Demodulation of Servo Tracking Signals Printed with a Lithographically Patterned Master Disk
Demodulation of the servo tracking signals magnetically printed on hard disks by using a lithographically patterned master disk has been studied. Position signal decoded from the printed servo pattern was successfully demonstrated on a spin stand. Position error evaluated in a prototype drive was 30% track pitch. Pulse timing shift control by compensating the pattern dimension, and introduction of more sophisticated servo control system for actively controlling the printed pattern eccentricity would be key issues for further improvements.