| 摘要 |
PURPOSE:To improve the quality of a tracking error signal and a preformat signal by forming a bit string for preformat signal and a guide groove in a protruding form. CONSTITUTION:Both the bit string 1 and the guide groove 2 are formed in a protruding form. Therefore, when applying an under layer 4 to upgrade the solvent-persistency of a transparent plastic substrate 3, a flowing-in is generated over approximately 2/3 of the entire surface of the medium except the areas of the bit string 1 and the guide groove 2. Therefore, shapes of the string 1 and the groove 2 are maintained about two times of conventional one, and the quality-lowering of the tracking error signal and the preformat signal decreases. The high and the width of the protrusion of the said groove and preformat are normally selected at approximately 0.05mum-0.15mum and 0.3mum-1.0mum, respectively. |
