Capacitance Sensing Ground Insertion Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional capacitance sensing systems face issues with signal disparity due to decoupled device grounds, leading to non-responses or false touch events, as counter sense currents can overpower sense signals.
Innovation Solution
Incorporating ground electrodes within the capacitance sensing network that induce grounding capacitance, allowing object-induced grounding capacitance to create a current sink path for counter sense currents, thereby enhancing signal strength and reducing adverse effects from decoupled device grounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional capacitance sensing networks are used without ground electrodes, then the sensing system has simpler structure, but counter sense currents overpower sense signals causing non-response or false touch events
Solution Approach 1:
The sensing network is segmented by introducing separate ground electrodes (112) that are interspersed among the transmit and receive electrodes. This segmentation allows the ground electrodes to specifically handle counter sense currents while the other electrodes focus on sensing, thereby improving touch detection accuracy without requiring complete redesign of the entire electrode system.
Solution Approach 2:
Ground electrodes act as an intermediary element between the decoupled device ground and the sensing circuitry. These electrodes provide a localized ground reference that mediates the interaction between the sensing signals and counter sense currents, enabling accurate touch detection even when the overall device ground is decoupled from user ground.
2Reliability
If ground electrodes are interspersed within the sensing network, then counter sense currents are reduced improving signal strength, but the electrode structure becomes more complex
Solution Approach 1:
The ground electrodes are merged with the existing transmit and receive electrode structures by being interspersed among them in the same sensing network. This merging approach allows the ground electrodes to work cooperatively with the sensing electrodes, reducing counter sense currents and improving signal strength while maintaining a unified electrode configuration rather than adding completely separate structures.
3Adaptability or versatility
If device ground is decoupled from user ground, then the device can operate in non-conductive environments, but counter sense currents cause false touch events or non-response
Solution Approach 1:
The patent applies local quality by providing ground electrodes at specific locations within the sensing network where counter sense currents are generated. Rather than requiring a global ground connection throughout the entire device, the ground electrodes provide localized ground references precisely where needed to counteract the adverse effects of decoupled grounds, enabling reliable touch sensing in non-conductive environments.
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 introduction of ground electrodes connected to a ground node during sensing operations improves signal strength by reducing counter sense currents, ensuring accurate object detection even when device grounds are decoupled from user grounds.
Implementation Method 1
Incorporating ground electrodes within the capacitance sensing network that induce grounding capacitance, allowing object-induced grounding capacitance to create a current sink path for counter sense currents
Data Source
AI summary
A capacitance sensing system can include a plurality of transmit (TX) electrodes disposed in a first direction; a plurality of first electrodes disposed in a second direction and coupled to the TX electrodes by a mutual capacitance, and coupled to a capacitance sense circuit when at least one TX electrode receives a transmit signal; and a plurality of second electrodes structures, interspersed with the first electrodes and coupled to a ground node at least while the one TX electrode receives the transmit signal.