Stylus Signal Decoding via Edge Sampling for Low Writing Delay
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Solution Overview
Problem
There is a delay in displaying a writing trace on a terminal device's touch panel due to decoding delays caused by bandwidth limitations and external noise in existing stylus technologies.
Innovation Solution
A signal decoding method that samples a modulation signal at a preset rate, determines edge signals, and decodes the signal based on these edge signals to reduce decoding time, eliminating the need for a comparator and improving decoding speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the modulation signal is decoded by using an operational amplifier, a comparator, and a decoding module, then the decoding can be completed, but a decoding delay occurs due to bandwidth limitations and external noise
Solution Approach 1:
The patent extracts and removes the comparator from the decoding circuit, keeping only the operational amplifier and decoding module. This extraction eliminates the bandwidth limitations and noise issues associated with the comparator while maintaining the necessary decoding functionality through the operational amplifier's signal processing capabilities.
Solution Approach 2:
The patent changes the circuit configuration by removing the comparator component, thereby altering the system's bandwidth characteristics and noise performance. This parameter change in the circuit architecture directly reduces the decoding delay while maintaining adequate decoding accuracy through the operational amplifier's optimized parameters.
2Ease of operation
If the stylus sends the decoded modulation signal and pressure signal to the terminal device, then the writing trace can be displayed, but there is a delay in displaying the writing trace on the TP
Solution Approach 1:
By removing the comparator from the signal processing chain, the patent eliminates a significant source of delay in the signal processing path. This extraction simplifies the overall system architecture and reduces the time required to process and transmit the writing signal from the stylus to the terminal device.
3Reliability
If a comparator is used in the decoding circuit, then the modulation signal can be decoded, but the bandwidth of the comparator causes decoding delay
Solution Approach 1:
The patent extracts the comparator from the decoding circuit, eliminating its bandwidth limitations. The operational amplifier alone is sufficient to perform the decoding function without the comparator's restrictive bandwidth characteristics, thereby improving decoding speed while maintaining reliability.
Data Source
AI summary
This application provides a signal decoding method, a decoding circuit, and a stylus. In one example, a to-be-measured signal is sampled to obtain a plurality of sampled signals. The to-be-measured signal is a modulation signal that carries an interference signal. The modulation signal is sent by a touch panel of a terminal device. At least two edge signals in the to-be-measured signal are determined based on the plurality of sampled signals. The to-be-measured signal is decoded based on the at least two edge signals to obtain the modulation signal.