Method for servowriting a patterned-media perpendicular magnetic recording disk using position error signal (PES) alignment fields

摘要

A servowriting method for a patterned-media magnetic recording disk uses a special position error signal (PES) alignment pattern located in each servo sector. A gross feedforward correction signal to compensate for gross eccentricity of the disk relative to the center of rotation of the servowriter spindle is applied to the actuator. With the gross feedforward correction applied to the actuator the read head generally follows a data track centerline and will detect signals from PES alignment fields as each servo sector passes the read head. This results in a readback signal at each servo sector that represents the fractional track-width radial offset of the read head in that servo sector from a data track centerline. The set of radial offsets for all of the servo sectors is used to modify or fine tune the gross feedforward correction signal that is applied during the servowrite process. This enables the servowriter write head to then precisely follow a track centerline so that the discrete islands in the PES fields can be magnetized according to the desired pattern.