| 摘要 |
PURPOSE:To expand the locking range of tracking control by arranging 1st and 2nd reflection marks while the position in the circumferential direction is deviated at both sides while clipping the center line of the recording track and arranging inversely in the radial direction of the base between adjacent recording tracks. CONSTITUTION:The 1st reflection marks 51 of each recording track and the 2nd reflection marks 52 are made adjacent with each other and the recording layer 3 without provision of each mark is made adjacent among adjacent recording tracks Tk-1, Tk, Tk+1. Thus, a difference signal P1-P2 corresponding to the deviation from the recording track center is obtained by the reflection luminous quantity from the 1st and 2nd reflection marks 51, 52 and when an optical head is moved in the radial direction of an optical recording medium to evade the deviation based on the difference signal P1-P2, it is possible to control properly the moving direction of the optical head and its moving quantity regardless of the quantity of the deviation of the convergence spot. |
