A New Electrophotographic Color Process

— Superposing Toner Images on a Photoconductor —

Abstract

This paper describes a new electrophotographic color process using a technology of superposing toner images on a photoconductor. The main technologies of this are an electrostatic latent image forming process and a non-contact development process
For the purpose of attaining high quality color prints, we have investigated and concluded the mechanisms and the process conditions as follows: (1) Charging phenomena of toner and photoconductor by a scorotron and discharging phenomena caused by exposure from above the toner layer and the photoconductor are studied. Then successive image forming above the toner layer and photoconductor should be controlled by means of the exposure power. (2) We developed the non-contact 2-component development method that prevents destruction of formerly developed toner images. Then the optimum condition of the non-contact development that doesn't generate defects like background stain, carrier deposition and color contamination is found. (3) A smaller toner and the order of developments are important to reduce the influence of superposing, and to improve the print quality.