| 摘要 |
PURPOSE:To remove efficiently the first toner, by providing a stirring member for separating a toner by stirring the second developer flowing down after developing the second electrostatic latent image, on an electrostatic attraction force operating position of an electrostatic attraction roll or its upstream. CONSTITUTION:The second developer 8 and the first toner 5a mixed in it are stirred in the process in which they are carried on the surface of a non-magnetic sleeve 7b, and a stirring impeller 12a. As a result, as for the first toner 5a, its charge quantity is reduced to nearly zero and its charging property is inverted, and its electrostatic coupling force with the second developer 8 becoms weak, therefore, the first toner 5a being in this state soars and is sucked to a path 12b by an sucking air flow. Also, the electrostatic polarity is inverted, the first toner 5a charged to negative polarity is coupled with the second developer 8 by electrostatic force and flows down, collides with a stirring member 12c and is separated, is attracted to an electrostatic attracting roll 12d, and in this case, too, the first toner 5a whose charge quantity is small soars, gets on sucking air and is sucked to the path 12b. |
