| 摘要 |
PURPOSE:To prevent dust and foreign matter from sticking to a corona charging line for a long period by sending heated or cooled air to the corona charging line. CONSTITUTION:A fan 5 is put in operation before printing operation starts, and air from which dust is removed through an air filter 6 is blown toward the charging line 2; and a high voltage is applied to the charging line to start corona discharge. A temperature sensor 8, on the other hand, detects the ambient temperature of the charging line 2, and its output is inputted to a heat exchanger 7 to control the temperature of the heated or cooled air to be sent to the charging line 2 through a duct 4 according to the output signal of the sensor 8. The output signal of the sensor 8 and the output signal of a reference level setting circuit 71 are inputted to a comparator 72, and the output of the temperature sensor 8 has a voltage proportional to the temperature and is applied to the heat exchanger 7. |
