Patterned Polarizing Plate for Liquid Crystal Display Diagonal Contrast
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Solution Overview
Problem
Liquid crystal display apparatuses suffer from lower contrast ratios at lateral sides compared to front sides, and the application of patterned films to viewer-side polarizing plates can generate Moiré and rainbow spots.
Innovation Solution
A liquid crystal display apparatus is designed with a viewer-side polarizing plate that includes a patterned layer with a first and second resin layer of different refractive indices, featuring engraved optical patterns and a flat section between them, which are aligned to optimize the pitch and width ratio of the patterned portion to the pixel width, ensuring a good diagonal contrast ratio while preventing Moiré and rainbow spots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a patterned film is applied to the viewer-side polarizing plate to improve lateral contrast ratio, then the diagonal contrast ratio is improved, but Moiré and rainbow spots are generated
Solution Approach 1:
The patterned layer is designed with spatially varying properties: different resin layers (first and second resin layers) with different refractive indices are arranged in a periodic pattern. This local variation in optical properties allows the pattern to selectively enhance diagonal contrast while controlling the generation of Moiré and rainbow spots through careful design of the pattern pitch and dimensions
Solution Approach 2:
The invention optimizes specific geometric parameters of the patterned layer to resolve the contradiction. The pitch P1 of the patterned portion and the pixel width P2 are maintained within a specific ratio range (7 ≤ P2/P1 ≤ 85). Additionally, the engraved optical patterns have an aspect ratio of 0.3 or more. These parameter adjustments allow the pattern to improve diagonal contrast ratio while preventing Moiré and rainbow spot generation
2Illumination intensity
If the pitch of the patterned portion is reduced to improve diagonal contrast ratio, then the viewing angle performance is improved, but Moiré spots are generated
Solution Approach 1:
The invention establishes an optimal parameter range for the pitch P1 of the patterned portion. By maintaining the ratio 7 ≤ P2/P1 ≤ 85 (where P2 is pixel width and P1 is pattern pitch), the design achieves sufficient diagonal contrast ratio improvement while avoiding the generation of Moiré spots. This parameter optimization balances the competing requirements
3Illumination intensity
If the patterned portion is designed with high aspect ratio to improve diagonal contrast ratio, then the lateral viewing performance is improved, but rainbow spots are generated
Solution Approach 1:
The invention specifies that engraved optical patterns in the patterned layer should have an aspect ratio of 0.3 or more. This parameter control, combined with the pitch optimization (7 ≤ P2/P1 ≤ 85), enables the pattern to enhance diagonal contrast ratio while preventing the generation of rainbow spots through controlled light interaction
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves a good diagonal contrast ratio and prevents the generation of Moiré and rainbow spots, thereby ensuring a better external appearance of the liquid crystal display apparatus.
Implementation Method 1
a patterned layer including a first resin layer and a second resin layer having different indexes of refraction
Data Source
AI summary
A liquid crystal display apparatus includes: a liquid crystal panel; and a viewer-side polarizing plate stacked on a light exit surface of the liquid crystal panel, and the viewer-side polarizing plate includes a patterned layer including a first resin layer and a second resin layer having different indexes of refraction; and a patterned portion including multiple engraved optical patterns and a flat section between adjacent engraved optical patterns of the multiple optical patterns is formed at an interface between the first resin layer and the second resin layer, and the liquid crystal display apparatus satisfies Equation 1 herein and the engraved optical patterns have an aspect ratio of 0.3 or more.