Shielding Electrode Noise Reduction in Touch Displays
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Solution Overview
Problem
In touch display devices, parasitic capacitance between touch electrodes and display driving electrodes leads to noise in touch sensing signals, reducing the performance of touch sensing.
Innovation Solution
A touch display device is designed with a shielding electrode between the signal lines and light emitting elements, electrically connected to a power line and feedback circuit. The feedback circuit receives a feedback signal from the shielding electrode and outputs a compensation voltage to reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If touch electrodes are disposed adjacent to signal lines or electrodes for display driving, then the device complexity is reduced and manufacturing is simplified, but parasitic capacitance is formed between touch electrodes and display driving electrodes, causing noise in touch sensing signals and reducing touch sensing performance
Solution Approach 1:
A shielding electrode is introduced as an intermediary component between the touch electrode and the display driving electrode (anode of light emitting element). This shielding electrode acts as a mediator that blocks or reduces the parasitic capacitance coupling between the touch electrode and the display electrode, thereby reducing noise in touch sensing signals while maintaining the adjacent disposal configuration for simplicity
2Ease of manufacture
If touch electrodes are disposed adjacent to signal lines or electrodes for display driving, then manufacturing is simplified, but noise in touch sensing signals occurs due to parasitic capacitance, reducing touch sensing performance
Solution Approach 1:
The shielding electrode serves as a mediator that can be integrated into the existing manufacturing process. By placing this additional layer between the touch electrode and display electrode, the patent maintains the simple adjacent disposal configuration for ease of manufacture while effectively blocking parasitic capacitance to improve touch sensing performance
3Reliability
If a shielding electrode is added between touch electrodes and display driving electrodes, then noise in touch sensing signals is reduced and touch sensing performance is improved, but device complexity increases
Solution Approach 1:
The shielding electrode is designed to serve multiple functions: it acts as a shield against parasitic capacitance, can be integrated with existing electrode structures, and maintains compatibility with the display driving scheme. This multi-functionality approach reduces the overall device complexity increase while achieving noise reduction and improved touch sensing performance
4Reliability
If a shielding electrode is added between touch electrodes and display driving electrodes, then noise in touch sensing signals is reduced and touch sensing performance is improved, but manufacturing becomes more difficult
Solution Approach 1:
The shielding electrode is nested within the existing multi-layer electrode structure of the display device. It is positioned between the touch electrode layer and the display driving electrode layer, utilizing the existing manufacturing layers and processes. This nesting approach allows the shielding function to be integrated without requiring completely new manufacturing steps, thereby reducing the increase in manufacturing difficulty while achieving improved touch sensing performance
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 implementation effectively reduces noise in touch sensing signals, improving the performance of touch sensing by minimizing parasitic capacitance between touch electrodes and display driving electrodes.
Implementation Method 1
a feedback circuit configured to receive a feedback signal from the shielding electrode via the at least one feedback line, and output a compensation voltage based on the feedback signal to the at least one power line that is electrically connected to the shielding electrode
Data Source
AI summary
A touch display device includes a shielding electrode disposed between a touch electrode and a signal line for driving the display. The shielding electrode enables a generation of a compensation voltage based on a feedback signal received from the shielding electrode. The compensation voltage compensates for noise on a voltage that is applied to the shielding electrode due to direct or indirect coupling between the signal line and the touch electrode. Thus, noise is, reduced in a touch sensing signal according to display driving, and improving the performance of touch sensing.