Calibration of ramp location in a disk drive employing spiral-based self servo writing

摘要

The location of a load/unload ramp in a disk drive is calibrated by monitoring servo spirals that are crossed by a magnetic read/write head during an unload process. Monitoring the number servo spirals crossed allows an accurate velocity of the read/write head to be determined. Based on this unload velocity and the time elapsed during the unload operation, a distance between an ID crash stop position and the load/unload ramp can be calculated quickly and accurately.

主权项

1. A method of writing servo information for data tracks on a data storage disk having a plurality of servo spirals formed thereon, the method comprising the steps of:
while moving a magnetic read head actuator radially across a surface of the data storage disk from a first radial position to a second radial position, monitoring (1) a number of servo spirals crossed until the magnetic read head actuator reaches the second radial position and (2) a time that elapses until the magnetic read head actuator reaches the second radial position; based on the number of servo spirals crossed and the time elapsed, computing a radial distance traveled by the magnetic read head actuator; and writing servo information on the data storage disk according to a servo self-write process, the servo self-write process using the computed radial distance traveled by the magnetic read head actuator.