| 摘要 |
PROBLEM TO BE SOLVED: To increase tracking signals and to improve a reading capability by providing grooves which form wobbling tracks having a larger depth than a prescribed value in a read-only region of an optical recording disk. SOLUTION: Wobbling grooves 26, which provide tracking information, are included in both a read-only region and a recording capable region. The grooves 26 practically have a V shape form. A depression 28 is formed in the groove 26 of a read-only region. A land 30 is provided between the grooves 26. During an injection molding process, the wobbling grooves 26 and the depressions 28 are picture set and formed on a substrate 22. The grooves 26 are made continuous and are extended through the read-only and recording capable regions. The depth of the grooves is made not less than 170 nm and is set in the range between 170 nm and 300 nm. Thus, the performance is practically improved during a writing and a reading. |
