Vertically-shifting electrostatic actuator and optical scanner employing the same

An optical scanner includes a mirror configured to reflect an incident light and a vertically-shifting electrostatic actuator configured to oscillate the mirror. The electrostatic actuator includes a frame having an installation space in a central portion and a drive electrode, a stationary electrode, a shifter, and a force application part installed in the installation space. Drive electrode fingers in the drive electrode and stationary electrode fingers in the stationary electrode are alternately disposed. The shifter may be connected either between the frame and the drive electrode or between the frame and the stationary electrode and vertically shifts either the drive electrode or the stationary electrode connected to the shifter when a vertical force is applied through the force application part.