| 摘要 |
PURPOSE:To prevent the decrease in image denisty at low humidity and obtain stable picture quality corresponding to humidity changes by automatically detecting humidity and automatically controlling developing time or the rate of toner supply thereby controlling the picture quality. CONSTITUTION:The drive motor 6 of a feed roller 6 which feeds recording paper 1 is regulated by a speed control circuit 7 and the control signal is applied to the speed control circuit 7 from a humidity detection circuit 8 which is formed by a resitance R1, amplifier AMP1 and moisture sensitive resistance 9. The moisture resistance 9 is a thin-film resistor whose resistance value changes with humidity and its resistance value decreases at high humidity and increases at low humidity. Hence, the output level of the AMP1 becomes high level at low humidity and low level at high himidity. Thereby, te stable recroding picture quality corresponding to temperature changes may be obtained and the moisture-resistant use range may be widened. |
