| 摘要 |
PURPOSE:To obtain a small-sized device by supporting an optical system movably in a vertical direction, and controlling driving current for the 1st and the 2nd coils on the basis of a prescribed error signal. CONSTITUTION:A couple of rectangular magnets 22 and 23 are arranged facing each other while an objective lens 21 constituting the optical system is interposed. The magnets 22 and 23 have platelike members 24 and 25 with high magnetic permeability on the opposite surfaces and are wound with the 1st and the 2nd coils 26a and 26b, and 27a and 27b independently so that they cross at right angles on the surfaces of the platelike members 24 and 25. The magnet 22 and 23 are magnetized as shown in a figure and are fixed to a rectangular annular frame 28 having high magnetic permeability to couple themselves mutually and magnetically. A frame 28 forms one magnetic closed loop as shown by arrows in the figure to reduce leakage of magnetic flux. |
