Noise Reduction Electrode for Touch Display Parasitic Capacitance
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Solution Overview
Problem
Parasitic capacitance between touch electrodes and driving electrodes in display devices degrades touch sensing performance by introducing noise in touch-sensing signals.
Innovation Solution
A touch display panel and device design that includes a noise reduction electrode arranged in areas where the first electrode is not present, between the second electrode and signal lines, to discharge noise and minimize its impact on touch electrodes, with the noise reduction electrode applying the same voltage as the second electrode to reduce load and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If electrodes and signal lines are arranged on the display panel to provide touch recognition function, then touch sensing capability is enabled, but parasitic capacitance generated between display electrode and touch electrode degrades touch sensing performance
Solution Approach 1:
A noise reduction electrode is introduced as an intermediary component between the signal line/first electrode and the second electrode adjacent to the touch electrode. This noise reduction electrode acts as a mediator to discharge noise generated in the signal line or first electrode, preventing it from coupling to the second electrode and subsequently affecting the touch electrode. The noise reduction electrode is arranged in areas where the first electrode is not present, creating an electrostatic shielding effect that reduces parasitic capacitance coupling without interfering with the touch sensing function.
2Reliability
If noise reduction electrode is arranged between second electrode and signal line to discharge noise, then touch sensing noise is reduced, but device structure complexity increases
Solution Approach 1:
The noise reduction electrode is merged with the existing electrode structure by arranging it in the same layer as the first electrode or integrating it into the encapsulation structure. The noise reduction electrode shares the same conductive material and fabrication process as other electrodes, combining multiple functions (noise reduction and structural support) into a single integrated component rather than adding a separate complex subsystem.
Solution Approach 2:
The noise reduction electrode is strategically positioned only in areas where the first electrode is not present, specifically in the non-active area or in regions where noise coupling is most problematic. This localized arrangement provides noise reduction functionality exactly where needed without unnecessarily complicating the entire electrode structure, maintaining simplicity in areas where noise reduction is not required.
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 design effectively mitigates noise in touch-sensing signals, improving touch sensing performance by reducing the influence of signal lines and driving electrodes on touch electrodes, thereby enhancing the accuracy and reliability of touch input detection.
Implementation Method 1
parasitic capacitance generated between the display electrode and the touch electrode may degrade the performance of touch sensing
Data Source
AI summary
A touch display device includes a substrate defining an active area and a non-active area around the active area; a touch pad in the non-active area; a plurality of signal lines; a signal line insulation layer; first electrodes; at least one noise reduction electrode on the signal line insulation layer and in a portion other than the area corresponding to the first electrodes; a second electrode over the plurality of first electrodes and the at least one noise reduction electrode; an encapsulation layer on the second electrode; touch lines on the encapsulation layer and connected to the touch pad; and touch electrodes on the encapsulation layer and electrically connected to at least one touch line. The encapsulation layer has a sloped surface between the touch pad and the touch electrodes, and the touch lines are arranged on the sloped surface of the encapsulation layer having a corresponding slope.