Patent ID: 8459855

Claim:
A novel LED based color-pixel backlight system, providing increased color gamut for color filter-less Liquid Crystal Display, comprising: a light guide, having four edges and two broad surfaces, with at least one edge transmitting UV or NUV rays and assembled with multiplicity of UV or NUV emitting LEDs and the other edges, opposite to and adjacent to the transmitting edge, coated with reflector, reflecting UV, NUV and visible rays, with its bottom surface coated with UV, NUV and visible light reflecting mirror and its top surface roughened to create pixelated patterns for extracting UV or NUV light from the light guide; said light guide having its top surface coated with two layers one over the other, comprising a reflective layer at the bottom and a black layer at the top; said two layers being coated everywhere except in the pixelated areas; means for connecting UV or NUV LEDs to electrical power to emit UV or NUV radiation; said pixelated patterns containing multiplicity of reflective islands with a coating of quantum dots on top of the reflective islands and in between the reflective islands, and the layers of quantum dots having a protective coating on their surfaces opposite to the inner surface of the reflective islands; said reflective islands reflecting the visible light generated by the quantum dots within the pixel and suppressing the visible light entering the pixel from adjacent pixels through single or multiple reflections on the surface of the said light guide; said reflective islands having sufficient space between them allowing sufficient UV or NUV rays entering the pixelated region; said layers of quantum dots forming red, blue and green light emitting pixels that convert the UV or NUV rays incident on them into visible red, blue and green colors of light, with pixel patterns, that travel upward towards a sheet of micro-lens; said sheet of micro-lens, said pixelated pattern containing quantum dots on the surface of the light guide and the color filter-less LCD, are all assembled such that the said sheet of micro-lens, said formed pattern on the surface of the light guide and the LCD are kept substantially in alignment to provide color pixel backlighting to the said color filter-less LCD.