| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piezoelectric element control device with reduced deviation between 'the output signal of a charge detecting circuit for detecting the amount of charge accumulated in the piezoelectric element' and 'the amount of the displacement of the piezoelectric element', particularly in low frequency regions. <P>SOLUTION: The piezoelectric control device is provided with a drive circuit 40 that applies a voltage to the piezoelectric element 10, a charge detecting circuit 20 that detects the amount of charge accumulated in the piezoelectric element 10, and a correction circuit 30 that performs signal processing on an output signal from the charge detecting circuit 20. The charge detecting circuit 20 comprises an operational amplifier 21, a feedback capacitor 22, and an inverting circuit 23. The electrostatic capacity Cs of the capacitor 22 is set to be 10-20 times the electrostatic capacity Cp of the piezoelectric element 10. The inverting circuit 23 regulates phases of the drive circuit 40 output and the charge detecting circuit 20 output. The correction circuit 30 has an input/ output characteristic that is roughly equivalent to the frequency characteristic of the 'amount of displacement of the piezoelectric element 10' to the 'output signal of the charge detecting circuit'. <P>COPYRIGHT: (C)2003,JPO |
