Are the Color Gamuts of CRT and LCD Triangular? An Experimental Study

Color LCD (Liquid Crystal Display) has been widely used for personal computers (PC) and video monitors because of its light weight, small volume, low power consumption and so on. Color reproductions for LCD panels are different from that of CRT (Cathode Ray Tube) display. This study describes the difference of color gamuts in different luminance level and the accuracy of color between CRT and LCD. In the present study, the reproduction color gamuts on the chromaticity diagram are measured in three types of displays, including two CRT types (BARCO Reference Calibrator Plus and ViewSonic PT775) and one LCD type (NEC MultiSync LCD 200). In the experiment, the tristimulus values XYZ for the combinations of three primary colors R(red), G(green), B(blue) were measured by varying the input digital levels. The digital levels which varied from 0 to 255 in every primary color were equally divided into 17 stages, including 0 and 255, and thus the tristimulus values of 4913 colors at each display were measures. Size and shape of color gamuts varied with the luminance, sampling distribution and color difference of LCD and CRT will be discussed. The higher the value of Y, the smaller the area of the color gamut, no matter which display type performed. The area of the color gamut of LCD is smaller than that of CRT in most levels of luminance. This paper discovered that some special patterns exist in color gamut diagrams. Finally, relationships among patterns have been clarified for characterizing the color gamuts of displays.
Presented at Display Technologies III, International Optoelectronics Symposium, Taipei, Taiwan, 26-27 Jul 2000. Pub. in Proceedings of SPIE, v4079 p271-276, 2000. ISSN 0277-786X. This article is from ADA398270 Display Technologies III Held in Taipei, Taiwan on 26-27 July 2000