| 摘要 |
<p>Substrate ridges (1b) are so formed as to divide a thin part (2) so that an energy beam striking the back of the substrate is sensed. Hence the strain of the thin part (2) is prevented and defocus during the sensing due to strain is also prevented. The distance from any point on the thin part (2) to a substrate frame (1a) or the substrate ridges (1b) is set sufficiently small, thereby reducing the substrate resistance and enabling high-speed read.</p> |
