PHYSICAL QUANTITY DETECTOR

摘要

PROBLEM TO BE SOLVED: To maintain the detection characteristics of an angular velocity detector at a good value regardless of pressure fluctuation in a closed space containing an angular velocity detector. SOLUTION: An angular velocity detector vibrates a vibrator 20 supported capable of vibration on a substrate 10 in a closed space in X-axis direction by drive electrodes 51-1 to 51-4 and detects the vibration of the vibrator in Y-axis direction by the Coriolis force generated when angular velocity works by detection electrodes 53-1 to 53-4. A servo amplifier 76 generates an output voltage Eox' so that the amplitude of the vibrator in X-axis direction becomes constant. The output voltage is a value indicating the pressure in the closed space and the servo amplifier 79 changes the voltage ERC so that the output voltage EOX' becomes constant, which is impressed to detune control electrodes 54-1 to 54-4. As the results, the detected vibration resonance frequency of the vibrator is changed and the gain (effective detection vibration Q value) in the drive frequency of.the vibrator is maintained constant.