Piezoelectric valve, method for driving piezoelectric valve, and optical particulate separator equipped with air-jet means using piezoelectric valve

A method for driving a piezoelectric valve, which includes a gas pressure chamber adapted to receive compressed gas supplied externally and an exhaust path adapted to discharge the compressed gas from the gas pressure chamber, the piezoelectric valve comprising:

• a valve disc placed in the gas pressure chamber and adapted to open and close the exhaust path;
• a piezoelectric element adapted to generate a driving force needed for operation of the valve disc, as a displacement;
• a displacement magnifying mechanism adapted to magnify the displacement of the piezoelectric element and apply the magnified displacement to the valve disc;
• and
• a driving unit for driving and thereby opening/closing the valve disc via expansion/contraction displacement of the piezoelectric element, wherein
• the driving unit includes a signal generator adapted to generate a signal including a first prepulse, a second prepulse, and a main pulse, applies a drive voltage to the piezoelectric element based on the signal generated by the signal generator, and drives and opens the valve disc by expanding the piezoelectric element.