High Efficiency Active Matrix Liquid Crystal Displays (HEAMLCD)

摘要

This high efficiency active matrix liquid crystal display (HEAMLCD) effort examined several alternatives to increasing the total power efficiency of an AMLCD flat panel display (FPD). It was determined that the color filters passed just one-sixth of incident light and that a re-design of the addressed cell assembly (ACA) based on color separation physical phenomena represented the best new technology opportunity to improve overall display power efficiency. Current liquid crystal display (LCD) sub-pixels are covered by red, green, or blue absorptive color filters; this method discards two-thirds of available white light by structure while transmitting just 50% of the desired color. Micro-optical elements based on refractive, diffractive, or interferometric color separation, were selected for pursuit in this effort. A diffractive color separation filter (DCSF) was designed to separate the colors and focus the desired red, green, blue wavelength bands onto the subpixel apertures. The black matrix already used in AMLCD designs is used to block the spill-over of undesired wavebands from adjacent subpixels. Several prototypes of a DCSF were designed, fabricated, tested, analyzed, and reported. An alternative approach using reflective color separation (RCS) dichroic filters was also tested. Several other potential techniques for improving the efficiency of AMLCD displays, including inorganic light emitting diode (LED) backlight technology, were examined and are discussed.