In-Cell Display Touch Pads With Segmented Test Signal Lines
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Solution Overview
Problem
Conventional auto probe inspection methods for in-cell type display panels can only inspect defects in the image output function, not the touch sensing function, leading to lower yield and increased manufacturing costs due to the shared elements for both functions.
Innovation Solution
A display panel design that includes a matrix-arranged touch block system with first, second, third, and fourth test signal lines, allowing the auto probing unit to supply distinct test signals to detect defects in both image output and touch sensing functions, using a switch unit to control signal routing and voltage levels for accurate defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If an in-cell type touch sensing function is integrated into the display panel using shared elements, then the display device can be made thin and light, but the defect rate of the display panel is affected by defects in the touch sensing function and conventional auto probe inspection cannot detect touch sensing defects
Solution Approach 1:
The patent segments the test signal supply by providing separate test signal lines (first through fourth test signal lines) for different touch block groups. This allows independent testing of different touch sensing regions, enabling detection of touch sensing defects without affecting the entire panel. The segmentation resolves the contradiction by maintaining thin design while adding dedicated test pathways for reliability verification.
Solution Approach 2:
The patent introduces test signal lines as intermediary elements that connect the auto probe inspection device to the touch blocks. These intermediary test signal lines enable the inspection device to supply test signals and detect touch sensing defects without disrupting the integrated in-cell structure. This resolves the contradiction by adding inspection capability while maintaining the thin, integrated design.
2Measurement precision
If separate test signal lines are added to enable touch sensing defect inspection, then defect detection accuracy is improved, but the device complexity increases
Solution Approach 1:
The test signal lines are designed to serve multiple functions: they can supply test signals for touch sensing defect inspection and also work with the shared elements for image output function inspection. This multi-functionality resolves the contradiction by achieving high measurement precision without proportionally increasing device complexity, as the same infrastructure serves multiple inspection purposes.
Solution Approach 2:
The patent adds test signal lines in a different dimensional organization - arranging them to correspond to different groups of touch blocks in matrix patterns. This dimensional organization allows systematic coverage of all touch blocks with a manageable number of test signal lines, resolving the contradiction between comprehensive defect detection and device complexity by efficiently organizing the test infrastructure.
Data Source
AI summary
A display panel includes a plurality of touch blocks matrix-arranged and corresponding to each of two or more adjacent pixel areas of the plurality of pixel areas, and first, second, third and fourth test signal lines through which first, second, third and fourth test signals are supplied by an auto probing unit. Accordingly, not only a defect in an image output function, but also a defect in a touch sensing function can be inspected prior to a modularization process by using the first, second, third and fourth test signals.