Active-Matrix Substrate Testing Signal Selection Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional testing techniques for active-matrix substrates face challenges in achieving sufficient testing accuracy and do not allow for the substitution or repair of demultiplexers, leading to issues with noise interference and defective component handling.
Innovation Solution
The implementation of an active-matrix substrate with a first and second selection circuit for each signal line block, allowing for the introduction of a fixed potential to non-selected signal lines to act as shields and enabling redundancy for circuit substitution during defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional testing techniques are used to test data lines in active-matrix substrates, then the number of connections to the testing device can be reduced by sequential selection, but sufficient testing accuracy cannot be obtained due to noise interference
Solution Approach 1:
The patent introduces a testing signal selection circuit that includes first selection circuits for each signal line block and a second selection circuit for every n-blocks. This multi-level selection structure acts as an intermediary system that properly routes testing signals to target data lines while isolating them from noise sources, thereby achieving both reduced connections and high testing accuracy
Solution Approach 2:
The patent divides the data lines into multiple signal line blocks, with each block handled by a dedicated first selection circuit. This segmentation allows the testing system to manage numerous data lines through hierarchical selection, reducing the number of direct connections to the testing device while maintaining the ability to test each line individually with high precision
2Ease of repair
If conventional testing techniques are used, then the number of connections is reduced, but substitution or repair of defective demultiplexers is not possible
Solution Approach 1:
The patent changes the operational parameters of the selection circuits by providing two different selection levels (first selection circuits for individual blocks and a second selection circuit for groups of blocks). This parameter change enables flexible circuit substitution, where defective first selection circuits can be replaced by activating corresponding circuits in the second selection level, thereby improving repairability without compromising reliability
3Productivity
If all data lines are connected simultaneously to a testing device for testing, then comprehensive testing can be performed, but the enormous number of connections required makes it unrealistic
Solution Approach 1:
The patent segments the data lines into multiple signal line blocks and introduces hierarchical selection circuits. The first selection circuits handle individual blocks while the second selection circuit manages groups of blocks, creating a multi-level routing structure that dramatically reduces the number of direct connections to the testing device while maintaining the capability to test all data lines efficiently
4Measurement precision
If sequential selection of data lines is used for testing, then the number of connections is reduced, but testing accuracy is insufficient due to noise interference from non-selected lines
Solution Approach 1:
The patent introduces a carefully designed selection circuit structure that acts as an intermediary between the testing signal source and the data lines. The first and second selection circuits work together to route testing signals precisely to target lines while providing electrical isolation from non-selected lines, thereby eliminating inductive noise interference and achieving high testing accuracy
Data Source
AI summary
An active-matrix substrate includes: a substrate; gate lines disposed on the substrate; source lines disposed on the substrate in a direction that crosses the gate lines; a first terminal provided for each of data line blocks obtained by grouping every m-lines (m being an integer greater than or equal to 2) of the source lines into a block; a first selection circuit provided for each of the data line blocks, for causing conduction between the first terminal and at least one source line selected from among the m source lines; a second terminal provided for every n-blocks (n being an integer greater than or equal to 2) of the data line blocks; and a second selection terminal provided for every n-blocks of the data line blocks, for causing conduction between the second terminal and at least one source line selected from among the m×n source lines.