Piezoelectric transformer driving device and image forming device

A piezoelectric transformer driving device, comprising:

• a piezoelectric transformer with a certain resonance frequency configured such that when an input voltage is intermittently applied to a primary side, an alternating high voltage is output from a secondary side;
• a switching part configured to generate the input voltage by switching based on a control signal having a control frequency, and configured to supply the voltage to the piezoelectric transformer;
• a switching control part configured to control the control frequency of the control signal based on a comparison result, and configured to supply the control signal to the switching part;
• a reference voltage waveform generation part configured to switch between a first voltage value as a target value, a second voltage value that is lower than the first voltage value, and a third voltage value that is higher than the first voltage value, within a given unit time so that a reference voltage waveform is generated;
• a monitor voltage generation part configured to generate a monitor voltage waveform based on the high voltage output from the piezoelectric transformer;
• and
• a comparison part configured to compare the reference voltage waveform with the monitor voltage waveform to generate a comparison result, and configured to supply the comparison result to the switching control part.