Electronic Device Refresh Switching for Stylus Signal Synchronization

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Solution Overview

Problem

Electronic devices struggle to maintain signal synchronization with styluses when switching between different refresh rates, leading to the inability to receive uplink signals and interact effectively.

Innovation Solution

The method involves switching the electronic device's refresh rate to ensure synchronization with the stylus by adjusting the refresh rate based on the stylus's signal frequency and proximity, using a combination of frame counting and distance detection to synchronize the device with the stylus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the electronic device switches between different refresh rates based on application scenarios, then power consumption and display performance are optimized, but the device cannot receive uplink signals from the stylus, causing loss of interaction capability

Engineering Contradiction:
Improvepower consumptionVSAvoidsignal reception reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements dynamic refresh rate adjustment based on detected usage scenarios. When stylus interaction is detected, the system dynamically switches to a refresh rate that is an integer multiple of the stylus signal frequency, ensuring reliable signal reception. When stylus interaction is not detected, the system uses lower refresh rates to reduce power consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system continuously monitors for stylus uplink signals and uses this feedback to adjust the refresh rate. When stylus signals are detected, the refresh rate is adjusted to synchronize with the stylus communication frequency, ensuring continuous reliable reception. This feedback mechanism resolves the contradiction by prioritizing signal reception reliability when needed while maintaining power efficiency during normal operation.

Inventive Principle:
Principle #23Feedback

2Reliability

If the electronic device uses a fixed refresh rate to maintain synchronization with the stylus, then signal reception is reliable, but the device cannot adapt to different application scenarios and power consumption increases

Engineering Contradiction:
Improvesignal synchronization reliabilityVSAvoidadaptability to application scenarios
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system dynamically adjusts the refresh rate based on the detected usage scenario. When stylus interaction is detected, it switches to a refresh rate synchronized with the stylus signal frequency. When not in use, it falls back to standard refresh rates, providing adaptability while maintaining synchronization reliability when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the refresh rate parameter based on operational context. By detecting whether the stylus is in use and adjusting the refresh rate accordingly, the system adapts to different application scenarios while maintaining signal synchronization reliability during stylus interaction periods.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the electronic device switches refresh rate without considering stylus signal frequency, then display performance is optimized, but handwriting intermittence occurs due to signal asynchrony

Engineering Contradiction:
Improvedisplay performanceVSAvoidhandwriting continuity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system monitors for stylus uplink signals and uses this feedback to determine when to adjust the refresh rate. When stylus signals are detected, the refresh rate is adjusted to match the stylus communication frequency, preventing handwriting intermittence. This feedback-driven approach ensures display performance and handwriting continuity are both maintained.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary detection of stylus presence and signal frequency before switching refresh rates. By detecting the stylus signal frequency in advance and pre-adjusting the refresh rate accordingly, the system prevents handwriting intermittence from occurring in the first place, ensuring continuous reliable interaction.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4276590B1Method for switching refresh rate, electronic device, and system
Publication Date: 2025.07.30 HONOR DEVICE CO LTD
  • EP4276590B1 patent drawingFigure 1A~1B
  • EP4276590B1 patent drawingFigure 2
  • EP4276590B1 patent drawingFigure 3

AI summary

Embodiments of this application provide a refresh rate switching method, an electronic device, and a system. The method is applicable to an electronic device. After being in a communication connection to a stylus, the electronic device may display a picture at a first refresh rate. Because a first frequency with which the stylus sends an uplink signal is an integer multiple of the first refresh rate, the electronic device may keep signal synchronization with the stylus. When a user does not use the stylus and puts the stylus aside, the user may operate the electronic device, so that a refresh rate of the electronic device is switched from the first refresh rate to a second refresh rate, where the first frequency is not an integer multiple of the second refresh rate. When the user holds the stylus again to approach a screen, the electronic device switches from the second refresh rate to a third refresh rate, where the first frequency is an integer multiple of the third refresh rate; and then after the electronic device sends a wake-up signal to the stylus, the stylus may intercept the wake-up signal, to send an uplink signal, and then the electronic device may receive the uplink signal from the stylus, and may keep signal synchronization with the stylus.