Transparent Conductive Material Replaces Black Matrix in TFT-LCD
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Solution Overview
Problem
Conventional TFT-LCD manufacturing processes require a costly and time-consuming step for forming a black matrix to prevent light leakage, which increases production costs and reduces efficiency.
Innovation Solution
A liquid crystal display device with a color-filter substrate and a thin-film-transistor substrate where a transparent conductive material covers the metal signal lines and pixel electrodes, maintaining a voltage difference below the liquid crystal cell's threshold voltage to prevent light leakage without the need for a black matrix.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a black matrix is formed through coating, developing, and exposure steps to prevent light leakage, then light leakage is avoided, but manufacturing cost increases and production efficiency decreases
Solution Approach 1:
The patent extracts and removes the black matrix formation steps (coating, developing, exposure) from the manufacturing process entirely. Instead of forming a separate black matrix layer, the invention uses the transparent conductive material pattern itself to define the pixel structure, eliminating the need for additional black matrix processing steps and thereby improving production efficiency.
Solution Approach 2:
The transparent conductive material serves multiple functions: it acts as both the pixel electrode and the definition structure for light emission areas, replacing the traditional separate functions of transparent conductive material and black matrix. This multi-functionality reduces process steps while maintaining light leakage prevention.
2Object-affected harmful factors
If a black matrix is formed through coating, developing, and exposure steps to prevent light leakage, then light leakage is avoided, but manufacturing cost increases
Solution Approach 1:
The patent extracts and removes the black matrix formation steps (coating, developing, exposure) from the manufacturing process entirely. Instead of forming a separate black matrix layer, the invention uses the transparent conductive material pattern itself to define the pixel structure, eliminating the need for additional black matrix processing steps and thereby improving production efficiency.
Solution Approach 2:
The patent merges the function of the transparent conductive material with the function previously performed by the black matrix. The transparent conductive material pattern directly defines both the electrical function (pixel electrode) and the optical function (light emission area boundary), combining multiple functions into a single element and reducing manufacturing complexity.
3Productivity
If transparent conductive material covers metal signal lines to prevent light leakage without black matrix, then manufacturing cost is reduced and production efficiency is enhanced, but voltage control precision must be maintained below threshold voltage
Solution Approach 1:
The patent changes the voltage parameter control approach by designing the transparent conductive material pattern and electrical connection structure to inherently limit the voltage difference between signal lines and common electrode to below the liquid crystal threshold voltage. This structural design approach to voltage control reduces the need for additional precision control measures while maintaining the desired electrical behavior.
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 approach eliminates the need for the black matrix formation process, reducing manufacturing costs and enhancing production efficiency while maintaining light leakage prevention.
Implementation Method 1
voltage difference between the transparent conductive material and the common electrode is smaller than a threshold voltage of liquid crystal cell
Implementation Method 2
liquid crystal is in a vertical status that block lights while not being controlled by any electric field
Data Source
AI summary
The present invention provides a liquid crystal display device, a color-filter substrate, a thin-film-transistor substrate and a manufacturing method thereof. The thin-film-transistor substrate has a pixel array and transparent conductive material. The pixel array has a plurality of thin-film-transistor units, pixel electrodes and metal signal lines. The transparent conductive material is mounted on the pixel array with an insulating layer placed therebetween, and correspondingly covers an area containing the thin-film-transistor units and the metal signal lines. And voltage difference between the transparent conductive layer and a common electrode of the color-filter substrate is smaller than a threshold voltage of liquid crystal cell. Therefore, without enough voltage difference for driving, the liquid crystal material between the transparent conductive material and the common electrode can maintain at a vertical status to block lights, so as to replace the function of traditional black matrix.