Method for compensating for poor uniformity of liquid crystal display having non-uniform backlight and display that exhibits non-uniformity compensating function

摘要

The invention relates to a method for compensating for poor uniformity of a liquid crystal display having a non-uniform backlight. By virtue of selecting a standard color that all cells can achieve to serve as a virtually primary color, the invention measures to give the relationship between the tri-stimulus values of the virtually primary color and those presented by the respective cells and records the resultant values to serve as compensation data. During operation of a display, the input image data are computed based on the compensation data for respective cells in accordance with the cell locations and converted into compensated image signals. As such, all of the cells are able to present the same chromaticity and brightness upon receiving the same image signal, thereby performing uniform chromaticity and brightness across the entire display.

主权项

1. A method for compensating for poor uniformity of a liquid crystal display having a non-uniform backlight, where said display comprises a non-uniform backlight, a liquid crystal display module disposed at a light exit side of the backlight and including a plurality of cells with adjustable light transmission ratios for displaying a picture made up of pixels, in which the cells are divided into a plurality of adjustment regions, a control device for controlling the respective light transmission ratios of the respective cells, and a memory device for storing compensation data which enables unification of brightness and chromaticity distribution of light passing through the respective adjustment regions based on brightness and chromaticity distribution of light received by the corresponding respective adjustment regions upon receiving illumination from the backlight, said method comprising the steps of:
a) obtaining compensation data that enables adjustment of the chromaticity of the respective adjustment regions to be in accord with a virtually primary color so as to unify the brightness and chromaticity distribution of light passing through the respective adjustment regions; b) obtaining image data of multiple image signals from an image source, with the image signals governing the respective light transmission ratios of the respective cells; c) computing the image signals of the image data in a weighted manner based upon the compensation data in accordance with the corresponding adjustment regions, thereby providing compensated image data that includes respective compensated image signals for the respective corresponding cells; and d) determining the respective light transmission ratios of the respective cells in the liquid crystal module according to the compensated image signals; wherein the virtually primary color is defined to have a red color component with a tri-stimulus value of (XrvYrv, Zrv), a green color component with a tri-stimulus value of (Xgv, Ygb, Zgv) and a blue color component with a tri-stimulus value of (Xbv, Ybv, Zbv), and wherein a given cell i of the cells is defined to present tri-stimulus values of (Xr, Yr, Zr)i for a red color component, (Xg, Yg, Zg)i for a green color component and (Xb, Yb, Zb)i for a blue light component as measured when corresponding liquid crystal valves are opened to have a largest light transmission ratio, and wherein the compensation data derived from a compensated image signal (S′r, S′g, S′b) for the cell i and a corresponding image signal (Sr, Sg, Sb)i has a relationship represented by the following equation:[Sr′Sg′Sb′]i=[XrXgXbYr⁢YgYbZrZgZb]i-1⁡[XrvXgvXbvYrvYgvYbvZrvZgvZbv]⁡[SrSgSb]i.