| 摘要 |
PURPOSE:To prevent the deformation of groove parts occurring in the mutual interference of exposing beams at the time of formation of a master disk and to improve the quality of preformat signals by shifting the position of the preformats of adjacent tracks. CONSTITUTION:The preformats are alternately shifted in position and are provided to the preformat forming parts 2 of the adjacent tracks. The increase in the width of the groove parts in the parts where the preformats are formed by the mutual interference of the exposing beam at the time of the formation of the master disk is thereby prevented and the intrusion of the preformat signals of the adjacent tracks as crosstalks is obviated. The quality of the preformat signals is thus improved. |
