In-Cell Touch Screen Using Conductive Black Matrix Electrodes
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Solution Overview
Problem
Current capacitance type In-Cell touch screens require additional manufacturing processes and higher costs due to the need for separate ITO touch electrodes, which also limit light transmittance and production efficiency, making them unsuitable for high-resolution products.
Innovation Solution
The use of a conductive black matrix divided into first and second touch electrodes, which are insulated and alternate with each other, eliminates the need for separate ITO electrodes, simplifies manufacturing, and improves light transmittance by integrating touch functionality within the existing layer structure of the display apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate ITO touch electrodes are added on the TFT array substrate, then touch functionality is achieved, but manufacturing cost increases and production efficiency decreases
Solution Approach 1:
The patent merges the touch electrode function with the existing TFT array substrate by using the source and drain electrodes of the TFT as the touch electrodes. This integration eliminates the need for separate ITO touch electrode layers and their associated manufacturing processes, thereby reducing manufacturing cost and improving production efficiency while maintaining touch functionality
Solution Approach 2:
The source and drain electrodes of the TFT array substrate are designed to serve dual functions: as driving electrodes for the liquid crystal display and as touch sensing electrodes. This multi-functionality approach allows the same structural elements to perform multiple roles, eliminating redundant components and simplifying the manufacturing process
2Reliability
If ITO touch electrodes are used, then touch sensitivity is achieved, but light transmittance is reduced to 60-80%
Solution Approach 1:
The patent uses the same transparent conductive material (ITO) for both the TFT electrodes and touch electrodes, ensuring uniform optical properties across the entire display structure. By integrating the touch electrodes with the existing TFT electrode structure rather than adding separate layers, the overall light transmittance is maintained at high levels while achieving sufficient touch sensitivity
3Reliability
If new film layers are added on the TFT array substrate, then touch functionality is achieved, but device complexity increases
Solution Approach 1:
The patent combines the touch electrode structure with the existing TFT array substrate structure, using the same source and drain electrodes for both display driving and touch sensing functions. This merging approach avoids adding new film layers and reduces structural complexity while achieving full touch functionality
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 reduces manufacturing costs, enhances production efficiency, and increases touch sensitivity by minimizing direct facing areas between electrodes, thereby improving light transmittance and touch accuracy.
Implementation Method 1
two layers of strip electrodes are manufactured, on a surface of the TFT array substrate. The two layers of strip electrodes are located in different planes and the strip electrodes in the two layers intersect with each other and serve as the touch drive lines and touch sensing lines of the touch screen respectively. A mutual capacitance is formed at an intersection between two strip electrodes located in different planes
Data Source
AI summary
Disclosed are an In-Cell touch screen and a display apparatus, the In-Cell touch screen comprising: an array substrate; an opposed substrate arranged to be opposed to the array substrate; a conductive black matrix provided on one side of the array substrate facing the opposed substrate or on one side of the opposed substrate facing the array substrate. The black matrix comprises a plurality of first touch electrodes and a plurality of second touch electrodes arranged to be insulated from each other and alternate with each other, one of the first touch electrode and the second touch electrode is applied with a touch scan signal, and the other one of the first touch electrode and second touch electrode is coupled with the touch scan signal and outputs a touch sensing signal. No separate touch electrode made of ITO material is required, and a pattern of the black matrix is provided in a non-opening region of the pixels, thus the light transmittance of the display apparatus can be prevented from being adversely affected by the touch electrode. Further, a mutual capacitance in a thickness direction of the touch screen is avoided, thus the touch sensitivity of the In-Cell touch screen can be improved.