JPH01237975A - Disk device - Google Patents

Abstract

PURPOSE:To attain satisfactory tracking control without reducing a recording information quantity by separating an eccentric error component and a deformation error component from tracking error data for the average central position of a reference track and calculating the control information for respective tracks. CONSTITUTION:A tracking error between the average central position of a track Ts and the center of a magnetic head device 7 is detected through a CPU 4, etc., from a regenerating signal by a servo head 7b concerning a servo area S of a reference track Ts provided at the outer-most side and inner-most side of plural data tracks Tb. A tracking control is executed, the track control data corresponding to the DC component, the deformation error component of the AC component and the eccentric error component calculated and detected finally are determined, the control data for respective tracks Tb are calculated and written from these control data to a memory 5. The tracking control is executed in accordance with the writing contents, and the satisfactory tracking control of a head device is executed without reducing the recording information quantity.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Field of industrial application B. Summary of the invention C. Prior art D. Problem to be solved by the invention E. Means for solving the problem 1. , relates to a disk device that performs recording and reproduction using a disk medium.

B. Summary of the Invention The present invention uses a disk medium provided with a plurality of data tracks having at least one servo area and a reference track having servo areas in multiple places around the entire circumference. Tracking error data with respect to the average center position is detected, an eccentricity error component and a deformation error component are separated from this tracking error data, data based on these two components is stored in a storage means, and this is used when scanning data tracks. By tracking the position of the recording/reproducing head device based on the data stored in the storage means, it is possible to perform good tracking control without reducing the amount of information that can be recorded on one data track. This is what I did.

C. Prior Art Conventionally, various types of disk devices have been known for recording and reproducing information signals using disk media.

In such a disk device, in order to improve the recording density on the disk medium, a recording/reproducing head device that faces the disk medium and performs recording/reproducing is positioned in the radial direction of the disk medium by controlling its position. so that the device accurately scans the data tracks formed on the disk medium.
It has been proposed to perform so-called tracking servo.

In a magnetic disk device using a magnetic disk as a disk medium, a sector servo method, for example, is adopted as a tracking servo method. Figure 13 shows
A magnetic disk used in a magnetic disk device employing this sector servo method is shown. That is, a servo area S of a predetermined length is formed at each predetermined angular position of each of a plurality of data tracks To formed on the magnetic disk (1). And data track T
The portion of D other than the servo area S is used as a data area for recording and reproducing information signals.

When this magnetic disk (1) is rotationally driven and the magnetic head device scans over the servo area S, the servo signal recorded in this servo area S is reproduced, and based on the state of this servo signal, the data track Ttl A radial positional deviation of the magnetic disk (1) between the magnetic head device and the magnetic head device is detected.

The position of the magnetic head device is controlled in the radial direction of the magnetic disk (1) based on the reproduced servo signal by a predetermined control means and drive means of the magnetic disk device, and the positional deviation between the magnetic head device and the data track TD is controlled. controlled so that it disappears. In this state, the magnetic head device reproduces the information signal recorded in the data area or records the information signal in the data area.

D Problems to be Solved by the Invention In a magnetic disk device that employs the sector servo method, in order to increase the number of data tracks To and increase the recording density of recorded information signals, it is necessary to improve the accuracy of the tracking servo. For example, it is possible to increase the number of servo areas S per rotation of the magnetic disk (1) and reduce the distance between the servo areas S.

However, if the number of servo areas S is increased, the accuracy of tracking servo is improved, but the area of the data area is reduced, and an increase in the amount of information that can be recorded on the magnetic disk (1) as a whole cannot be expected.

By the way, the data track TD for the magnetic head device
The deviation is a periodic fluctuation with one rotation of the magnetic disk +11 as one period. The main reason for this periodic fluctuation is that the frequency is the same as the rotation frequency of the magnetic disk (1), the eccentric component due to eccentricity with respect to the rotation center of the magnetic disk (1), and the twice the rotation frequency of the magnetic disk (1). It is a deformation component due to symmetrical deformation of the magnetic disk (1), for example, elliptical deformation. in this case,
Eccentricity occurs, for example, when the magnetic disk (1) is chucked, and deformation occurs, for example, due to anisotropy of the base plastic. The eccentric component is constant in any data track To of the magnetic disk (1), but the deformation component is the data track T of the magnetic disk (1).
It is small at the inner circumference of O and becomes large at the outer circumference.

The present invention takes these points into consideration and aims to enable good tracking control without reducing the amount of information that can be recorded on one data track.

