Touch Panel Ghost Touch Filtering via Pressure Threshold Validation
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Solution Overview
Problem
Capacitive touch screens are prone to 'ghost touches' due to conductive foreign substances and electromagnetic noise, leading to malfunction and reduced response speed and sensitivity.
Innovation Solution
Incorporating a pressure sensor to differentiate between valid and invalid touch inputs by using pressure information, where a valid touch input is recognized based on a pressure value greater than or equal to a threshold, thereby disregarding ghost touches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a capacitive touch screen is used for touch recognition, then multi-touch capability and low malfunction probability are achieved, but ghost touches occur due to conductive foreign substances and electromagnetic noise
Solution Approach 1:
A pressure sensor is introduced as an intermediary component between the touch screen and the control logic. This pressure sensor provides additional information (pressure values) that mediates the decision-making process for validating touch inputs, helping to distinguish genuine touches from ghost touches without compromising the capacitive touch screen's multi-touch capability
Solution Approach 2:
The system changes the parameter used for touch validation by incorporating pressure values from the pressure sensor alongside the capacitive touch detection. By establishing a threshold for pressure values, the system transforms the single-parameter capacitive detection into a multi-parameter validation process, where ghost touches are filtered out based on insufficient pressure
2Reliability
If touch driver configuration is used to remove ghost touch based on duration or form, then ghost touch prevention is achieved, but response speed and sensitivity are reduced
Solution Approach 1:
The patent replaces the software-based temporal analysis (duration and form checking) with a physical measurement approach using pressure sensing. Instead of analyzing the temporal characteristics of touch signals, the system immediately validates touches based on pressure magnitude, substituting a mechanical sensing approach for software-based temporal filtering and thereby maintaining fast response speed
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 approach effectively reduces the occurrence of ghost touches without compromising response speed or sensitivity, ensuring accurate user input recognition.
Implementation Method 1
a pressure sensor that obtains pressure information corresponding to the touch input
Implementation Method 2
The capacitive touch screens may recognize a touch input based on a variation of the amount of charge of an electrode included in a touch panel
Data Source
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AI summary
An electronic device is provided. The electronic device includes a display, a first sensor, a second sensor, and a processor configured to obtain, using the first sensor, location information corresponding to an active area of the display, in response to contact between an external object and the display, obtain, using the second sensor, pressure information corresponding to a pressure applied to the display resulting from the contact between the external object and the display, and determine a validity of the location information based on whether the pressure information satisfies a designated condition.