| 摘要 |
PURPOSE:To suppress the focus resonance of an optical disk by attaching vibration suppressing sealing material to a drive base board through an adhesive layer. CONSTITUTION:This optical disk 1 is constituted into the sandwich structure of a disk base board 2 whose bit transcribing surface 3 is covered with a protection film 5, the elastic adhesive layer 6 and the sealing material 7, and vibration transmitted from an optical disk drive side is suppressed by the adhesive layer 6 and the sealing material 7. Besides, the sum of the wall thickness T1 of the base board 2 (including transcribing surface 3), the wall thickness T2 of a reflecting film layer 4 and the wall thickness T3 of the protection film layer 5 is made thinner than the maximum allowable thickness T7 of a disk standard and thicker than the minimum allowable thickness T8. |
