Display Device Dual-Bank Structure Light Extraction
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Solution Overview
Problem
Current display devices face challenges in achieving high light emission efficiency due to limitations in the design and structure of light emitting elements and reflective electrodes, which affect the overall performance and efficiency of the display.
Innovation Solution
The proposed display device incorporates a specific structure with a first and second bank on a substrate, a light emitting element between the electrodes, a reflective electrode on the bank, and a color conversion layer, where the second bank is disposed on the top surface of the first bank and not on its side surfaces, and the reflective electrodes are strategically placed to enhance light reflection and emission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional single-layer bank structure is used, then the device complexity is low, but the light emission efficiency is insufficient
Solution Approach 1:
The bank structure is divided into a first bank and a second bank disposed at different heights. The first bank has a first top surface and side surfaces, while the second bank is disposed on the first top surface at a second height greater than the first height. This segmentation allows different regions of the bank to serve different functions: the first bank provides a base structure with reflective electrode for light reflection, while the second bank creates an elevated region for color conversion layer placement, thereby improving light emission efficiency through optimized optical path management.
Solution Approach 2:
The dual-layer bank structure implements local quality by creating regions with different heights and functions. The first bank region provides structural support and light reflection, while the second bank region provides an elevated platform for color conversion. This local differentiation optimizes the optical properties in different regions, improving overall light emission efficiency without requiring complete restructuring of the entire device.
2Illumination intensity
If the reflective electrode is placed only on the substrate, then the manufacturing process is simple, but the light reflection efficiency is limited
Solution Approach 1:
The reflective electrode is extended from the substrate onto the side surfaces of the first bank, utilizing the vertical dimension. This dimensional extension allows the reflective electrode to capture and reflect light from multiple angles, including light that would otherwise be lost at the edges and interfaces. The reflective electrode on the side surfaces creates additional reflection paths, significantly improving light reflection efficiency compared to a flat substrate-only configuration.
Solution Approach 2:
The reflective electrode acts as an intermediary between the light emitting element and the surrounding structure. By placing the reflective electrode on the side surfaces of the first bank, it mediates the light path by reflecting light that would otherwise be trapped or lost, redirecting it toward the color conversion layer and ultimately improving the overall light extraction and emission efficiency of the device.
3Area of stationary object
If the second bank is disposed on side surfaces of the first bank, then the color conversion layer area is increased, but the manufacturing precision requirements increase
Solution Approach 1:
The second bank is disposed asymmetrically on the first top surface rather than on the side surfaces. This asymmetric placement on the horizontal plane simplifies the manufacturing process by avoiding the need for precise vertical alignment on multiple faces. The second bank's position is optimized to maximize the color conversion layer area while maintaining manufacturability, as horizontal placement is easier to control than multi-faceted vertical placement.
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 improves light emission efficiency by optimizing the placement and structure of the banks and reflective electrodes, leading to enhanced light reflection and transmission, thereby improving the overall performance of the display device.
Implementation Method 1
a reflective electrode disposed on the first bank
Implementation Method 2
The color conversion layer may include a color conversion particle that converts a color of light
Data Source
AI summary
A display device includes a first electrode and a second electrode disposed on a substrate; a first bank disposed on the substrate, the first bank protruding in a thickness direction of the substrate; a light emitting element disposed on the first electrode and the second electrode; a reflective electrode disposed on the first bank; a second bank disposed on the first bank; and a color conversion layer disposed in an area surrounded by the second bank.