| 摘要 |
PURPOSE:To adjust a position in three directions orthogonal to one another highly independently of one another, by controlling movement in the tracking direction and the tangential direction in the state where an object lens holding body is floated electromagnetically. CONSTITUTION:When positive and reverse currents in the same direction are flowed to a pair of driving coils 26, a ring-shaped permanent magnet 23 is moved forward and backward in a tracking direction Tr; and when similar currents are flowed to a pair of driving coils 27, the ring-shaped permanent magnet 23 is moved forward and backward in a tangential direction Ta. Consequently, an object lens 11 is moved freely in the tracking direction, the tangential direction, and the composite direction by controlling currents flowed to driving coils 26 and driving coils 27 to perform accurate tracking. Since this driving in the tracking direction and the tangential direction is performed in the floating state where the ring-shaped permanent magnet 23 and a cylindrical body 22 are not brought into contact with parts mechanically except a damping supporting material 24 because of electromagnetic repulsive force, it is superior in operating characteristics very much. There is no margin of interference between the tracking direction and the tangential direction, namely, occurrence of crosstalk. |
