| 摘要 |
PURPOSE:To obtain a small-sized velocity meter, which can be mass-produced at low cost, by forming a vibrator in the shape of a beam supported on both ends by a base body. CONSTITUTION:A lower electrode 4 is divided into an electrode 9 for driving and electrodes 8a, 8b for detection. When an upper electrode 6 is used as a common ground and an electric field having frequency close to the cantilever natural frequency of a vibrator 1 is applied to the electrode 9, cantilever vibrations are excited in the direction of V by the vibrations of a PZT piezoelectric film 5. When the vibrator 1 is moved in the direction V at velocity V, Coriolis force Fc works on the vibrator 1 when rotational angular velocity OMEGA is applied around the axis of a cantilever in the axial direction of the cantilever. The force deflects the vibrator 1 in the direction perpendicular to the direction of vibrations. When force is applied in the directions of OMEGA and Fc, compressive stress works on the electrode 8a side and tensile stress to the electrode 8b side. When voltage between the electrode 8a and a ground is represented by Va and voltage between the electrode 8b and the ground by Vb, a signal resulting from cantilever vibrations is offset in a signal by Coriolis force when difference Va-V2b of both voltage is taken, and only the signal by Coriolis force can be read. |
