| 摘要 |
PURPOSE:To ensure the accurate drive control of an objective lens by using two plate spring elements holding a buffer layer to form a pair of tracking control springs which supports elastically an objective lens and adhearing a viscous layer on the outer surface of at least one of four plate spring elements. CONSTITUTION:When the tracking control springs receive vibrations, a difference of vibration characteristics is produced between plate spring elements 22 and 22 since a viscous layer 24 is provided on the outer surface of one of both elements 22. This produces a damping function via a silicone resin layer 23, i.e., a buffer layer set between both elements 22 to prevent the generation of the resonance despite a low level of rigidity of the plate spring. Furthermore the elements 22 are reinforced by both layers 23 and 24. This can prevent the generation of a backling phenomenon. It is not intended that the rigidity is increased by increasing the thickness of the tracking control spring. Therefore the spring characteristics are neither deteriorated nor the drive control function of the tracking compensation is impaired. |