E. Means for Solving the Problems The present invention provides a system in which a plurality of data tracks To each having a servo area S at one location and a reference trunk 1's having a servo area S at multiple locations over the entire circumference are provided. means for detecting tracking error data with respect to the average center position of the provided disk medium (1) and the reference trunk; and means for separating eccentricity error components and deformation error components from the tracking error data; , storage means for storing data based on the two separated components, and means for tracking and controlling the position of the recording/reproducing head device based on the data stored in the storage means when scanning the data track 'I''D. It is equipped with the following.

F Function In the above configuration, when scanning the data track 'I'm, the recording/reproducing head device scans the reference track '1'.
Since the position is drama king controlled based on the tracking error data detected by s, the servo area S
The recording/reproducing head device is also subjected to tracking control in other parts. Moreover, in the above configuration, the tracking error data detected from the reference trunk 1゛s is
Each data track T is separated into an eccentricity error component that is constant in any data track D, and a deformation error component that is small at the inner circumference of the data track TD and large at the outer circumference.

Tracking control data corresponding to this is formed, and the recording/reproducing head device is tracked and controlled using this data.

As a result, good tracking control is performed without reducing the amount of information that can be recorded on one data track To.

G. Example Hereinafter, an example of the present invention will be described with reference to FIG. In this example, a magnetic disk is used as the disk medium.

In the figure, (1) is a magnetic disk. A plurality of data tracks TD are formed on this magnetic disk (1). These data tracks 'ro are formed concentrically around the rotation center of the magnetic disk (1), and each center line is arranged at a predetermined pitch shown by p in FIG. 2 in the radial direction of the magnetic disk (1). (For example, 32μl11
). These data tracks TD
, servo areas S in which servo signals are recorded and data areas S in which information signals are recorded are arranged alternately along the rotational direction R of the magnetic disk (1).

The data area has a predetermined width (for example, 2
6μI), and this data area includes, in addition to the information signal, the number of the data track To (trunk number), the length area S of each data area, at least one location in one data track TD, In this example, it is provided at the AWJ location, and in this servo area S, a servo signal recording pattern S1 in which a servo signal of frequency f1 is recorded and a servo signal recording pattern S2 in which a servo signal of frequency f2 is recorded are formed. . These servo signal recording patterns 31. S
2 each have a predetermined distance (for example, 10 μm) indicated by W2 in FIG. 2 in the radial direction of the magnetic disk (1), and are provided alternately in the radial direction of the magnetic disk (1). Moreover, these servo signal recording patterns SL.

S2 is arranged at a pitch equal to the pitch of the data track "I"D (for example, 32 μm), and at a half pitch (for example, 16 μm) to the center line of the data track "I'o".
μm) in the radial direction of the magnetic disk (1). That is, the servo signal recording patterns SL and S2 are formed at an intermediate position between two adjacent data tracks=I'o.

Further, a reference track Ts is provided on the outermost circumferential side and the innermost circumferential side of the plurality of data tracks To. On the reference trunk rs, servo areas S similar to the servo areas S of the data track TD described above are provided at predetermined locations, 32 locations in this example, at equal angular intervals over the entire circumference.

Further, (2) is a disk rotation drive means for holding and rotationally driving the magnetic disk (1). This disk rotation driving means (2) includes a spindle motor (not shown), and the rotation of this spindle motor is as follows:
Controlled by CPU (41).

Further, (3) is a recording/reproducing means. This recording/reproducing means (3) has a predetermined l'I! indicated by W3 in FIG. ii(
For example, an erasing magnetic head (7a) having a width of 32 μm) and a recording/reproducing magnetic head (7a) having a predetermined width (for example, 26 μm) narrower than the width of the erasing magnetic belly button (7a) indicated by W4 in FIG. A magnetic head device (7b) consisting of a magnetic head device (7b)
) is provided. In the reproduction mode, the erasing magnetic head (7a) reproduces the servo signals recorded in the servo signal recording patterns Sl and S2, and in the recording mode, it reproduces the servo signals and erases data already in the data area. The recorded information signal is controlled to be erased. Furthermore, in the reproduction mode, the recording/reproducing magnetic head (7b) reproduces the information signal and ID signal recorded in the data area, and in the recording mode, it reproduces the ID signal and also reproduces the ID signal recorded in the data area. It is controlled to record the information signal accordingly.

A reproduction signal from the recording/reproducing magnetic head (7b) is supplied to the CPU (4) via a head amplifier (7c).

Furthermore, the reproduced signal of the erasing magnetic head (7a) is filtered through a band-pass filter (
8) and pan 1 for extracting only the frequency f2 component
- fed to the pass filter (9); The output signals of the bandpass filters (8) and (9) are then supplied to level detection circuits (10) and (11) that perform envelope detection, peak detection, etc., respectively.

