| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk medium capable of correcting offset of a tracking signal due to inclination of a disk and optical axis movement of an objective lens and to make it possible to obtain a precise tracking control signal when unbalance of diffracted light due to a guide groove is detected, and the information is recorded/reproduced while tracking controlling. SOLUTION: This medium is provided with a groove 62 carved in nearly a concentrical circular shape and plural sectors provided along the groove 62, and is constituted so as to record the information in the form capable of optically reading. In such a case, each sector is provided with a mark 64 for showing the start point of the sector, a reflection surface 62 provided behind the mark 64 and having a length of a size or above of a spot and a recording area provided behind the deflection surface 63, and the reflection surface 63 is constituted on a part without the groove as a flat surface, and it is formed extending over plural tracks. |
