| 摘要 |
PROBLEM TO BE SOLVED: To make the width of a formed mark train constant regardless of an information pattern even performing recording operation by a heat mode in a simple recording method by providing pre-grooves on both sides of an information track and selecting them so as to satisfy a specified condition. SOLUTION: In an information medium capable of optically recording/ reproducing information, pre-grooves are provided on both sides of an information track and, by representing the depth by d and the width by w, they are selected so as to satisfy d>=w. Since a recording film is hardly stuck to the pre-groove or a recording film whose characteristic is extremely different from the recording film of the information track is stuck, recording in a pre-groove is not substantially performed even when recording on the information track is performed by sticking out in the pre-groove. Consequently, the formed width of a mark is limited to the information track and the mark train of a fixed width is made regardless of the information pattern. |
