| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a developing device which can achieve energy saving and cost reduction, and an image forming apparatus and a process cartridge. <P>SOLUTION: The developing device includes a hopping electrical field generator means to generate an electrical field for causing toner to hop between electrodes on a toner carrier, wherein the hopping electrical field generator means includes a positive-phase pulse voltage generation circuit, a negative-phase pulse voltage generation circuit, a first power source being a DC power source that is floating from an electric ground for supplying a bias for setting a peak value of pulse voltages, and a second power source being a DC power source having a polarity identical to a polarity of toner charge, which is provided between a low potential side of the first power source and the ground and whose output level is varied. The timing at which a switching element connected to a high potential output side of a pulse generation circuit is turned ON is delayed from the timing at which a switching element connected to a low potential side of the pulse generation circuit is turned ON. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
