| 摘要 |
PURPOSE:To attain the high efficient drive of a focus actuator part by providing a power supply switching means switching the 1st voltage level into the 2nd voltage level higher than the 1st voltage level with a focus search of an objective lens is requested. CONSTITUTION:An L level control signal is fed from an operation control circuit (not shown in figure) incorporating a microcomputer or the like is fed to a control terminal 23 in the focus servo state and an H level control signal is fed in the focus servo state. Thus, a power voltage V1 is impressed to a BTL drive circuit 18 in the focus servo state, the peak value of a pulse width modulation signal is suppressed lower, the focus actuator part is driven with a large duty ratio and efficient state. Further, a power voltage V2 is fed to the circuit 18 in the focus search state to increase the peak of the pulse width modulation signal and the gain to drive the focus actuator part. Thus, the focus actuator part is driven with a high efficiency and low power consumption is attained.
|
