| 摘要 |
PURPOSE:To record only the original image on a copy and to prevent the unnecessary image except the original image from appearing on the copy irrespectively of the background color of the original by performing development after erasing selectively the electrostatic latent image obtd. by exposing except the original image. CONSTITUTION:The beginning end position Y1 and terminal end position Y2 of an original in the exposing position in the direction X coinciding with the turning position of a photosensitive drum 11 are read when the drum 11 turns to the position where the electrostatic latent image forming surface of the drum 11 faces an eraser 18. The eraser 18 is so controlled as to energize the light emitting diodes in the corresponding region between the beginning end Y0 and Y1 of the exposing position in the direction Y and between Y2 and the terminal end Y3 of the exposing position. Only the electrostatic latent image obtd. from the original remains after such control is performed repeatedly for all the exposing regions. The electrostatic latent image formed on the drum 11 by the exposing of the part except the original is erased by the eraser before developing and therefore the solid black image is not transferred on recording paper. |
