Touch Sensor Ghost Point Detection via Asynchronous Electrode Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Projected capacitive touch sensor devices face challenges in distinguishing between actual touch signals and ghost point touch signals caused by water droplets, which can lead to false touch detection.
Innovation Solution
A touch sensor device with a sensor pad configuration featuring four independent electrodes - two transmission electrodes, one sensing electrode, and a grounding electrode, where the transmission electrodes are asynchronously enabled to form different sensing capacitances, allowing for accurate differentiation between actual touch and ghost point signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional touch sensor with single sensing electrode is used, then the device structure is simple, but it cannot distinguish ghost point touch signals from actual touch signals
Solution Approach 1:
The sensing electrode is divided into multiple independent electrodes (first sensing electrode, second sensing electrode, third sensing electrode) with different spatial arrangements. Each electrode forms separate sensing capacitances with transmission electrodes, enabling the system to segment and differentiate between actual touch signals and ghost point signals through comparative analysis of multiple capacitance variations.
2Reliability
If multiple electrodes are added to distinguish ghost points, then touch signal accuracy improves, but the device complexity increases
Solution Approach 1:
The grounding electrode is extracted as a separate independent element from the traditional sensor structure. This grounding electrode forms a third sensing capacitance with the transmission electrodes, providing an additional reference measurement that helps isolate and eliminate ghost point signals while maintaining structural organization and control over the increased complexity.
Solution Approach 2:
The multiple sensing electrodes are arranged in asymmetric positions relative to the transmission electrodes, with each electrode having distinct spatial relationships and gap configurations. This asymmetric arrangement creates unique capacitance signatures for different touch locations, enabling the system to differentiate between actual touches and ghost points based on the specific capacitance variation patterns.
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 device effectively distinguishes between actual touch signals and ghost point signals by varying sensing capacitances in opposite tendencies, ensuring reliable touch detection without complex circuit calculations.
Implementation Method 1
the sensing electrode and the transmission electrode are capable of being electrically coupled to each other to form the sensing capacitance
Implementation Method 2
the first electrode, the second electrode and the third electrode are coplanar
Data Source
AI summary
A touch sensor device provided herein includes a sensor pad disposed on a carrier, wherein the sensor pad includes a first electrode, a second electrode, a third electrode and a grounding electrode. The first electrode surrounds a periphery of the second electrode and a first gap is formed between the first electrode and the second electrode. The first electrode surrounds a periphery of the third electrode, and a second gap is formed between the first electrode and the third electrode. The grounding electrode surrounds a periphery of the pad sensor, wherein a third gap is formed between the first electrode and the grounding electrode.