OLED Efficiency Degradation Compensation via Interdependency Curves

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Solution Overview

Problem

Existing OLED displays face challenges in accurately compensating for aging and stress-related efficiency degradation due to varying stress conditions, leading to inconsistent luminance and electrical performance over time.

Innovation Solution

A method is developed to determine interdependency curves for OLEDs under different operating conditions, including temperature and stress, to calculate correction factors for compensating efficiency degradation, which involves measuring electrical parameters and updating characterization correlation curves based on stress history and initial device characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If OLED displays operate under varying stress conditions, then the device can handle different operating environments, but the efficiency degradation becomes inconsistent and difficult to compensate

Engineering Contradiction:

Improveoperating environment rangeVSAvoidefficiency degradation measurement accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by developing separate interdependency curves for different operating conditions (temperature, stress levels). Instead of using a single compensation curve, the system dynamically selects or interpolates between multiple curves based on actual operating parameters, allowing accurate compensation across varying environments while maintaining measurement precision.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If a single interdependency curve is used for compensation, then the system complexity is reduced, but the compensation accuracy deteriorates under varying stress conditions

Engineering Contradiction:

Improvecompensation system complexityVSAvoidluminance consistency

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent segments the compensation system by creating multiple interdependency curves, each corresponding to specific operating conditions (different temperatures, stress levels). This segmentation allows the system to maintain high reliability and luminance consistency by selecting the appropriate curve for current operating conditions, rather than using a single averaged curve that would compromise accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamics by making the interdependency curve selection dynamic rather than static. The system continuously monitors operating conditions and dynamically switches between or interpolates among multiple pre-characterized curves, ensuring optimal compensation accuracy adapts to real-time changes in temperature and stress conditions.

Inventive Principle:

Principle #15Dynamics

3Loss of time

If compensation is applied without considering stress history, then the processing time is reduced, but the compensation accuracy for efficiency degradation worsens

Engineering Contradiction:

Improvecompensation processing timeVSAvoidefficiency degradation calculation accuracy

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-characterizing and storing multiple interdependency curves covering various operating conditions during manufacturing or initial calibration. This preliminary work eliminates the need for real-time complex calculations, allowing the system to quickly retrieve and apply the appropriate pre-computed curve based on current conditions, thus maintaining both speed and accuracy.

Inventive Principle:

Principle #10Preliminary action

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 ensures accurate compensation for OLED efficiency degradation across various stress conditions, maintaining consistent luminance and electrical performance by adjusting programming voltages dynamically, thereby extending the display's operational life and maintaining image quality.

Implementation Method 1

The OLEDs emit light based on current supplied through a drive transistor

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentUS10699648B2System and methods for extracting correlation curves for an organic light emitting device

Publication Date: 2020.06.30 IGNIS INNOVATION

AI summary

A method of compensating for efficiency degradation of an OLED in an array-based semiconductor device having arrays of pixels that include OLEDs, including determining for a plurality of operating conditions interdependency curves relating changes in an electrical operating parameter of said OLEDs and the efficiency degradation of said OLEDs, the plurality of operating conditions can include temperature or initial device characteristics as well as stress conditions to more completely determine interdependency curves for a wide variety of OLEDs. In some cases interdependency curves are updated remotely after fabrication of the array-based device. Some embodiments utilize degradation-time curves and methods which do not require storage of stress history.