| 摘要 |
PURPOSE:To permit adequate control of a bright part potential in a developing position by controlling the quantity of a light beam in accordance with the bright part potential and dark par potential and setting the bright part potential in a prescribed range. CONSTITUTION:A detecting means which detects the bright part potential and dark part potential of a photosensitive body between an exposing position and the developing position and a control means 11 which is inputted with the potential signals of the bright part potential and dark part potential detected by said detecting means, detects the fluctuation in the dark part potential in the exposing part and controls the quantity of the laser beam according to the fluctuation to set the bright part potential at the prescribed value are provided. More specifically, if the dark part potential is fluctuated by changes in temp., electric charge characteristic by photofatigue, etc., the control means 11 makes the prescribed computation with such fluctuation as a parameter and controls the driving voltage of a laser beam generator by the result of the computation, thereby setting the quantity of the laser beam 12 so as to maintain the prescribed level of the bright part potential. The exact control of the bright part potential in the developing device is thereby permitted. |
