| 摘要 |
PURPOSE:To make high-precision tracking and focusing controls possible by allowing a position adjusting coil, which is so wound that a plane vertical to the magnetization direction of a magnet provided on a moving body is formed, to face the magnet. CONSTITUTION:An object lens 5 is allowed to face a disc surface, and a reading spot is projected to an information track through the lens 5, and the reflected light is allowed to pass the lens 5 to read recorded information by a detecting means. At this time, the reflected light is used to detect deviations in tracking and focus directions, and electric signals corresponding to these deviations are outputted and are applied as correcting currents to tracking and focusing coils 13 and 12, and a magnet 8 is driven in tracking and focusing directions. Thus, a tracking spring 10 and a focusing spring 7 are shifted in tracking and focus directions respectively while being kept parallel, and as the result, the lens 5 is moved to an optimum position while keeping the optical axis vertical to the disc. |
