| 摘要 |
PROBLEM TO BE SOLVED: To easily and accurately select a recording layer of an optical disk having a multilayered recording layer and to accurately reproduce desired information recorded in the recording layer. SOLUTION: The optical disk 21 has first and second recording layers 24, 26 laminated on one surface of a substrate 22, and a protective layer 28 formed on the second recording layer 26 to protect the second recording layer. By controlling the reflectance of one of the first recording layer 24 and the second recording layer 26 to be higher than the reflectance of the other recording layer, the first or second recording layer 24, 26 is selected based on the difference in the quantity of light of laser beam reflected from each layer and then the information recorded in the first or second recording layer 24, 26 is reproduced. |
