| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a developing device capable of performing a satisfactory image formation for a long period of time by reducing variation in toner concentration and bulk level of developer as much as possible in the trickle system developing device using two-component developer, and to provide an image forming apparatus. <P>SOLUTION: The developing device has a stirring member for conveying and stirring developer in a developing tank, and a developer carrier. The developing device includes: a developer supply tank; a trickle system discharging mechanism; a developer quantity detecting means; a stirring member rotation control means; and a control means for controlling the operation of supply of toner and carrier to the developing tank when a toner concentration is lower than predetermined reference toner concentration. When a determination is made that a quantity of developer in the developing tank is below a predetermined level (S110), the stirring member rotation control means increases the number of rotations of the stirring member (S120). <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
