Capacitive Touch Panel RC Loading Reduction via Sync Electrode Driving
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Solution Overview
Problem
Conventional capacitive touch panels experience significant RC loading issues, leading to deformation of sensing signals, particularly in larger panels, which results in poor performance due to excessive capacitance between driving and sensing electrodes.
Innovation Solution
A capacitive touch panel configuration where one or more driving electrodes and sensing electrodes are synchronically driven by a sync driving signal, while the remaining driving electrodes are grounded, reducing RC loading by minimizing capacitance between driven and non-driven electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a driving signal is applied to a single driving electrode while other electrodes are grounded, then the touch sensing function is achieved, but significant RC loading occurs causing signal deformation
Solution Approach 1:
The patent segments the electrode driving into multiple groups. Instead of grounding all non-active electrodes, the electrodes are divided into first groups (driven by sync signal) and second groups (grounded). This segmentation reduces the capacitance load on each driving electrode while maintaining touch sensing functionality across the entire panel.
Solution Approach 2:
The patent implements dynamic electrode grouping where the first and second groups can be selectively switched. The controller can change which electrodes belong to which group based on the sensing requirements, allowing flexible adaptation to different touch panel configurations and reducing RC loading dynamically.
2Reliability
If all sensing electrodes are connected to reduce RC loading, then signal deformation is reduced, but the complexity of the driving circuit increases
Solution Approach 1:
The patent merges the driving function with the sensing function by applying the same sync driving signal to both driving electrodes and certain sensing electrodes. This combining of functions allows multiple electrodes to be driven simultaneously without requiring separate complex driving circuits for each electrode.
Solution Approach 2:
The sync driving signal serves multiple functions simultaneously: it drives the driving electrodes for signal transmission and also drives the sensing electrodes to reduce their capacitance load. This multi-functionality reduces the need for separate dedicated driving circuits for each electrode type.
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 significantly reduces RC loading, enhancing signal integrity and overall performance of the touch panel, especially in larger sizes by ensuring clear and accurate touch signal detection.
Implementation Method 1
The driving signal 16 is, through a mutual capacitance coupling, transmitted to a sensing electrode, for example, Y6
Implementation Method 2
A finger touch to the sensor provides a capacitive couple from the conductive layer to the body. The location of the contact point is detectable by a controller that measures a change in a capacitively coupled electrical signal at the touch location
Data Source
AI summary
The present invention relates to a capacitive touch panel. In one embodiment, the capacitive touch panel includes a plurality of driving electrodes and a plurality of sensing electrodes spatially arranged in a matrix, and a driver electrically coupled to the touch sensor matrix and configured to generate a driving signal to synchronically drive one or more driving electrodes and the sensing electrodes, such that at least one sensing electrode is not driven by the driving signal. The remaining driving electrodes are grounded. The not-driven sensing electrodes sense and transmit a sensing signal of a touch.