Patent ID: 8265511

Claim:
A power source device comprising: an oscillator generating a clock; a frequency division unit dividing the clock to output a pulse; a sequence generation unit generating an “N” number of sequences, in which each element has substantially the same occurrence rate, with respect to each switching of the pulse by synchronizing with the pulse; a frequency division ratio setting unit setting a frequency division ratio of the pulse; a switching element driven by the pulse; and a piezoelectric transformer outputting an alternating current high voltage from a secondary side thereof when a primary side thereof is intermittently applied with a voltage by the switching element, wherein the generated sequence and the set frequency division ratio are compared to output the pulse of a fractional-M frequency and the pulse of a fractional-M+1 frequency, wherein an average frequency division ratio of the pulse of the fractional M frequency and the pulse of the fractional-M+1 frequency is determined by (M×α)+(M+1)×β/(α+β), where the α represents the number of the pulses of the fractional-M frequency and the β represents the number of the pulses of the fractional-M+1 frequency per unit time, and wherein the average frequency division ratio and the frequency division ratio become substantially equal to each other at a generation cycle of the sequence, and become approximated to each other in a period shorter than the sequence generation cycle.