| 摘要 |
PURPOSE:To prevent the decrease in copy quality owing to humidity change and ease the restriction on the use environment of the apparatus by controlling the bias voltage being applied to the photoreceptor of a developing part by the detection signal of the humidity sensor of the photoreceptor. CONSTITUTION:A voltage-variable bias voltage applying circuit 4 is connected to a magnetic brush 2 to prevent the deposition of toner powder on the non-image parts and the production of photographic fog. The bias voltage applying circuit 4 is connected with a humidity detector 5 to detect the humidity in the installation environment of the electrophotographic copier body with a sensor and let a correct bias be generated in the voltage applying circuit 4. Hence, development is executed in the state wherein the bias voltage corrected according to the environments has been applied. The restrictions upon the use environments of the apparatus are considerably eased by this and the degradation in quality of the copy images owing to humidity change may be prevented. |
