| 摘要 |
PURPOSE:To enlarge the allowable range of disk skew by optically correcting regenerative waveform distortion caused by coma aberration generated by the disk skew even when the number of openings at an objective lens is large. CONSTITUTION:Correcting boards 21A and 21B provided with a aspherical surface shape are moved within a plane vertical to an optical axis by a correcting board driving means corresponding to the disk skew amount of an optical disk 8. Thus, even when the number of openings at an objective lens 5 is large, the regenerative wave distortion caused by the frame aberration generated by the disk skew is optically corrected. |
