17.4: Low-cost Method to Improve Viewing-Angle Characteristics of Twisted-Nematic Mode Liquid-Crystal Displays

By processing pixel data, a low-cost halftone method is proposed to improve viewing-angle characteristics of TN-mode TFTLCDs. The algorithm reduces the occurence of pixels in natural images with mid-tone graylevels, preserving the local luminance. The improvement in viewing-angle characteristics occurs with some loss of image detail. As the pixel density is increased, the halftone pattern becomes less noticeable.