High resolution gray scale ionographic printing requires the ability to deposit different amounts of charge on specific but very small areas of an image receiving dielectric. The dynamic process of the dielectric surface charging has been studied. It is being shown that with increase of the deposited charge the trajectories of charged particles are more increasingly affected by the blooming effect.This effect becomes the major limiting factor in attainment of high resolution printing which at the moment for Delphax printers using monocomponent inductive toner is about 18 lines/mm.
Print quality deterioration can also be caused by the latent image fringing electrostatic field. In some cases, particularly if dark and very light areas are to be printed side by side, the fringing field influence can result in the pattern shape or printed gray level degradation. Possible compensation for it by using multiple dielectric layer as the image receptor is discussed.
Igor Kubelik, Igor Kubelik,
"Limiting factors of high-resolution and gray-scale ionographic printing", Proc. SPIE 1252, Hard Copy and Printing Technologies, (1 May 1990); doi: 10.1117/12.19770; https://doi.org/10.1117/12.19770