Hybrid servo pattern and demodulation ayatem for direct access storage device actuator positioning

摘要

A hybrid servo actuator positioning system that simultaneously demodulates servo burst amplitude and phase information in each sector. Servo burst amplitude demodulation is used for conventional track-following. Servo burst phase information is used for high-speed seeking of the target track without resorting to decoding a complete Gray code sector identification field. The disclosed hybrid servo system provides more actuator positioning information in less disk space than do conventional systems employing amplitude servo demodulation or phase servo demodulation alone.