An optical head structure, movable to scan over a disk surface, includes a fixed optical arrangement. Fine focussing and side-to-side adjustments for scanning are effected by movements of another lens mounted on a substantially stationary part of the system structure. The movable lens is generally aligned...http://www.google.fr/patents/US4712887?utm_source=gb-gplus-shareBrevet US4712887 - Optical system for fast access optical data storage device
Optical system for fast access optical data storage device
