| 摘要 |
PURPOSE:To speed up the conveyance of a recording medium from a white picture area to a black one by varying the carrying speed of the recording medium according to the number of lines of black or white picture elements. CONSTITUTION:When a line number detecting means 20b counts black or white picture element lines exposed by a photosensitive drum 1 after an electrophotographic process is executed, a potential switching means switches the polarity of a transfer potential applied to a transfer means according to the number of detected black or white picture lines and individually controls transfer to the white picture element area and transfer to the black picture element area. In this case, a carrying system varying means 20c varies the carrying speed of the recording medium according to the number of detected black or white picture element lines. Consequently, the conveyance of the recording medium from the white picture element area to the black one is sped up. |
