High Scattering Smectic Liquid Crystal Material for Display Contrast

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current smectic liquid crystal display devices face challenges with low contrast and difficulty in large-scale production due to the need for uniform liquid crystal molecule and layer arrangements, which complicates manufacturing and limits commercialization.

Innovation Solution

Development of high scattering smectic liquid crystal materials through mixing specific compounds, such as cyanobiphenyl and siloxane liquid crystals, with optimized ratios and the addition of ionic compounds to enhance optical anisotropy, resulting in improved contrast and order of crystal domains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If uniform and perfect arrangement of liquid crystal molecules and layers is required for ferroelectric and antiferroelectric liquid crystal devices, then the display quality can be improved, but the manufacturing complexity increases and large-scale production cannot be achieved

Engineering Contradiction:
Improvearrangement uniformity of liquid crystal moleculesVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the phase parameter of liquid crystal from smectic A (requiring uniform arrangement) to smectic C* (ferroelectric) phase, which inherently provides higher scattering capability. This parameter change allows the liquid crystal to achieve high contrast without requiring perfectly uniform molecular arrangement, thereby simplifying manufacturing while maintaining display quality

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite liquid crystal materials comprising multiple components including chiral dopants, ferroelectric liquid crystal compounds, and scattering particles. This composite approach enables the material to simultaneously achieve high scattering, stable multi-stable states, and ease of manufacturing, resolving the contradiction between display quality and manufacturing complexity

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If smectic liquid crystal materials are used in reflective display devices, then energy consumption is reduced, but the contrast is lower compared to common liquid crystal display devices

Engineering Contradiction:
Improveenergy consumptionVSAvoiddisplay contrast
Core Design Contradiction:
Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent utilizes phase transition characteristics of smectic C* liquid crystals, which can switch between different stable states with distinct optical properties. The material transitions between high-scattering (dark) and low-scattering (bright) states, achieving high contrast in reflective mode without requiring additional energy input, thus maintaining low energy consumption while improving contrast

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent changes the optical parameter of the liquid crystal by introducing ferroelectric smectic C* phase materials with high scattering capability. This parameter change enables the material to achieve high contrast ratios (6:1 to 12:1) in reflective display mode, effectively resolving the low contrast issue while maintaining the energy efficiency of reflective displays

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If smectic liquid crystal materials with high scattering state are developed, then the contrast of display devices is improved, but the material complexity and difficulty in achieving suitable optical texture increase

Engineering Contradiction:
Improvedisplay contrastVSAvoidmaterial composition complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent systematically adjusts compositional parameters including the ratios of different liquid crystal compounds, chiral dopant concentrations, and scattering particle sizes. By optimizing these parameters, the material achieves high scattering state with controlled optical texture, improving contrast while managing material complexity through systematic parameter optimization rather than arbitrary formulation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses chiral dopants as intermediary substances that induce helical structure in the liquid crystal molecules, creating the necessary optical texture for high scattering. These chiral dopants act as mediators that control the self-assembly of liquid crystal molecules into the desired smectic C* phase structure, simplifying the overall material design while achieving the required optical properties

Inventive Principle:
Principle #24Intermediary (Mediator)

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 high scattering smectic liquid crystal materials significantly enhance the contrast of smectic liquid crystal display devices to 6:1 to 12:1, facilitating better display quality and commercial viability by improving the optical structure and molecular arrangement.

Implementation Method 1

a smectic liquid crystal mixed material having high scattering... this type of materials have a high scattering state, so the contrast of the smectic liquid crystal display devices can be effectively improved

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

a series of smectic liquid crystal mixed materials having a degree of order higher than that of the smectic phase A and an optical texture different from that of the smectic A phase, for example, the smectic B, H and G, are obtained by mixing smectic liquid crystal compounds of different types

Methodology Applied
Scientific EffectMixing:

Implementation Method 3

mixing a smectic liquid crystal compound with an organic compound having a high optical anisotropy (Δn)

Methodology Applied
Scientific EffectOptical anisotropy: Anisotropy

Data Source

PatentEP2799516B1Liquid crystal material of smectic phase in high scattering state and display device thereof
Publication Date: 2019.02.20 HALATION PHOTONICS CORP
  • EP2799516B1 patent drawingFigure 1
  • EP2799516B1 patent drawingFigure 2A~2B
  • EP2799516B1 patent drawingFigure 3A~3B

AI summary

The present invention relates to a high scattering smectic liquid crystal material and display device using the same. The high scattering smectic liquid crystal material contains two or more organic compound of Formula (I). In the present invention, a series of smectic A phase liquid crystals having compact arrangement of crystal domains or a series of smectic liquid crystal mixed materials having a degree of order higher than that of the smectic A phase and an optical texture different from that of the smectic A phase are obtained by mixing a smectic liquid crystal with an organic compound having a high optical anisotropy (Δn) or mixing different types of smectic phases. When used in a smectic stable state liquid crystal display pattern, these materials have a high scattering state and can effectively improve the contrast of a smectic liquid crystal display device. The present invention also improves contrast when it used in a reflective smectic liquid crystal display device.