Patent ID: 7515325

Claim:
An optical device comprising: a fixed portion having a first light reflection portion; a movable portion having a first surface that faces the fixed portion and a second surface opposite to the first surface, the movable portion having a second light reflection portion formed on the first surface of the movable portion, the second light reflection portion facing the first light reflection portion with a first gap being formed between the first light reflection portion and the second light reflection portion, the movable portion being movable with respect to the fixed portion so as to change the first gap between the first light reflection portion and the second light reflection portion, the first light reflection portion and the second light reflection portion being configured to reflect light that enters into the optical device from the outside of the optical device repeatedly between the first light reflection portion and the second light reflection portion so as to cause interference and emit light having a wavelength corresponding to a size of the first gap to the outside of the optical device; a first electrode portion fixed to the fixed portion so as to face the second light reflection portion near the first light reflection portion with a second gap being formed between the second light reflection portion and the first electrode portion; a second electrode portion facing the second surface of the movable portion with a third gap being formed between the second surface of the movable portion and the second electrode portion, one of the first electrode portion and the second electrode portion serving as a detection electrode for detecting a capacitance between the movable portion and the detection electrode, another of the first electrode portion and the second electrode portion serving as a drive electrode; and a circuit operable to generate a potential difference between the movable portion and the drive electrode so as to generate an electrostatic attraction force therebetween for changing a position and/or a posture of the movable portion, wherein the circuit includes a switching unit operable to switch the first electrode portion and the second electrode portion between a function of the detection electrode and a function of the drive electrode.