OLED Image Sticking Reduction via Target Location PWM Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional image sticking reduction techniques for organic light emitting display devices using simultaneous emission techniques suffer from gamma distortion and are not suitable for reducing power consumption effectively.

Innovation Solution

A method that sets target locations for image sticking reduction by analyzing images, controlling the emission period of the organic light emitting display device using a pulse width modulation (PWM) signal, and adjusting the emission period based on a data change threshold value to minimize power consumption and prevent gamma distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional image sticking reduction techniques reduce data voltages based on sum-value, then image sticking is reduced, but gamma distortion is caused

Engineering Contradiction:

Improveimage sticking reductionVSAvoidgamma distortion

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies different treatment to different regions of the display by identifying target locations where image sticking frequently occurs. Instead of uniformly reducing data voltages across the entire display, the invention selectively applies image sticking reduction only to identified target locations, thereby preventing gamma distortion in non-target areas while still addressing image sticking problems in specific regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The display is segmented into target locations and non-target locations based on image sticking characteristics. The patent divides the display area into regions that require image sticking reduction and regions that do not, allowing differential control strategies to be applied to each segment, thus avoiding uniform gamma distortion.

Inventive Principle:

Principle #1Segmentation

2Use of energy by moving object

If emission period is reduced to lower power consumption, then power consumption is reduced, but image sticking may increase

Engineering Contradiction:

Improvepower consumptionVSAvoidimage sticking

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements periodic monitoring of sum-value changes to dynamically adjust the emission period. By periodically checking whether the sum-value variation exceeds a threshold, the system can alternately reduce or maintain the emission period based on current display conditions, achieving both power savings and image sticking prevention through periodic adaptation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The emission period is made dynamic rather than fixed. The patent adjusts the emission period based on real-time sum-value variations, allowing the system to extend or reduce the emission period as needed. This dynamic adjustment enables the system to optimize power consumption while preventing image sticking under varying display conditions.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If target locations are manually set, then flexibility is improved, but device complexity increases

Engineering Contradiction:

Improveflexibility in setting target locationsVSAvoidcomplexity of target location setting

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements automatic target location setting through feedback mechanisms that monitor image sticking patterns and sum-value changes. The system automatically identifies target locations based on where image sticking frequently occurs, eliminating the need for manual configuration while adapting to different display scenarios. This feedback-driven approach provides flexibility without increasing device complexity.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Effectively reduces image sticking and power consumption while preventing gamma distortion by applying the image sticking reduction algorithm only to target locations, ensuring high-quality image display with reduced luminance without voltage reduction.

Implementation Method 1

a plurality of pixel circuits may simultaneously emit light in the low level period of the second power voltage

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Implementation Method 2

controlling an emission period of the organic light emitting display device based on a pulse width modulation (PWM) signal

Methodology Applied

Scientific EffectPulse width modulation: Phase Modulation

Data Source

PatentUS9269292B2Method of setting target locations for reducing image sticking, organic light emitting display device, and method of driving the same

Publication Date: 2016.02.23 SAMSUNG DISPLAY CO LTD

AI summary

A method of setting target locations for reducing image sticking is provided. According to the method, a plurality of images, each of the images being displayed during each frame by an organic light emitting display device are acquired. The target locations at which image sticking frequently occurs are set by comparing the images. Image data corresponding to the target locations are stored in a memory unit. A plurality of pixel circuits may simultaneously emit light in the organic light emitting display device.