| 摘要 |
PURPOSE:To slow down the movement of an actuator by providing a 2nd current source supplying a current smaller than that of a 1st current source for focus pulling in, and supplying a current of the 2nd current source to the actuator when a lens approaches a medium to some degrees or over. CONSTITUTION:When a current supplied from a 1st current source 8 and a lens approaches a medium to some degrees, a focus sum signal (a) and a focus error signal (c) are outputted from a head. When a 2nd comparator 3 detects it that the focus sum signal (a) exceeds a voltage through the further approach, the 2nd comparator 3 outputs a sum detection signal (b) top throw a 1st switch 7 to the position of the 2nd current source 9. Since the current supply from the 2nd current source 9 is smaller than the current of the 1st current source 8, the movement of the actuator 2 slows down more than that by the current supply of the 1st current source 8 only. |
