| 摘要 |
A read/write head for a optical disk drive, comprises a lens holder ( 8 ), a support frame ( 11 12, 16 ), means ( 15 ) for suspending the lens holder ( 8 ) in the support frame which means constrain movement of the lens holder ( 8 ) relative to the support frame, allowing only an at least limited translation in a focussing direction (z), parallel to the optical axis of a lens ( 7 ) in the lens holder ( 8 ), an at least limited translation in a tracking direction (y), perpendicular to the focussing direction (z), and an at least limited rotation about an axis in a tangent direction (x), perpendicular to both the focussing and the tracking direction, and actuator means, comprising only two conductive focussing coils ( 9, 10 ) with a winding axis parallel to the focussing direction (z), each positioned relative to a magnetic circuit ( 11, 12 ) in such a way that a current flowing through a coil ( 9, 10 ) gives rise to a force between the lens holder ( 8 ) and the support frame in the focussing direction (z). The winding axes of the two focussing coils ( 9, 10 ) are positioned on opposite sides of a plane through the center of mass of the lens holder ( 8 ), and parallel to the focussing and the tangent direction. The focussing coils ( 9, 10 ) are spaced apart in the tangent direction (x).
|
