Single-Sheet O-Plate Polarizing Plate For Uniform Reflectivity

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Solution Overview

Problem

Existing polarizing plates for organic light emitting diode displays suffer from non-uniform reflectivity between the front and lateral sides, necessitating a solution that improves screen uniformity while reducing reflectivity and manufacturing complexity.

Innovation Solution

A polarizing plate comprising a polarizer and a single-sheet O-plate type liquid crystal retardation layer with specific retardation ratios and tilt angles, optimized for uniform reflectivity and thickness reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a double-sheet type retardation layer (HWP layer and QWP layer) is used, then reflectivity reduction at front and lateral sides can be achieved, but device complexity and manufacturing process complexity increase

Engineering Contradiction:
ImprovereflectivityVSAvoidretardation layer structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the functions of the HWP layer and QWP layer into a single integrated retardation layer. This single layer simultaneously provides the half-wave and quarter-wave retardation effects needed for reflectivity reduction at both front and lateral sides, eliminating the need for separate layers while maintaining the optical performance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single-sheet retardation layer is designed to perform multiple functions: it acts as both a half-wave plate and a quarter-wave plate depending on the viewing angle. This multi-functionality allows the layer to reduce reflectivity effectively at both front and lateral sides without requiring separate specialized layers for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Object-affected harmful factors

If a double-sheet type retardation layer is used, then reflectivity reduction can be achieved, but manufacturing process complexity increases

Engineering Contradiction:
ImprovereflectivityVSAvoidmanufacturing process
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent combines what would traditionally require two separate manufacturing processes (making HWP and QWP layers separately) into a single manufacturing process. The single-sheet retardation layer is produced as one integrated component, reducing the number of assembly steps, alignment requirements, and quality control checkpoints needed during manufacturing.

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If reflectivity reduction at front and lateral sides is achieved, then screen uniformity improves, but manufacturing complexity increases

Engineering Contradiction:
Improvescreen uniformityVSAvoidretardation layer structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The single-sheet retardation layer is designed with spatially varying optical properties that are optimized for different viewing angles. The layer structure incorporates local quality variations that enable effective reflectivity reduction specifically at front and lateral sides while maintaining simplicity in the overall layer configuration.

Inventive Principle:
Principle #3Local quality

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 uniform reflectivity across the front and lateral sides, reducing manufacturing complexity and costs, and enhancing display quality.

Implementation Method 1

a retardation layer stacked on a lower surface of the polarizer, wherein the retardation layer has a maximum ratio of 1.1 to 1.8 and a minimum ratio of 0.3 to 0.7

Methodology Applied
Scientific EffectBirefringence: Birefringence

Implementation Method 2

the retardation layer may include an O-plate type liquid crystal retardation layer

Methodology Applied
Scientific EffectLiquid crystal optical modulation: Liquid Crystals

Implementation Method 3

a polarizer; and a retardation layer stacked on a lower surface of the polarizer

Methodology Applied
Scientific EffectPolarization: Polarisation

Data Source

PatentEP4641267A1Polarizing plate and optical display device
Publication Date: 2025.10.29 HOARDSUN HENGXIN(WUXI) MATERIALS CO LTD
  • EP4641267A1 patent drawingFigure 1
  • EP4641267A1 patent drawingFigure 2
  • EP4641267A1 patent drawingFigure 3

AI summary

A polarizing plate and an optical display device comprising same are provided, the polarizing plate comprising: a polarizer; and a phase difference layer laminated on the lower surface of the polarizer, wherein in the phase difference layer, the maximum value of the ratio expressed by formula 1 is 1.1 to 1.8 and the minimum value is 0.3 to 0.7. [Formula 1] Ratio B/A (A is the front surface phase difference (unit: nm) of the phase difference layer at wavelength of 550 nm, and B is an inclined phase difference (unit: nm) measured at wavelength of 550 nm with rotation of the phase difference layer by +60° or - 60° about a fast axis of the phase difference layer as the rotational axis.