| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to record and/or reproduce two optical information recording media with light transmissive layers different from each other without switching an optical system by arranging a light transmissive member on a part of an optical path between an objective lens and a light transmission protective layer. SOLUTION: The thickness of the light transmmssive member 30 on an optical disk recording area 40B is set in a difference between the thickness 1.2mm of the light transmission protective layer 45B on the optical disk recording area 40B and the thickness 0.6mm of the light transmission protective layer 45C of a high density optical disk recording area 40C, that is 0.6mm. Since the thickness of the light transmissive member 30 is made such a thickness, luminous flux passing through a light transmissive part 302 is made incident on the light transmission protective layer 45C to be focused on a recording layer 47C. |
