METHOD OF READING INFORMATION FROM DIFFERENT OPTICAL DISC AND OPTICAL DISC DRIVING DEVICE

摘要

PURPOSE: To substantially remove a wave front aberration in a reflected light beam. CONSTITUTION: Positioning and number of openings and appropriately provided, so as to permit the objective lens 34 of optical disk driving mechanism to focus the light beam on a spot in the optical medium of one optical disk 36 having a cover plate with one thickness. When another optical disk having the cover plane with different thickness is used, a liquid-crystal compensating lens 48 operates in an optical path between a light source 22 and the objective lens to focus the light beam on the spot in the optical medium of another optical disk.