Touch Chip Async Idle Control for Low-Power Touch Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The power consumption of touch systems in electronic devices is significant and affects overall device performance, particularly in standby time, due to inefficient mode transitions and data reporting frequencies.
Innovation Solution
Implementing a touch system control method that reduces scanning and data reporting frequencies when no valid touch signal is detected, transitioning between active, async idle, and idle modes to conserve power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the touch system maintains high scanning frequency and data reporting frequency to ensure quick response to touch inputs, then touch responsiveness is improved, but power consumption increases
Solution Approach 1:
The patent implements dynamic frequency adjustment based on touch state detection. The system transitions between different operating modes (active mode with high scanning frequency, async idle mode with reduced reporting frequency, and idle mode with minimal scanning) according to whether touch signals are detected, thereby adapting the scanning and reporting frequencies to actual usage conditions rather than maintaining constant high frequency
Solution Approach 2:
The patent employs periodic scanning at different frequencies depending on the operating mode. In active mode, scanning occurs at high frequency (e.g., 120Hz or higher), while in async idle mode scanning continues at the same frequency but reporting is reduced, and in idle mode scanning occurs at lower frequency. This periodic action with varying frequencies optimizes the balance between responsiveness and power consumption
2Measurement precision
If the touch system uses high scanning frequency to detect touch positions accurately, then touch detection precision is improved, but data processing load and power consumption increase
Solution Approach 1:
The system dynamically adjusts the data reporting frequency based on the operating mode. In active mode, data is reported at high frequency to maintain precise touch tracking. In async idle mode, the touch chip continues scanning at high frequency to maintain detection precision but reports data at a reduced frequency to the host. In idle mode, both scanning and reporting frequencies are reduced, thereby optimizing the balance between measurement precision and processing load
3Use of energy by moving object
If the touch system transitions quickly between active and idle modes to conserve power, then power consumption is reduced, but mode transition delays occur that degrade touch responsiveness
Solution Approach 1:
The patent introduces an intermediate async idle mode that serves as a buffer between active mode and idle mode. When leaving active mode, the system first transitions to async idle mode where scanning continues at high frequency but reporting is reduced, preparing the system for power savings while maintaining the ability to quickly respond to touch. This preliminary action avoids the delay of immediately transitioning to full idle mode, thereby reducing mode transition delays while still conserving power
Data Source
Figure 1
Figure 2
Figure 3
AI summary
This application provides a touch system control method and an electronic device. The method includes: in an active mode, controlling, by a touch chip, a touch panel to perform two-dimensional data scanning at a first frequency to obtain first scanned data, where the first scanned data is used for detecting a touch position; sending, by the touch chip, the first scanned data to a host at the first frequency; when the host determines, according to the first scanned data, that no valid touch signal is detected on a screen of the electronic device, switching, by the host, to an async idle mode and sending a first command for switching to the async idle mode to the touch chip; and switching, by the touch chip, to the async idle mode according to the first command, where in the async idle mode, the touch chip controls the touch panel to perform two-dimensional data scanning at the first frequency to obtain second scanned data, and sends the second scanned data to the host at a second frequency; the second frequency is less than the first frequency; and the second scanned data is used for detecting whether there is a conductor approaching the touch screen. Therefore, the power consumption of the host can be reduced, thereby reducing the overall power consumption of the electronic device.