Capacitive Touchscreen Water Interference Detection
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Solution Overview
Problem
Capacitive touchscreens fail to recognize finger touch regions when water is present on their surface, preventing normal operation.
Innovation Solution
The method involves acquiring current capacitance values for each sensing point, subtracting a preset capacitance value to determine capacitance differences, and using these differences to differentiate between touch regions and water-covered regions, allowing the device to determine the touch region even with water present.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If water is present on the capacitive touchscreen surface, then the touchscreen can still physically detect capacitance changes, but the electronic device cannot accurately recognize the finger touch region
Solution Approach 1:
The touchscreen surface is divided into multiple sensing points that independently detect capacitance values. By segmenting the detection into discrete points and comparing each point's capacitance change against threshold values, the system can distinguish between water presence (affecting multiple points uniformly) and finger touch (affecting specific localized points), thereby maintaining touch recognition accuracy despite water interference
Solution Approach 2:
The system changes the detection parameter from absolute capacitance values to capacitance difference values (ΔC). By calculating the difference between current capacitance and reference capacitance at each sensing point, and comparing this difference against predetermined thresholds, the system can differentiate between water-induced capacitance changes and finger-touch-induced capacitance changes, resolving the interference problem
2Measurement precision
If the touchscreen uses traditional capacitance detection method, then the detection process is simple, but it fails to differentiate between water and finger touch
Solution Approach 1:
The system performs preliminary detection by acquiring capacitance values at multiple sensing points before making a touch determination. It calculates capacitance differences for each point and compares these differences against predetermined threshold values in advance, allowing the system to identify water presence and distinguish it from finger touches before final touch recognition, thereby improving measurement precision
Solution Approach 2:
The patent introduces an intermediary processing layer that calculates capacitance difference values (ΔC = C_current - C_reference) and compares them against threshold values. This intermediary step acts as a mediator between the raw capacitance detection and the final touch recognition, enabling the system to differentiate between water and finger touch by analyzing the pattern and magnitude of capacitance changes across multiple sensing points
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
Enables the capacitive touchscreen to accurately determine touch regions even when water is on the surface, allowing users to perform normal touch operations.
Implementation Method 1
acquiring a current capacitance corresponding to each sensing point on a capacitive touchscreen
Data Source
Figure 1~1A
Figure 1B~1C
Figure 1D~2
AI summary
The present invention provides an information processing method and an electronic device, so as to resolve a technical problem in the prior art, with an electronic device configured with a capacitive touchscreen, that the electronic device cannot recognize a finger touch region of a user when there is water on a surface of the capacitive touchscreen. The method in the present invention includes: acquiring a current capacitance corresponding to each sensing point on a capacitive touchscreen of an electronic device; separately subtracting a preset capacitance from the current capacitance corresponding to each sensing point to obtain a capacitance difference corresponding to each sensing point, where the preset capacitance is a capacitance of any one of each sensing point when there is neither water nor a finger touch operation on the capacitive touchscreen; and determining, according to the capacitance difference corresponding to each sensing point, a touch region on which a finger touch operation on the capacitive touchscreen acts. The present invention allows a user to perform an operation on a water-covered capacitive touchscreen.