Patent ID: 7855820

Claim:
An oscillator device, comprising: a supporting base plate; a torsion spring; and a movable member; wherein said movable member is supported by said torsion spring, for torsional oscillation relative to said supporting base plate about a torsional axis; wherein said torsion spring has an X-shaped section being perpendicular to said torsional axis and a top surface and a bottom surface each being defined by a (100)-equivalent surface of monocrystal silicon, and wherein a distance L 1 connecting bottoms of concavities formed at the top surface and bottom surface, respectively, and a distance L 2 connecting bottoms of concavities defined at side surfaces of the X-shaped torsion spring as well as a rate of change α i of inertia moment of said movable member around the torsion axis, with a change of a thickness t of said supporting base plate, satisfy the following relation: L 1 /L 2 =C 1·Exp{ C 2·(α i +C 3)}+ C 4·α i +C 5 where C 1=5.0*10^−1 C2=−4.4 C 3=4.6*10^−2 C 4=−6.0*10^−1 1.5<C5<1.7.