| 摘要 |
PURPOSE:To make a movement of a focal distance large even if an incident angle is small, and also to make a device small in size by constituting as one body a tracking control device and a focusing control device. CONSTITUTION:When a current flows to the first coil 29, a lens barrel 25 slides through the inside of a cylindrical body 31 and moves in the upper and lower directions together with a mirror 27, and executes a focusing control. The inner side face of the first yoke 22 is opposed to the lower half of the second coil 30. Accordingly, a force is generated between a magnetic flux emitted from the inner side face of the first yoke 22, and a current of the lower half of the second coil 30, and a bobbin 26 moves in the upper or lower direction. Therefore, when a current direction of the second coil 30 of the right side is set, for instance, so that the right side moves in the lower direction, when the left side of the bobbin 26 moves in the upper direction, the mirror 27 and the lens barrel 25 turn clockwise, a focus of an emitted light moves in the left direction, and a tracking control is executed. In that case, even if an incident angle theta is small, a large focus moving distance D (d1+d2) can be obtained. |
