Multicolor electrophotographic imaging process

Abstract

A method of electrophotographic color reproduction by forming sequentially superimposed toner images of each color successively on the photoconductive surface of an electrophotographic recording member. The photoconductive surface is charged uniformly by a corona generator to a predetermined charge level. The charged surface is exposed to a first color radiation pattern from a source thereof to form a latent electrostatic charge image on said surface. The resulting latent charge image is toned with one color toner to produce a first toner image. The resulting toner image is dried. Thereafter, a charge is applied uniformly to the same photoconductive surface including those portions thereof carrying the dried first toner image in a manner so that the generated charged ions effectively tunnel through the dry adjacent toner particles defining first toner image to reach the photoconductive surface. The resulting charge potential is uniformly distributed over the entire photoconductor surface, including the toned and untoned areas thereof. Thereafter, the entire charged surface is exposed to a second radiation color pattern from a source thereof, the radiation penetrating the first toner image to produce a second latent electrostatic charge image on said overall surface. Toning is effected with a second color toner to define a second toned color toner image superimposed in proper registry. The second toner image is dried and the aforementioned steps are repeated until the desired number of color toner images superimposed one upon the other are completed to form a desired composite color toner image. The complete image is transferred to an image receptor in a single transfer step to achieve the desired print reproduction.