| 摘要 |
PROBLEM TO BE SOLVED: To reduce the structural parts and also to prevent a twisting resonance phenomenon by integrally forming a turntable no be mounted with an optical disk and a driving magnet out of a magnet material. SOLUTION: At the time of molding a driving magnet part 25 integrally with a turntable part 26 and a shaft part, this molding is performed orienting polar anisotropy so as to arrange an axis of easy magnetization of particles of the magnet material from a position as the center of a magnetic pole 29 to the center of its adjacent magnetic pole 29 as shown by a broken line. By this orientation, leakage magnetic flux of the driving magnet part 25 to the outside is suppressed as compared with the case of isotropy (no orientation) or radially directional anisotropy, thus increasing effective magnetic flux contributing to rotational driving force. |
