| 摘要 |
PURPOSE:To set an effective range (image forming range) of a drum (base body) by controlling position of a blade by scraping off toner within a range of pressurized contact of the toner on the drum (base body) by the blade brought to a position in pressurized contact to the rotating drum (base body). CONSTITUTION:The photoconductive toner 1 is contained in a toner container 2 with a magnetic carrier. A sleeve 4 facing the conductive and rotating drum 3 is provided in the container 2. The sleeve 4 is rotated in a direction of an arrow A, the drum 3 is rotated in a direction of an arrow B, and both the facing periphery surfaces of the two are moved in the same direction. Then, two pieces of blades 5 and 6 are provided in a downstream side of the sleeve 4 so that a position where it is brought into a pressurized contact with the drum 3 and a position separated from the drum 3 can be taken. The blades 5 and 6 are driven by solenoids 11 and 12 through retaining plates 7 and 8 and arms 9 and 10. The solenoids 11 and 12 are controlled at a control part. Size of a transfer sheet is made known from the sheet size setting information at an operation part and from information from a loaded sheet cassette by the control part, and the position of the blades 5 and 6 are controlled according to that size. |
