An optical memory device includes a cylindrically-shaped optical information recording medium and at least one optical head disposed around the information recording medium for irradiating the information recording medium with a light spot for recording or reproduction of information. The optical head...http://www.google.de/patents/US5109374?utm_source=gb-gplus-sharePatent US5109374 - Small-sized optical memory device and information processing apparatus utilizing cylindrically shaped information recording medium
