公开(公告)号：SG64425A1

公开(公告)日：1999-04-27

申请号：SG1997002067

申请日：1997-06-16

Applicant: IBM

Inventor： CHAINER TIMOTHY JOSEPH ,  SCHUTLZ MARK DELORMAN ,  WEBB BUCKNELL CHAPMAN ,  YARMCHUK EDWARD JOHN

IPC: G11B5/55 ,  G11B5/596 ,  G11B21/08 ,  G11B20/12

Abstract: A self-servowriting system and method for implementation in a storage device such as a disk drive are described. Two problems associated with self-propagation are greater mechanical disturbances and the growth of errors during many thousands of servowriting steps. Error growth is attributable to the special properties of servo loops as applied to a repetitive self-propagation process. Greater resistance to mechanical disturbances and reduction in error growth are achieved, in part, by adjusting a step amplification factor, S, at the initiation of servowriting to within desired parameters. However, S is known to vary with movement of the head in a direction transverse to the direction of the tracks. This problem is addressed by the present invention, wherein S is determined at a plurality of transverse transducer positions. S is dependent upon the closed loop response of the servo system C and upon a set of step-to-step correction factors f. S is therefore determined by monitoring an indicium of S such as C, and is adjusted by adjusting either C or f to provide a value of S which falls within an acceptable range of values. Determination of S is scheduled to occur at predefined intervals. The intervals may be fixed or adjusted adaptively based upon the measured variation of S with transducer position.