Omnidirectional Antireflection Optical Filter for OLED
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Solution Overview
Problem
Current optical filters for organic light-emitting devices suffer from strong viewing angle dependence, leading to deteriorated antireflection performance and reduced visibility due to reflected external light, especially on the sides.
Innovation Solution
An optical filter configuration comprising a first retardation film with in-plane optical axis and quarter-wave phase retardation characteristics, a second retardation film with an optical axis tilted along the thickness direction, and a linear polarizer with an absorption axis, which together provide omnidirectional antireflection performance by controlling light polarization and phase delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional low molecular weight hole transport materials are used, then device fabrication is simpler, but device stability and lifetime are insufficient
Solution Approach 1:
The patent uses composite materials by combining low molecular weight hole transport materials with specific host materials (e.g., Alq3, BCP, TPBi) to create stable organic light-emitting device layers. This composite approach allows the device to maintain fabrication simplicity while achieving enhanced stability and lifetime through the synergistic properties of the material combination.
2Illumination intensity
If optical filters are used to improve color purity, then color quality is enhanced, but device complexity increases
Solution Approach 1:
The patent extracts the color filtering function from separate optical filter components and integrates it directly into the organic light-emitting device structure through specifically designed emitting layers. This allows color purity to be achieved without adding external filter components, thereby maintaining device simplicity while enhancing color quality.
Solution Approach 2:
The patent merges the light emission function and color filtering function into a single integrated device structure. By designing the organic light-emitting layers with specific host-guest combinations, the device simultaneously generates light and filters wavelengths to achieve high color purity without requiring separate filter components.
3Adaptability or versatility
If conventional hole transport materials with broad absorption spectra are used, then material selection is easier, but color purity of emitted light is reduced
Solution Approach 1:
The patent applies local quality by selecting hole transport materials and host materials with specifically tailored absorption spectra that are optimized for particular color ranges. Rather than using materials with broad absorption, the invention uses materials with targeted absorption characteristics (e.g., specific blue, green, or red absorption bands) to achieve high color purity while maintaining material selection flexibility for different device requirements.
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 proposed optical filter significantly improves antireflection performance on both the front and side surfaces, enhancing visibility and display quality of organic light-emitting devices by effectively preventing external light reflection across various viewing angles.
Implementation Method 1
an optical filter which transmits blue light emitted from the light-emitting layer and absorbs green light and red light
Implementation Method 2
organic light-emitting device which emits blue light and has a long lifetime
Data Source
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AI summary
The present application relates to an optical filter and an organic light-emitting display device. The optical filter of the present application has excellent omnidirectional antireflection performance on the side as well as the front. The optical filter can be applied to an organic light-emitting device to improve visibility.