High Efficient Color-Separation Backlight

Abstract

To replace the color filter in the conventional display, we describe a color-separation backlight consisting of three modules: the light collimation module, the light guide and the micro-lens array. With angularly positioned color LEDs, the displaying method requires only two two-color filter layers to display color images. In the light collimation module, the angular rays of two colors from each LED are collimated by a reflective cup and a collimation lens. After entering the light guide, which is composed of V-groove structures at the bottom above a reflective layer, the angular collimated color beams are redirected to the normal of the top surface of light guide. Finally, the output rays are converged by a micro-lens array and mapped into corresponding sub-pixel positions for efficiently displaying color image. The three main advantages of such technology are the reduction of the dye color filter layers from conventional 3 to 2, the gain factor of transmission efficiency two times more than that of conventional color filters, and the larger color gamut.