| 摘要 |
PURPOSE:To improve the follow-up characteristic of a focus control and tracking control by composing an optical system holder essentially of an acrylonitrile- butadiene-styrene copolymer packed with carbon fiber. CONSTITUTION:An objective lens holder 1 is inserted in a supporting shaft 11 through a bearing, a focusing coil 3 is wound on the outer peripheral part of the holder 1, and oblong tracking coils 4a and 4b are installed under the coil 3. The neutral point of the objective lens holder 1 is retained by a neutral point retaining rubber 5 fixed to an optical head 9, and the objective lens holder 1 can be freely rotated in a horizontal direction and slid in a vertical direction within the retaining limits. The objective lens holder 1 is formed with a material obtained by incorporating 15-50wt%, to the total weight, carbon fiber into the acrylonitrile-butadiene-styrene copolymer as a reinforcing material. Consequently, a lightweight holder having excellent rigidity and electrical insulating property can be obtained. Accordingly, the follow-up characteristic of the focus control and tracking control is excellent, and the performance is not deteriorated even in the high-frequency region. |
