| 摘要 |
PURPOSE:To obtain a miniature, lightweight driving device with the sufficient capacity required to move an objective lens by employing the constitution that a movable made of a permanent magnet generates a closed-loop magnetic field passing through two counter fixed yokes and the space between the fixed yokes. CONSTITUTION:Movable body 3 made of a permanent magnet is fitted to fixed member 5 via leaf spring 4 in the same body with lens holding frame 2 made of a nonmagnetic material containing objective lens 1 and made movable in the direction of arrow A. Since fixed yokes 61 and 62 of magnetic materials are provided opposing mutually with movable member 3 held at right angles to movement direction A, a magnetic flux generated by movable member 3 passes through fixed yokes 61 and 62 and space 7. For this purpose, flowing currents through coils 81 and 82 as shown by the marks in the figure moves movable member 3, i.e. objective lens 1 in one direction of arrow A (to right) with the sufficient capacity proportional to the flowed currents. |
