| 摘要 |
PURPOSE:To make an optical disk rotation and drive device thin and small size by constituting such that a magnetic body, which is coaxial with a guide groove formed on the substrate and magnetized at a position smaller than the inner-most diameter of the guide groove, is fixed on the substrate. CONSTITUTION:The center hole between two substrates 7 and 7' forming the guide groove 8 on either surface is fitted to the external cylindrical face of a drilled boss with a collar 6. The inner and outer peripheral parts of the substrates 7 and 7' are faced and arranged at a fixed interval through the collar and a cylindrical spacer, respectively. In terms of an optical disk 1 hermetically formed in one body, the drilled boss 6 is formed with the magnetized magnetic body. The magnetic body is produced from a sintered magnet made of ferrite or rare metal, alloy including them or a magnetic plastic. If the optical disk 1 is used, a permanent magnet can be removed from a turntable 9, whereby an optical disk rotation and drive device can be scaled down in a thin shaped. |
