| 摘要 |
PROBLEM TO BE SOLVED: To reproduce the information recorded on the disks having different specifications employing a simple constitution. SOLUTION: A polarizing filter 5 is arranged between an objective lens 6, which collects the light beams from a light source 1 on the signal surface of a disk 7, and the source 1. A circular shaped opening 5a is formed at the center of the filter 5 and P polarized light beams pass through the opening 5a and S polarized light beams are shut off. The P polarized beams pass the opening 5a and are made incident on the lens 6 as a large luminous flux. The S polarized beams are made incident as the luminous flux which is limited depending on the opening region. |
