| 摘要 |
PURPOSE:To prevent the reduction of the copying concentration, by detecting the difference of temperature between the open air and the inside of a copier and controlling the charging high-voltage power source output according to the difference of temperature to compensate the charged potential. CONSTITUTION:An open air temperature detecting thermistor TH1 is installed at the side of th sucking port of a cooling fan to receive no effect of the increase of temperature within a copier. While a detecting thermistor TH2 for the temperature within the copier is set at a place such as the area close to an exhaustion port where an analogous degree is secured between the copying concentration and the increase of temperature when the continuous copying is carried out. The difference of potential between both ends of the thermistors TH1 and TH2 is supplied to a differential amplifier 1. Thus an output proportional to the increase of temperature within the copier can be obtained at the output side, and this output is supplied to a high voltage power source 2 to control the high voltage output. Thus the reduction of the charged potential caused by the increase of temperature can be compensated. As a result, the reduction of the copying concentration can be prevented. |
