| 摘要 |
PURPOSE:To eliminate the need for an iron-made yoke and to prevent drive magnets in focus and track directions from being interferred by adopting the constitution that an objective lens is driven in the focus direction by a coil wound directly around the objective lens and a magnet only. CONSTITUTION:A holder 4 is fitted to a support base 2 to which two track magnets 1a, 1b are fixed via two plate springs 3a, 3b and track coils 5a-5d are fitted to the outside of the holder 4. Further, cylindrical focus magnets 6a, 6b are fixed to the inside of the holder 4 vertically while the same polarity (repulsive direction) are adhered by two each, the objective lens 8 around which a focus coil 9 is wound directly is fixed to the outer peripheral and the objective lens 8 is driven respectively in the focus and radil directions by flowing current to the focus coil 9 and track coils 5a-5d. |
