| 摘要 |
PROBLEM TO BE SOLVED: To always electrify a photoreceptor drum by appropriate electrification potential even when ambient temperature or ambient humidity is changed by receiving temperature data from a temperature sensor and humidity data from a humidity sensor and setting voltage applied to an electrifying roller in accordance with each data. SOLUTION: When the power source switch of an electrophotographic printer is turned on, the temperature sensor 33 and the humidity sensor 34 respectively detect the ambient temperature and the ambient humidity at that time. A power source CPU 31 processes a current flowing to the sensors 33 and 34 to the temperature data and the humidity data and transmits them to a power source control circuit 36. The circuit 36 sets the voltage applied to the electrifying roller 3 by a power source 17 to be higher as the temperature and the humidity are lower in accordance with the temperature data and the humidity data received from the CPU 37. The power source 17 keeps applying the set voltage until the power source switch of the electrophotographic printer is turned off. Thus, the electrification potential of the surface of the photoreceptor drum is always kept as a proper value. |
