JPS63263674A - Track servo method for rotary disk device - Google Patents

Abstract

PURPOSE:To always attain highly accurate track servo even if a deviation between sectors is large by previously storing a track deviation due to eccentricity to execute track servo. CONSTITUTION:Reproduced signals from a head 1 are inputted to a comparator 4 through BPFs 2a, 2b having respective frequency f1, f2 and peak detecting and holding circuits 3a, 3b and a deviation of each servo signal is detected. Its deviation signal is inputted to a memory 12 through A/D converters 11, 16. On the other hand, signals from the BPFs 2a, 2b are inputted to an address counter 13 and its address value is inputted to the memory 12. A signal for increasing an address value by one step is inputted from a terminal 14 to the memory 12 through a switch 15 and track deviations detected by servo signals are written in respective addresses of the memory 12. When a switch 15 is turned on after completing the writing, a signal read out from the memory 12 is added to a signal outputted from the circuit 4 by an adder 17 and the added signal is sent to an actuator 6 to execute track servo.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a track servo method for a rotating disk device such as a hard disk device.

[Summary of the invention]

The present invention relates to a track servo method for a rotating disk device, in which the amount of track deviation due to disk eccentricity obtained from a servo signal is stored, and track servo is performed using the stored deviation amount, the reproduced servo signal, and K. This makes it possible to perform extremely high-precision track sensors.

[Conventional technology]

In a rotating disk device such as a hard disk device, the tracks on the rotating disk are divided radially into a plurality of sectors as shown in Fig. 3, and data signals are recorded in the sectors of each track. The beginning of (
It has been proposed (see Japanese Patent Laid-Open No. 56-2526 "6", etc.) to record a K servo signal (shown with diagonal lines) and perform track servo of the head using this servo signal.

That is, FIG. 4 shows a part of the track drawn in the running direction of the head, and a servo signal of, for example, two frequencies C'f1e /2) is recorded (formatted) in advance at the beginning of each sector. For example, as shown in FIG.
e/2 Pandonos filter (62a) (62b)
These filters (62a) (62b
) is detected by the peak detection and hold circuit (
63a) (63b) A comparator circuit K is supplied to extract the amount of track deviation for each servo signal, and this signal is supplied to a head actuator MK for positioning the head 6υ through an amplifier can. . This K causes the head to perform track servo, and the data signals of each sector are recorded and reproduced.

However, this outfit is f! tic, if there is eccentricity in the rotation of the disk, the amount of track deviation at that time will be K as shown by the solid line in FIG. On the other hand, the amount of track deviation detected by each serve signal (x3 s Xb # Xc...
...) is the amount of deviation of the head of the sector, so it is one sector behind by one minute, and even if a serve is performed to correct this, the corrected head position 6υ As shown by the broken line in the figure, the amount of deviation due to eccentricity between sectors is always under-corrected. Therefore, when the amount of eccentricity between sectors becomes large, the control accuracy of the serve deteriorates significantly.

[Problem that the invention seeks to solve]

As described above, the conventional technology has problems such as difficulty in sufficiently correcting track deviations caused by eccentricity of the disk.

[Means for solving problems]

The present invention provides a rotating disk in which a plurality of concentric tracks are formed, these tracks are divided radially to form sectors, and a data signal is recorded in the sector of each track. A serve signal is recorded at the beginning of the sector, and at least the amount of track deviation of the head due to the eccentricity of the rotating disk obtained from the servo signal reproduced at the start of the serve is stored (memory a'a > The stored track deviation amount and the reproduced servo signal (comparison port l18 (
4)) This is a track servo method for a rotating disk device in which track servo of the head described above is performed.

[Effect]

According to this, since the amount of track deviation due to eccentricity is stored in advance and the track search is performed, it is possible to always perform the track search with high accuracy even when the amount of eccentricity between sectors is large. - [Example] - Fig. 1 shows an example of an apparatus for realizing the method of the present application. In this figure, the reproduced signal from the head (1) is passed through a non-no-dono filter (2a) with a frequency of /1 and f2 (
2b) and these filters (2a) (2b
) are supplied to a comparison circuit (4)K through three peak detection and hold circuits (3g) and (3b), respectively, and the amount of track deviation for each serve signal is extracted.

