| 摘要 |
PURPOSE:To detect precise toner residual by arranging a detecting part a part of which is composed of a magnetic material on a position to which the resistance of a developer flowing on a developer carrying member is applied and the magnetic force of the carrying member is also applied so as to be moved. CONSTITUTION:A selenium drum 30 to be rotated in the arrow direction while carrying an electrostatic image is developed by a developing device 20 to form a toner image and a transferred image is formed by an unshown transfer device. In the device 20, a toner flow 9 formed by rotating a developing sleeve 5 in the arrow direction collides with a resistance receiving part 4 of a toner residual detecting member 1, the member 1 is rotated around a shaft 3 in the clockwise direction and a magnet 16 adhered to the leading end of a foot 2 is separated from a reed switch 17 to turn off the switch 17. Then, the toner flow 9 is regulated by a toner layer thickness regulating member 7 and carried to a developing area. If the toner is lacked, the toner flow 9 is also reduced and pressing force Fr applied to the resistance receiving part 4 is also reduced, so that the switch 17 is turned on. Thus, the residual can be precisely detected. |
