| 摘要 |
PURPOSE:To obtain an electrophotographic copying impossible original by forming a toner image corresponding to an original image by a toner of the same color as that of transfer paper, on light translucent transfer paper. CONSTITUTION:Light translucent transfer paper has a whiteness degree of the same extent that the existence of a toner image is not confirmed, when an image formation is executed by a white toner, and also, it will suffice that a difference of the passed quantity of light between a part when the toner image exists and a part where it does not exist in enough. In this state, an original to be confidential is set onto an original placing table and copying is executed, and a white toner image corresponding to an original image is formed on the transfer paper. As for an obtained copy, an image is formed by a white toner on white transfer paper, and an image information part becomes difficult to be decoded. In such a way, even if copying is executed by an electrophotographic copying machine as an original, an image corresponding to the former original is not formed on the copy obtained in a state that the whole surface remains white, and it functions as a copying impossible original. |
