| 摘要 |
PROBLEM TO BE SOLVED: To embody an optical disk with which production is easy and errors in information reading are decreased. SOLUTION: A substrate 2 having the optical depth of grooves 4 within a range of λ/7 to λ/5 with respect to the wavelength λ of a light source for information reproduction is produced. The crosstalks between the adjacent lands 3 and grooves 4 are thereby decreased. A ground surface layer 5, a recording layer 6 and a protective layer similar to this layer 5 are formed on this substrate 2. Header information is recorded as phase changes only on the one recording layer 6 on the lands 3 or the grooves 4, by which the need for providing the substrate 2 with prepits for header information is eliminated. The regions on the tracks having no header information are accessed in accordance with the header information of the adjacent tracks in the case of the access to these regions. |
