| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress fogging by suppressing variation in electrification amount of toner on a toner supporting roller. <P>SOLUTION: A regulating bias voltage which has the same polarity as an electrification polarity of toner is applied to a conductive regulating blade, and the conductive regulating blade is abutted on the toner supporting roller, and an insulating external additive (for example, silica particles) and a conductive external additive (for example, titanium oxide particles) in the toner satisfy any of the following first to third conditions: the first condition is that a volume average grain diameter of the conductive external additive is larger than a volume average grain diameter of the insulating external additive; the second condition is that a volume average grain diameter of the conductive external additive is larger than a volume average grain diameter of the insulating external additive, wherein coverage in the toner is higher than that of the conductive external additive; and the third condition is that coverage of the conductive external additive in the toner is higher than coverage of the insulating external additive that is larger in volume average grain diameter than the conductive external additive. <P>COPYRIGHT: (C)2011,JPO&INPIT |
