Display Timing Signal Control for Seamless Refresh Rate Switching

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Solution Overview

Problem

Existing display devices face issues with power consumption and responsiveness due to dynamic changes in synchronization signal intervals, leading to noticeable brightness differences in displayed images.

Innovation Solution

The electronic device maintains the scan-on time of the display driver IC while adjusting the timing of the timing signal in response to synchronization signals, allowing seamless refresh rate switching without altering the scan-on time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the interval of the synchronization signal is shortened to increase refresh rate, then responsiveness is improved, but processor power consumption increases

Engineering Contradiction:
ImproveresponsivenessVSAvoidprocessor power consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the scan-on time adjustable rather than fixed. The display driver IC dynamically adapts the scan-on time duration based on the refresh rate being used, allowing optimal power consumption at each refresh rate while maintaining high responsiveness when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of scan-on time duration in response to synchronization signal interval changes. When the refresh rate increases (shorter interval), the scan-on time is extended to provide sufficient data transmission time, preventing processor overload and excessive power consumption while maintaining responsiveness.

Inventive Principle:
Principle #35Parameter changes

2Use of energy by moving object

If the interval of the synchronization signal is lengthened to decrease refresh rate, then processor power consumption decreases, but responsiveness deteriorates

Engineering Contradiction:
Improveprocessor power consumptionVSAvoidresponsiveness
Core Design Contradiction:
Use of energy by moving objectVSSpeed

Solution Approach 1:

The system dynamically adjusts the scan-on time based on the active refresh rate. When operating at lower refresh rates, the scan-on time can be reduced, allowing the processor to consume less power while still meeting the data transmission requirements for the current refresh rate, thus maintaining optimal responsiveness for the active mode.

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If the scan-on time is changed when switching refresh rates, then power consumption can be optimized, but brightness differences become noticeable

Engineering Contradiction:
Improvepower consumptionVSAvoidimage brightness consistency
Core Design Contradiction:
Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent implements feedback by continuously monitoring the scan-on time duration and adjusting it based on the actual refresh rate being used. This closed-loop control ensures that the scan-on time is always appropriate for the current refresh rate, optimizing power consumption while preventing brightness inconsistencies that would occur with fixed or improperly adjusted scan-on times.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The scan-on time parameter is dynamically changed in direct response to refresh rate changes. This coordinated parameter adjustment ensures that power consumption is optimized for each refresh rate while maintaining consistent image brightness, as the scan-on time is precisely matched to the data transmission requirements of each refresh rate mode.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If the processor operates at high speed to transmit data within short scan-on time, then responsiveness is improved, but power consumption increases

Engineering Contradiction:
Improvedata transmission speedVSAvoidprocessor power consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The processor operates dynamically at different speeds matched to the active refresh rate. When refresh rate is high, the processor operates at higher speed with extended scan-on time; when refresh rate is low, the processor operates at lower speed with reduced scan-on time. This dynamic operation allows the processor to consume only the necessary power for the current performance requirement.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes both the processor operation speed and scan-on time duration together as coordinated parameters. This joint parameter adjustment allows the system to achieve high productivity when needed while consuming less power during lower-demand periods, resolving the contradiction between transmission speed and power consumption.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4022599B1Electronic device and method for controlling timing signal
Publication Date: 2025.11.26 SAMSUNG ELECTRONICS CO LTD
  • EP4022599B1 patent drawingFigure 1
  • EP4022599B1 patent drawingFigure 2
  • EP4022599B1 patent drawingFigure 3

AI summary

According to an embodiment, an electronic device may include at least one processor, a display, a memory configured to store image frames, and a display controller configured to output the image frames. The at least one processor may be configured to transmit a first image frame to be output through the display, based on a first timing signal received from the display controller, identify a state of the electronic device, transmit first control information for changing a timing of the first timing signal, in response to transmitting the first control information for changing the timing of the first timing signal, receive a second timing signal from the display controller, and transmit, to the memory, a second image frame to be output through the display, based on the received second timing signal. The timing of the second timing signal may differ from the timing of the first timing signal.