| 摘要 |
<p>An objective lens-driving unit comprises a lens supporting means (11) for supporting the objective lens (2) having an optical axis vertical to a recording medium (6) on which light beams converge through the objective lens (2) so as to attain optical recording, optical playing and optical erasing of information on the recording medium; and intermediate supporting means for supporting said lens supporting means (11) by use of springs (12) that are movable in the tracking direction (x); at least one driving means (16,21) for driving said lens supporting means (11) in the tracking direction (x); a driving means (23,28) for driving said intermediate supporting means in the focussing direction (y), wherein said tracking direction-driving means (16,21) comprises a magnetic circuit (16) that produces magnetic flux in the circumferential direction of the recording medium (6), and a tracking direction-driving coil (21) that is positioned to cross a gap (20) formed in the magnetic circuit to thereby receive an electro-magnetic force due to an interaction between the magnetic field of the magnetic circuit (16) and the current passing through said coil (21), said tracking direction-driving coil (21) being positioned within the excitation area of the magnetic circuit (16) even when said coil (21) moves in the focussing direction (y).</p> |
