to use other devices such as a voice coil motor or a DC)
In that case, transfer control corresponding to each case will be introduced.

〔Effect of the invention〕

As described above, a servo track in which servo information is written in correspondence with an internal index signal is formed on the information recording medium, and the head device is moved to this servo track at any time to apply servo control to the head device. According to this invention, the servo is positioned at the fine track position of the servo track, and based on the positioning information at this time, the servo is moved back to the recording track position before movement and positioned at the fine track position of the recording track. By reading the information, it is possible to position the head device at the correct track position, providing an efficient disk drive with less wasted time during positioning, and writing servo information only to specific tracks to make them servo tracks. Therefore, other tracks can be used for recording/reproducing over the entire circumference, and there is no need to reduce the rotational speed of the magnetic disk, making stable recording/reproducing possible.

[Brief explanation of drawings]

1 to 5 are for explaining a disk drive device according to an embodiment of the present invention. FIG. 1 is a block diagram showing a control system, and FIG. 2 is a recording track and servo track of a magnetic disk. 3 is an explanatory diagram showing the outline of the recording track and servo track of the magnetic disk, FIG. 4 is a block diagram showing an example of a servo circuit, FIG. 5 is a bottom view of the disk drive device, FIG. 6 is a partially cutaway perspective view of a main part of a specific example of a conventional disk drive device. 1...Magnetic disk, 2...Magnetic head, 3...
DD motor, 8... Swing 7-me, 11... Stepping motor, 21... Head amplifier, 22... Drive circuit, 23... Servo circuit, D... Data zone, F... Servo signal, O3T, MST, TST...
Servo track group, MST+, MSTz, MSTt
, MSTa...Servo track, OSZ,, ○
SZ,, MSZ,, MSZ,, ISZ,, l5zz・
... Servo zone, T... Recording track, IN,, I
N2...Internal index signal. Figure 3 Figure 4

Claims (2)

[Claims] (1) In a recording medium drive device that writes or reads signals to or from a recording track on an information recording medium via a head device, in a method of positioning the head device with respect to the recording track, a preset The head device forms a servo track in which a number of servo information is written in correspondence with an internal index only at a preset track position of the information recording medium, and at the time of writing or reading, the servo track is moved from the recording track to be written or read at any time. The drive voltage supplied to the transfer motor of the head device is controlled using the read servo information to position the head device at a fine track position relative to the servo track. Along with returning to the recording track,
A head positioning control method comprising positioning a head device at a fine track position of a target recording track based on positioning information to a fine track position with respect to a servo track. (2) In the statement of claim (1), the transport motor of the head device is a stepping motor, and the servo tracks are adjacent to each other the same number of tracks as the number of steps in 1/2 period of the stepping motor. A head positioning control method characterized in that: