Legibility study of multiplexed twisted nematic LCDs based on colorimetry and matching tests

The effect of driving waveform, reflective vs backlit transmissive mode, and contrast polarity, on the legibility of a multiplexed twisted nematic (TN) LCD were investigated. The backlit transmissive mode with a white display pattern on dark background (W/B contrast) resulted in superior display legibility, while the reflective mode TN LCD with a dark display pattern on white background (B/W contrast) resulted in the second best legibility. The maximum legibility was obtained at a lower operating voltage for the LCD with W/B contrast compared with the B/W contrast; we believe this can be attributed to the nonlinear response of the human eye.