Patent ID: 8634734

Claim:
A power supply circuit comprising: an alternating current voltage generation unit which generates an alternating current voltage having a shape of a rectangular wave; a voltage conversion unit which converts the alternating current voltage generated by said alternating current voltage generation unit into a predetermined output voltage; and an adjustment unit which monitors the output voltage and adjusts a driving pattern for driving said alternating current voltage generation unit in accordance with a waveform distortion generated in a rectangular wave of the output voltage, wherein the driving pattern is a pattern having, in a half cycle of the rectangular wave of the alternating current voltage, a first ON period during which the alternating current voltage is applied to said voltage conversion unit, an OFF period during which the alternating current voltage is not applied to said voltage conversion unit, and a second ON period during which the alternating current voltage is applied to said voltage conversion unit, and said adjustment unit adjusts a ratio of the first ON period, the OFF period, and the second ON period so that the waveform distortion decreases.