| 摘要 |
PURPOSE:To shorten the longest access stroke of an optical head and to improve access efficiency by segmenting a recording region to plural small recording regions and providing directory regions to the respective small recording regions. CONSTITUTION:The recording region 3 is segmented to plural pieces of the small recording regions 4-6 sectioned radially by a specified width. The tracks on the outermost circumferences of the respective small recording regions 4-6 are the directory regions 4a-6a. The control information for controlling the information to be recorded in the small recording regions 4-6 to which the directory information respectively belong is recorded in said directory regions. The longest access stroke of the optical head is thereby shortened and the access efficiency is improved. |
