High-voltage power-supply apparatus, and image formation apparatus

An image formation apparatus for forming an image on a print medium with a high output voltage, comprising

• the high-voltage power-supply apparatus for outputting the high-voltage output voltage includes:
• a controller configured to output a control signal containing a pulse with a variable drive frequency;
• a switching unit configured to be switched by the control signal and output a drive signal;
• a piezoelectric transducer having a predetermined resonant frequency, and configured to be driven by the drive signal and output a high-voltage output voltage;
• a current detector configured to detect an electric current of a load connected to an output side of the piezoelectric transducer and output a current-detection result;
• and
• a lower-limit-value setup unit configured to set a frequency lower limit value for the drive frequency of the controller, wherein
• the controller is configured to make the frequency lower limit value variable in accordance with the current-detection result.