Patent ID: 8625229
Filing Date: 2014-01-07
Classification: G11B

Abstract:
1. A method for generating reference servo information for a magnetic recording disk drive that includes a processor, memory associated with said processor, a spindle for rotating the disk about a rotational axis, a read head and a write head, and a voice coil motor (VCM) actuator for moving the read head and write head across the disk, the disk having a plurality of generally concentric generally circular data tracks radially spaced by a track pitch (TP) and containing discrete magnetizable data dots, the method comprising: (a) generating a generally random magnetization pattern for the dots in an annular region of the disk; (b) maintaining the read head at a radial position while rotating the disk; (c) detecting with the read head a reference signal from a plurality of angularly spaced disk sectors in said annular region; (d) storing in memory data representative of the reference signal for each sector; (e) moving the read head radially by a radial increment less than TP; and continuing steps (b) through (e) until the read head has been moved radially across said annular region.