| 摘要 |
PURPOSE:To improve development efficiency without increasing the size of a developing device by impressing an AC developing bias to a developer in a development area and specifying the charging rate of the developer between about 0.05 and 0.15. CONSTITUTION:The developer De is stored in the developing tank 4 in a developing device MD, and mixed and stirred as shown by a developer stirring blade 5 driven as shown by an arrow (c), but the developer is supplied onto the circumferential surface of a developing sleeve 2 by plural bucket fitted to the circumferential surface of a bucket roll 6 driven as shown by an arrow (d) during development. While the developer is attracted magnetically, the transportation amount is specified by a specifying plate 7 for upstanding tufts and the developer is transported as shown by an arrow (b) and used for development in the development area. Either one or both of the voltage value of an AC developing bias or (and) the charging rate of the developer is (are) adjusted to vary the development efficiency optionally and also to vary developed picture density. |
