| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve drive accuracy of a piezoelectric actuator (hereinafter, simply described as a piezo). <P>SOLUTION: A piezo driving device is provided with: an inductor connected to a piezo in series; a charging path for executing power supply to a series circuit of the inductor and the piezo from a power supply circuit via a charging switch; and a discharging path connected to the series circuit in parallel so as to discharge charges of the piezo via a discharging switch. When an inputted drive signal becomes high, the piezo is charged and expanded by repeatedly turning on/off the charging switch in the state where the discharging switch is turned off. When the drive signal becomes low, the piezo is discharged and contracted by executing discharge switching control for repeatedly turning on/off the discharging switch in the state where the charging switch is turned off. However, the discharging switch is left in an on-state, particularly, from the end of discharge switching control to the start of next driving. A piezo voltage is thereby surely set at almost 0 V at the next driving start time. <P>COPYRIGHT: (C)2009,JPO&INPIT |
