Stylus Signal Synchronization for Refresh Rate Switching

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Solution Overview

Problem

Existing stylus systems fail to timely detect changes in the refresh rate of electronic devices, leading to synchronization issues and impaired interaction when the refresh rate is switched during different application scenarios.

Innovation Solution

The stylus detects the refresh rate of an electronic device by monitoring uplink signals at the least common multiple of the supported refresh rates, ensuring timely synchronization without additional signaling interactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the stylus sends downlink signals based on the electronic device's refresh rate, then signal synchronization is maintained, but the stylus cannot timely detect refresh rate switching

Engineering Contradiction:
Improvesignal synchronizationVSAvoiddetection delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The electronic device feeds back uplink signals to the stylus at different intervals corresponding to different refresh rates (60Hz or 90Hz). The stylus monitors these uplink signals to detect the current refresh rate and adjust its downlink signal transmission accordingly, creating a closed-loop feedback system that enables timely detection and adaptation to refresh rate changes

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the monitoring interval of uplink signals based on the detected refresh rate. When the electronic device switches between 60Hz and 90Hz refresh rates, the stylus adapts its sampling frequency accordingly, making the system flexible and responsive to changing operational conditions without requiring complex signaling protocols

Inventive Principle:
Principle #15Dynamics

2Loss of time

If the stylus monitors uplink signals at the least common multiple of refresh rates, then refresh rate switching is detected timely, but monitoring complexity increases

Engineering Contradiction:
Improvedetection speedVSAvoidmonitoring complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The stylus changes its monitoring parameters (sampling frequency) based on the detected refresh rate. By monitoring at the least common multiple frequency (180Hz for 60Hz and 90Hz systems) and dynamically adjusting the effective sampling rate, the stylus can detect refresh rate transitions efficiently without requiring multiple dedicated monitoring circuits or complex synchronization protocols

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4266161B1Method applied to signal synchronization system, and system, stylus and electronic device
Publication Date: 2025.04.02 HONOR DEVICE CO LTD
  • EP4266161B1 patent drawingFigure 1~2A
  • EP4266161B1 patent drawingFigure 2B
  • EP4266161B1 patent drawingFigure 3

AI summary

Embodiments of this application provide a method applied to a signal synchronization system, a system, a stylus, and an electronic device. The system includes a stylus and an electronic device. The electronic device supports a first refresh rate and a second refresh rate. The method includes: after an electronic device is wirelessly connected to a stylus, the electronic device samples a downlink signal from the stylus based on a third refresh rate, where the third refresh rate is equal to a first refresh rate or a second refresh rate; and the stylus sends the downlink signal to the electronic device based on the third refresh rate, and samples an uplink signal from the electronic device at a fourth refresh rate, where the fourth refresh rate is the least common multiple of the first refresh rate and the second refresh rate. In the embodiments of this application, after the stylus is connected to the electronic device, the uplink signal from the electronic device may be monitored by using the least common multiple of all refresh rates supported by the electronic device, so that the switching of the refresh rate of the electronic device can be detected in a timely manner, thereby achieving a small time delay and high efficiency.