| 摘要 |
PURPOSE:To obtain a smooth action and to reduce substantially composition parts by providing a cylindrical moval coil for surrounding a guide rail made of a ferromagnetic material and giving a slidable thrust bearing structure capable of sliding smoothly the inner surface of the movable coil and the outer periphery of the guide rail. CONSTITUTION:Cylindrical boice coils for drive 3a and 3b are fixed at both sides of an optical head 2, and at its inner periphery guide rails 5a and 5b and smooth and slidable thrust bearing members 4a and 4b are securely fitted. The guide rails 5a and 5b are made of ferromagnetic material, and their outer peripheries are surface-treated by ''Teflon(R)'' coating, etc., whereby the voice coils 3a and 3b can move smoothly. Magnets 6a and 6b are disposed in parallel and opposite to the guide rails 5a and 5b in such a way that said magnets are securely stuck to yokes 7a and 7b. A magnetic field produced by the guide rail 5, magnet 6 and yoke 7 is crossed by a coil 3, which leads the entire optical head 2 to drive in the direction of an arrow. Thus a smooth action can be obtained and composition parts can be substantially reduced. |
