Patent ID: 8316710

Claim:
A physical quantity measuring apparatus comprising: a first function of generating a voltage used for position-controlling a movable body; a second function of detecting a position of said movable body during a position detecting period; a third function of calculating a control amount necessary to keep said movable body at a predetermined position on the basis of a detection result by said second function, and causing said first function to generate a control voltage corresponding to said calculated control amount to keep said movable body at said predetermined position during a position controlling period; and a fourth function of setting said position detecting period and said position controlling period in a time-sharing manner so that said position detecting period and said position controlling period do not overlap with each other; wherein said movable body is disposed in a casing provided with electrostatic supporting electrodes and common electrodes; said movable body being displaced within said casing depending on voltages applied from said first function to said electrostatic supporting electrodes; said second function being configured to apply position-detecting carrier voltages having different frequencies respectively to said electrostatic supporting electrodes as a position detecting signal, and take in, from said common electrodes, said position detecting signal applied to said movable body through said electrostatic supporting electrodes; said third function being configured to perform synchronous detection on said position detecting signal taken in from said common electrodes to detect said position detecting carrier voltages, control a value of said control voltage for each of said electrostatic supporting electrodes in accordance with results of said synchronous detection to keep said movable body at said predetermined position, and calculate acceleration or angular velocity of said movable body in accordance with said results of said synchronous detection; and the position-detecting carrier voltages are applied to all of the electrostatic supporting electrodes at a same timing within a same period.