Stacked Polarizing Plates Enhance Display Contrast Ratio
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Solution Overview
Problem
Current liquid crystal display devices face challenges in achieving a high contrast ratio due to limitations in polarization degree and distribution of polarizing plates, with high-polarization plates being expensive and inefficient.
Innovation Solution
The implementation of a stacked-layer structure using multiple polarizing plates with absorption axes arranged in parallel or cross nicol states over light-transmissive substrates, potentially combined with a retardation film, to enhance contrast ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single polarizing plate is used, then the device structure is simple, but the contrast ratio is insufficient
Solution Approach 1:
The single polarizing plate is divided into multiple polarizing plates (first, second, third, and fourth polarizing plates) with different absorption axis orientations. This segmentation allows each plate to perform a specific function in controlling light polarization, collectively achieving a higher contrast ratio while maintaining reasonable structural complexity.
2Illumination intensity
If multiple polarizing plates are stacked, then the contrast ratio is enhanced, but the device complexity increases
Solution Approach 1:
The four polarizing plates are arranged with asymmetric absorption axis orientations relative to the substrate normal. Specifically, the absorption axes are oriented at different angles (e.g., 0°, 45°, 90°, 135°) to optimize light transmission and leakage control. This asymmetric arrangement enhances contrast ratio while managing the complexity of the multi-plate structure through deliberate geometric optimization.
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
This configuration significantly enhances the contrast ratio of liquid crystal display devices by optimizing light transmission and leakage, providing better black display performance compared to single-layer polarizing plates.
Implementation Method 1
polarizing plates stacked outside the first light-transmissive substrate or the second light-transmissive substrate, in which the stacked polarizing plates are arranged so that absorption axes of the stacked polarizing plates are arranged so as to be in a parallel nicol state
Data Source
AI summary
The invention provides a display device of which a contrast ratio is enhanced. By providing stacked polarizing plates so as to be in a cross nicol state, a contrast ratio of a display device can be enhanced. The stacked polarizing plates are stacked outside a light-transmissive insulating substrate in a parallel nicol state. When the number of polarizing plates is four or five in total, a contrast ratio becomes the highest.