| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piezoelectric actuator with a protection mechanism that protects the piezoelectric actuator from being broken even if an abnormal voltage and an abnormal current are applied, and a protection mechanism unit. <P>SOLUTION: The piezoelectric actuator with the protection mechanism protects a piezoelectric actuator element (16) from an input of the abnormal voltage or the abnormal current, and comprises the piezoelectric actuator element (16) driven by an input of a drive signal, and an overvoltage restriction element (Va) that is connected to the piezoelectric actuator element (16) in parallel therewith, and restricts the application of the overvoltage to the piezoelectric actuator element (16). For example, when the drive signal of the overvoltage is input to the piezoelectric actuator, the resistance of the overcurrent restriction element (Va) is abruptly lowered, to make a current flow. By this, since an improper signal is blocked from the piezoelectric actuator element (16), the piezoelectric actuator element (16) can be protected from unanticipated breakage. <P>COPYRIGHT: (C)2007,JPO&INPIT |
