Patent ID: 7046293

Claim:
A power supply circuit, comprising: a control circuit; a first circuit for generating a positive polarity voltage, said first circuit including a rectifying circuit and a capacitor; a positive polarity voltage outputting terminal for outputting the positive polarity voltage from said first circuit; a second circuit for generating a negative polarity voltage; a negative polarity voltage outputting terminal for outputting the negative polarity voltage from said second circuit; a ground terminal for providing a reference potential for both of said positive polarity voltage and said negative polarity voltage; and a short circuit for short-circuiting substantially between said positive polarity voltage outputting terminal and said negative polarity voltage outputting terminal in response to a power-off signal provided by the control circuit; wherein the power-off signal stops operation of the first circuit and the second circuit and discharges residual charges of the capacitor by said short circuit; and wherein said first circuit includes a chopper circuit for generating a low first positive voltage.