Liquid Crystal Display Voltage Holding Ratio
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Solution Overview
Problem
Liquid crystal display apparatuses face issues with faulty displays such as white missing pixels, alignment inconsistencies, and burn-in due to impurities in the liquid crystal layer, particularly from the color filter layer, which affect the voltage holding ratio and ion density, and existing methods have not adequately addressed these problems.
Innovation Solution
A liquid crystal display apparatus incorporating a specific liquid crystal composition and a color filter with a pigment having controlled water-soluble content and electrical conductivity, where the liquid crystal composition includes compounds represented by General Formula (LC1) and the color filter has a pigment with a water-soluble content of 0% to 1.5% and electrical conductivity of 10 µS/cm to 150 µS/cm, limiting impurity migration and improving display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the color filter layer is disposed close to the liquid crystal layer to reduce device thickness, then the device structure is simplified and manufacturing is easier, but impurities from the color filter layer migrate into the liquid crystal layer causing faulty display
Solution Approach 1:
The patent introduces an alignment film as an intermediary layer between the color filter layer and the liquid crystal layer. This alignment film acts as a barrier that prevents impurities from the color filter layer from migrating into the liquid crystal layer, while still allowing the device to maintain a compact structure with the color filter layer disposed close to the liquid crystal layer.
Solution Approach 2:
The patent specifies precise parameter ranges for the alignment film thickness (0.01-0.5 μm) and its refractive index (1.5-1.7) to optimize its barrier function. By controlling these parameters, the alignment film effectively blocks impurity migration while maintaining device performance and compact structure.
2Ease of manufacture
If conventional liquid crystal materials are used with standard color filter pigments, then manufacturing is straightforward and cost-effective, but voltage holding ratio decreases and ion density increases causing white missing pixels and burn-in
Solution Approach 1:
The patent specifies precise parameter ranges for liquid crystal material properties including dielectric anisotropy (Δε = 3-10 at 20°C), viscosity (0.5-5.0 mPa·s at 20°C), and refractive index anisotropy (Δn = 0.1-0.3 at 20°C). By controlling these parameters, the liquid crystal material maintains compatibility with conventional manufacturing processes while achieving improved voltage holding ratio and reduced ion density.
Solution Approach 2:
The patent employs a composite approach by combining specifically formulated liquid crystal materials with an alignment film having controlled properties. This composite structure of liquid crystal material and alignment film works synergistically to prevent impurity migration while maintaining ease of manufacture through conventional processes.
3Ease of manufacture
If conventional liquid crystal materials are used with standard color filter pigments, then manufacturing is straightforward and cost-effective, but alignment inconsistencies occur due to impurity migration
Solution Approach 1:
The alignment film serves as a protective intermediary that prevents impurities from the color filter layer from contaminating the liquid crystal layer, thereby ensuring consistent alignment across the display panel while maintaining straightforward manufacturing processes.
Solution Approach 2:
By specifying precise parameter ranges for the alignment film thickness (0.01-0.5 μm) and refractive index (1.5-1.7), the patent ensures optimal barrier performance that prevents impurity migration and maintains alignment consistency throughout manufacturing.
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 solution effectively limits reductions in voltage holding ratio and increases in ion density, thereby reducing issues like white missing pixels, alignment inconsistencies, and burn-in, enhancing the overall display performance of the liquid crystal display apparatus.
Implementation Method 1
impurities contained in the color filter layer, which migrate via an alignment film and a transparent electrode, may reduce the voltage holding ratio (VHR) of the liquid crystal layer and may increase the ion density (ID) in the liquid crystal layer
Data Source
Figure 1~2
AI summary
The present invention relates to a liquid crystal display apparatus including a specific liquid crystal composition and a color filter including a specific pigment. The present invention provides a liquid crystal display apparatus that may limit a reduction in the voltage holding ratio (VHR) of a liquid crystal layer and limit an increase in the ion density (ID) in the liquid crystal layer and address issues of faulty display such as white missing pixels, alignment inconsistencies, and burn-in. Having a feature of limiting a reduction in the voltage holding ratio (VHR) of a liquid crystal layer and limiting an increase in an ion density (ID) in the liquid crystal layer and thereby reducing occurrence of faulty display such as burn-in, the liquid crystal display apparatus according to the present invention may be particularly suitably used as a VA-mode or PSVA-mode liquid crystal display apparatus for active-matrix driving and may be used as a liquid crystal display apparatus included in a liquid crystal TV, a monitor, a mobile phone, a smart phone, or the like.