Light Emitting Display Anode Curvature and Concave Bank
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Solution Overview
Problem
Light emitting display apparatuses face inefficiencies in light extraction due to total reflection and optical waveguide losses, leading to reduced light extraction and front light extraction efficiencies.
Innovation Solution
A light emitting display apparatus with a concave bank layer and an anode having a side mirror shape is designed to minimize light spreading and redirect trapped light towards the front direction, improving light extraction efficiency and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional planar structure is used, then the device structure is simple, but light extraction efficiency is low due to total reflection and optical waveguide losses
Solution Approach 1:
The patent applies curvature by forming a protrusion portion on the insulating layer and configuring the reflective layer to cover the side portion of the protrusion portion, creating a curved/mirrored surface that redirects trapped light in lateral directions toward the front direction, thereby improving light extraction efficiency without significantly complicating the manufacturing process
Solution Approach 2:
The patent introduces a vertical dimension by forming a protrusion portion that extends upward from the planar insulating layer. This three-dimensional structure creates additional light extraction paths in the vertical direction while the reflective layer on the side portion redirects light, effectively addressing the two-dimensional light trapping problem
2Loss of energy
If a reflective layer is added on the side portion of the protrusion, then front light extraction efficiency is improved, but device complexity increases
Solution Approach 1:
The reflective layer serves multiple functions: it reflects light that would otherwise be lost in lateral directions back toward the front direction, and it is integrated into the existing anode structure as part of the first electrode. This multi-functionality improves front light extraction efficiency without proportionally increasing device complexity
Solution Approach 2:
The reflective layer is merged with the first electrode (anode) structure, combining the electrical function and the optical reflection function into a single integrated component. This reduces the number of separate layers and simplifies the overall device structure while achieving improved light extraction
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 increases external quantum efficiency by 6.39% and front light extraction efficiency by 5.50%, enhancing the overall light emission efficiency and reducing power consumption.
Implementation Method 1
the loss in total reflection refers to a degradation in light extraction efficiency due to the light trapped inside the light emitting display apparatus, of the light emitted from the light emitting layer, by total reflection at an interface between a substrate and the air
Implementation Method 2
the loss in optical waveguide refers to a degradation in light extraction efficiency due to the light trapped inside by total reflection at an interface of components inside the light emitting display apparatus
Data Source
AI summary
A light emitting display apparatus can include an insulating layer on a substrate and the insulating layer includes a base portion and a protrusion portion. The light emitting display apparatus further includes a first electrode covering an upper portion of the base portion and a side portion and an upper portion of the protrusion portion. The light emitting display apparatus further includes a bank layer covering a portion of the insulating layer and a portion of the first electrode and having a concave portion. The light emitting display apparatus further includes a light emitting layer on the first electrode and the bank layer, and a second electrode on the light emitting layer.