| 摘要 |
PURPOSE: To obtain a sturdy, reliable and protected optical disk for recording by specifying a transparent plate and a protective cover. CONSTITUTION: A transparent plate 1 is provided with a thickness of about 1mm with that of the first layer 2 comparatively thin and a few microns. An optical beam 6 is emitted from a laser source into the focal point surface of an objective lens adjusted to coincide with the plane of the second layer 3. The optical disk also contains a protective cover 5 as a formed body forming the disk surface of the side opposite from the transparent plate 1. This protective cover 5 is formed by stamping a sheet, forming a concentric annular adhesive surface 8, 9, with the outer circumferential part of the second layer 3 and its center part near the hole 7, so as to hermetically seal the closed annular space 4. |
