OLED Quad-Pixel Architecture for Aperture Ratio and Lifetime

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current organic light emitting devices (OLEDs) face limitations in achieving a commercial blue OLED with saturated CIE coordinates and sufficient device lifetime, which affects the rendering of deep blue colors in displays.

Innovation Solution

A quad-pixel configuration is used, comprising red, green, light blue, and deep blue-emitting devices, where the deep blue device is shared between pixels, allowing for a more stable and long-lived light blue device to render colors including a deep blue component, while minimizing the overall impact on lifetime and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a commercial blue OLED with saturated CIE coordinates is used, then deep blue color rendering is improved, but device lifetime is reduced

Engineering Contradiction:

Improvedeep blue color renderingVSAvoiddevice lifetime

Core Design Contradiction:

Illumination intensityVSDuration of action of stationary object

Solution Approach 1:

The patent combines a light blue OLED and a deep blue OLED within the same pixel to render deep blue colors. The light blue OLED provides stability and long lifetime, while the deep blue OLED provides the necessary color saturation. By merging these two devices and controlling their emission ratios, the system achieves deep blue color rendering without sacrificing overall device lifetime.

Inventive Principle:

Principle #5Merging (Combining)

2Area of stationary object

If the aperture ratio of OLED displays is increased, then fill factor is improved, but current density increases reducing lifetime

Engineering Contradiction:

Improveaperture ratioVSAvoidoperational lifetime

Core Design Contradiction:

Area of stationary objectVSDuration of action of stationary object

Solution Approach 1:

The patent applies local quality by having different sub-pixels (light blue and deep blue) with different characteristics within the same pixel. The light blue sub-pixel is designed for stability and longevity, while the deep blue sub-pixel is optimized for color saturation. This local differentiation allows the overall pixel to achieve high aperture ratio while maintaining long operational lifetime through the stable light blue component.

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

This configuration enhances the fill factor and operational lifetime of OLED displays by reducing current density and increasing the aperture ratio, enabling the rendition of a wide color gamut without significant shortcoming in deep blue rendering.

Implementation Method 1

OLEDs make use of thin organic films that emit light when voltage is applied across the device

Methodology Applied

Scientific EffectElectroluminescence: Electroluminescence

Data Source

PatentEP2507836B1OLED display architecture with improved aperture ratio

Publication Date: 2014.06.18 UNIVERSAL DISPLAY CORP

Figure 1
Figure 2
Figure 3

AI summary

A device such as a display region that includes a plurality of multi-color pixels is provided. Each pixel may have several types of organic light emitting devices that operate as sub-pixels, and at least one type of device may be shared by multiple pixels. Less-used and/or more efficient device types, such as deep blue and green light emitting devices, may be shared between multiple pixels, leading to an improved aperture ratio and fill factor for the device.