Patent ID: 7224097

Claim:
A comb-shaped actuator comprising: a substrate having an opening formed therein; a fixed electrode comprising a fixed electrode base portion provided along an inner side of the opening on the substrate and a plurality of fixed electrode finger groups arranged in parallel with each other in the shape of teeth of a comb throughout a predetermined length on the fixed electrode base portion; a movable electrode located in the opening of the substrate and comprising a movable electrode base portion and a plurality of movable electrode fingers arranged in parallel with each other in the shape of teeth of a comb facing the fixed electrode throughout a predetermined length, the movable electrode being movable by an attracting force generated between the fixed electrode finger and the movable electrode finger subject to an electric field or a magnetic field applied between the movable electrode and the fixed electrode upon arranging the movable electrode fingers and the fixed electrode fingers in an interdigital pattern with a gap between them; and a suspension supporting member connecting the movable electrode integrally with the substrate and suspending movably the movable electrode from the substrate, both the fixed electrode and the movable electrode comprising a plurality of electrode finger units containing two fixed electrode fingers next to each other and the movable electrode finger interposed between the two fixed electrode fingers, at least two of the electrode finger units comprising off-centered electrode finger units having one of the movable electrode fingers being off-centered with respect to a central position between two of the fixed electrode fingers, the off-centered electrode finger units being located on both sides of a central line dividing both the fixed electrode and the movable electrode along the opening into two parts, and directions of off-centering of the both sides being inverse to each other.