Encapsulation Layer Protrusions for OLED Light Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light emitting display devices face reduced light extraction efficiency due to total reflection caused by differences in refractive indices between various layers, leading to dissipation of generated light.
Innovation Solution
An uneven pattern with protrusions is introduced in the encapsulation layer, comprising alternating inorganic and organic films, to scatter and diffract light, thereby reducing total reflection and enhancing light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an encapsulation layer with flat layers is used, then the device structure is simple and easy to manufacture, but light extraction efficiency is reduced due to total reflection at layer interfaces
Solution Approach 1:
The patent introduces protrusions with curved surfaces into the encapsulation layer to replace the flat interface. These curved protrusions scatter and diffract light at the interface, reducing total reflection and improving light extraction efficiency while maintaining ease of manufacture through conventional patterning techniques
Solution Approach 2:
The patent transitions from a two-dimensional flat encapsulation layer interface to a three-dimensional interface with protrusions. This dimensional change creates additional light extraction pathways by introducing vertical relief features that scatter light in multiple directions, thereby reducing total reflection losses
2Loss of energy
If protrusions are added to the encapsulation layer to improve light extraction, then light extraction efficiency increases, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The encapsulation layer is segmented into multiple functional sub-layers: a lower encapsulation layer, a pattern layer containing the protrusions, and an upper encapsulation layer. This segmentation allows the light-extraction function to be localized to the pattern layer while the other layers maintain protective and encapsulative functions, thereby managing device complexity through functional decomposition
Solution Approach 2:
The pattern layer acts as an intermediary between the lower and upper encapsulation layers. It introduces the protrusion structure that improves light extraction without requiring the entire encapsulation system to be complex. The intermediary pattern layer isolates the complexity to a specific functional zone
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 significantly improves light extraction efficiency and reduces power consumption by effectively scattering and diffracting light generated from the emission layer, addressing the issue of internal total reflection in organic light emitting display devices.
Implementation Method 1
An uneven pattern with protrusions is introduced in the encapsulation layer, comprising alternating inorganic and organic films, to scatter and diffract light, thereby reducing total reflection and enhancing light extraction efficiency.
Implementation Method 2
An uneven pattern with protrusions is introduced in the encapsulation layer, comprising alternating inorganic and organic films, to scatter and diffract light, thereby reducing total reflection and enhancing light extraction efficiency.
Data Source
AI summary
An organic light emitting display device, including: a substrate; a display unit formed on the substrate; and an encapsulation layer formed on the display unit, in which the encapsulation layer includes a lower layer formed on the display unit, at least one pattern layer formed on the lower layer, and an upper layer formed on the pattern layer, and the lower layer includes at least one of an inorganic film and an organic film, and the pattern layer includes an uneven pattern having a plurality of protrusions which are spaced apart from each other, formed on the lower layer, and a filling layer disposed on the uneven pattern, and the upper layer includes at least one of an inorganic film and an organic film.