| 摘要 |
PURPOSE:To improve productivity by forming magnetic films for the purpose of clamping the disk. CONSTITUTION:A disk-shaped substrate is constituted by forming tracking grooves and pits on one surface of a plastic base material 1 produced by an injection molding method and is formed with a mirror surface on one surface. The center pin of the spindle part of a disk drive device is centered by a central hole 1a. A hard coating 2 for hardening the surface, preventing electrostatic charge and improving the resistance to water and moisture is applied on the mirror surface side. An optical recording medium 3 is formed on the recording surface side and a protective coating 4 is applied thereon. The magnetic film is formed by screen printing in the inside peripheral part of the substrate. Then, the productivity is good and since the centering of the disk is executed only by the central hole of the substrate and, therefore, the accuracy of the relative position of the film part 6 with the substrate is not required and the need for aligning the center of the substrate and the center of the magnetic film is eliminated. The productivity is thereby greatly improved. |
