| 摘要 |
PURPOSE:To expand an area which can record exact information, and to enlarge the recording capacity by forming a pit whose area and depth are large, in an area in which a pit length becomes smaller than a diameter of a laser spot. CONSTITUTION:An exposure strength of a groove is strengthened in proportion to a distance from the center of an optical master disk, extending from the center of the optical master disk to the outside peripheral edge. On the other hand, an exposure strength of a pit part is strengthened in proportion to a distance from the center of the optical master disk, in an area A in which a pit length is above a diameter of a laser spot. Also, in an area B in which the pit length becomes smaller than the diameter of the laser spot, the exposure strength is corrected so that a ratio of an exposure quantity of the groove and the pit is kept constant, irrespective of the pit length. |