The output signals of these level detection circuits (10) and (11) are sent to the H/D converter (13) via a changeover switch (12). This changeover switch (12) is for time-division use of the AID converter (13). The output data of the A/D converter (13) is then supplied to CP tJ (41).

Further, (6) is a moving means to 7 which is controlled by the CPU f41. The magnetic head device (7) moves the magnetic disk (1) by this head moving means (6).
movement is controlled over the inner and outer circumferences of the This head transfer 01
The means (6) includes a coarse movement step motor (14a) and a fine movement step motor (14b), and these step motors (1, 4a) and (14b) are
A control signal is supplied and controlled via the CPU (41 to A/l) converter (15). In particular, tracking control data is supplied to the fine movement step motor (14b) via the CPU (4,1 to l)/A converter (15), and this fine movement step motor (14b)
b) is finely controlled.

Further, (16) is a head position detection device, and the magnetic head device (7) is a reference track 'r' of the magnetic disk (1).
This is to detect whether or not it is located at a position corresponding to s.

The output signal of this head position detection device (16) is transmitted to the amplifier (
17) to the CPU (41).

In addition, (5) is a storage device consisting of, for example, a RAM, (1
8) is an operation input device, and (19) is a display device, each of which is connected to the CPU (41).

In addition, CPU (41 is A/L) converter (13
) is used to calculate tracking error data representing the product of the positional deviation between the magnetic head device (7) and the data track To, or the so-called off-track amount. That is, the servo signal, which is the reproduced signal of the erasing magnetic head (7a), is a product of the servo signals recorded in the servo signal recording patterns Sl and s2, and each servo signal is passed through a bandpass filter. (8) and (9). When there is no off-track, the erasing magnetic head (7d) comes into sliding contact with the servo signal recording patterns S1 and S2 with the same width, and the servo signals in the sliding contact portions are reproduced. Therefore, the level F of the servo signal reproduced from the servo signal recording patterns S1 and S2, respectively.
The levels of 1 and F2 will be equal to each other. Furthermore, when there is an off-track, the erasing magnetic head (7a) comes into sliding contact with the servo signal recording patterns S1 and S2 at different widths, and the servo signals in the sliding contact portions are reproduced. Therefore, the servo signal recording pattern st
The levels of levels F1 and D2 of the servo (No. 6) that are reproduced from F1 and S2 are different from each other depending on the off-track amount. Therefore, from the change in the ratio of levels F1 and D2, the CP U (In 41, l-racking error data is calculated.

In addition, the CPU (41 is a magnetic head for recording and reproducing (7)
The information signal recorded in the data area is reproduced from the reproduction signal supplied from b) via the head amplifier (7C), and the data area is also reproduced by supplying the information signal to the recording/reproducing magnetic head (7b). The information signal is recorded.

Further, CP Ll (41) is configured to perform predetermined operations as shown in the flowcharts of FIGS. 3, 5, and 6 in relation to position control of the magnetic head device (7). That is, a first operation (JOBI) for performing detection 1 calculation and storage of i-ranking error data.

Magnetic head device! ¥(7) to the specified data track 'I
- second operation (JOB2) and data track T sent to o.

The third operation (JOB
3).

The flowchart in Figure 3 is 1. This indicates JOBl. That is, if a recalibration command (RECAL command) is issued at predetermined intervals, for example every 5 minutes,
In step ■, the magnetic head device (7) has 0 trunk,
That is, it is sent to the position of the outermost reference track rs. The magnetic head device (7) is located on the outermost reference track '1.
゛The head position detection device (16) determines whether or not it has been sent to S.
The decision is made based on the output signal of.

The magnetic head device (7) is located on the outermost reference trunk 'I''S.
When the subroutine CALL is sent to the position shown in FIG. In this subroutine CALL, the outermost reference track Ts is reproduced, and in step 0, 3 of the entire circumference of this reference track Ts is reproduced.
Tracking error data for two servo areas S is calculated. Then, it is checked from this tracking error data whether there is a DC component (deviation component between the average center position of the reference track "rs" and the center of the magnetic head device (7)).DC component There is (NG
), tracking control data for the DC component is calculated in step 0, and tracking control of the magnetic head device (7) is performed based on the calculated trunking control data Do. return. The above-described operation is then repeated until the DC component disappears.

In addition, when it is judged that there is no DC component (OK) in step ①, in step 0, this criterion 1 - rank T
Tracking error data for 32 servo @ areas S around the entire circumference of s is calculated. This tracking error data is an AC component (tracking error data with respect to the average center position of the reference track Ts). and,
From this tracking error data, it is checked whether there are A or C components. There are A and C components (NG)
When it is determined that The tracking control in (7) is performed and the process returns to step 0. The above-mentioned operation is then repeated until the AC component becomes zero.

