Display Panel Compensation Electrode for In-Cell Touch Crosstalk
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Solution Overview
Problem
In in-cell touch screens, the short distance between touch electrodes and signal lines in display panels leads to coupling capacitance, causing crosstalk and reduced touch precision.
Innovation Solution
A display panel design with a first electrode layer comprising insulated common and compensation electrode portions, where the compensation electrode receives a non-fixed potential compensation signal, overlapping with touch electrodes to cancel out interference from varying display signals, improving touch precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If in-cell touch screen structure is adopted to reduce device thickness, then integration degree is improved, but coupling capacitance between signal lines and touch electrodes increases causing crosstalk and reduced touch precision
Solution Approach 1:
A compensation electrode is introduced as an intermediary element between the signal line and the touch electrode. This compensation electrode receives a compensation signal that is opposite in phase to the display signal, thereby canceling out the coupling capacitance effect and reducing crosstalk interference on the touch electrode.
Solution Approach 2:
The patent changes the electrical parameter (potential) of the compensation electrode dynamically according to the display signal. By adjusting the compensation signal parameter to be opposite in phase to the display signal, the system actively compensates for the coupling capacitance effect, transforming a static structural problem into a dynamic electrical solution.
2Measurement precision
If compensation electrode is added to reduce crosstalk, then touch precision is improved, but device structure becomes more complex
Solution Approach 1:
The compensation electrode is merged with the existing electrode structure in the display panel. Instead of adding a completely separate component, the compensation electrode is integrated into the electrode layer, sharing fabrication processes and structural space with the common electrode, thereby minimizing the increase in device complexity.
Solution Approach 2:
The compensation electrode serves multiple functions: it acts as a touch sensing electrode, a compensation element to cancel crosstalk, and an integral part of the display electrode structure. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device 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
The compensation signal effectively reduces noise and interference from display signals, enhancing touch precision by canceling out inductive capacitance variations, thereby improving overall touch performance.
Implementation Method 1
coupling capacitance is easily generated between a display signal and a touch signal
Implementation Method 2
coupling capacitance is easily generated between a display signal and a touch signal, so crosstalk is caused
Data Source
AI summary
A display panel includes a substrate, a pixel defining layer, a first electrode layer, and a touch function layer. The pixel defining layer is disposed on a side of the substrate and includes multiple pixel openings. The first electrode layer is disposed on the side of the pixel defining layer and includes a common electrode portion and a compensation electrode portion, where the common electrode portion and the compensation electrode portion are insulated from each other, and part of the common electrode portion is disposed in a pixel opening. The touch function layer is disposed on the side of the first electrode layer and includes a touch electrode, where the compensation electrode portion and the touch electrode overlap with each other, and none of the compensation electrode portion and the touch electrode overlaps with the pixel opening.