| 摘要 |
PROBLEM TO BE SOLVED: To decrease the fluctuation of modulation degree even when a pre-pit signal is reproduced without applying tracking servo operation. SOLUTION: A pre-pit for modulating the intensity of reflected light or transmitted light is provided, a pre-pit string in which the pre-pit is arranged in the scanning direction of a converged light beam is formed, an area in which the pre-pit string is lined up with a fixed pitch is provided, and an area in which the pre-pit string is lined up with a pitch <=7/10 is provided. Consequently, the amplitude of a reproduced pre-pit signal without applying tracking servo on the control area of an optical disk is hardly fluctuated, the degree of modulation becomes constant and the reproduction of information becomes effective. |
