Liquid Crystal Composition with Optically Active Compound
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current liquid crystal compositions for active matrix liquid crystal display devices face challenges in achieving a balance of high maximum and low minimum temperature range, low viscosity, suitable optical anisotropy, large dielectric anisotropy, high specific resistance, stability to ultraviolet light and heat, and long service life, while maintaining a short response time and high contrast ratio.
Innovation Solution
A liquid crystal composition containing optically active compounds with an octahydro binaphthalene or binaphthalene skeleton, combined with specific compounds that enhance dielectric anisotropy and viscosity, is used to create a formulation that balances these characteristics, including a polymerizable component for improved stability and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the maximum temperature of the nematic phase is increased to extend the usable temperature range, then the service temperature range is improved, but the viscosity at high temperature increases causing longer response time
Solution Approach 1:
The patent modifies molecular parameters by introducing specific structural features (fluorine substitution, cyclic structures, and optically active compounds) to compounds in the liquid crystal composition. These parameter changes enable the composition to maintain low viscosity across a wide temperature range, achieving both high maximum nematic phase temperature (90°C or higher) and fast response time (5 milliseconds or less at 20°C).
Solution Approach 2:
The patent creates a composite liquid crystal composition by combining multiple compounds with specific structural characteristics: compounds of formula (1) and (2) as main components, compounds of formula (3) to (6) as additional components, and optically active compounds as additives. This composite approach achieves synergistic effects that simultaneously extend the nematic phase temperature range and maintain fast response characteristics.
2Use of energy by moving object
If compounds with large dielectric anisotropy are used to reduce threshold voltage and power consumption, then electrical efficiency is improved, but optical anisotropy may become unsuitable affecting contrast ratio
Solution Approach 1:
The patent carefully adjusts molecular parameters by selecting compounds with specific structural features that balance dielectric and optical anisotropy. The use of fluorine-substituted compounds, cyclic structures, and optically active compounds enables simultaneous achievement of large dielectric anisotropy (for low threshold voltage and power consumption) and suitable optical anisotropy (for high contrast ratio), resolving the trade-off between electrical efficiency and optical performance.
3Illumination intensity
If optically active compounds are added to achieve short helical pitch for improved alignment and contrast, then optical performance is improved, but the composition complexity increases
Solution Approach 1:
The patent achieves short helical pitch (5 μm or less) by carefully controlling the concentration and structural parameters of optically active compounds in the composition. By limiting the optically active compound content to 0.01-5% by weight and selecting compounds with specific molecular structures, the patent achieves improved optical performance (short pitch for better alignment and contrast) while minimizing composition complexity and maintaining manufacturability.
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 composition achieves a short response time, high voltage holding ratio, low threshold voltage, large contrast ratio, and extended service life, suitable for various operating modes in liquid crystal display devices.
Implementation Method 1
large positive or negative dielectric anisotropysmall electric power consumption
Implementation Method 2
suitable optical anisotropyLarge contrast ratio
Implementation Method 3
containing an optically active compound having an octahydro binaphthalene skeleton or a binaphthalene skeletonshort helical pitch
Data Source
AI summary
Provided are a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, large dielectric anisotropy and a short helical pitch, or the liquid crystal composition having a suitable balance regarding at least two of the characteristics; and an AM device including the composition. The liquid crystal composition contains a specific optically active compound as an additive, and a specific compound having high maximum temperature or small viscosity as a first component, and may contain a specific compound having positive dielectric anisotropy as a second component, or a specific compound having negative dielectric anisotropy as a third component.