| 摘要 |
PROBLEM TO BE SOLVED: To prevent resonance between a vibrator and a diaphragm and prevent stopping of oscillation of the vibrator. SOLUTION: The vibration detection device comprises a detection vibrator 21 which is provided on the diaphragm 11 and has a first vibrator 211, a second vibrator 212, and a third vibrator 213, a compensation vibrator 22 which is provided on the diaphragm 11 and has a fourth vibrator 221, a fifth vibrator 222, and a sixth vibrator 223, a magnet 5 for generating a magnetic field for the detection vibrator 21 and the compensation vibrator 22, an amplifier 23 which inputs an excitation current to the first vibrator 211 to vibrate it and generates and outputs an excitation current corresponding to the electromotive force generated in the second vibrator 212, a current source 24, and a frequency detection section 28 for detecting the vibration frequency of the detection vibrator 21 on the basis of the excitation current. The fourth vibrator 221 vibrates caused by the excitation current which is input in a direction allowing a Lorentz force to be generated in the direction opposite to a Lorentz force generated in the first vibrator 211. COPYRIGHT: (C)2008,JPO&INPIT
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