A direction sensor in a tracking and focus servo system of an optical disk drive is presented. The direction sensor calculates a direction sum signal and a tracking error signal from side elements of detectors in an optical pick-up unit of the optical disk drive. A first direction can be indicates when...http://www.google.fr/patents/US6813228?utm_source=gb-gplus-shareBrevet US6813228 - Tracking and focus servo system with direction sensor
Tracking and focus servo system with direction sensor
