Light Modulator Retardation Film for Black-Mode Leakage Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Light modulating devices using anisotropic film base materials face issues with decreased driving performance due to phase differences, leading to light leakage in the black mode, and mechanical weaknesses such as cracks and shrinkage.

Innovation Solution

Incorporating a retardation film with specific in-plane phase differences and an optically anisotropic layer at strategic positions within the light modulating device, along with polymer films, to control omnidirectional light leakage and enhance mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If an anisotropic film base material is introduced to improve mechanical strength and heat resistance, then mechanical properties are improved, but light leakage occurs in the black mode due to phase difference

Engineering Contradiction:
Improvemechanical strengthVSAvoidlight leakage
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

A retardation film is introduced as an intermediary component between the anisotropic film base material and the light modulation layer. This retardation film compensates for the phase difference generated by the anisotropic film base material, thereby eliminating light leakage in the black mode while preserving the mechanical strength and heat resistance benefits of the anisotropic material

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention controls the phase difference parameter of the anisotropic film base material within a specific range (0.5 nm to 500 nm) and adjusts the retardation film's optical parameters to compensate for this phase difference. By changing and controlling these optical parameters, the system achieves both mechanical strength and black mode performance

Inventive Principle:
Principle #35Parameter changes

2Object-generated harmful factors

If an isotropic film base material is used to avoid phase difference issues, then light leakage is reduced, but mechanical strength decreases and cracks or shrinkage occur due to heat

Engineering Contradiction:
Improvelight leakageVSAvoidmechanical strength
Core Design Contradiction:
Object-generated harmful factorsVSStrength

Solution Approach 1:

The invention uses a composite structure combining anisotropic film base material (for mechanical strength) with a retardation film (for optical compensation). This composite approach allows the system to simultaneously achieve the mechanical advantages of anisotropic materials and the optical performance of phase-difference-compensated structures, avoiding both light leakage and mechanical weakness

Inventive Principle:
Principle #40Composite materials

3Strength

If the phase difference of the film base material is increased to improve mechanical properties, then mechanical strength is improved, but driving performance decreases due to light leakage

Engineering Contradiction:
Improvemechanical strengthVSAvoiddriving performance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The retardation film serves as a mediator that decouples the relationship between mechanical strength and driving performance. It allows the anisotropic film base material to maintain high phase difference for mechanical strength while the retardation film compensates for the optical effects, thereby preserving driving performance

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention optimizes the phase difference parameter of the anisotropic film base material within a controlled range and uses the retardation film to adjust the overall optical path difference. This parameter optimization ensures that mechanical strength is improved while driving performance is maintained through compensatory optical design

Inventive Principle:
Principle #35Parameter changes

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 effectively controls light leakage in the black mode while maintaining excellent optical and mechanical properties, enabling versatile applications with transmittance variability.

Implementation Method 1

A retardation film having an in-plane phase difference for light with a wavelength of 550 nm in a range of 100 nm to 300 nm is formed on the second surface of the first substrate or the second substrate

Methodology Applied
Scientific EffectPhase difference control: Birefringence

Data Source

PatentEP4187314B1Optical modulation device
Publication Date: 2026.04.01 LG CHEM LTD
  • EP4187314B1 patent drawingFigure 1
  • EP4187314B1 patent drawingFigure 2
  • EP4187314B1 patent drawingFigure 3

AI summary

The present application relates to a light modulating device. The present application can provide a light modulating device applicable to various applications by controlling omnidirectional light leakage in a black mode while having excellent optical properties such as transmittance variable properties and mechanical properties, and the like.