Touch Screen Capacitance Reference Value Determination
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Solution Overview
Problem
Existing touch screen technologies face challenges in accurately determining capacitance reference values due to environmental variations, leading to inaccurate touch state judgments.
Innovation Solution
A method and apparatus for determining a stable capacitance reference value by processing an original reference value through fitting to obtain a candidate reference value, which is then corrected using data from multiple capacitor nodes to ensure accuracy, even in the presence of exceptions like finger touches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the original reference value is used directly as the capacitance reference, then the determination process is simple, but the reference value becomes inaccurate due to environmental variations such as temperature changes
Solution Approach 1:
The patent applies preliminary action by pre-establishing a fitting relationship between capacitor nodes before actual touch detection. The system pre-calculates reference values for multiple capacitor nodes and stores them, so that when environmental conditions change, the system can quickly retrieve and apply the pre-established fitting relationship without performing complex real-time calculations, thus maintaining accuracy while controlling complexity.
Solution Approach 2:
The patent introduces an intermediary element - the fitting relationship model - that mediates between the original reference values and the actual capacitance measurements. This model serves as a bridge that accounts for environmental variations by establishing mathematical relationships between capacitor nodes, allowing the system to compensate for temperature and other environmental effects without directly measuring each variation.
2Measurement precision
If the reference value is re-determined based on original capacitance values or current capacitance values, then adaptation to environmental changes is attempted, but the determined capacitance value remains inaccurate
Solution Approach 1:
The patent implements feedback by continuously monitoring the capacitance values of multiple capacitor nodes and using the pre-established fitting relationship to determine the most appropriate reference value. The system compares current measurements with the fitting model, identifies outliers or touched nodes, and adjusts the reference selection accordingly, creating a closed-loop system that adapts to environmental changes while maintaining accuracy.
Solution Approach 2:
The patent applies partial action by selecting only the most reliable capacitor nodes for reference determination rather than using all nodes equally. The system identifies and excludes nodes that are touched or affected by noise, using only the clean, reliable nodes to establish the reference value, thus achieving accurate adaptation without being misled by abnormal readings.
3Stability of the object's composition
If multiple capacitor nodes are used to determine the reference, then the reference value becomes more stable, but the calculation complexity and processing time increase
Solution Approach 1:
The patent applies preliminary action by pre-establishing the fitting relationship between all capacitor nodes during initialization or calibration phases. This pre-computed model captures the spatial and electrical relationships between nodes, allowing the system to quickly determine reference values during operation by simply applying the pre-established relationships to current measurements, rather than performing complex multi-node analysis in real-time.
4Adaptability or versatility
If the current capacitance value is used as the reference, then the system adapts quickly to environmental changes, but accuracy decreases when touches or noise interfere with the measurement
Solution Approach 1:
The patent implements feedback by continuously monitoring capacitance values and using the fitting relationship to identify and exclude touched or noisy nodes from reference determination. The system compares current readings against the pre-established model, detects deviations indicating touches or interference, and adjusts the reference selection to use only reliable nodes, thus maintaining both adaptability and accuracy.
Solution Approach 2:
The patent converts the potential harm of touched or noisy nodes into a benefit by using them as indicators to identify and exclude problematic areas. When a node shows abnormal capacitance changes, the system uses this information to adjust the reference determination, effectively using the 'harmful' touched nodes to improve the accuracy of the overall reference by excluding them from the calculation.
Data Source
AI summary
A method and apparatus for determining a reference value of a touch screen, and an electronic terminal thereof are provided. The method includes: determining a candidate reference value of a touch screen according to an original reference value and a reference fitting relationship of the touch screen, wherein the reference fitting relationship is determined according to the original reference value of the touch screen and a capacitance value of a capacitor node on the touch screen in a first frame; correcting the candidate reference value; and determining a stable reference value of the touch screen according to the corrected candidate reference value. According to embodiments of the present disclosure, the candidate reference value is closer to the actual capacitance reference, such that accuracy of the determined stable reference value is ensured as much as possible.