Optical Display Module Retardation Layers for Lateral Contrast
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Solution Overview
Problem
Liquid crystal displays, particularly IPS-mode displays, suffer from lower contrast ratio and light leakage at lateral sides, necessitating a solution to improve contrast while minimizing light leakage.
Innovation Solution
An optical display module comprising a first polarizing plate with a positive C layer retardation layer and an optical display panel with a second retardation layer, where the layers satisfy specific retardation value relationships to enhance contrast ratio and reduce light leakage at lateral sides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If IPS-mode liquid crystal display is used to achieve wider viewing angle, then viewing angle is improved, but contrast ratio at lateral side deteriorates and light leakage occurs
Solution Approach 1:
The patent applies parameter changes by precisely controlling the retardation values of the first retardation layer (Rth1: 50-150 nm) and second retardation layer (Rth2: 20-80 nm), and their thicknesses (d1: 1-5 μm, d2: 1-5 μm). By adjusting these optical parameters, the invention achieves improved lateral contrast ratio while maintaining the wide viewing angle characteristic of IPS-mode displays, resolving the contradiction between viewing angle and lateral contrast performance.
Solution Approach 2:
The patent employs composite materials by combining multiple retardation layers with different optical properties (first retardation layer with positive C-axis orientation, second retardation layer with negative C-axis orientation) between the polarizing plate and liquid crystal panel. This composite structure enables simultaneous achievement of wide viewing angle and high lateral contrast ratio by compensating for the optical defects of IPS-mode displays.
2Device complexity
If conventional polarizing plate structure is used, then device complexity is low, but light leakage at lateral side occurs and contrast ratio deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the polarizing plate into multiple functional layers: a polarizer layer, a first retardation layer with positive C-axis orientation, and a second retardation layer with negative C-axis orientation. This segmented structure allows each layer to perform its specific optical function, effectively suppressing lateral light leakage and improving contrast ratio while maintaining reasonable device complexity.
Solution Approach 2:
The patent implements local quality by assigning different optical characteristics to different regions and layers of the polarizing plate structure. The first and second retardation layers have opposite C-axis orientations, creating localized optical compensation that specifically addresses lateral viewing performance without affecting the overall simplicity of the display structure.
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 module significantly improves contrast ratio and suppresses light leakage at lateral sides, achieving luminance reduction in black mode and maintaining uniformity in white mode.
Implementation Method 1
the first retardation layer including at least a positive C layer; the optical display panel includes a second retardation layer therein
Data Source
AI summary
Provided are an optical display device module and an optical display device including same, the optical display device module comprising an optical display device panel, and a first polarizing plate arranged on at least one surface of the optical display device panel, wherein the first polarizing plate includes a first polarizer and a first phase difference layer arranged between the first polarizer and the optical display device panel, the first phase difference layer includes at least a positive C layer, the optical display device panel includes a second phase difference layer therein, and the second phase difference layer and the first phase difference layer satisfy formula 1 and formula 2.