OLED Pixel Definition Film Nanoparticle Light Redirection
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Solution Overview
Problem
Organic light emitting display devices face inefficiencies in internal light emission and side color shifts due to wave-guided light being lost between electrodes, leading to reduced light efficiency and color consistency.
Innovation Solution
Incorporating nanoparticles into the pixel definition film, which are dispersed based on the film's inclination angle, either at the interface or within the film, to redirect and enhance light emission, improving light efficiency by up to 200% and reducing side color shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If wave-guided light is allowed to propagate between electrodes, then light emission structure is simple, but light efficiency is reduced due to light loss
Solution Approach 1:
The patent converts the harmful wave-guided light that would otherwise be lost between electrodes into a beneficial component by redirecting it back into the light emission path using the pixel definition film with nanoparticles, thereby improving internal light efficiency while maintaining the simple electrode structure
Solution Approach 2:
The pixel definition film containing nanoparticles serves as an intermediary component between the organic light emitting layer and the electrode, redirecting wave-guided light back into the optical path without requiring modification of the electrode structure itself
2Illumination intensity
If nanoparticles are dispersed at the interface of the pixel definition film, then light redirection is effective for small inclination angles, but manufacturing precision is reduced due to dispersion control difficulty
Solution Approach 1:
The patent makes the nanoparticle dispersion dynamic by allowing the distribution to vary according to the inclination angle of the pixel definition film, with nanoparticles concentrated at the interface for small angles and uniformly dispersed for larger angles, optimizing light redirection for each configuration
Solution Approach 2:
The patent changes the dispersion parameter of nanoparticles based on the inclination angle parameter of the pixel definition film, adjusting the spatial distribution of nanoparticles to match different geometric configurations and optimize light management
3Ease of manufacture
If nanoparticles are uniformly dispersed within the pixel definition film, then manufacturing is easier, but light redirection effectiveness is reduced for specific angles
Solution Approach 1:
The patent adjusts the dispersion parameter of nanoparticles based on the inclination angle parameter, using uniform dispersion for larger inclination angles where it is easier to manufacture, and interface-concentrated dispersion for smaller angles where maximum light redirection is needed
4Loss of energy
If projection structure is added to change light path, then light efficiency is improved, but device complexity increases
Solution Approach 1:
The patent merges the light redirection function into the pixel definition film by incorporating nanoparticles directly into it, combining the structural role of the pixel definition film with the optical redirection function that would otherwise require a separate projection structure
Solution Approach 2:
The pixel definition film is given multiple functions: it defines pixel boundaries, protects the organic light emitting layer, and redirects wave-guided light back into the optical path through embedded nanoparticles, eliminating the need for dedicated projection structures
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 nanoparticles effectively redirect wave-guided light, enhancing internal light efficiency and minimizing side color shifts, thereby improving the overall performance and color consistency of the organic light emitting display devices.
Implementation Method 1
The pixel definition film includes nanoparticles that change a path of light emitted from the organic light emitting layer
Implementation Method 2
The projection structure may be made of a resin having a similar refractive index to the first electrode
Data Source
AI summary
An organic light emitting display device includes a substrate, a thin film transistor on the substrate, an organic light emitting element including a first electrode connected to the thin film transistor, an organic light emitting layer on the first electrode, and a second electrode on the organic light emitting layer, and a pixel definition film disposed on the substrate to expose a part of the first electrode. The pixel definition film includes nanoparticles that change a path of light emitted from the organic light emitting layer.