An optical pickup system for selectively detects an information signal from, e.g., a pair of optical disks loaded on a disk tray, wherein each of the optical disks may have a different thickness. The optical pickup system includes a light source for generating a first and a second light beams having...http://www.google.ca/patents/US5995473?utm_source=gb-gplus-sharePatent US5995473 - Optical pickup system capable of selectively reading a multiple number of optical disks
