Aromatic Polymer Mediator for Reflective LCD Flickering
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Solution Overview
Problem
Existing liquid crystal display devices with reflective electrodes experience flickering and image sticking due to charge-transfer reactions during long-term low-voltage driving, which existing technologies fail to effectively suppress.
Innovation Solution
Incorporating an aromatic polymer with a specific structure between the liquid crystal layer and the alignment film or within the alignment film to facilitate an efficient charge-transfer reaction between the reflective electrode and the aromatic polymer, thereby reducing the charge-transfer reaction with the liquid crystal compound.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a reflective electrode is used in a liquid crystal display device to achieve low-voltage driving, then power consumption is reduced, but charge-transfer reactions occur between the reflective electrode and liquid crystal compound causing flickering and image sticking
Solution Approach 1:
The patent introduces an intermediary substance (aromatic compound or polymer layer containing aromatic groups) between the reflective electrode and the liquid crystal layer. This intermediary acts as a mediator that accepts charge from the reflective electrode through charge-transfer reactions, preventing direct charge-transfer reactions between the reflective electrode and the liquid crystal compound. The aromatic groups in the intermediary have high electron affinity and can effectively capture charges, thereby eliminating the harmful charge-transfer reactions that cause flickering and image sticking while maintaining the low-voltage driving characteristics of the reflective electrode.
Solution Approach 2:
The patent converts the harmful charge-transfer reaction into a beneficial process by directing it toward the intermediary substance instead of the liquid crystal compound. The charge-transfer reaction that previously caused damage (flickering and image sticking) is now harnessed to populate the intermediary with charges, which then safely recombine or dissipate without affecting the liquid crystal molecules. This transforms the problematic charge-transfer mechanism into a protective function that shields the liquid crystal layer from charge-induced damage.
2Power
If low-voltage driving is implemented using liquid crystal compounds with alkoxy groups, then power consumption is reduced, but charge-transfer reactions with the reflective electrode cause flickering and image sticking
Solution Approach 1:
The patent places an intermediary layer containing aromatic compounds or polymers with aromatic groups between the reflective electrode and the liquid crystal layer. This intermediary serves as a charge-accepting buffer that intercepts charges from the reflective electrode before they can react with the liquid crystal compound. The aromatic structures in the intermediary have suitable energy levels to accept charges from the reflective electrode, preventing direct interaction between the electrode and the liquid crystal molecules, thereby eliminating flickering and image sticking while preserving low-voltage driving capability.
Solution Approach 2:
The patent redirects the charge-transfer reaction away from the liquid crystal compound and toward the intermediary substance. By designing the intermediary with appropriate electronic properties (aromatic groups with suitable LUMO levels), the harmful charge-transfer reaction is converted into a beneficial charge-capture mechanism. The intermediary safely accommodates the charges that would otherwise damage the liquid crystal, transforming a destructive process into a protective function that enables reliable low-voltage operation.
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 suppresses flickering and image sticking during long-term driving of liquid crystal display devices with reflective electrodes, maintaining high visibility and low power consumption.
Implementation Method 1
an efficient charge-transfer reaction occurs between the charge generated on the reflective electrode and the aromatic polymer
Implementation Method 2
a liquid crystal layer sandwiched between the first substrate and the second substrate and containing a liquid crystal material that contains a liquid crystal compound containing an alkoxy group and has negative anisotropy of dielectric constant
Implementation Method 3
a first substrate provided with a reflective electrode configured to reflect ambient light
Data Source
AI summary
The present invention provides a liquid crystal display device which includes a reflective electrode, which achieves its low-voltage driving, and which suppresses flickering caused during its driving and image sticking caused by its long-term driving. The liquid crystal display device of the present invention includes: a first substrate provided with a reflective electrode configured to reflect ambient light; a second substrate facing the first substrate; a liquid crystal layer sandwiched between the first substrate and the second substrate and containing a liquid crystal material that contains a liquid crystal compound containing an alkoxy group and has negative anisotropy of dielectric constant; an alignment film provided on at least one of the first substrate and the second substrate on a side facing the liquid crystal layer; and an aromatic polymer that is present between the liquid crystal layer and the alignment film and/or within the alignment film and has a specific structure.