| 摘要 |
PURPOSE:To make it possible to move an objective lens in a fixed direction as much as fixed by flowing currents through a couple of coils corresponding to a tracking error. CONSTITUTION:Yokes 2 and 2' are coupled with permanent magnets 1 fitted to fixed members 10 and 10', and movable member 6 made of a permanent magnet is arranged between those yokes, which are wound with coils 4 and 4' to provide a magnetic field as shown by arrow A. Movable member 6 is anchored to lens holding frame 8 holding object lens 7 and while one-side terminals of leaf springs 9 and 9' are fixed to holding frame 8, the other-side ones are also bonded to fixed members 10 and 10'. Thus, objective lens 7 is installed being displaceable crossing its optical axis and information track at right angles as shown by arrow B. Supplying coils 4 and 4' with currents corresponding to a tracking error applies movable member 6 made of the permanent magnet with arrow-B-directional force, and therefore objective lens 7 is displaced in the same direction, thereby correcting the tracking error. |
