| 摘要 |
PROBLEM TO BE SOLVED: To carry out precise and high-speed speed changing control by realizing ZCLV rotation control without using an expensive rotary encoder and to enable ZCLV rotation changing control also on a land in an optical disk having a spiral or concentric recording track. SOLUTION: In an optical disk recording medium 1 having a spiral or concentric recording track 2, at least a part of a recording track 2 has a guide groove, the information recording area of a recording medium 1 is divided into plural zones Z1-Zn in the radial direction, when the recording medium 1 is rotated at a constant angular velocity, the guide groove G is meandered in the radial direction with a prescribed frequency corresponding to each zone in each zone of the plural zones and the spatial frequency of meandering motion is made to be almost fixed for every zone. |
