OLED Optical Control Layer Viewing Angle
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Solution Overview
Problem
Conventional organic light emitting devices (OLEDs) suffer from limited viewing angle and color change issues due to constructive interference limitations, which affect their display characteristics and production efficiency.
Innovation Solution
Incorporating an optical control layer with a thickness of 5000 to 10,000 Å, formed with organic materials having a refractive index of 1.4 to 2.5, between the transmitting or transflective electrode and the emission layer, which includes hole injection and transport layers, to achieve constructive interference 4 to 7 times within the visible light wavelength area, thereby enhancing viewing angles and reducing color changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the optical control layer thickness is increased to achieve more constructive interference, then the viewing angle characteristics improve, but the device thickness increases
Solution Approach 1:
The patent optimizes the thickness parameter of the optical control layer to a specific range (5000-10000 Å) to achieve constructive interference of 4-7 times. This parameter optimization resolves the contradiction by finding the optimal thickness that provides sufficient constructive interference for good viewing angle characteristics while avoiding excessive device thickness.
Solution Approach 2:
The patent uses composite material structure with the optical control layer formed of organic materials having specific refractive indices (1.4-2.5) positioned between the transmitting electrode and emission layer. This composite structure enables precise control of optical interference effects to improve viewing angle without proportionally increasing overall device thickness.
2Stability of the object's composition
If the optical control layer is designed to generate constructive interference, then color stability improves, but the manufacturing precision requirements increase
Solution Approach 1:
The patent specifies a thickness range (5000-10000 Å) and refractive index range (1.4-2.5) for the optical control layer materials. By providing ranges rather than fixed values, the patent balances color stability requirements with manufacturing feasibility, allowing sufficient tolerance for production variations while maintaining optical interference effects.
Solution Approach 2:
The patent employs standard organic material layers (hole injection layer and hole transport layer) that can be formed using conventional OLED manufacturing processes. This approach allows replication of proven material systems with known processing parameters, reducing manufacturing precision requirements compared to using novel or exotic materials.
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 the viewing angle characteristics and reduces color change effects, maintaining a wide color gamut and stable light output across various viewing angles, enhancing the overall display performance and manufacturing efficiency of OLEDs.
Implementation Method 1
light sources generated from the emission layer impart constructive interference of 4 to 7 times within a wavelength area of visible light
Data Source
AI summary
An organic light emitting device may include an emission layer between a reflecting electrode and one of a transmitting or transflective electrode, and an optical control layer formed with an organic material that is 5000 to 10,000 Å thick between the transmitting or transflective electrode and the emission layer.