| 摘要 |
PURPOSE:To obtain a spotless copy by maximizing the amount of illuminating light for an original having dark ground color and at the same time, self-biasing the developing electrode. CONSTITUTION:For an original 5 having dark ground color, illuminating light is strengthened by turning fluorescent lamps 6, 7 equipped with an aperture, when they are turned to the maximum graduation, the graduated dial is stopped by a click mechanism. When the graduated dial is further turned beyond the stopping point, a switch operates and voltage applied to a developing sleeve 20 is changed from fixed voltage to the same electric potential with the photosensitive layer support of a drum 1, and the developing bias becomes self-bias that varies with the surface potential of the photosensitive layer. |
