Organic Light-Emitting Display Device with Micro Lens Array and Optical Member

Solution Overview

Problem

Organic light-emitting display devices face reduced light extraction efficiency and reflection performance due to the application of micro lens arrays (MLAs), which increase diffuse reflection components.

Innovation Solution

An organic light-emitting display device is designed with an overcoating layer having a lens array at the emission region of each sub-pixel, an organic light-emitting diode on the overcoating layer, and an optical member including a phase difference layer, linear polarizer, reactive mesogen, and dichroic dye to improve light extraction efficiency while minimizing diffuse reflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a micro lens array (MLA) is attached to improve light extraction efficiency, then light extraction efficiency is improved, but diffuse reflection increases and reflection performance deteriorates

Engineering Contradiction:

Improvelight extraction efficiencyVSAvoiddiffuse reflection

Core Design Contradiction:

Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The optical member is divided into multiple regions: a first region with the lens array for light extraction, a second region with a reflective layer for specular reflection, and a third region without either structure. This segmentation allows each region to perform its specific function without interfering with others, resolving the contradiction between light extraction and reflection performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different parts of the optical member have different optical properties: the first region has light extraction enhancement through lensing, the second region has high reflectivity through metallic coating, and the third region maintains original substrate properties. This local differentiation allows simultaneous optimization of light extraction and reflection performance in different areas.

Inventive Principle:

Principle #3Local quality

2Productivity

If an MLA structure is applied to extract captured light, then optical efficiency is improved, but total reflectance and diffuse reflectance increase significantly

Engineering Contradiction:

Improveoptical efficiencyVSAvoidreflection performance

Core Design Contradiction:

ProductivityVSIllumination intensity

Solution Approach 1:

The optical member is divided into multiple regions: a first region with the lens array for light extraction, a second region with a reflective layer for specular reflection, and a third region without either structure. This segmentation allows each region to perform its specific function without interfering with others, resolving the contradiction between light extraction and reflection performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different parts of the optical member have different optical properties: the first region has light extraction enhancement through lensing, the second region has high reflectivity through metallic coating, and the third region maintains original substrate properties. This local differentiation allows simultaneous optimization of light extraction and reflection performance in different areas.

Inventive Principle:

Principle #3Local quality

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

The solution enhances light extraction efficiency and maintains reflection performance by reducing diffuse reflection, achieving higher luminance and lower power consumption compared to conventional MLA-structured devices.

Implementation Method 1

a lens array provided at an emission region of each sub-pixel

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

an optical member provided under the substrate, the optical member including a phase difference layer

Methodology Applied

Scientific EffectPhase difference: Birefringence

Implementation Method 3

a linear polarizer

Methodology Applied

Scientific EffectPolarization: Polarisation

Implementation Method 4

a dichroic dye

Methodology Applied

Scientific EffectDichroism: Dichroic Filter

Data Source

PatentUS10522600B2Organic light-emitting display device

Publication Date: 2019.12.31 LG DISPLAY CO LTD

AI summary

Disclosed is an organic light-emitting display device having a micro lens array (MLA) structure applied to a display panel in order to improve light extraction efficiency. In the organic light-emitting display device, an optical device, including a reactive mesogen (RM) and a dye, is provided between a polarizer and a quarter wave plate (QWP) to block light spreading to a viewing angle, thereby reducing a diffuse reflection component due to the application of the MLA structure.