Patent ID: 6255760
Filing Date: 2001-07-03
Classification: G01C

Abstract:
A driving apparatus of a piezoelectric vibrator, comprising:a piezoelectric vibrator having a pair of drive electrodes on one surface of a vibrating leg and a pair of output electrodes on another surface of the vibrating leg; first and second I/V converting mechanisms to convert first and second current outputs, which are detected from said pair of drive electrodes, into first and second voltage outputs; first and second binarizing mechanisms to convert said voltage outputs into first and second digital outputs with reference to a predetermined threshold level; a phase shifting mechanism to generate a reference signal from said first and second digital outputs; an amplitude control mechanism to add a predetermined bias voltage to said reference signal; a low-pass filter to shift a phase of an output of said amplitude control mechanism and convert a rectangular wave into a sine wave; and a driving mechanism to generate a drive signal to amplitude-driving the piezoelectric vibrator from an output from the low-pass filter, wherein said drive signal is generated with reference to a median of a phase differential between said first and second current outputs.