Transparent Electrode Frame Shielding for LCD Light Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Active matrix liquid crystal display devices without a black matrix on the opposed substrate suffer from light leakage in the frame portion due to insufficient light shielding, especially in normally white mode TN systems, which affects display quality and increases production costs.
Innovation Solution
A constant-potential transparent electrode is placed in an upper layer to cover the gaps between opaque electrodes with different electric potentials in the frame portion, shielding the strong electric fields that cause light leakage and maintaining the black state by preventing backlight penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a light shielding layer composed of opaque electrode is added to prevent light leakage, then light leakage is reduced, but manufacturing processes increase
Solution Approach 1:
The patent combines the light shielding function with the existing transparent electrode structure. The transparent electrode serves dual purposes: it maintains the normally black mode display characteristic and simultaneously acts as a light shielding layer to prevent light leakage in the frame portion, eliminating the need for separate opaque electrode layers
Solution Approach 2:
The transparent electrode is designed to perform multiple functions: it serves as an electrode for electric field application in the display pixel areas and simultaneously functions as a light shielding layer in the frame portion to prevent backlight leakage, thereby reducing the number of separate components needed
2Object-affected harmful factors
If a black matrix is provided on the opposed substrate to prevent light leakage, then light shielding ability is improved, but production cost increases
Solution Approach 1:
The patent extracts and eliminates the black matrix from the opposed substrate while maintaining effective light shielding functionality through the transparent electrode structure in the frame portion, thereby reducing material costs and simplifying the overall device structure
Solution Approach 2:
The patent replaces the expensive black matrix material with a transparent electrode that can be integrated into the existing substrate structure, using materials and processes that are more cost-effective while achieving the same light shielding function
3Ease of manufacture
If laminated pattern including color layers is used in frame portion, then production cost is reduced, but light shielding ability becomes insufficient
Solution Approach 1:
The patent changes the optical parameter of the frame portion by introducing a transparent electrode with specific optical properties that provide effective light shielding while maintaining transparency in the display areas, thereby achieving both cost reduction and sufficient light shielding ability
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
This solution effectively reduces light leakage in the frame portion, maintaining high display quality without the need for additional light shielding layers, thereby reducing production costs and enhancing the performance of liquid crystal display devices, especially in normally black mode IPS and VA systems.
Implementation Method 1
a gap between opaque electrodes which are closely located and whose electric potentials are different from each other in a frame portion around a display area of the active matrix substrate is covered with a constant-potential transparent electrode arranged in an upper layer of the gap
Data Source
AI summary
Disclosed is an active matrix liquid crystal display device including: an active matrix liquid crystal display device of a normally black mode which includes an active matrix substrate and an opposed substrate and in which a black matrix is not provided on the opposed substrate, wherein a gap between opaque electrodes which are closely located and whose electric potentials are different from each other in a frame portion around a display area of the active matrix substrate is covered with a constant-potential transparent electrode arranged in an upper layer of the gap.