Touch Sensor Noise Cancellation via Reference Electrodes
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Solution Overview
Problem
Existing electronic devices with touch-based input methods face challenges in achieving reliable sensing due to noise interference and sensitivity issues in their sensor layers, which affect the accuracy of touch input detection.
Innovation Solution
The electronic device incorporates a sensor layer with a sensor control circuit that includes a non-ideal element estimator, calculator, and converter, utilizing reference signals to generate a noise signal and output a coordinate signal by adding or subtracting sensing signals, thereby improving sensing reliability and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a sensor layer is added to enable touch-based input methods, then user input capability is improved, but noise interference and sensitivity issues arise that worsen sensing reliability
Solution Approach 1:
The patent introduces reference electrodes as intermediary elements between the sensing electrodes and the signal processing circuit. These reference electrodes serve as mediators that help isolate and eliminate noise from the sensing signals, thereby improving sensing reliability while maintaining the touch-based input capability enabled by the sensor layer
Solution Approach 2:
The patent implements a feedback mechanism where the sensor control circuit continuously monitors and processes signals from multiple electrodes, using the reference electrodes to generate noise signals that are fed back to cancel out interference in the sensing signals, thus improving reliability without compromising input capability
2Reliability
If reference electrodes are added to reduce noise interference, then sensing reliability is improved, but device complexity increases
Solution Approach 1:
The patent merges the reference electrodes with the existing sensor layer structure, integrating them into the same conductive layer rather than adding completely separate components. This combining approach reduces device complexity by utilizing the existing structural framework while still providing the noise reduction benefits of reference electrodes
Solution Approach 2:
The reference electrodes serve multiple functions: they act as noise references for signal processing, provide electrical connection points within the sensor layer, and maintain the structural integrity of the conductive layer. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity
3Measurement precision
If multiple sensing signals are processed to remove noise, then signal-to-noise ratio is improved, but processing time and computational complexity increase
Solution Approach 1:
The patent performs preliminary noise estimation and signal processing actions by continuously monitoring reference electrodes and pre-calculating noise compensation values. This preliminary action allows the system to reduce noise interference before it significantly degrades the sensing signal, thereby improving signal-to-noise ratio while minimizing the time required for subsequent processing
Data Source
AI summary
An electronic device including: a display layer; a sensor layer disposed on the display layer and including first and second electrodes; and a sensor driver to drive the sensor layer and including a signal generation circuit to transmit a transfer signal to the first electrodes, an input detection circuit to receive a sensing signal from the second electrodes, and a sensor control circuit, wherein the input detection circuit is configured to: receive first, second and third sensing signals, and wherein the sensor control circuit includes: a non-ideal element estimator to output a noise signal based on the second sensing signal and the third sensing signal; a calculator to output an output signal by adding or subtracting the first sensing signal and the noise signal; and a converter to output a coordinate signal by converting the output signal into a digital signal.