| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power-savable drive circuit and a drive method for an electromechanical transducer (piezoelectric element), and a driver which uses the electromachanical transducer. <P>SOLUTION: This drive circuit is equipped with a drive voltage applying part which is composed of first to fourth switching elements 111, 112, 121 and 122 for applying a drive voltage to a piezoelectric element 10a which expands and contracts by the application of the applied drive voltage; a charging/discharge part which is composed of fifth to eighth switching elements 131, 132, 141, and 142 for charging and discharging charge between the piezoelectric element 10 and a capacitor 100 connected in parallel with the piezoelectric element 10a; and a control circuit 60a which controls the drive voltage application part and the charge and discharge part so that it recharges the charge charged in the capacitor 100 in the piezoelectric element 10a, inverting its polarity after charging the charge which has been charged in the piezoelectric element 10a in the capacitor 100, while it inverts the polarity of the drive voltage applied to the piezoelectric element 10a. Hereby, the charges charged in the electromechanical transducer are utilized effectively and power can be saved as compared with the case of a conventional drive circuit which does not utilize the charges effectively. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
