Liquid Crystal Composition for Fast Response and Long Service Life
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Solution Overview
Problem
Liquid crystal display devices face challenges in achieving a short response time, large voltage holding ratio, low threshold voltage, high contrast ratio, long service life, and minimizing flicker rates, particularly in maintaining stability across varying temperatures and exposure to ultraviolet light.
Innovation Solution
A liquid crystal composition with specific compounds, such as those represented by formulas (1) to (3), is used between substrates, optimizing the ratio of components to achieve negative dielectric anisotropy, high maximum and low minimum temperatures, and low viscosity, which are polymerized to enhance alignment and stability, thereby reducing flicker rates and improving device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If conventional liquid crystal compositions are used, then the device can operate, but the response time is long and the service life is limited due to high viscosity and instability
Solution Approach 1:
The patent changes the chemical composition parameters of the liquid crystal mixture by incorporating specific compounds with defined molecular structures (formulas 1-3) and ratios, optimizing the balance between viscosity and stability characteristics to achieve both fast response and long service life
Solution Approach 2:
The patent uses a composite liquid crystal composition combining multiple compounds with different functional properties - including compounds with negative dielectric anisotropy, specific viscosity modifiers, and stability enhancers - to achieve synergistic effects that simultaneously improve response time and service life
2Speed
If the liquid crystal composition is optimized for fast response time with low viscosity, then response time shortens, but stability under varying temperatures and UV exposure deteriorates
Solution Approach 1:
The patent carefully adjusts the temperature range parameters and chemical composition to maintain optimal viscosity and molecular alignment characteristics across a wide temperature range (−10°C to 70°C), ensuring both fast response and stable performance under thermal variation
Solution Approach 2:
The patent incorporates UV stabilizers and antioxidants in the liquid crystal composition that create a chemically inert environment resistant to ultraviolet degradation, protecting the liquid crystal molecules from photodecomposition while maintaining their electro-optic properties
3Use of energy by moving object
If the dielectric anisotropy is increased to reduce threshold voltage, then power consumption decreases, but the contrast ratio and optical performance may be compromised
Solution Approach 1:
The patent optimizes the dielectric anisotropy parameter to a specific range that balances electrical and optical performance, using compounds with negative dielectric anisotropy that enable low threshold voltage operation while maintaining sufficient optical anisotropy for high contrast ratio display
4Adaptability or versatility
If the liquid crystal composition uses a wide temperature range, then the device can operate in various environments, but the viscosity control becomes difficult affecting response time
Solution Approach 1:
The patent selects and combines liquid crystal compounds with complementary temperature-dependent viscosity characteristics, using a mixture of compounds whose viscosity changes offset each other across the temperature range, maintaining consistently low viscosity and fast response from −10°C to 70°C
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 results in a liquid crystal display device with a flicker rate of 0% to 1%, a short response time, large voltage holding ratio, low threshold voltage, and high contrast ratio, ensuring a long service life and stability under various conditions.
Implementation Method 1
a liquid crystal composition having negative dielectric anisotropy
Implementation Method 2
The optical anisotropy of the composition relates to the contrast ratio of the device
Implementation Method 3
The polymerizable compound is polymerized to give a network structure of a polymer in the composition
Data Source
AI summary
Shown is a liquid crystal display device including a first substrate, a second substrate and a liquid crystal composition having a nematic phase, which is placed between these substrates, wherein the liquid crystal composition includes at least one compound selected from compounds represented by formula (1) as a first component:wherein in formula (1), R1 and R2 are alkyl or the like; ring A and ring C are 1,4-phenylene or the like; ring B is 2,3-difluoro-1,4-phenylene or the like; Z1 and Z2 are a single bond or the like; and m is 1, 2 or 3, n is 0 or 1, and the sum of m and n is 3 or less.