| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve detection sensitivity. <P>SOLUTION: An acceleration sensor 10, including: an oscillator unit 12 including a first piezoelectric vibrating reed 16 that performs bending vibration; a 90°-phase shifting unit 20 for shifting by 90°and outputting a phase angle of an output signal of the oscillator unit; a phase shift circuit unit 22 arranged at an output side of the 90°-phase shifting unit 20, provided with a second piezoelectric vibrating reed 24 that has the same resonance frequency as the first piezoelectric vibrating reed 16 and performs bending vibration, and having a point-symmetrical phase shift characteristics around the resonance frequency of the second piezoelectric vibrating reed 24; and a phase shift modification output unit 45 which outputs, on the basis of a phase shift of an output signal of the phase shift circuit unit 22 and an output signal of the oscillator unit 12, a signal corresponding to the phase difference between both of them, wherein the first piezoelectric vibrating reed 16 and the second piezoelectric vibrating reed 24 are arranged so that the axial line directions of their vibrating arms are directed in opposite directions. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
