| 摘要 |
PURPOSE:To control displacement accurately by controlling the charge injecting amount of a piezoelectric element corresponding to the displacement. CONSTITUTION:Driver for a piezoelectric element 1 comprises a displacement detecting means 10, a switching means 11, a current control means 16, an impedance converting circuit 18, an integrator 25, first and second differential amplifiers 17, 26, a comparator 27, a zero-cross detector 28, a sample-and-hold means 29, an absolute value amplifier 30, a switch 31, and the like. Displacement of the element 1 is detected through a detecting means 10 and the difference is operated through a first differential amplifier 17 then it is held 29, and the amount of charge is controlled corresponding to the displacement. |
