Organic Electroluminescent Display Bump Thickness Optimization
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Solution Overview
Problem
Existing organic electroluminescent displays face challenges in achieving uniform light intensity and improved display quality, particularly in bottom emission type displays, where light reflection and output efficiency are compromised.
Innovation Solution
The organic electroluminescent display incorporates a substrate with pixel and non-pixel regions, a first electrode, an organic light emitting layer, a reflective second electrode, a pixel defining layer, and bumps with varying thicknesses on the pixel regions to optimize light reflection and output, ensuring uniform light intensity and enhanced display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a reflective second electrode is used in bottom emission type displays, then light reflection efficiency is improved, but light intensity uniformity across the pixel region deteriorates
Solution Approach 1:
The patent applies local quality by creating bumps with varying thicknesses at different locations within the pixel region. Specifically, the bump thickness is greater at the center of the pixel region and smaller at the edges, allowing different parts of the reflective electrode to have different optical characteristics. This non-uniform bump structure compensates for the non-uniform light reflection, achieving uniform light intensity across the pixel region while maintaining high reflection efficiency.
2Ease of manufacture
If uniform bump thickness is used across the pixel region, then manufacturing simplicity is maintained, but light output uniformity deteriorates
Solution Approach 1:
The patent implements local quality by varying the bump thickness across the pixel region, with greater thickness at the center and smaller thickness at the edges. This spatial variation in bump dimensions is designed to compensate for non-uniform light reflection characteristics, achieving uniform light output across the pixel region.
Solution Approach 2:
The patent applies parameter changes by modifying the bump thickness parameter across different locations of the pixel region. The bump thickness is systematically varied from the center to the edges of the pixel region, creating a gradient structure that optimizes light reflection uniformity. This controlled parameter variation enables uniform light output while maintaining manufacturing feasibility through established bump formation techniques.
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 allows for increased light intensity and uniform brightness across the pixel region, improving display quality by concentrating light on center regions and optimizing optical characteristics through controlled bump thickness, thereby enhancing the overall performance of the organic electroluminescent display.
Implementation Method 1
an organic light emitting layer formed on the first electrode and capable of generating light
Implementation Method 2
the light generated from the organic light emitting layer may be reflected by the cathode and then may be outputted to the external system. Thus, the cathode of the bottom emission type organic electroluminescent display includes a conductive material for reflecting light
Data Source
AI summary
An organic electroluminescent display is disclosed. The organic electroluminescent display includes a substrate having a pixel region and a non-pixel region, a first electrode disposed on the pixel region, an organic light emitting layer disposed on the first electrode and capable of generating light, a second electrode disposed on the organic light emitting layer and including a conductive material capable of reflecting light, a pixel defining layer disposed on the non-pixel region, and a bump disposed on the pixel region and capable of reflecting light to the substrate. The pixel region may include multiple pixel regions defined in the substrate. The bump may include multiple bumps. At least two bumps may have thicknesses different from each other.