| 摘要 |
PROBLEM TO BE SOLVED: To make applicable a signal recording surface to recording/reproducing devices having optical systems designed with different transparent substrate thickness by changing the thickness of the transparent substrate from the signal recording surface of an optical disk to a light beam incident surface. SOLUTION: When reproduction is performed by using an optical pickup designed at the substrate thickness 0.6mm, the light beam 106 is made incident from the transparent substrate 102 side, and is converged on the signal recording surface 101, and a recorded signal is reproduced by a change of a reflection light quantity by a translucent film 104. Further, when the reproduction is performed by using the optical pickup designed at the substrate thickness 1.2mm, the light beam 107 is made incident from the transparent substrate 103 side, and is converged on the signal recording surface 101, and the recorded signal is reproduced by the change of the reflection light quantity by the translucent film 104. |
