| 摘要 |
PURPOSE: To prevent the deformation of a data track by cancelling the unbalanced radial tension and the secular stress relaxation of a double sided recording disk(SD) with a stretched surface. CONSTITUTION: An annular supporting body 12 is provided with an annular external and internal ridges 28, 42 rising on both sides of the body. A recording medium film 14, 16 is stretched and arranged in the annular recessed part of the supporting body 12. The recording medium film 14, 16 is secured in a state stretched in the radial direction, and is provided with anisotropy in the mechanical characteristics affecting track stability. Then, matching is made so that the specific dihedral angle formed by the recording medium film 14, 16 is not more than 10 degrees. As a result, deformation of a data track is prevented, improving stability in track dimensions. |
