| 摘要 |
<p>A system for controlling a light focusing unit to adjust a focus of light impinging on a track in a rotatable optical disc (1). This control system includes a unit (27) for moving the light focusing unit (25) in a direction perpendicular to a plane of the optical disc (1); a unit (25, 24a, 23, 22, 29a, 29) for producing a focus error signal and a track error signal; and a unit (4) for controlling a position of the light focusing unit (25) through said moving unit (27) in response to the focus error signal and the offset parameter. The system further includes an offset setting unit for continuously setting, during an offset adjustment mode, a plurality of offset parameters to the position control unit (4), to determine a maximum amplitude of the track error signal, and to set the offset parameter producing the maximum amplitude of the track error signal to the position control unit (4). In a normal operation, the system effects the focus control in response to the set offset parameter and the focus error signal. </p> |
