| 摘要 |
PROBLEM TO BE SOLVED: To stably output a prescribed constant voltage and reduce a voltage drop between the output voltage and a member to which a voltage is outputted even if the member to which a voltage is outputted is applied with an external voltage higher than the output voltage. SOLUTION: A constant voltage of 400V is outputted from an output terminal A of a high-voltage power supply 30 and is applied to a development roller 4. Here, when the developing roller is raised to potential higher than 400V by the surface potential of a photoreceptor drum 8, a source voltage of an FET31 becomes higher than a gate voltage resulting in the FET going into an on-state. Thus, a current that flows from the photoreceptor drum to the development roller quickly flows to a ground through a source terminal S, a drain terminal D, and a resistor R6. As a result, the potential of the developing roller that has been raised decreases abruptly toward 400V. COPYRIGHT: (C)2004,JPO&NCIPI
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