| 摘要 |
PURPOSE:To absorb the vibrations of a ring spring, by sticking an approximately circular doughnut-shaped rubber sheet to the ring spring which holds a lens used to read out optically the information out of an optical information recording medium. CONSTITUTION:A lens reads the information out of the reflected light after irradiating the light to an optical information medium. This lens is held by a ring spring 14. Back-forth fine adjustment is given to the position of the lens to obtain a correct focus. For this purpose, the spring 14 is made of copper of extremely small thickness, for example, with a soft structure, and at the same time a spiral blanked part 16 is provided to the spring 14. Then a doughnut- shaped rubber sheet 15 (hatch part) is stuck to the spring 14. As a result, the extra vibrations given toward the tracking direction are absorbed without deteriorating the low rigidity secured in the axial direction of the lens. This processing ensures the accurate automatic focusing to reduce reading errors and to improve both S/N and reading speed. |
