PURPOSE: To form a two-color output copy by cyclically scanning (passing) an original document corrected with fluorescent dye, that is, dystuff of a desired color once.

CONSTITUTION: Light reflected on the original document 30 and passing a red filter, for instance, forms three electrification level patterns on a photoreceptor. At a black area part 30A, reflected light leaves an area part (high level) which is not discharged, and in a white background area part 30B, the reflected light forms a low discharge level. The light made incident on red fluorescent dye excites the dyestuff, and the incident light of the low level is emitted as the red light again. Therefore, it is added to the reflected red light so as to show apparent reflectivity higher than that of the white paper(effect 'whiter' than 'white color'). The emission in which the red is enhanced is discharged until the photoreceptor becomes a 3rd level lower than the white background, that is, the white level, and the electrification pattern of the 3rd level is developed. Thus, two-color output copy is formed.