Patent ID: 8549742

Claim:
A high-voltage power supply device comprising: a circuit board having a piezoelectric transformer and a switching element, wherein the circuit board comprises: a capacitor and an inductor forming a resonance circuit for driving the piezoelectric transformer, and a capacitance element connected across a ground and a power-supply side of the inductor, wherein the capacitance element, the inductor and the piezoelectric transformer are arranged on the circuit board in such a manner that the piezoelectric transformer is solder-mounted after the capacitance element and the inductor are solder-mounted, and wherein the capacitance element charges electric charge in accordance with a pyroelectric voltage produced in the piezoelectric transformer such that the electric charge in accordance with the pyroelectric voltage is reduced before the electric charge is applied to the switching element, when the circuit board on which the switching element, the capacitor, the inductor and the piezoelectric transformer are arranged is conveyed into a solder tank to solder the switching element, the capacitor, the inductor and the piezoelectric transformer to the circuit board.