| 摘要 |
PROBLEM TO BE SOLVED: To provide a driver for a capacitive element that can reduce the peak value of the induced voltage produced at an electrode of a capacitive element lower. SOLUTION: A parallel circuit, consisting of a high impedance PMOS (transistor) 31 and a low impedance PMOS 32 and a parallel circuit, consisting of a high impedance NMOS 33 ad a low impedance NMOS 34 are connected in series between a point to which a drive voltage is applied and ground, a parallel circuit consisting of a high-impedance PMOS 44 and a low-impedance PMOS 45 and a parallel circuit consisting of a high-impedance NMOS 46 ad a low- impedance NMOS 47 are connected in series, and connecting points of the respective parallel circuits are respectively connected to electrodes of a piezoelectric element 57. When the electrode 57a of the piezoelectric element is at a low level, an electrode 57b is at a high level and the piezoelectric element is charged from the electrode 57a, first, the PMOS 31 is made conductive and then the PMOS 32 is made conductive after the lapse of a prescribed time. Thus, the peak value of a positive induced voltage produced in the opposite electrode 57b can be suppressed lower.
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