| 摘要 |
PURPOSE:To obtain a positioning control circuit with simple constitution, by driving two condenser lenses with a pair of focus tracking actuator and control circuits corresponding to the actuators. CONSTITUTION:A first beam 91 emitted from an optical system 9 in an optical head cabinet 8 is condensed on the recording track of a recording medium 6 via a condender lens 2, and forms a micro light spot 92. Also, a second beam 93 is condensed on the recording track via a condenser lens 3, and forms a micro light spot 94. Focus control which condenses the first and the second beams 91 and 93 on the recording medium is performed by focus actuator 11, a position detector (not shown in figure) in a focusing direction of A, and a servo control mechanism. Meanwhile, tracking control is performed by a track ing actuator 12 provided on a movable part 1, a positioner 10 which moves the whole of the optical head cabinet 8 in a tracking direction, position detectors 95 and 96 for the light spots 92 and 94 in the tracking direction, and the servo control mechanism consisting of a first and a second control circuits 13 and 14.
|
