TFT Substrate Gate Line Defect Detection Module
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Solution Overview
Problem
In large liquid crystal display devices, detecting disconnection of gate lines is challenging due to insufficient gate power supply from a single gate driver, especially when gate drivers are integrated on both sides of the TFT substrate, as gate power is applied to both sides of a disconnection, making it difficult to detect line disconnections.
Innovation Solution
A module and method that involve separating each gate line into two portions connected to different gate drivers, using a data signal generator to supply test data signals, and an operation signal generator to manage gate power through multiple stages, allowing for simultaneous or sequential application of clock and start signals to detect voltage levels at pixel electrodes, thereby identifying defects like disconnections or shorts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If gate drivers are integrated on both sides of the TFT substrate to supply gate power to all gate lines, then the gate power supply coverage is improved, but the defect detection capability deteriorates because gate power is applied to both sides of a disconnection making it difficult to detect line disconnections
Solution Approach 1:
The patent divides the gate lines into first gate lines extending from the first gate driver and second gate lines extending from the second gate driver. This segmentation allows each gate driver to independently control its respective gate lines, enabling defect detection by comparing voltage levels between corresponding first and second gate lines that should have equal voltages if no disconnection exists.
2Device complexity
If a single gate driver is used to supply gate power to all gate lines, then the device complexity is reduced, but the gate power supply coverage for large display devices becomes insufficient
Solution Approach 1:
The patent employs multiple gate drivers (first gate driver and second gate driver) positioned at different locations to supply gate power to different sets of gate lines. This segmentation of the gate driver function allows sufficient coverage for large display devices while maintaining manageable complexity through standardized driver modules.
Solution Approach 2:
Each gate driver is designed to perform multiple functions: supplying gate power to its respective gate lines during normal operation and enabling defect detection through voltage level comparison with corresponding gate lines from the other driver. This multi-functionality reduces overall system complexity.
3Area of stationary object
If gate power is applied to both sides of gate lines with dual gate drivers, then the gate power supply coverage is improved, but the defect detection accuracy deteriorates because disconnection cannot be easily detected
Solution Approach 1:
The patent applies different detection strategies to different regions: first gate lines are compared with corresponding second gate lines locally to detect disconnections. The detector measures voltage levels at specific test points along the gate lines, providing localized defect detection with high precision while maintaining overall power supply coverage.
Data Source
AI summary
The present invention relates to a module and method for detecting a defect of a thin film transistor (TFT) substrate, which can detect disconnection of a gate line of the TFT substrate having gate drivers provided with a dual structure in which the gate drivers are provided at both sides of the gate lines. There is provided a module and method for detecting a defect of a TFT substrate, wherein gate lines are separated into two portions by cutting a central region of the gate lines, gate power is supplied to the gate lines of which central portions are cut through gate drivers provided at both sides of the gate lines, and a signal of a negative voltage level is supplied to data lines, so that disconnection of the gate lines can be detected.