JPS5476159A - Photoreceptor for electrophotography - Google Patents

Abstract

PURPOSE: To enable two color original to be copied in one copying process by laminating respectively specific photoconductive layers in two layers on a conductive substrate.

CONSTITUTION: A first photoconductive layer 12 such as Se and a second photoconductive layer 13 composed of photoconductive particles such as Cds and a binder are laminated on a conductive base 11. While this photoreceptor 1 is being evenly radiated with light hυA of a color A, its layer 13 is evenly charged to negative by a charger 2. The light hυA transmits through the layer 13 and is absorbed in the layer 12 to make the layer 12 conductive, due to which positive charges are induced at the boundary face between the layer 12 and layer 13. Next, positive charging is applied by a charger 3, after which the two color original is white-image-exposed. In the positions corresponding to the white ground of the original, the layer 13 is made conductive by the light hυB and the layer 12 by the light hυA because of the light hυA₊B and the surface potentials become approximately zero. In the positions corresponding to the color A, the negative surface potentials apear and in the unexposed parts, the positive surface potentials are retained, thus the images are developed by toners T₁, T₂ of respectively different polarities.

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