| 摘要 |
PURPOSE:To prevent either positive or negative ghost, by extending exposure width of a photoreceptor at preexposure to be operated before a charging step, and changing a light intensity in accordance with the memory characteristics of a photoreceptor. CONSTITUTION:Preexposure is conducted with a remaining charge erasion lamp 9 before charging the photoreceptor of a photosensitive drum 1 with a primary charger in order to remove an after image effect of the photoreceptor, and a few kinds of plates different from one another in light transmittance are provided as controlling plates 11 between the lamp 9 and the drum 1 to select them in accordance with the photoreceptor. A positive ghost tends to occur in strong preexposure, but it can be erased by weakening the light. Preexposure width of the photoreceptor is preferably made equal to the whole width of a predestaticizer 10 or the width A+B, thus permitting an image freed of a ghost and a fringe effect to be obtaned by extending an exposing time even when the light is weak. |
