| 摘要 |
PURPOSE:To obtain sharp picture images irrespectively of humidity condition by detecting the high humidity condition or condensation condition at the inside and outside of a device body and controlling the high voltage current to be applied to an electrifier. CONSTITUTION:When the high humidity condition or condensation condition around an electrostatic drum 8 is detected with a switching element 22, the signal from a detecting part 23 is conducted to a control system 25. When the moisture responsive film 29 of the element 22 absorbs moisture in the high moisture condition, the resistance of the element 22 changes. Thereupon, an adequate detecting level is regulated with a variable resistor 34 connected to a terminal 33, by which the signal from the terminal 33 is inputted to the system 25. Thus the quantity of the electrostatic charge on the drum 8 is changed to increase or decrease the amt. of the toners to be stuck on the drum 8 by controlling the high voltage current to be applied to the electrifier in the above- mentioned way, whereby the sharp copies are obtained irrespectively of the humidity condition. |
