Suppression of color mixing in UV LED based color pixel backlight for liquid crystal display

摘要

A ultra-violet based color pixel backlight system for color filter-less Liquid Crystal Display, comprising multiplicity of LEDs, emitting UV or NUV light in the wavelength range of 150 nm to 390 nm, assembled at one edge of a UV transmitting light guide, which has other three edges and bottom surface coated with UV reflecting layer and its top surface etched with UV and NUV extracting pixel patterns that contain phosphors that emit different colors of light in red, blue and green region when excited by UV or NUV light. The etched pixels contain Aluminum islands underneath the phosphor layers to reflect the visible rays generated by the phosphors of the pixel and suppress the visible light leaving the pixel as well as suppress the visible light from adjacent pixel entering the pixel. Thus suppressing the color mixing that could occur without the incorporation of Al islands. LCD without color pixels, a micro-lens sheet and the light guide with color pixels are placed in substantial alignment to provide a color pixel backlight system for LCD. Thus red, blue and green pixels of light from the light guide passes through the intended red, blue and green pixels of the color filter-less LCD, resulting in color pixel backlighting that enhances the optical efficiency of LCD.