LED Display Flicker Reduction via Synchronized Clock Idle Times

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Solution Overview

Problem

LED display devices experience flicker due to mismatched lighting and refresh cycles, leading to eye strain, reduced concentration, and dizziness, especially when resolution or frame rate of input image signals changes.

Innovation Solution

An LED display device adjusts idle time periods corresponding to LED driving clock signals based on the number of clock signals per frame, controlling the generation of these signals to ensure uniform or almost uniform idle times, thereby reducing flicker by synchronizing the driving and idle periods across all LED lines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If LED display devices quickly repeat lighting and refreshing tens to hundreds of times per second, then the display can produce images and videos, but fine shaking or blinking (flicker) occurs when lighting cycle and refresh cycle are different

Engineering Contradiction:
Improverefresh rateVSAvoidflicker
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies periodic action by synchronizing the LED lighting cycles with the refresh cycles through periodic idle time periods. The controller generates idle time periods that align the lighting and refreshing operations to occur at regular, synchronized intervals, eliminating the mismatch that causes flicker while maintaining high refresh rates for image display

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent uses dynamics by adjusting the idle time periods based on the number of LED driving clock signals corresponding to one frame. The controller dynamically modifies the timing parameters of the LED driving clock signals to ensure that the lighting and refreshing cycles remain synchronized even when resolution or frame rate changes, thereby preventing flicker under varying operating conditions

Inventive Principle:
Principle #15Dynamics

2Speed

If the lighting cycle and refresh cycle are different, then the display can operate at high speeds, but eye strain, reduced concentration, and dizziness occur due to flicker

Engineering Contradiction:
Improvelighting and refresh speedVSAvoideye strain and dizziness
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent implements feedback by using a controller that monitors the number of LED driving clock signals corresponding to one frame and adjusts the idle time periods accordingly. This closed-loop control ensures that the lighting and refreshing cycles remain synchronized, eliminating flicker and its harmful effects on users while maintaining high operating speeds

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If resolution or frame rate of input image signals changes, then the display can adapt to different content requirements, but there is a high possibility of flicker occurring

Engineering Contradiction:
Improveresolution and frame rate adaptabilityVSAvoidflicker
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies dynamics by making the idle time periods adjustable based on the number of LED driving clock signals corresponding to one frame. When resolution or frame rate changes, the controller dynamically recalculates and adjusts the timing parameters to maintain synchronization between lighting and refreshing cycles, preventing flicker while preserving adaptability to different content requirements

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3469577B1Light emitting diode display device and method of operating the same
Publication Date: 2022.05.11 SAMSUNG ELECTRONICS CO LTD
  • EP3469577B1 patent drawingFigure 1
  • EP3469577B1 patent drawingFigure 2
  • EP3469577B1 patent drawingFigure 3

AI summary

A method of operating a light emitting diode (LED) display device is provided. The method includes determining idle time periods respectively corresponding to LED driving clock signals, based on a number of LED driving clock signals corresponding to one frame, controlling generation of the LED driving clock signals, based on the determined idle time periods, and driving an LED module in a unit of an LED line, based on the generated LED driving clock signals. As the LED display device automatically adjusts idle time periods of the LED driving clock signals, the occurrence of flicker in the LED display device may be reduced.