Magnetic disk drive

Abstract

In order to achieve narrow track pitch by measuring, storing and compensating common average values for repeatable runout components between adjacent tracks in a head positioning control system for a magnetic disk drive, there are provided: means for calculating a compensated signal for the average value of the repeatable runout of each servo sector of at least two tracks of servo information reproduced from a magnetic disk, on the basis of an inverse function of the sensitivity characteristics of the tracking control system; means for storing the calculated signal; and means for compensating the servo signal on the basis of this signal.

1 - 11 . (canceled)  
   
   
       12 . A magnetic disk drive comprising: 
 a magnetic disk having a plurality of tracks on which serve information is stored;    a magnetic head for recording/reproducing information to/from said magnetic disk; and    a supporter for supporting and positioning said magnetic head over said magnetic disk; wherein    said supporter is adjustable on the basis of the average value of the repeatable runout for servo sectors in a plurality of different tracks.    
   
   
       13 . The magnetic disk drive according to  claim 12 , wherein the adjustment of said supporter is performed by means for compensating the servo signal.  
   
   
       14 . The magnetic disk drive according to  claim 13 , wherein a servo signal compensation value based on said average value of the repeatable runout is stored in a non-volatile memory or on said magnetic disk.  
   
   
       15 . The magnetic disk drive according to  claim 12 , further comprising a compensator for compensating the control signal to said supporter, on the basis of the average control signal to said supporter for each servo sector of a plurality of tracks, and the average value of the repeatable runout for each servo sector in a plurality of tracks.  
   
   
       16 . The magnetic disk drive according to  claim 12 , wherein said average value of the repeatable runout is calculated on the basis of positional error signals.  
   
   
       17 . The magnetic disk drive according to  claim 12 , wherein said supporter is adjusted on the basis of a compensation value corresponding to a plurality of zones divided in a radial direction of said magnetic disk, and said compensation value is calculated on the basis of the repeatable runout.  
   
   
       18 . A magnetic disk drive comprising: 
 a magnetic disk having a plurality of zones divided in the radial direction of said magnetic disk, each of said zones having a plurality of tracks;    a magnetic head for recording/reproducing information to/from said magnetic disk;    a supporter for supporting and positioning said magnetic head over said magnetic disk; and    a compensator for compensating signals for controlling said supporter; wherein    said compensator compensates said signals on the basis of compensation values corresponding to each of said zones.    
   
   
       19 . The magnetic disk drive according to  claim 18 , wherein said signals are servo signals read from said magnetic disk by said magnetic head.  
   
   
       20 . The magnetic disk drive according to  claim 18 , wherein each of said compensation values is calculated on the basis of a repeatable runout average value of each of said zones.  
   
   
       21 . The magnetic disk drive according to  claim 20 , wherein said repeatable runout average value is the average value of the synchronous vibration for servo sectors in a plurality of tracks of each of said zones.  
   
   
       22 . The magnetic disk drive according to  claim 18 , wherein said compensation values are stored in a non-volatile memory or on said magnetic disk.  
   
   
       23 . The magnetic disk drive according to  claim 20 , wherein said repeatable runout average values are stored in said non-volatile memory or on said magnetic disk.