Touch Circuit Polarity Mixing Driving Method
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Solution Overview
Problem
Touch sensitivity is reduced in low ground mass states due to the retransmission phenomenon where a driving signal is introduced as noise into the response signal, affecting the capacitance change detection between touch electrodes.
Innovation Solution
A touch circuit with a polarity mixing driving method is implemented, where adjacent touch electrodes receive driving signals with different polarities, and a touch control circuit controls the polarity of the driving signals to reduce noise interference and improve sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional touch driving method is used, then the touch circuit can operate normally, but touch sensitivity is reduced in low ground mass states due to retransmission noise
Solution Approach 1:
The patent applies polarity inversion by alternating the polarity of driving signals applied to adjacent touch electrodes. Instead of using the same polarity for all electrodes, the invention inverts the polarity for adjacent electrodes, causing retransmission noise to have opposite polarities that cancel each other out during differential sensing, thereby eliminating the harmful noise effect
Solution Approach 2:
The patent changes the electrical parameter (polarity) of the driving signal applied to touch electrodes. By dynamically alternating the polarity of driving voltages applied to adjacent electrodes, the system transforms the static driving method into a dynamic one that actively cancels noise, improving touch sensitivity without changing the fundamental circuit architecture
2Measurement precision
If driving signals with the same polarity are applied to all touch electrodes, then the circuit operation is simple, but noise interference increases and sensitivity decreases
Solution Approach 1:
The patent implements periodic action by alternating the polarity of driving signals in a regular pattern across adjacent touch electrodes. This periodic polarity switching creates a systematic cancellation of retransmission noise, improving measurement precision while maintaining a relatively simple control structure that follows a predictable alternating pattern
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 polarity mixing driving method enhances touch sensitivity in low ground mass states by minimizing noise interference and accurately detecting capacitance changes, thereby improving the overall touch sensing performance.
Implementation Method 1
The TSP generates capacitance between the driving electrode and the sensing electrode. A change in the capacitance may indicate a touch or proximity of an external object.
Implementation Method 2
A touch circuit with a polarity mixing driving method is implemented, where adjacent touch electrodes receive driving signals with different polarities
Data Source
AI summary
The present disclosure relates to a touch circuit and a touch sensing method. A touch circuit may include a driving circuit configured to transmit a driving signal to a touch electrode, a sensing circuit configured to sense a change in capacitance generated in the touch electrode, and a touch control circuit configured to control a polarity of the driving signal transmitted by the driving circuit. The polarity of the driving signal controlled by the touch control circuit may be determined based on a location of the touch electrode. Touch sensitivity can be improved by differently controlling a polarity of a driving signal transmitted to an adjacent touch electrode.