| 摘要 |
PROBLEM TO BE SOLVED: To prevent a situation in which a superposed voltage exceeds a leak voltage when generating the superposed voltage formed by superposing a DC voltage on an AC voltage as a developing bias and the like for an image forming apparatus. SOLUTION: A high voltage power supply device 100 comprises: a pulse oscillation section 811 for outputting a pulse signal used for forming a waveform of an AC voltage; a level shift circuit 82, an AC amplifier circuit 83 and a transformer circuit 84 for generating an AC voltage having a level corresponding to the pulse signal; the AC amplifier circuit 83 for amplifying the generated AC voltage; a DC bias generation circuit 90 for superposing a DC voltage on the amplified AC voltage; a reference voltage changing section 833 for changing a reference voltage of the AC amplifier circuit 83 to 0(V) or a predetermined voltage value; and a switch control section 812 for allowing the reference voltage changing section 833 to change the reference voltage to 0(V) when the pulse oscillation section 811 starts to output a pulse signal, so that the waveform of the AC voltage amplified by the AC amplifier circuit 83 does not fall below 0(V). COPYRIGHT: (C)2013,JPO&INPIT |
