| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical recording medium wherein recording and/or reproduction of higher density can be performed and capacity is enlarged and to provide an optical disk system. <P>SOLUTION: In the optical disk system, an optical disk 40 having a light transmission layer 41 composed of a light transmissive base body having 0.44 to 0.6 mm thickness and formed so that a laser beam is made incident thereon, a recording layer 43 on which the laser beam is condensed by passing through the light transmissive base body, a reflection layer 45 and a protective cover layer 46 is irradiated with the laser beam by using an objective lens 2 having a numerical aperture NA of 0.55 to 0.70 so that the laser beam is condensed toward the recording layer 43 from the surface side of the light transmission layer 41 of the optical disk 40. <P>COPYRIGHT: (C)2007,JPO&INPIT |
