| 摘要 |
PURPOSE:To reduce the mass of a movable part by driving an objective, a condenser lens and a photodetector separately from a laser light source. CONSTITUTION:Lenses 25 and 27, and a photodetector 28 are fixed to a lens barrel 29, and a driving circuit 32 performs focusing and tracking. A light source 20, a collimator lens 21, a polarization beam splitter 23, etc., are separated from the lens barrel 29, and the mass of a movable part is small. |
