Abstract: A movable plate is provided to a pendulum displaceable by external vibration. A fixed plate is provided to a position opposite to the movable plate. A displacement detector detects an electrostatic capacitance between the plates. A servo amplifier supplies to a force coil, a current in an amount associated with the detection result. A current circuit and a load resistor of the force coil convert the current into a detection signal and output the signal. When the movable plate and the fixed plates, which are conducted to each other, are contacted, the electrostatic capacitance between the plates is removed. A processor detects a change in the detection signal due to the removal of the electrostatic capacitance, and then determines that the plates are contacted.

Abstract: A movable plate is provided to a pendulum displaceable by external vibration. A fixed plate is provided to a position opposite to the movable plate. A displacement detector detects an electrostatic capacitance between the plates. A servo amplifier supplies to a force coil, a current in an amount associated with the detection result. A current circuit and a load resistor of the force coil convert the current into a detection signal and output the signal. When the movable plate and the fixed plates, which are conducted to each other, are contacted, the electrostatic capacitance between the plates is removed. A processor detects a change in the detection signal due to the removal of the electrostatic capacitance, and then determines that the plates are contacted.

Abstract: A focal detecting means (35) of a controller (25) controls an actuator driver (38) to actuate an actuator (12) to vibrate an objective lens (3) in a direction along an optical axis. An output of a focus error signal from a signal generator (27) is checked by a signal detecting means (46) and presence of a workpiece is determined when the signal is detected. When the presence of the workpiece is detected, the focal detecting means (35) moves the objective lens (3) along the optical axis by the actuator (12) and a focus position is recognized with reference to a position signal from a position detecting means (49) together with the focus error signal, where the objective lens (3) is moved to the focus position for focusing.

Abstract: A focal detecting means (35) of a controller (25) controls an actuator driver (38) to actuate an actuator (12) to vibrate an objective lens (3) in a direction along an optical axis. An output of a focus error signal from a signal generator (27) is checked by a signal detecting means (46) and presence of a workpiece is determined when the signal is detected. When the presence of the workpiece is detected, the focal detecting means (35) moves the objective lens (3) along the optical axis by the actuator (12) and a focus position is recognized with reference to a position signal from a position detecting means (49) together with the focus error signal, where the objective lens (3) is moved to the focus position for focusing.