Alignment Film Anchoring Regions for LCD Transmittance and Adhesion
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Solution Overview
Problem
Existing liquid crystal display devices face limitations in transmittance, image-sticking characteristics, and seal adhesion due to the absence of strong anchoring regions in alignment films and poor adhesion between alignment films and sealing materials.
Innovation Solution
A liquid crystal display device configuration that includes an alignment film with a mixture of first and second polymers on the TFT substrate, where the first polymer serves as a strong anchoring region and the second polymer as a weak anchoring region, both chemically bonded to the sealing material, enhancing transmittance and image-sticking characteristics while improving seal adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a zero-surface anchoring film is used to improve transmittance, then transmittance is improved, but response speed and image-sticking characteristics deteriorate
Solution Approach 1:
The alignment film is designed with spatially varying anchoring strengths: a first region with strong anchoring force and a second region with weak anchoring force. This local differentiation allows the film to simultaneously provide the weak anchoring needed for high transmittance in the display area while maintaining strong anchoring in border areas to ensure proper response speed and eliminate image sticking.
Solution Approach 2:
The alignment film is segmented into functionally distinct regions: a first alignment film portion with strong anchoring characteristics and a second alignment film portion with weak anchoring characteristics. This segmentation enables independent optimization of different functional requirements within a single alignment film structure.
2Illumination intensity
If a copolymer alignment film with high weak-anchoring part content is used to improve transmittance, then transmittance is improved, but adhesion to sealing material deteriorates
Solution Approach 1:
The alignment film structure provides different chemical compositions in different regions: the first region contains copolymer with high weak-anchoring part content (70-90%) for improved transmittance, while the second region contains copolymer with lower weak-anchoring part content for improved adhesion to sealing material. This local compositional variation resolves the contradiction between transmittance and adhesion.
3Illumination intensity
If a copolymer alignment film with high weak-anchoring part content is used to improve transmittance, then transmittance is improved, but alignment property deteriorates
Solution Approach 1:
The alignment film provides different anchoring strengths in different regions: the first region with strong anchoring force ensures proper alignment property and liquid crystal orientation, while the second region with weak anchoring force improves transmittance. This spatial differentiation of anchoring strength allows simultaneous achievement of good alignment property and high transmittance.
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 configuration results in improved transmittance, image-sticking characteristics, and seal adhesion, addressing the limitations of previous technologies by integrating strong and weak anchoring regions and enhancing the alignment film's interaction with the sealing material.
Implementation Method 1
The alignment film contains a first polymer and a second polymer of a different type from the first polymer and is chemically bonded to the sealing material, and the first polymer and the second polymer in the alignment film are mixed in a surface layer in contact with the liquid crystal layer
Implementation Method 2
the first polymer and the second polymer having different photo-functional groups
Data Source
AI summary
A liquid crystal display device of the present invention includes a thin-film transistor substrate, a counter substrate facing the thin-film transistor substrate, a liquid crystal layer provided between the thin-film transistor substrate and the counter substrate, an alignment film provided on the thin-film transistor substrate; a sealing material which bonds together the thin-film transistor substrate and the counter substrate at the periphery of the liquid crystal layer, and a polymerized layer provided on the liquid crystal layer-side surface of the alignment film. The alignment film contains a first polymer and a second polymer of a different type from that of the first polymer and is chemically bonded to the sealing material, the first polymer and the second polymer contained in the alignment film are mixed in a surface layer in contact with the liquid crystal layer, and the first polymer and the second polymer have different photo-functional groups.