| 摘要 |
<P>PROBLEM TO BE SOLVED: To stably perform information recording to a record layer by surely detecting groove meandering parts even in an optical disk having a substrate in which record layers and grooves are formed in this order seen from a direction where laser beams are emitted. <P>SOLUTION: A pregroove 16 has a plurality of meandering parts 40 in the optical disk having the substrate in which the recording layers and pregrooves 16 are formed in this order seen from the direction where laser beams for recording and/or reproduction are emitted. A meandering part 40 has a first bent part 44 that is bent toward a first groove 42a adjacent to one of a corresponding land 36 and a second bent part 46 that is bent toward the land 36 from a second groove 42b adjacent to the other of the land 36, and satisfies 0. 8<T1/T2<2. 0 when the amount of projection to the first groove 42a of the first bent part 44 is set to T1 and the amount of projection to the land 36 of the second bent part 46 is set to T2. <P>COPYRIGHT: (C)2007,JPO&INPIT |
