Capacitive Touch Error Compensation Under Power and EMI Noise
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Solution Overview
Problem
Capacitive touch screen devices experience touch recognition errors due to environmental factors such as radiation noise from electric and magnetic fields, and unstable power supplies from Travel Adapters, leading to inaccuracies in touch coordinate detection.
Innovation Solution
The implementation of a method that compensates touch errors in capacitive touch screen devices using noise reduction filters, touch sensitivity adjustments, and frequency changes, with error occurrence counts determining the application of these compensation schemes, and setting reference counts based on external power supply connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a capacitive touch scheme is employed to increase display area and eliminate separate input units, then space utilization is improved and display area is increased, but touch recognition errors occur due to environmental capacitance variations
Solution Approach 1:
The patent implements a feedback mechanism by continuously monitoring touch coordinates and comparing them with predicted coordinates based on device orientation and environmental data. When deviations exceed a threshold, the system automatically triggers compensation adjustments, creating a closed-loop control system that maintains touch accuracy despite environmental variations.
Solution Approach 2:
The system dynamically adjusts touch sensitivity parameters and coordinate calibration values based on detected environmental conditions. By changing these parameters in response to capacitance variations caused by electric fields, magnetic fields, or power supply instability, the system compensates for environmental interference and maintains accurate touch recognition.
2Measurement precision
If noise reduction filters and compensation schemes are applied to improve touch recognition accuracy, then touch detection precision is improved, but device complexity increases
Solution Approach 1:
The patent applies compensation selectively rather than continuously. It monitors touch errors and only activates noise reduction filters and compensation schemes when error thresholds are exceeded, avoiding the need for always-on complex processing and reducing overall system complexity while maintaining precision when needed.
Solution Approach 2:
The system performs self-calibration and self-compensation using its own resources. It automatically detects touch errors, identifies environmental interference sources, and applies appropriate compensation without requiring external calibration tools or complex additional hardware, thereby improving precision without proportionally increasing complexity.
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
Effectively reduces touch recognition errors by applying appropriate noise reduction filters and sensitivity adjustments, ensuring accurate touch detection even in noisy environments and with unstable power supplies, thereby enhancing the reliability of capacitive touch screen devices.
Implementation Method 1
If employing a capacitive touch scheme, a portable electronic device determines a touch coordinate by sensing a variation of capacitance that occurs at a time when the user touches the touch screen with the finger or a suitable pointing device
Implementation Method 2
If employing a resistive touch scheme, a portable electronic device determines a touch coordinate by sensing pressure at a time when a user touches the touch screen with a finger or a pointing device
Implementation Method 3
the portable electronic device using the capacitive touch scheme can suffer a touch recognition error because a capacitance variation error takes place due to the effects of an electric field and a magnetic field surrounding a device
Implementation Method 4
the portable electronic device using the capacitive touch scheme can suffer a touch recognition error because a capacitance variation error takes place due to the effects of an electric field and a magnetic field surrounding a device
Data Source
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AI summary
An apparatus and method for compensating for a touch error in an electronic device with a touch screen. A method for compensating a touch error includes identifying if a touch error takes place and, when the touch error takes place, compensating the touch error using at least one touch error compensation scheme among a group of touch error compensation schemes including: a noise reduction filter addition scheme, a touch sensitivity adjustment scheme, and a touch frequency change scheme.