| 摘要 |
PURPOSE:To simplify and thin the constitution of the titled device by fitting a control coil forming a closed loop by combining respective coils like a cross in parallel with two rectangular axes, a focus axis and a radial axis, respectively so as to surround the 2nd magnetic york rectangularly each other. CONSTITUTION:A focus error signal extracted from an error detecting circuit is applied to a focus control coil 42. The coil 42 receives force based upon Fleming's left-hand rule and focusing plate spring bodies 23 are elastically deformed by the force and moved in parallel along a focus axis F. Consequently, an objective lens 25 is controlled at its driving of the axial direction F. A radial error signal extracted from a radial error detecting circuit is applied to a radial control coil 41. A spring supporting body 21 is turned in one direction of the horizontal direction or the other direction around a rotary shaft 20 on the basis of the elastic displacement of a viscoelastic substance 22 and a lens holder 24 is deformed at its turning through the plate spring 23. Consequently, the objective lens 25 is controlled at its driving correctly along the ridial axis R direction. |
