Polarizing Plate Retardation Layer Design for Low Reflectivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polarizing plates for organic light emitting diode displays face challenges in achieving low reflectivity at both front and lateral sides, while maintaining an ellipticity of about 65% or more at an incidence angle of 60°, and reducing the thickness of the retardation layer.
Innovation Solution
A polarizing plate is designed with a polarizer and sequentially stacked first and second retardation layers on its lower surface, where the first retardation layer has an in-plane retardation of about 180 nm to 220 nm, and the second retardation layer has an in-plane retardation of about 80 nm to 100 nm, both at a wavelength of 550 nm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a 1/4 retardation layer alone or a laminate of 1/2 and 1/4 retardation layers is used, then the polarizing plate structure is simple, but the ellipticity at 60° incidence angle is insufficient (less than 65%)
Solution Approach 1:
The retardation layer is divided into multiple sub-layers with different retardation values (1/16, 1/8, 1/4 wavelength layers) and specific thickness ratios. This segmentation allows each layer to contribute differently to the overall optical performance, achieving the required 65% ellipticity at 60° incidence while maintaining a manageable structural complexity.
2Length of stationary object
If the thickness of the polarizing plate is reduced, then the overall device size decreases, but the reflectivity control and optical performance deteriorate
Solution Approach 1:
The patent optimizes the thickness parameters of each retardation layer (1/16, 1/8, 1/4 wavelength layers) and their relative ratios to achieve low reflectivity at both front and lateral sides. By precisely controlling the thickness parameters within specific ranges, the patent reduces overall plate thickness while maintaining effective reflectivity control through the cumulative optical effect of the multi-layer structure.
3Length of stationary object
If the retardation layer thickness is reduced, then the polarizing plate becomes thinner, but the ability to achieve required ellipticity and control reflectivity is compromised
Solution Approach 1:
Instead of using a single thick retardation layer, the patent segments it into multiple thinner layers (1/16, 1/8, 1/4 wavelength layers) with optimized thickness ratios. This segmentation enables better control over optical properties while reducing overall thickness, as each layer contributes specifically to the cumulative ellipticity and reflectivity control.
Solution Approach 2:
The patent uses a composite structure of multiple retardation layers with different optical characteristics (different wavelength relationships and retardation values). This composite approach allows the thinner overall structure to achieve the required optical performance through the synergistic effect of layers with complementary properties.
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 polarizing plate achieves low reflectivity at both front and lateral sides and maintains an ellipticity of about 65% or more at an incidence angle of 60°, while allowing for a reduction in thickness, thereby enhancing the screen quality of optical display apparatuses.
Implementation Method 1
the first retardation layer has an in-plane retardation of about 180 nm to about 220 nm... the second retardation layer has an in-plane retardation of about 80 nm to about 100 nm
Data Source
AI summary
A polarizing plate and an optical display apparatus including the same are provided. A polarizing plate includes a polarizer; and a first retardation layer and a second retardation layer sequentially stacked on a lower surface of the polarizer, and the first retardation layer has an in-plane retardation of about 180 nm to about 220 nm at a wavelength of about 550 nm; and the second retardation layer has an in-plane retardation of about 80 nm to about 100 nm at a wavelength of about 550 nm.