Organic EL Display Panel Insulating Layer Opening Pattern
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Solution Overview
Problem
In organic electroluminescence (EL) display panels, low-cost ink application methods like ink jetting face challenges with insufficient ink spread due to concave pixel electrodes, leading to uneven film thickness and luminance issues, which affect luminous efficiency and panel service life.
Innovation Solution
The design includes a substrate with pixel electrode layers, an insulating layer having elongated first openings and shorter second openings, and a light-transmissive counter electrode layer, facilitating uniform ink spread and maintaining high luminous efficiency by optimizing the reflector structure for improved light extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a low-cost ink application method such as an ink jet method is used for constituting a reflector including organic light emitting layers, then manufacturing cost is reduced, but insufficient ink spread occurs due to concave first members, resulting in ununiform film thickness
Solution Approach 1:
The insulating layer is divided into multiple regions with different opening patterns: first openings (concave) for light extraction enhancement and second openings (flat) for uniform ink application. This segmentation allows different functional zones within the same pixel electrode layer, resolving the contradiction between cost reduction and manufacturing precision.
Solution Approach 2:
Different regions of the insulating layer are designed with different local properties: the first openings provide light extraction efficiency while the second openings provide uniform ink spread. This local differentiation enables simultaneous achievement of high luminous efficiency and uniform film thickness without increasing overall manufacturing complexity.
2Loss of energy
If concave first members are provided on pixel electrode surfaces to improve light extraction efficiency, then luminous efficiency is enhanced, but ink spread becomes insufficient, causing luminance unevenness
Solution Approach 1:
The pixel electrode surface is segmented into two types of openings: first openings with concave structures for light extraction enhancement, and second openings with flat surfaces for uniform ink application. This segmentation allows simultaneous optimization of both light extraction efficiency and luminance uniformity.
Solution Approach 2:
The second openings act as intermediary regions that facilitate uniform ink application across the pixel electrode surface, mediating between the light extraction function of the first openings and the requirement for uniform organic light emitting layer formation. This intermediary structure ensures reliable ink spread while maintaining high luminous efficiency.
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 ensures uniform film thickness and high luminous efficiency across pixels, reducing luminance unevenness and extending panel service life while maintaining high light extraction efficiency.
Implementation Method 1
pixel electrode layers that are made of a light-reflective material and are arranged on the substrate in the matrix
Implementation Method 2
light emitting layers in which organic electroluminescence occurs in the first opening and the second openings
Data Source
AI summary
An organic electroluminescence (EL) display panel having pixels arranged in a matrix of rows and columns includes: a substrate; pixel electrode layers that are made of a light-reflective material and are arranged on the substrate in the matrix; an insulating layer that is provided above the substrate and the pixel electrode layers; organic functional layers that are provided above the pixel electrode layers; and a light-transmissive counter electrode layer that is provided above the organic functional layers, wherein the insulating layer has a first opening and second openings for each of the pixel electrode layers, the first opening being elongated in a column direction, the second openings each being shorter than the first opening in the column direction and being lined up adjacent to the first opening, and the organic functional layers include light-emitting layers in which organic electroluminescence occurs in the first opening and the second openings.