| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a disc that has a robust high-speed reproduction inhibition function. <P>SOLUTION: The track on the disc is made meandering in the amplitude larger than the de-tracking margin but smaller than the eccentricity of the disc, and at a frequency which has an enough gain for suppression in the tracking servo range at a steady speed revolution. Alternatively, the disc has a signal surface or reproducing surface wobbling in the disc thickness direction with the amplitude larger than the focal depth but smaller than the disc surface wobbling and at a frequency which has an enough gain for suppression in the focus servo range at a steady speed revolution. <P>COPYRIGHT: (C)2003,JPO |
