Liquid Crystal Composition for IPS and TN Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display elements face challenges with display defects such as burn-in and drip marks due to variations in liquid crystal injection amounts and sensitivity to pressure changes, particularly in large or small-sized displays, requiring a composition with positive dielectric anisotropy, low viscosity, and stability against heat and light for high yield and quality.
Innovation Solution
A composition combining specific liquid crystal compounds represented by General Formulas (i), (M-1), and (M-4) is developed, optimizing dielectric anisotropy, viscosity, and solubility to maintain high-speed responsiveness and stability, suitable for IPS and TN type liquid crystal display elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the liquid crystal composition uses a positive Δ∈ with high absolute value for high-speed responsiveness, then the response speed is improved, but the viscosity tends to increase which slows down the response
Solution Approach 1:
The patent uses a composite liquid crystal composition containing multiple compounds including cyclic carbonate compounds (Formulas i, M-1, M-4), esters of carboxylic acids with 4-8 carbon atoms, and other liquid crystal compounds. This composite approach allows optimization of both dielectric anisotropy and viscosity by combining compounds with complementary properties, achieving high-speed responsiveness without excessive viscosity increase.
Solution Approach 2:
The patent specifies precise compositional parameters: cyclic carbonate compounds at 5-80 mass%, esters of carboxylic acids with 4-8 carbon atoms at 15-80 mass%, and controlled ranges for other components. By optimizing these parameter ranges, the composition achieves the balance between positive dielectric anisotropy (for fast response) and acceptable viscosity levels.
2Speed
If the liquid crystal composition is optimized for high-speed responsiveness with low viscosity, then the response speed is improved, but the stability against heat and light deteriorates
Solution Approach 1:
The composite composition combines cyclic carbonate compounds (providing fast response and low viscosity) with stable ester compounds and other liquid crystal materials (providing thermal and photostability). This composite structure achieves both high-speed responsiveness and excellent stability against heat and light through synergistic effects of the components.
Solution Approach 2:
The patent introduces specific compounds as intermediaries that mediate between the fast-response cyclic carbonates and the stability-providing esters. These intermediary compounds (including specific liquid crystal compounds in Formulas M-1 and M-4) bridge the properties of different components, ensuring both speed and stability are achieved simultaneously.
3Quantity of substance
If the liquid crystal injection amount is increased to fill large-sized substrates, then the filling is improved, but display defects such as spots and contrast failure occur
Solution Approach 1:
The patent optimizes the liquid crystal composition parameters (viscosity, surface tension, dielectric constant) to enable precise control of injection amount. The specific formulation with cyclic carbonates and ester compounds provides optimal rheological properties that allow accurate dosing even in large-volume injections, preventing display defects while ensuring complete substrate filling.
4Manufacturing precision
If the liquid crystal composition is optimized for small injection amounts in small-sized displays, then the injection precision is improved, but control within certain range becomes difficult
Solution Approach 1:
The patent formulates the liquid crystal composition with optimized viscosity (through cyclic carbonate and ester compound ratios) and surface tension properties that enable precise injection control. These parameter optimizations allow small injection amounts to be delivered accurately without requiring complex control systems, simplifying the manufacturing process while maintaining high precision.
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 high-speed responsiveness, suppresses display defects, and ensures high yield by maintaining stability against heat and light, effectively addressing the challenges of burn-in and drip marks in liquid crystal display elements.
Implementation Method 1
a liquid crystal composition having a positive Δ∈ is used... a driving mode in which a liquid crystal composition having a positive Δ∈ is vertically aligned when no voltage is applied, and a horizontal electric field is applied thereto for displaying
Implementation Method 2
a liquid crystal phase over a temperature range as wide as possible around room temperature... a high nematic phase-isotropic liquid phase transition temperature (Tni) are required
Implementation Method 3
low viscosity... a low viscosity (η)... the liquid crystal composition having a low rotational viscosity (γ1) is required
Data Source
AI summary
Provided is a composition which has a liquid phase over a wide temperature range, a low viscosity, an excellent solubility at low temperature, high specific resistance, high voltage retention rate, and stability against heat or light, and further a liquid crystal display element of, for example, such as an IPS type or a TN type, which has excellent display qualities by using the composition, and in which display defects such as burn-in or drip marks are hardly caused, at a high yield. Provided is a composition including one or more compounds represented by General Formula (i), one or more compounds represented by General Formula (M-1), and one or more compounds represented by General Formula (M-4), and a liquid crystal display element using the composition.