| 摘要 |
PURPOSE:To improve the adhesion durability with a disk medium by adopting hub structure with plastic insert for a magnetic substance and adhering a nonmagnetic substance such as a plastic film to the surface of the magnetic substance. CONSTITUTION:A thermoplastic resin 7 is used to apply insert forming to the magnetic substance 6 as a magnet adsorption body as the structure of a hub 2, then the adhering strength with the plastic material as the disk medium is remarkably improved. In selecting the thickness of the plastic film 8 at the surface of the magnetic substance 6, the relative distance between a magnet 4 and the magnetic substance 6 is adjusted and the magnet attracting force is relaxed. Thus, the adhering strength with an optical disk medium is high and the magnetizing force is controlled by a simple method, then an optical disk with high quality is obtained. |