A signal indicating this amount of deviation is supplied to the output terminal Q3 through the AD conversion circuit (11). Further, the signal from the nosend pass filter (2a) or (2b) is supplied to an address counter 03 configured in a ring shape with a step number equal to the number of sectors of a rotating disk (not shown), and this address value is stored in the memory ( I7Jric supplied.

Furthermore, a signal that increases the address value by one step from the terminal a4 is added to the address value from the counter (13) through the switch aS.

Furthermore, the signal from the memory a3 is supplied to the adder αn1lc through the DA conversion circuit α port, and is added to the signal from the comparison circuit (4). This added signal is supplied through an amplifier (5) to a head actuator (6)K for positioning the head (1).

In this apparatus, first, during one arbitrary rotation after the rotation of the rotating disk is stabilized, the switch r1S is turned off and the memory az is placed in a writing state. This is K
Therefore, as shown in FIG. 2A, each address of the memory a3 stores the amount of track deviation (Xl j
X2...Xn) are written respectively. At this time, the signal from the DA conversion circuit a11g is
0” and a tracker is being performed.

Next, when the above-mentioned writing is completed, the memo IJ n'lj is put into a read state and the switch σ9 is turned on. As a result, each address in the memory 13 is read out one step earlier, and this read signal is applied to the comparison circuit (4).
) are added and supplied to the actuator (6).

Therefore, in the above-mentioned apparatus, if the head (1) is located at the position indicated by the diagonal line in the initial state as shown in FIG. 2B, then the amount of track deviation at this time
The 7 actuator (6) is driven so that the amount of deviation added by the signal X1 from 7J is corrected, and thereafter,
+ X2) # (Xc + X3)...
By driving so as to correct..., the head is track servoed as shown by the broken line in the figure. In other words, by using the signal written in Memo!J (121), , it is possible to perform correction without a delay of one minute per sector.

In this way, according to the above-mentioned apparatus, since the amount of track deviation due to eccentricity is stored in advance and the track serve is performed, highly accurate track serve can always be performed even when the amount of eccentricity between sectors is large.

In the above-mentioned device, the amount of deviation due to eccentricity is considered to be unchanged between the inner and outer peripheries, but if thermal expansion or the like is taken into account, the above-mentioned writing may be repeated at predetermined intervals.

Further, in the above-mentioned device, the configuration surrounded by a dashed line such as mesori az can also be realized using a CPU (ll, etc.).

〔Effect of the invention〕

According to this invention, the amount of track deviation due to eccentricity is memorized in advance and the amount of track deviation due to eccentricity is stored in advance. This makes it possible to always perform highly accurate track serve even when the amount of eccentricity between sectors is large.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an example of a device for realizing the present invention,
FIG. 2 is a diagram for explaining the technique, and FIGS. 3 to 6 are diagrams for explaining the conventional technique. (1) a head, (2a) and (2b) are non-noise filters, (3a) and (3b) are detection hold circuits, (
4) is a comparison circuit, (5) is an amplifier, (6) is a helad actuator, and 01 is a CPU. 03 is a memory, and αn is an adder.

Claims (1)

[Claims] A plurality of tracks are formed concentrically on a rotating disk, and these tracks are divided radially to form sectors, and a data signal is recorded in the sector of each track, and the data signal is recorded in the sector of each track. A servo signal is recorded at the beginning of the sector, and at least the amount of track deviation of the head due to the eccentricity of the rotating disk obtained from the servo signal reproduced at the start of servo is stored, and the amount of track deviation recorded above at the time of servo is stored. A track servo method for a rotating disk device, wherein track servo of the head is performed using the reproduced servo signal and the reproduced servo signal.