Polarizing Plate With Aligned Acicular Particles for Brighter Displays

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Solution Overview

Problem

Existing liquid crystal displays face challenges in achieving high visibility and brightness without visibility-enhancing layers, require high hardness to withstand external impacts, and are prone to curling and cracking.

Innovation Solution

A polarizing plate comprising a polarizer with a first optically functional layer containing aligned acicular particles and a second optically functional layer made of a cured actinic radiation curable resin, which enhances visibility and brightness while providing high hardness and reducing thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a visibility-enhancing layer with pattern is used to improve visibility and brightness, then visibility and brightness are improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
ImprovebrightnessVSAvoidstructure complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent removes the visibility-enhancing layer with pattern from the structure, achieving high visibility and brightness through the optical properties of the polarizing plate itself, specifically by controlling the orientation of acicular particles in the optically functional layer

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the orientation parameters of acicular particles (aspect ratio, alignment angle, distribution) in the optically functional layer to achieve visibility enhancement without requiring additional patterned layers, thereby simplifying the overall structure

Inventive Principle:
Principle #35Parameter changes

2Length of moving object

If the viewer-side polarizing plate is made thinner to reduce thickness, then thickness is reduced, but hardness and impact resistance deteriorate

Engineering Contradiction:
ImprovethicknessVSAvoidhardness
Core Design Contradiction:
Length of moving objectVSStrength

Solution Approach 1:

The patent uses a composite structure in the optically functional layer incorporating acicular particles (such as titanium oxide, zirconium oxide, or calcium carbonate) with specific aspect ratios (5:1 to 60:1) embedded in a resin matrix, providing both thinness and high hardness (2H or more on pencil hardness scale)

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent creates local anisotropy by aligning acicular particles at specific orientations (average angle of -10° to +10° relative to the light absorption axis) to enhance optical properties and mechanical strength simultaneously, achieving high hardness without increasing thickness

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If the polarizing plate structure is simplified to reduce manufacturing complexity, then manufacturing ease is improved, but visibility enhancement capability deteriorates

Engineering Contradiction:
Improvemanufacturing easeVSAvoidvisibility
Core Design Contradiction:
Ease of manufactureVSIllumination intensity

Solution Approach 1:

The patent achieves visibility enhancement by precisely controlling parameters of the acicular particles (aspect ratio of 5:1 to 60:1, orientation angle of -10° to +10°, and distribution uniformity with standard deviation of 15° or less) within a simple layered structure, eliminating the need for complex patterned layers while maintaining high visibility

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent incorporates specific inorganic particles (titanium oxide, zirconium oxide, zinc oxide, calcium carbonate, Boehmite, aluminum borate, calcium silicate, magnesium sulfate, or potassium titanate) with controlled morphology and orientation into the optically functional layer, providing both optical enhancement and mechanical properties in a manufacturable structure

Inventive Principle:
Principle #40Composite materials

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 improves visibility and brightness without patterns, offers high hardness for durability, and prevents curling and cracking, while maintaining a compact form factor.

Implementation Method 1

the second optically functional layer includes a cured product of a composition comprising an actinic radiation curable resin

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

the first optically functional layer contains anisotropic particles including acicular particles, the acicular particles being aligned in an in-plane direction

Methodology Applied
Scientific EffectOptical anisotropy: Anisotropy

Data Source

PatentEP4625007A1Polarizing plate and optical display device
Publication Date: 2025.10.01 HOARDSUN HENGXIN(WUXI) MATERIALS CO LTD
  • EP4625007A1 patent drawingFigure 1~3
  • EP4625007A1 patent drawingFigure 4~6
  • EP4625007A1 patent drawingFigure 7~10

AI summary

Provided are a polarizing plate and an optical display device including the polarizing plate, the polarizing plate comprising a polarizer, and a first optical functional layer and a second optical functional layer sequentially stacked on one surface of the polarizer, wherein the first optical functional layer includes anisotropic particles, the anisotropic particles include needle-shaped particles, the needle-shaped particles are oriented in the in-plane direction of the first optical functional layer, the average value of the orientation angles formed by the light absorption axis of the polarizer and the longitudinal direction of the needle-shaped particles is -10° to +10° when the light absorption axis of the polarizer is 0° , the standard deviation of the orientation angles is 15° or lower, and the second optical functional layer includes a cured product of a composition containing an active energy ray-curable resin.