LCD Grayscale Optimization for Wide-Angle Color Shift
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Solution Overview
Problem
Current liquid crystal displays (LCDs) experience color shift phenomena at wide view angles, which existing 2D1G technology attempts to mitigate by dividing pixel units into main and sub pixel areas with different data and gate lines, but the optimal setting of grayscale values for these areas to minimize color shift and maintain display quality is unresolved.
Innovation Solution
A method that calculates and sets grayscale values for main and sub pixel areas based on actual and theoretical luminance values at front and slant view angles, using specific equations to ensure minimal luminance differences and adherence to previous grayscale values, thereby reducing color shift and achieving an excellent display effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If 2D1G technology is adopted to divide pixel units into main pixel area and sub pixel area with different data signals, then color shift at wide view angles is reduced, but the complexity of grayscale value setting increases and display quality at front view angle may deteriorate
Solution Approach 1:
The patent applies parameter changes by establishing mathematical relationships between grayscale values of main and sub pixel areas. It transforms the complex multi-parameter optimization problem into a solvable system by defining equations that relate LvMα, LvSα, LvMβ, LvSβ to the area ratio a:b, and by setting constraints (Gmx≧Gm(x−1), Gsx≧Gs(x−1)) to ensure monotonicity. This allows automated calculation of optimal grayscale values without manual trial-and-error.
2Object-affected harmful factors
If different grayscale values are input to main pixel area and sub pixel area to reduce color shift, then color shift is mitigated, but display quality at front view angle may be compromised
Solution Approach 1:
The patent changes parameters by dynamically adjusting grayscale values based on view angle characteristics. It uses the mathematical model to calculate specific grayscale values Gmx and Gsx for each pixel unit, ensuring that the luminance combination satisfies both the area ratio constraint and the minimization of luminance difference at slant view angles, while maintaining gamma≈2.2 at front view angle.
Solution Approach 2:
The patent applies local quality by treating main and sub pixel areas differently within the same pixel unit. Each area receives customized grayscale values optimized for its specific function: main pixel area for front view display quality and sub pixel area for compensating slant view color shift. This localized optimization resolves the contradiction between reducing color shift and maintaining display quality.
3Object-affected harmful factors
If grayscale values are optimized for slant view angle, then color shift is reduced, but gamma curve deviation at front view angle increases
Solution Approach 1:
The patent uses parameter changes to balance gamma accuracy and color shift reduction. The mathematical model incorporates constraints that ensure the combined luminance of main and sub pixel areas maintains gamma≈2.2 at front view angle (α=0°) while simultaneously minimizing luminance differences at slant view angles (β=30°-80°). This dual-constraint optimization resolves the contradiction between gamma accuracy and color shift mitigation.
Data Source
AI summary
A grayscale value setting method for a liquid crystal panel is disclosed which includes obtaining actual luminance values of each grayscale G of the liquid crystal panel at front and slant view angles; dividing actual luminance values according to the area ratio of the main pixel area M and the sub pixel area S, and establishing corresponding relationships between the grayscale and the actual luminance values in the main and the sub pixel areas; calculating theoretical luminance values of each grayscale; setting a grayscale combination, such that a sum of difference values between actual and theoretical luminance values of the front and slant view angle are minimal; and repeating the last step to obtain grayscales respectively input to the main pixel and the sub pixel areas at all of grayscales of the liquid crystal panel. A liquid crystal display setting a grayscale value using the above method is also disclosed.