Method of electrophotographic phosphor deposition

Abstract

In accordance with the present invention, a method of electrophotographically manufacturing a luminescent screen assembly on a photoreceptor disposed on an interior surface of a faceplate panel for a color CRT includes the steps of: charging the photoreceptor to establish a substantially uniform electrostatic voltage thereon; positioning the panel on an exposure device having a light source therein; exposing selected areas of the photoreceptor to visible light from the light source to affect the voltage thereon, without affecting the voltage on the unexposed area of the photoreceptor; and depositing a triboelectrically charged, first color-emitting phosphor onto the selected areas of the photoreceptor. The charging, positioning, exposing and depositing steps are repeated for a second and a third triboelectrically charged, color-emitting phosphor. The present method is an improvement over prior methods because after each of the phosphor deposition and panel recharging steps, the light source is offset in the exposure device by an amount determined by the voltage difference between the photoreceptor and the phosphor, or phosphors, previously deposited onto the panel, thereby counteracting the repulsive effect of the previously deposited phosphor and minimizing the misregister of subsequently deposited phosphors.