Touch Panel Edge Coordinate Accuracy Using Virtual Sensing Lines
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Solution Overview
Problem
Conventional coordinate calculation methods in touch panels often result in inaccuracies when a touch position is near the edge, as they rely on signals from only two sensing lines, leading to erroneous coordinate determination.
Innovation Solution
A method that involves detecting the signal strengths of sensing lines, determining the existence of edge sensing lines, generating a virtual sensing line, and calculating the actual coordinate through a weighted average using system-generated coordinates of the sensing lines and the virtual line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional weighted average methods are used for coordinate calculation, then the calculation is simple and fast, but the coordinate accuracy is poor when touch position is near the edge of the touch panel
Solution Approach 1:
The patent applies preliminary action by pre-defining virtual sensing lines at the edge positions of the touch panel and pre-establishing the correspondence between sensing lines and coordinates. When an edge touch is detected, the system can immediately use the pre-configured virtual sensing line information to perform accurate coordinate calculation without complex real-time processing, thus improving coordinate accuracy while maintaining calculation efficiency.
2Reliability
If only two sensing lines are used for edge touch point calculation, then the detection process is simple, but the coordinate determination becomes erroneous
Solution Approach 1:
The patent introduces virtual sensing lines as intermediary elements to resolve the insufficiency of actual sensing lines at edge positions. These virtual sensing lines act as mediators that provide the necessary third reference point for accurate coordinate calculation using the weighted average method, thereby improving coordinate determination reliability without requiring additional physical sensing lines.
Solution Approach 2:
The patent applies copying by creating virtual copies of sensing lines at the edge positions of the touch panel. These virtual sensing lines are mathematical constructs that replicate the functionality of actual sensing lines, allowing the system to perform accurate coordinate calculations at edges by treating the virtual line as if it were a physical sensing line, thus improving reliability without increasing physical hardware complexity.
3Measurement precision
If the touch position is close to the edges of the touch panel, then the touch detection range is reduced, but the conventional calculation methods produce large errors
Solution Approach 1:
The patent applies dimensionality change by extending the sensing line concept from the physical dimension to the virtual dimension. By introducing virtual sensing lines that exist in the mathematical/model dimension rather than the physical dimension, the system can handle edge touch cases where physical sensing lines are insufficient, thereby improving coordinate accuracy across the entire touch panel surface including edges.
Data Source
AI summary
A method for improving coordinate accuracy of a touch panel having sensing lines arranged to form an array includes the steps of: detecting existence of a touch point influencing at least one sensing line; determining existence of an edge sensing line; providing signal strengths to the at least one sensing line and a sensing line immediately adjacent to the at least one sensing line; generating a virtual sensing line extending out the touch panel and immediately adjacent to the at least one sensing line; providing a signal strength to the virtual sensing line; and obtaining actual coordinate of the touch point by weighing coordinates of the at least one sensing line, the sensing line immediately adjacent to the at least one sensing line and the virtual sensing line via system generated coordinates.