Low-Absorption Color Filters for Flat-Panel Display Devices

A proposed technique for color filtering in a liquid-crystal or other flat-panel display device would make it possible to brighten the display without increasing the amount of light supplied from behind the panel. The need for the proposed technique arises as follows: At present, each pixel in a typical color liquid-crystal display device contains three dye filters: red, green, and blue. Each filter transmits its single primary color and absorbs the other colors, so that less than one-third of the available light is used for viewing. In addition, the liquid-crystal display uses polarized light, so that half of the incident unpolarized illumination is necessarily wasted. The net result is that less than one-sixth of the incident unpolarized light is utilized. One does not have the option of increasing the illumination substantially to brighten the display because the increase in heat generated by absorption of light in the filters could harm the display device.