Liquid Crystal Display Device Impurity Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display devices face issues such as white spots, alignment unevenness, and image sticking due to impurities in the color filter layer affecting the voltage holding ratio and ion density of the liquid crystal layer, which existing methods have not adequately addressed.
Innovation Solution
A liquid crystal display device utilizing a specified liquid crystal composition and color filter with specific dyes and pigments, including diketopyrrolopyrrole pigment, halogenated copper phthalocyanine pigment, and anionic/cationic organic dyes, to prevent decreases in voltage holding ratio and ion density, thereby resolving display defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the thickness of the alignment film and transparent electrode is reduced to achieve better isolation, then the direct influence of color filter layer impurities on the liquid crystal layer is minimized, but the voltage holding ratio decreases and ion density increases
Solution Approach 1:
The patent changes the chemical composition parameters of the liquid crystal material by introducing specific compounds (compounds of formula (1) and compounds of formula (2)) with particular molecular structures containing fluorine atoms and specific functional groups. This chemical parameter change enables the liquid crystal to resist impurity influence while maintaining voltage holding ratio and reducing ion density, resolving the contradiction between isolation effectiveness and electrical performance.
2Ease of manufacture
If conventional liquid crystal compositions are used with color filter layers, then manufacturing is simpler, but display defects such as white spots, alignment unevenness, and image sticking occur due to impurity effects
Solution Approach 1:
The patent uses a composite liquid crystal composition combining multiple components: compounds of formula (1) as main liquid crystal material, compounds of formula (2) as additives, and optional compounds of formula (3). This composite material approach maintains manufacturing simplicity while achieving high display quality by preventing impurity-induced defects through the synergistic effects of the composite composition.
3Quantity of substance
If impurities in the color filter layer are reduced by purifying pigments, then the direct effect on liquid crystal layer is minimized, but the voltage holding ratio still decreases and ion density increases due to the thin structure of alignment film and electrode
Solution Approach 1:
The patent introduces compounds of formula (1) and (2) as intermediary substances between the color filter layer and the liquid crystal layer. These compounds act as mediators that prevent direct interaction between impurities in the color filter layer and the liquid crystal layer, while maintaining proper electrical characteristics. The intermediary compounds form a protective interface that blocks impurity diffusion without compromising voltage holding ratio.
Data Source
AI summary
The present invention provides a liquid crystal display device capable of preventing a decrease in voltage holding ratio (VHR) of a liquid crystal layer and an increase in ion density (ID) and resolving the problem of display defects such as white spots, alignment unevenness, image sticking, and the like. The liquid crystal display device of the present invention is characterized by preventing a decrease in voltage holding ratio (VHR) of a liquid crystal layer and an increase in ion density (ID) and suppressing the occurrence of display defects such as image sticking and the like, and is thus particularly useful for a VA-mode or PSVA-mode liquid crystal display device for active matrix driving, and can be applied to liquid crystal display devices such as a liquid crystal TV, a monitor, a cellular phone, a smart phone, and the like.