DISPLAY SCREEN, IN PARTICULAR COLOR DISPLAY SCREEN, SURFACE-COATED RED LIGHT EMITTING SUBSTANCE AND METHOD OF PRODUCING THE SAME

摘要

PURPOSE: A surface-coated red light-emitting substance having a simpler chemical structure and a display screen having very sharp absorption edge are provided to enhance a contrast and to reduce a reflectance. CONSTITUTION: A color display screen comprises a display carrier and a red light-emitting substance including colored pigment of tantalum nitride(Ta3N5) which may be coated with an oxide material. The display cover includes the surface coated tantalum nitride pigment-including red light-emitting substance. A suspension of the tantalum nitride pigment is added dropwise to the suspension of the powdery red light-emitting substance (as the pH is kept in the range of 6.8-7.5) to precipitate the red light-emitting substance including the pigment, followed by filtration and drying to produce the objective surface-coated red light-emitting substance.