| 摘要 |
PURPOSE:To increase copying efficiency and to simplify control by preventing generation of inefficient exposure by setting linear velocity of a latent image carrier in a monochrome mode to be faster than linear velocity in a color, editing, or color erasing copying mode. CONSTITUTION:The device is constituted so that the following control is carried out by CPU through an operating part. When linear velocity of a photosensitive body 18, electrifying quantity to the photosensitive body 18, and impressing bias voltage to a developing roller are made constant, light emitting quantity of an illuminating device 11 is made larger in the image formation where a color dissolving filter is utilized than when it is not utilized. Further, when linear velocity, exposing quantity, and the bias voltage are made constant, the electrifying quantity is lowered when the filter is utilized than when it is not utilized. Further, when the linear velocity, the light emitting quantity, and the electrifying quantity are made constant, the bias voltage is raised when the filter is utilized than when it is not utilized, and even when the potential of a base surface is rather high due to inefficient exposure, toner is prevented from adhering there. Thus inefficient exposure quantity is prevented, the copying efficiency can be increased, and further, the control can be simplified. |
