In-Cell Touch Screen Electrode Staggered Concave-Convex Structure
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Solution Overview
Problem
In-cell capacitive touch screens face interference between touch signals and display signals due to the proximity of electrode layers, leading to a lower signal-to-noise ratio and reduced touch sensitivity.
Innovation Solution
The array substrate incorporates a common electrode layer with driving and sensing electrodes arranged in a staggered concave-convex structure, increasing the boundary length between electrodes, which enhances mutual capacitance and signal emission intensity, while an organic film layer with low dielectric constant reduces parasitic capacitance and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the electrode layer is integrated inside the display panel to reduce thickness and weight, then the display device becomes lighter and thinner with increased light transmittance, but the proximity of the electrode layer to the touch screen electrode causes interference between touch signals and display signals, leading to a lower signal-to-noise ratio
Solution Approach 1:
The common electrode layer is divided into multiple isolated island electrodes through etching, rather than being a continuous layer. This segmentation creates physical separation between the touch sensing electrodes and the display electrode, reducing capacitive coupling and signal interference while maintaining the in-cell structure's thinness and light transmittance advantages
Solution Approach 2:
An organic insulating film layer is introduced between the divided common electrode and the touch sensing electrode. This intermediary layer provides electrical isolation to reduce parasitic capacitance and signal interference, while the via holes in the insulating film allow selective electrical connection where needed, enabling the system to achieve both thinness and low interference
2Measurement precision
If the common electrode layer is divided into driving and sensing electrodes with concave-convex structures, then the boundary length between electrodes is increased to enhance mutual capacitance and signal-to-noise ratio, but the structural complexity of the electrode pattern increases
Solution Approach 1:
The common electrode is segmented into discrete island electrodes with concave-convex boundaries, creating increased perimeter length for enhanced mutual capacitance sensing. The segmentation pattern is systematically designed to maximize boundary length while maintaining manufacturability through standard photolithography processes
Solution Approach 2:
The electrode structure utilizes concave-convex geometric parameters to increase boundary length between driving and sensing regions. By optimizing the shape parameters (concave/convex depth and width) of the island electrodes, the design achieves higher mutual capacitance sensitivity without proportionally increasing fabrication complexity
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 configuration improves touch sensitivity by increasing the signal-to-noise ratio and maintaining display functionality without compromising light transmittance, resulting in a more sensitive and efficient in-cell touch screen.
Implementation Method 1
an organic film layer with low dielectric constant reduces parasitic capacitance and noise
Implementation Method 2
adjacent driving sub-electrodes and sensing sub-electrodes have concave-convex structures in a staggered arrangement at borders and are insulated from each other
Data Source
AI summary
An array substrate, an in-cell touch screen and a touch display device are provided. The array substrate includes a common electrode layer, wherein the common electrode layer is provided with a plurality of driving electrodes and a plurality of sensing electrodes with extending directions perpendicular to each other, each of the driving electrodes includes a plurality of driving sub-electrodes which are connected to one another, each of the sensing electrodes includes a plurality of sensing sub-electrodes which are connected to one another, and adjacent driving sub-electrode and sensing sub-electrode have concave-convex structures in a staggered arrangement at an border and are insulated from each other.