| 摘要 |
PURPOSE:To ensure stable focusing and tracking, by coupling firmly an objective lens, a focusing lens and a photodetector and giving independent displacement to these optical elements in two directions. CONSTITUTION:An objective lens 34, a focusing lens 36-1 and a photodetector 36-2 are coupled firmly to each other via a magnetic material 33 and are moved in a body. These optical elements are attached to a base 22 via spring members 31 and 24. This optical system can be moved in the focusing direction by controlling the current supplied to coils 41a and 41b and in the tracking direction by controlling the current supplied to coils 51a and 51b, respectively. |
