| 摘要 |
PURPOSE:To suppress warping of an optical disc effectively while enhancing the reading accuracy with a magneto-optical head by providing a second protective layer of a resin shrinking on setting on a first protective layer. CONSTITUTION:The optical disc comprises a molded substrate 2 provided with protrusions and recesses for signal and a recess 2A caused by a stamper stopper in the surface thereof, a recording layer 4 applied onto the molded substrate 2 on the information recording plane side, and a protective layer 6 applied onto the recording layer. The protective layer 6 comprises a first protective layer 6A laminated on the recording layer 4, and a second protective layer 6B laminated on the molded substrate 2 including the recess 2A wherein the second protective layer 6B is composed of a resin shrinking upon setting. Since the expanding action of the recording layer 4 with respect to the molded substrate 2 is offset by the shrinking action of the second protective layer 6B, high reading accuracy of a magneto-optical head can be maintained for a long term. |
