| 摘要 |
<p>An optical disk on which there are a number of pits (1,31) corresponding to data bits to be reproduced by a light beam spot emitted from reproducing means (13), the light beam spot having maximum light intensity at a position having a given offset in a radial direction with respect to a center of each of the pits to detect the pits on the optical disk, and which is rotated by rotating means,
characterized in that a length of each of the pits is set at such a value as to satisfy a condition of following equation:
where PLn[m] indicates the length of each of the pits measured in a track tangential direction at a depth pd/2 in a condition that a depth of a deepest portion of each of the pits recorded in the optical disk at the radius r1of the optical disk and with a length corresponding to the code length nT in a predetermined modulation method is pd, a predetermined reproducing frequency fnT[1/s] of a 2nT pitch signal in the radius r1, and the scanning linear velocity of the optical disk in the radius r1 is Sr1 [m/s].</p> |
