OLED Pixel Compensation for Luminance Uniformity and Lifespan

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Solution Overview

Problem

Conventional OLED display degradation compensation methods accelerate pixel degradation by continuously increasing current in degraded pixels, leading to image quality issues and reduced display lifespan.

Innovation Solution

A display device and method that detect degraded regions based on pixel deviation data, adjust compensation data to minimize current flow in degraded pixels and maximize it in adjacent regions, and determine correction based on image characteristic constants to prevent image quality degradation and extend display life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If compensation data is continuously increased to maintain luminance in degraded pixels, then image quality is maintained, but pixel degradation is accelerated

Engineering Contradiction:
Improveluminance uniformityVSAvoidpixel lifespan
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The display panel is divided into degraded regions and non-degraded regions based on degradation data. Different compensation strategies are applied to each region: degraded pixels receive reduced compensation to slow further degradation, while non-degraded pixels receive increased compensation to maintain luminance uniformity. This segmentation resolves the contradiction by treating different pixel groups differently based on their degradation state.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The compensation data is adjusted locally for each pixel based on its degradation level. Pixels in degraded regions receive different compensation values compared to pixels in non-degraded regions. This local quality approach allows the system to maintain overall luminance uniformity while applying conservative compensation only where necessary, preventing accelerated degradation in already compromised pixels.

Inventive Principle:
Principle #3Local quality

2Reliability

If compensation data is reduced to slow pixel degradation, then pixel lifespan is extended, but image quality deteriorates due to visible degradation

Engineering Contradiction:
Improvepixel lifespanVSAvoidluminance uniformity
Core Design Contradiction:
ReliabilityVSIllumination intensity

Solution Approach 1:

The compensation approach merges two strategies: conservative compensation for degraded pixels (to extend lifespan) and enhanced compensation for non-degraded pixels (to maintain image quality). By combining these opposing approaches in a unified compensation scheme, the system achieves both extended pixel lifespan and maintained luminance uniformity across the display panel.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The compensation data parameters are dynamically adjusted based on degradation data. The system changes the compensation parameter values differently for degraded versus non-degraded pixels, optimizing the balance between extending pixel lifespan and maintaining image quality. This parameter change strategy allows flexible adaptation to different degradation states.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If uniform compensation is applied to all pixels, then manufacturing simplicity is maintained, but image quality deteriorates due to luminance differences between degraded and non-degraded regions

Engineering Contradiction:
Improvecompensation implementation simplicityVSAvoidluminance uniformity
Core Design Contradiction:
Ease of manufactureVSIllumination intensity

Solution Approach 1:

The compensation data is made dynamic rather than static. The system continuously updates compensation values based on real-time degradation data from each pixel. This dynamic approach allows the compensation scheme to adapt to changing degradation patterns, maintaining luminance uniformity while accommodating the complexity of differential degradation across the display panel.

Inventive Principle:
Principle #15Dynamics

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

This approach reduces pixel degradation, maintains image quality, and extends the display device's lifespan by optimizing compensation data distribution and detection of perceived degradation regions.

Implementation Method 1

A data voltage corresponding to image data is applied to each of the pixels to flow a driving current at the OLED so that the OLED emits light at a desired luminance

Methodology Applied
Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP3252750B1Display device and method for compensating pixels of display device
Publication Date: 2022.10.12 LG DISPLAY CO LTD
  • EP3252750B1 patent drawingFigure 1
  • EP3252750B1 patent drawingFigure 2
  • EP3252750B1 patent drawingFigure 3

AI summary

A pixel compensation module according to one embodiment of the present disclosure detects a degraded region with reference to degradation data corresponding to each of pixels included in a display panel, determines a first compensation gain so as to decrease final compensation data of pixels included in the degraded region, and determines a second compensation gain so as to increase final compensation data of pixels included in an adjacent degraded region to correct compensation data of the pixels.