Further, when it is determined in step (2) that there is no AC component (OK), the process returns.

In the flowchart of FIG. 3, the finally calculated tracking control data Do for the DC component and the 1-rough king control data DOo=DO3z for the AC component are stored in the storage device (5) in step (2).
is written and saved.

Next, in step ■, a seek command (5EEK command) is issued, and in the operation of JOB2, the magnetic head device (7)
It is sent to the position of base *+- rank "T's" on the innermost circumference.

Whether or not the magnetic head device (7) has been sent to the innermost reference track TS is determined based on the output signal of the head position detection device (16). The flowchart in Figure 5 is as follows:
This indicates JOB2. When a seek command is issued,
In step (2), the magnetic 7F device (7) is sent to the position of the innermost reference trunk Ts. Then, in step (2), a settling wait is performed and the operation ends.

Further, in step (2), when the magnetic head device (7) is sent to the position of the innermost reference track Ts, in step (2),
Go to subroutine CALL. Then, in the same manner as in step (2), trunking control data DI for D99 minutes and tracking control data DIo=DI3t for the AC component are calculated. Then, in step (2), the tracking control data DI is finally calculated.

DIo''DI3t is written and saved in the storage device (5) in step (2).

Next, in step (2), from the tracking control data D Oo to DO31 for the AC component in the outermost reference trunk Ts written in the storage device (5),
The eccentricity error component D OG ~D Oz'1 and the deformation error component D Og = D Oj's are separated.

In this case, the eccentricity error component is the head scanning trajectory T in FIG.
As is clear from the above, the rotational speed of the magnetic disk (1) is f
Hz, it is expressed as k 5in (2πf t+a) and becomes a sinusoidal signal of r llz as shown in FIG. On the other hand, as is clear from the head scanning trajectory T in FIG. 9, the deformation error component is i! when the rotational speed of the magnetic disk (1) is f)Iz. 5in(4πft+
β), and as shown in FIG. 10, it becomes a 2 rHz sine wave signal. Here, k and f are constants, and α1β is the initial phase.

From this, the tracking control data DO.

By subtracting DOIC~D031 from ~DO1s and dividing by 2 to obtain data d6~d1'5, eccentricity error components DCB+~DOt's and DOt'e
~■]03'1 is d6~d□'5 and -d
6 to -d1'5.

Also, tracking control data D Oo = D O
ts and DOIG-DO31 are respectively added and then divided by 2 to obtain data ddi~a1'I. Then, the deformation error components Doji~Do crystal and D01''=,~Do crystal are d3~d1, respectively. 't.

Therefore, the tracking control data D Oo~D O
From 31, data d:o''d x'5 and d:
')~d1''S is calculated, the eccentricity error component D06~1〕○]'1 and the deformation error component Dog~D0
3″1 is separated.

Similarly, tracking control data D I o for the AC component on the innermost reference track Ts
``From DI 31, eccentricity error component DI6~I)l''
1 and the deformation error component D l g -D I5 are separated.

Here, since the amount of eccentricity is constant from the innermost circumference ID to the outermost circumference OD as shown in FIG.
As the eccentricity error components D6 to D3'1 at o, the eccentricity error components D06 to D03'l or DIIS-D13't at the outermost and innermost reference tracks Ts can be used, but in this example, the measurement Taking into account errors, the average value is calculated. Furthermore, as shown in FIG. 12, the amount of deformation increases from the innermost circumference ID to the outermost circumference 01), so assuming that this increase is linear, between the innermost circumference ID and the outermost circumference O
When there are X tracks between f), K (K=1
~X) The deformation error components Do(k) to D31(k)'' in the data track 'ro' of the track are as follows.

In the end, the tracking control data Do=I)at for the AC component in the data track To of K (K=1 to X) tracks from the outer circumference side is calculated and sequentially written into the storage device (5).

Furthermore, since the tracking control data for the DC component is constant from the innermost circumference ID to the outermost circumference OD, the tracking control data DDC for the DC component in each data track ゛D is used as the reference track T of the outermost circumference and the innermost circumference. Although the tracking control data Do or Dl for the DC component at s can be used, in this example, the average value □ is used in consideration of the measurement DO+Dl error. In the end, vC in each data track 1゛D
Tracking control data Doc for the component is written.

Next, in step ■, a seek command is issued and JOB2
With this operation, the magnetic head device (7) is sent to the 0 track, that is, the position of the outermost reference track 'FS, and the operation is completed.

