| 摘要 |
PURPOSE:To maintain surface potential of a photoreceptor always constant and to obtain a stable image, by generating correction voltage in accordance with the result of measurement of the surface potential, and applying this to a corona charger. CONSTITUTION:The surface potential of photoreceptor 1 soon after charging with charger 2 is measured using electrometer probe 3.When the measured value is equal to the reference value, application voltage to corona charger 4 provided at the position before the exposure point of photoreceptor 1 is made zero, when it is higher than the reference value, AC high voltage 12 corresponding to this difference is applied to corona charger 4, and when lower, DC high voltage 13 is applied to charger 4, permitting surface potential of photoreceptor 1 to be corrected and to become the reference value before exposure. |
