Touch Panel Pressure Calibration via Local Area Segmentation
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Solution Overview
Problem
Touch panels often suffer from defects such as inconsistent electrode widths and surface bending, leading to measurement errors when detecting touch pressure, which affects user experience and accuracy.
Innovation Solution
A pressure calibration method that divides the touch panel into smaller calibration areas, measures pressure at specific points, and calculates a pressure calibration function to correct for local defects, using mutual capacitance sensing between electrodes to gather data and calculate calibrated pressure values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure measurement is performed across the entire touch panel surface, then comprehensive pressure data is obtained, but measurement errors occur due to local defects and tolerances
Solution Approach 1:
The touch panel surface is divided into multiple calibration areas, with each area having its own calibration function. This segmentation allows local defects to be contained within specific calibration areas rather than affecting the entire panel, thereby improving measurement precision while maintaining reliability across different regions.
Solution Approach 2:
Different calibration functions are applied to different calibration areas based on their specific characteristics. Each calibration area has its own calibration parameters stored in memory, allowing the system to adapt to local variations and defects in each region, thus improving both measurement precision and reliability.
2Measurement precision
If the touch panel is divided into multiple calibration areas, then measurement accuracy improves, but device complexity increases
Solution Approach 1:
The calibration system is segmented into multiple calibration areas, each with its own calibration function stored in memory. This allows the complex calibration data to be organized in manageable segments rather than requiring a single complex calibration model for the entire panel.
Solution Approach 2:
The system automatically selects and applies the appropriate calibration function based on the touch location coordinates. The processor automatically determines which calibration area contains the touch point and retrieves the corresponding calibration parameters from memory, making the complex calibration process transparent to the user.
3Productivity
If calibration points are measured at vertexes of calibration areas, then calibration efficiency improves, but coverage of calibration data decreases
Solution Approach 1:
The calibration system uses vertex points of calibration areas to establish local calibration functions. Each vertex measurement provides critical boundary information that defines the calibration characteristics of its surrounding calibration area, ensuring adequate coverage while maintaining efficiency.
Solution Approach 2:
The calibration function derived from vertex measurements is applied to the entire calibration area. The calibration parameters obtained from measuring at vertexes are used to represent and correct pressure measurements across the whole calibration area, balancing measurement efficiency with adequate calibration coverage.
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 method effectively reduces measurement errors by accurately calibrating pressure values across the touch panel, improving user experience and accuracy by accounting for defects in the touch panel surface.
Implementation Method 1
gathering a touching event by utilizing mutual capacitance sensing between the first electrodes and the second electrodes
Data Source
AI summary
A pressure calibration method, applicable to a touch panel which sequentially comprises a first electrode layer, an elastic dielectric layer and a second electrode layer, the first electrode layer includes multiple first electrodes in parallel to a first axis, the second electrode layer includes multiple second electrodes in parallel to a second axis, the pressure calibration method comprising: retrieving a depression event according to mutual capacitance sensing between the first electrodes and the second electrodes; finding a corresponding calibration area according to coordinate of the depression event; when a calibration area where the touching event locates exists, taking the found calibration area as the corresponding calibration area; otherwise, taking a nearby calibration area which is closest to the touching event as the corresponding calibration area; and calculating a calibrated pressure value according to a pressure sensing value of the depression event and a pressure calibration function of the corresponding calibration area.