Liquid-Crystalline Medium for High Resistivity and Wide Temperature Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid-crystalline mixtures for electro-optical displays based on the ECB effect lack high resistivity, wide operating temperature range, short response times, and low threshold voltage, making it difficult to produce high-quality displays with acceptable contrast and grey shade capabilities.
Innovation Solution
A liquid-crystalline medium is developed using a mixture of compounds with negative dielectric anisotropy, specifically formulated with compounds of certain structural formulas, which provide high resistivity, low viscosity, and a suitable temperature range, enabling improved electro-optical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid-crystalline mixtures are used for electro-optical displays based on the ECB effect, then electro-optical functionality is achieved, but high resistivity and wide operating temperature range cannot be simultaneously obtained
Solution Approach 1:
The patent employs composite liquid-crystalline mixtures combining multiple compounds with specific structural formulas (I, I*, II, III) to achieve both high resistivity and wide operating temperature range. The mixture comprises compounds with negative dielectric anisotropy and specific molecular structures that work synergistically to provide both electrical stability and thermal performance.
Solution Approach 2:
The patent systematically adjusts chemical parameters of the liquid-crystalline compounds, including substituting alkyl/alkenyl groups at positions R1-R8, varying the L1-L4 substituents (F, Cl, CF3, CHF2), and controlling the s parameter (0 or 1), to optimize both resistivity and temperature range simultaneously.
2Reliability
If liquid-crystalline mixtures are formulated to achieve high resistivity, then electro-optical stability is improved, but response times become slower
Solution Approach 1:
The patent optimizes the balance between resistivity and response time by carefully selecting and adjusting the parameters of the liquid-crystalline compounds, including the types of alkyl/alkenyl groups, the L1-L4 substituents, and the s parameter, to achieve optimal electro-optical performance.
3Use of energy by moving object
If liquid-crystalline mixtures are used to achieve low threshold voltage, then energy efficiency is improved, but contrast and grey shade capabilities deteriorate
Solution Approach 1:
The patent uses composite liquid-crystalline mixtures with specifically designed compounds (formulas I, I*, II, III) that work together to provide both low threshold voltage and high contrast capability, achieving a balance between energy efficiency and display 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 medium achieves high resistivity, low threshold voltage, and stable performance over a wide temperature range, enhancing display contrast and response times, particularly suitable for projection displays.
Implementation Method 1
The principle of electrically controlled birefringence, the ECB effect, or the DAP effect (deformation of aligned phases) was described for the first time in 1971
Implementation Method 2
liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy
Implementation Method 3
high values for the optical anisotropy Δn
Data Source
AI summary
Disclosed is a liquid-crystalline medium based on a mixture of polar compounds having negative dielectric anisotropy, which contains at least one compound of formula Iand at least one compound of formula I*,and their use in an electro-optical display.