17.3: Color Correction in TFTLCD Displays for Compensation of Color Dependency with the Viewing Angle

Most today's twisted nematic TFTLCD displays show a color dependency with the viewing angle. This paper describes a method for compensation of the pixel color variations in these displays relative to a single viewer position. The color correction can be recomputed automatically as the viewer position changes, as long as the position is known. The method determines the color correction required for each pixel of the screen, such that a single viewer for a given position can see the color unaffected by the viewing angle differences to the screen. Color is measured in few points over the screen relative to a viewer position, and then an interpolation procedure is used to compute the color correction for each intermediate pixel, between the measured positions. The measurements for different positions of the viewer are used in a second interpolation procedure for computing color correction for intermediate position of the viewer between the measured positions. The method was experimented for portable and desktop displays. It was found that, for relative small viewing angle variations, with acceptable approximation, the color variation with the viewing angle can be modeled as variations of the transfer function. It was found that the proposed method can also be effectively used to compensate for panel uniformity.