CSD-a new unified threshold metric of evaluating LCD viewing angle by color saturation degradation

• Published in: Journal of display technology 2006-06, Vol.2 (2), p.106-113
• Main Authors: Chen, S.-F.F., Cheng, W.-C.W., Shieh, H.-P.D.
• Format: Article
• Language: English
• Subjects: Cathode ray tubes; Chromium; Color; Color saturation degradation (CSD) metric; contrast ratio metric; Degradation; Display devices; Displays; Effectiveness; just-noticeable difference (JND); Liquid crystal devices; Liquid crystals; liquid-crystal device (LCD) viewing angle evaluation; Luminance; Photonics; Psychology; psychophysical evaluation; Saturation; Thin film transistors; Thresholds; Viewing; Visual
• ISSN: 1551-319X; 1558-9323
• DOI: 10.1109/JDT.2006.874504

Lower luminance contrast ratio and chromatic changes affect the visual performance (i.e. color shift) of a thin-film transistor liquid-crystal device (TFT-LCD) at large viewing angles. The de facto method of defining viewing angle, contrast ratio of luminance, fails to represent the substantial visual performance viewed at a larger angle. We found the degradation of color saturation, dS*/dthetas, to be an appropriate metric to aid the conventional viewing angle definition (CR ges 10). We empirically determined the threshold for defining the color viewing angles of TFT-LCDs, CVA = {thetaspardS*/dthetas| les 0.03}, which reflects the variation not only in chromaticity but also in luminance. The proposed metric was evaluated by psychophysical experiments, whose results validate the efficacy of the proposed metric