Patent ID: 7750767

Claim:
A micro electro mechanical system (MEMS) device comprising: a stage which operates in a vibration mode; an axle which supports the stage and allows rotation of the stage; and a capacitive sensor which detects a rotational state of the stage, wherein the capacitive sensor comprises: a sensing arm which extends from an end of the stage in parallel with the axle, the sensing arm being spaced a distance from the axle; a plurality of driving combs which extend from the sensing arm in a direction crossing the axle, the driving combs being rotated together with the stage; a plurality of fixed combs which are arranged in parallel with each other and fixedly supported for engagement with the driving combs, the fixed combs including surfaces overlapping opposite surfaces of the driving combs in accordance with a rotation of the driving combs; and a capacitance sensing portion which detects a capacitance change of the driving combs and the fixed combs via the overlapping surfaces of the driving combs and the fixed combs.