| 摘要 |
PURPOSE:To attain accurate tracking, through the adjustment of a current by supporting a coil formed with electric wires wired in crossing with four pins at the four corners and a center fulcrum of a moving plate formed incorporatedly with a mirror, in a magnetic path freely shakingably. CONSTITUTION:A support shaft 11 is provided at the lower center of a moving plate 10 incorporated with a mirror 1 and supported freely shakingably in a round hole 13 of a damper 12 made of rubber provided at the center of a pole piece member 9. Four pins 13a-d are fitted at the four lower corners of the moving plate 10, electric wires surrounding the four pins in a quadrilateral and tying diagonal lines form a coil and the wires are connected to leads 16 and 17. The said coil is inserted in an air gap of the magnetic path consisting of a permanent magnet 8, a yoke 3, yoke planes 5,5' and 6,6', and pole pieces 9a-d. The direction and magnitude of current flowing to the coil are controlled and the mirror 1 is displaced, allowing to control the spot of a laser light for accurate tracking. |
