Single Sensor Capacitive Touch Detection via Resistance Segmentation
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Solution Overview
Problem
Current capacitive touch detection systems require multiple touch sensors to cover a given size of touch panel, leading to increased complexity and cost, and struggle to accurately distinguish multiple touch points on a single-layer conductive material.
Innovation Solution
A single touch sensor is used to detect touch on multiple touch surfaces by employing different electrical resistances between the sensor and each surface, allowing for long-term and short-term measurements to differentiate and compute the capacitance changes, thereby reducing the number of sensors needed and improving touch accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple touch sensors are used to cover a given size of touch panel, then touch detection coverage and accuracy are improved, but device complexity and cost increase
Solution Approach 1:
A single touch sensor is designed to serve multiple touch surfaces by utilizing different electrical resistance paths to distinguish between multiple touch points, eliminating the need for separate sensors for each surface
Solution Approach 2:
The touch panel is divided into multiple touch surfaces with different resistance values, allowing a single sensor to differentiate between them based on the resistance characteristics of each surface
2Device complexity
If multiple touch surfaces are connected to a single sensor with different electrical resistances, then the number of sensors is reduced, but measurement precision for distinguishing multiple touch points deteriorates
Solution Approach 1:
Each touch surface is assigned a distinct electrical resistance characteristic, creating local differentiation that allows the single sensor to identify and distinguish between multiple touch points based on their unique resistance signatures
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 allows for efficient multi-touch detection using a single sensor, reducing complexity and cost while maintaining high accuracy in identifying touch points on a single-layer capacitive touch panel.
Implementation Method 1
Capacitive sensing is a technology for detecting proximity, position, etc., based on capacitive coupling effects
Implementation Method 2
employing different electrical resistances between the sensor and each surface, allowing for long-term and short-term measurements to differentiate and compute the capacitance changes
Data Source
AI summary
A touch sensing system comprising a set of touch surfaces in a touch panel including a population of touch surfaces; and at least one touch alert generator separately alerting for touch on each of, and both of, at least first and second touch surfaces from among the population of touch surfaces, wherein the alert generator is operative to determine capacitance of said first touch surface, determine touch object capacitance of said first and second touch surfaces, and compute a difference between the two capacitances, thereby to generate an approximation for touch object capacitance of said second touch surface.