Electrode Anti-Reflective Coating for Outdoor Display Visibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The outdoor visibility of organic light emitting display devices is compromised due to reflectance from electrodes inside the display panel, especially when a polarizer is removed, leading to decreased luminance.
Innovation Solution
Incorporating a semi-transmissive metal layer, a transparent metal layer, and a reflective metal layer in the gate, source, and drain electrodes, which reduces reflectance through destructive interference, and using a buffer layer with a multi-layer structure of silicon dioxide and silicon nitride to minimize external light reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a polarizer is arranged on the lower surface of the base substrate to improve outdoor visibility, then reflectance of external light is reduced, but luminance of the display panel decreases
Solution Approach 1:
The invention extracts and removes the polarizer from the display structure, eliminating the component that causes luminance loss while addressing external light reflection through alternative means (anti-reflective coating on electrodes)
Solution Approach 2:
The invention converts the harmful effect of electrode reflectance into a beneficial anti-reflective property by applying a specific coating that creates destructive interference for reflected light, thereby reducing external light reflection without blocking emitted light
2Illumination intensity
If electrodes with high reflectance are used to improve light emission efficiency, then luminance is enhanced, but outdoor visibility deteriorates due to increased external light reflection
Solution Approach 1:
The invention changes the optical parameters of the electrode surface by applying an anti-reflective coating with specific refractive index and thickness, transforming the electrode from a high-reflectance surface to a low-reflectance surface that maintains light emission efficiency while reducing external light reflection
Solution Approach 2:
The invention uses a composite structure consisting of the electrode material combined with an anti-reflective coating layer, creating a multi-layer composite that optimizes both light emission and reflection reduction properties
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 outdoor visibility by reducing reflectance from the electrodes and external light reflection, maintaining luminance without the need for a polarizer.
Implementation Method 1
Incorporating a semi-transmissive metal layer, a transparent metal layer, and a reflective metal layer in the gate, source, and drain electrodes, which reduces reflectance through destructive interference
Implementation Method 2
using a buffer layer with a multi-layer structure of silicon dioxide and silicon nitride to minimize external light reflection
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
An organic light emitting display device is discussed. The organic light emitting display device according to an embodiment includes a base substrate, a buffer layer disposed on the base substrate, and a thin film transistor disposed on the buffer layer. The organic light emitting display device further includes an organic light emitting diode connected to the thin film transistor and disposed on the thin film transistor. The thin film transistor includes a gate electrode, a source electrode, and a drain electrode. At least one of the gate, source, and drain electrodes of the thin film transistor includes a semi-transmissive metal layer, a transparent metal layer, and a reflective metal layer to improve outdoor visibility of a display panel by reducing reflectance of the electrodes even though a polarizer is removed.