Method and apparatus for writing servo data with perpendicular magnetic recording in a disk drive

Abstract

There is disclosed a servo writing method in which servo data is recorded by a perpendicular magnetic recording system. In the servo writing method, at the time of perpendicular magnetic recording of the servo data on a disk, a servo writing operation is executed including an offset process set based on the hard-easy transition shift (HETS) phenomenon.

1 . A disk drive for perpendicular magnetic recording, comprising: 
 a magnetic head including a write head and a read head suitable for the perpendicular magnetic recording; and    a disk medium which has an Hn value set based on a relation between inverse magnetic domain generated magnetic field characteristics (Hn) and hard-easy transition shift (HETS) phenomenon and on which servo data is recorded by a perpendicular magnetic recording system beforehand.    
   
   
       2 . The disk drive according to  claim 1 , wherein the Hn value of the disk medium is 800 (1/(4π)×10 3  A/m) or more.  
   
   
       3 . The disk drive according to  claim 1 , wherein the Hn value of the disk medium is 1000 (1/(4π)×10 3  A/m) or more.