Effects of corotron size and parameters on the dielectric substrate surface charge

Effects of variation of parameters of a corona device (corotron) used in electro-photographic machines on the amount of surface charge build-up on the surface of dielectric substrate were studied. Particular attention was given to the effect of corotron dimension including wire–shields and wire–plate distances, substrate thickness, shields insulation and the substrate speed on the amount of substrate surface charge. The computational analyses were performed for a two-dimensional cross-section of the corotron under steady-state condition. The Maxwell equations were solved and the electrical quantities in a rectangular positive single wire corotron were evaluated. The simulation results showed that for a fixed wire voltage, the corotron size, the substrate thickness, insulation of shields and the substrate speed will affect the distributions of electrical quantities in the corotron. The wire–substrate distance and the substrate speed, however, were found to be the main parameters that control the amount of surface charge build-up on the substrate.