| 摘要 |
PURPOSE:To obtain stably images of high quality even if the line speed of an image carrier is changed, by driving an agitating means and the image carrier by systems independent of each other and making the operating speed of the agitating means constant independently of the variance of the line speed of the image carrier. CONSTITUTION:An impeller 2 and screws 5 and 3 of two, upper and lower stages are driven by an independent driving unit 10 including a driving transmission belt 11, a transmission wheel 12, and a driving motor 13 so that the best development condition is not broken even if the line speed is changed by conversion of the copy size to change speeds of an image carrier 9 and a magnet roll 1. Thus, optimum toner density and toner electrification quantity of a developer are always held, and copies of good quality are ensured stably though the line speed is changed. |