Further, the flowchart in FIG. 6 shows JOB3. That is, a seek command is issued, and in the operation of JOB2, the magnetic head device (7) moves to a predetermined data track T.
When sent to o, in step ■, from the storage device (5),
Tracking control data on the data track TD is read out, and tracking control is performed based on this tracking control data. Then, at step (■), the process waits for settling, and then proceeds to step (○).

In this step [phase], trafking error data for the servo area S provided in the data track To is calculated. Then, it is checked from this trafficking error data whether there is a DC component and an AC component. When it is determined that there are a DC component and an AC component (NG), tracking control data (error data) for the DC component and AC component are calculated in step (2).

Then, tracking control of the magnetic head device (7) is performed with this calculated error data taken into account, and the process returns to step. The above-described operation is then repeated until the DC component and AC component disappear.

Also, since the step, there are no DC and AC components (
When it is determined that the tracking control data is OK, the adjustment of the tracking control data is completed.

In this example, the recording/reproducing head device (7)
When scanning the data track To, the tracking control data in the data rack I'o formed by scanning the reference track Ts is read out from the storage device (5), and the tracking control data is applied to the data track I'o. Since tracking control is performed based on the servo area S
Tracking control is also performed in other parts. Moreover, the l-roughing control data for the AC component in each data track 1'D converts the tracking control data for the AC component formed by scanning the reference track Ts into an eccentric error component and an eccentricity error component that are constant in any data track To. , is formed after being separated into deformation error components that are small at the inner circumference and large at the outer circumference of the data track To. Therefore, according to this example, there is an advantage that good tracking control can be performed without reducing the amount of information that can be recorded on one data track To.

In the above embodiment, the reference track 'Fs is provided with 32 servo areas S over the entire circumference, but generally there are 2N (N is a positive integer) servo areas S. In the case where the servo area S is formed in
Similarly to the above embodiment, the eccentricity error component and the deformation error component can be separated from the tracking control data for the AC component formed by scanning the reference track 1's, and the tracking control data for the AC component in each data track To can be separated. can be formed.

Further, in the above embodiment, the reference trunks Ts are provided at the outermost and innermost sides of the plurality of data tracks To, respectively, but the positions of the reference tracks Ts are not limited to this. Alternatively, there may be only one reference trunk Ts. When one reference track Ts is provided, the eccentricity error components of the tracking control data for the DC component and the tracking control data for the AC component in each data track 1'D are essentially constant in each data track 'rD. The deformation error component of the tracking control data with respect to the AC component in each data track '1'D is calculated by scanning the reference track Ts of
- Since it is small at the inner circumference of rank To and large at the outer circumference, it is estimated from what is obtained by scanning this one reference track 1's.

Furthermore, the data stored in the storage device (5) may be the tracking error data itself.

In this case, the tracking control data required when actually supplying the head moving means (6) is stored in a separate storage means, and when the tracking control data is actually supplied to the head moving means (6), the tracking control data is based on the tracking error data. All you have to do is get it.

Further, the present invention is not limited to devices using magnetic disks as described above, but can be applied to devices that employ a so-called sector servo method and record and reproduce information signals using various recording methods.

H Effects of the Invention According to the invention described above, when scanning a data track, the position of the recording/reproducing head device is track-controlled based on the tracking error data detected by the reference track. , Tracking control of the recording/reproducing head device (a) 11 is performed even in areas other than the servo area, and the tracking error data detected from the reference track has an eccentricity error component that is constant for any data track, and an eccentricity error component that is constant for any data track. is separated into deformation error components that are small at the inner circumference and large at the outer circumference, and tracking control data corresponding to each data track is formed based on these two components, so the amount of information that can be recorded on one data track is (There is an advantage that good tracking control is performed without reducing the

[Brief explanation of the drawing]

Figure 1 is a configuration diagram showing one embodiment of the present invention, Figures 2 to 1
FIG. 2 is a diagram for explaining this, and FIG. 13 is a diagram for explaining a conventional example. (11 is a magnetic disk, (2) is a disk rotation drive means, (3) is a recording/reproducing means, (4) is a CPU, (5) is a storage device, (6) is a head moving means, (7) is a magnetic head It is a device.

Claims (1)

[Scope of Claims] A disk medium provided with a plurality of data tracks having at least one servo area and a reference track having servo areas at a plurality of places over the entire circumference; means for detecting tracking error data with respect to the center position; means for separating eccentric error components and deformation error components from the tracking error data; storage means for storing data based on the two separated components; and means for tracking and controlling the position of the recording/reproducing head device based on the data stored in the storage means during scanning.