Touch Controller Phase Modulation for Low-Bandwidth Position Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing touch control technologies require large bandwidth to simultaneously transmit signals to multiple electrodes, which is inefficient and aims to reduce bandwidth while maintaining performance.
Innovation Solution
A touch controller using phase modulation, with a signal generation module that performs in-phase and inverting-phase code transmissions to two transmitting electrodes, and a demodulation module that processes these signals to determine touch position, allowing for precise coordinate detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two signals with different frequencies are used for code transmission on two transmitting electrodes, then the signals can be distinguished during demodulation, but the bandwidth occupied is large
Solution Approach 1:
The patent changes the modulation parameter from frequency to phase. Instead of using different frequencies to distinguish signals, the invention uses different phases (0° and 180°) of the same frequency carrier wave. This allows multiple electrodes to share the same frequency resource while maintaining signal distinguishability through phase differences, thereby reducing bandwidth occupation.
Solution Approach 2:
The patent employs periodic phase inversion in the code transmission process. The modulation signal alternates between 0° and 180° phases in a periodic manner, creating distinct signal patterns for different electrodes. This periodic action enables the receiving electrode to distinguish between signals from different transmitting electrodes through phase detection, achieving signal separation without requiring different frequencies.
2Quantity of substance
If phase modulation is used to reduce bandwidth, then bandwidth requirements are reduced, but the system complexity increases due to phase mixing and integration requirements
Solution Approach 1:
The demodulation process is segmented into distinct functional modules: phase mixing units that separately process signals from different transmitting electrodes, integration units that accumulate the mixed signals over time, and a decoding unit that reconstructs the original code. This segmentation allows the complex demodulation task to be divided into manageable, independent stages, making the system more implementable and maintainable.
Solution Approach 2:
The patent introduces phase mixing as an intermediary process between signal reception and code decoding. The mixing operation with reference signals (at 0° and 180° phases) acts as a mediator that converts phase-modulated signals into amplitude-modulated intermediate signals, which are then easier to integrate and decode. This intermediary step simplifies the overall demodulation complexity by transforming the problem into a more tractable form.
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 reduces bandwidth requirements while achieving precise touch position detection by swapping signals with different phases, enabling more accurate coordinate determination.
Implementation Method 1
the signal generation module is configured to perform an in-phase code transmission at a first time so that the receiving electrode receives an in-phase code receiving signal correspondingly, and perform an inverting-phase code transmission at a second time
Implementation Method 2
The first mixer and the first integration unit is arranged for performing in-phase frequency mixing and integration on the in-phase code receiving signal and the inverting-phase code receiving signal
Implementation Method 3
The first mixer and the first integration unit is arranged for performing in-phase frequency mixing and integration on the in-phase code receiving signal and the inverting-phase code receiving signal
Data Source
AI summary
The application discloses a touch controller to determine a position where a user touches a touchscreen. The touchscreen includes a first transmitting electrode, a second transmitting electrode and a receiving electrode. The touch controller includes a signal generation module and a demodulation module. The signal generation module is configured to perform an in-phase code transmission at a first time so that the receiving electrode receives an in-phase code receiving signal correspondingly, and perform an inverting-phase code transmission at a second time so that the receiving electrode receives an inverting-phase code receiving signal correspondingly. The demodulation module is configured to determine the position where the user touches the touchscreen according to the in-phase code receiving signal corresponding to the first time and the inverting-phase code receiving signal corresponding to the second time.