Touch Device Combining Self and Mutual Capacitance Sensing
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Solution Overview
Problem
Current touch sensing technologies face challenges in achieving high sensitivity for both single-touch and multi-touch operations, with self-capacitance methods providing high sensitivity but prone to 'ghost points' and mutual capacitance methods offering limited sensitivity and hovering functionality.
Innovation Solution
A touch device and driving method that combine self-capacitance and mutual capacitance methods by using first and second electrodes with a touch controller to apply driving signals and detect capacitances, allowing for simultaneous self and mutual capacitance sensing, enabling high sensitivity and multi-touch functionality while preventing ghost points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If self capacitance method is used, then sensitivity is improved, but ghost points occur during multi-touch
Solution Approach 1:
The patent combines self-capacitance and mutual-capacitance methods into a unified touch sensing system. The controller switches between self-capacitance sensing (for high sensitivity single-touch detection) and mutual-capacitance sensing (for accurate multi-touch detection), merging the advantages of both methods to eliminate ghost points while maintaining high sensitivity.
2Adaptability or versatility
If mutual capacitance method is used, then multi-touch operation is enabled, but sensitivity is reduced
Solution Approach 1:
The patent implements dynamic switching between self-capacitance and mutual-capacitance sensing modes based on the touch situation. The controller dynamically selects the appropriate sensing method: self-capacitance for single-touch scenarios requiring high sensitivity, and mutual-capacitance for multi-touch scenarios requiring accurate touch point differentiation, thus optimizing performance for each specific case.
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
The combined approach enhances touch sensitivity, enabling accurate single-touch and multi-touch recognition with high sensitivity and hovering functionality, effectively addressing the limitations of both self-capacitance and mutual capacitance methods.
Implementation Method 1
The touch sensor may include a sensing condenser including sensing electrodes that may transfer a sensing signal and identify whether a touch exists or a touch location by sensing a change in charged capacitance
Data Source
AI summary
A touch device includes first and second electrodes intersecting each other, and a touch controller. The touch controller is configured to: apply a first driving signal to the first electrodes; selectively apply a second driving signal to the second electrodes; and detect self capacitances of at least one of the first electrodes and a first portion of the second electrodes intersecting the first electrodes. The at least one of the first electrodes is configured to receive the first driving signal, and the first portion of the second electrodes is configured to receive the second driving signal. The touch controller is further configured to detect mutual capacitances between the at least one of the first electrodes and a second portion of the second electrodes intersecting the first electrodes, in which the second portion of the second electrodes is configured not to receive the second driving signal.