Transparent OLED Cathode Segmentation for Brightness and Transmittance
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Solution Overview
Problem
Conventional transparent OLED display technologies face challenges in forming a cathode layer with separate hollow areas due to the impossibility of creating an ideal mask with independent metal masking structures, leading to low transmittance and emission brightness issues.
Innovation Solution
A cathode layer structure with continuous coverage portions and narrow portions arranged in a matrix, where the signal lines overlap with both the narrow and strip-shaped protrusion areas, allowing for increased emission brightness and improved transmittance by reducing the adverse influence of the cathode layer on transmittance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If an ideal mask with independent metal masking structures is used to form separate hollow areas in the cathode layer, then the transmittance and emission brightness can be improved, but it is technically impossible to achieve such a mask structure
Solution Approach 1:
The cathode layer is segmented into multiple independent cathode regions corresponding to different sub-pixels, with hollow areas between them. This segmentation allows each cathode region to be independently formed while maintaining the required mask structure feasibility through a unified mask design that creates all hollow areas simultaneously.
Solution Approach 2:
The mask design implements local quality by having different regions of the mask with different properties: metal masking structures in areas requiring cathode deposition and transparent or open areas where hollow spaces should be formed. This local differentiation enables the formation of separate hollow areas without requiring an impossible suspended mask structure.
2Ease of manufacture
If the cathode layer is made continuous to ensure electrical conductivity, then the manufacturing is easier, but the transmittance decreases due to reduced hollow areas
Solution Approach 1:
The cathode layer is divided into multiple discrete cathode regions rather than a continuous layer. Each region corresponds to a specific sub-pixel and is electrically isolated from others, allowing hollow areas to exist between them while maintaining sufficient electrical conductivity within each region for proper cathode function.
Solution Approach 2:
The parameters of the cathode layer are optimized by controlling the size, shape, and spacing of individual cathode regions and their corresponding hollow areas. By adjusting these parameters, the patent achieves a balance where each cathode region maintains adequate conductivity while the overall structure provides sufficient transmittance through the hollow areas.
3Reliability
If the cathode layer thickness is increased to improve electrical conductivity and reduce resistance, then the emission brightness improves, but the transmittance decreases
Solution Approach 1:
By segmenting the cathode layer into discrete regions with hollow areas between them, the patent reduces the overall amount of cathode material in the light path. This allows for optimized local thickness in each cathode region - thick enough to ensure good conductivity and low resistance, but with sufficient hollow space between regions to maintain high transmittance.
Solution Approach 2:
The cathode layer implements local quality variations where individual cathode regions have optimized thickness and material composition tailored to their specific function, while the hollow areas between them provide high transmittance. This local differentiation allows simultaneous optimization of both electrical conductivity and optical transmittance.
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 achieves enhanced emission brightness and improved transmittance by optimizing the cathode layer structure through evaporation processes, allowing for uniform signal transmission and reduced resistance, thereby improving the overall display performance.
Implementation Method 1
the cathode layer is formed by an evaporation process
Data Source
AI summary
A transparent OLED panel and a display device are provided. The transparent OLED panel includes a cathode layer, which includes a cathode area and a plurality of hollow areas arranged in a matrix. The cathode area includes continuous coverage portions and narrow portions. Each continuous coverage portion includes flat areas arranged along the second direction and strip-shaped protrusion areas extending along the first direction and arranged along the second direction. The transparent OLED panel further includes a plurality of signal lines extending along the first direction. In a direction perpendicular to a plane where the panel is located, an orthogonal projection of the signal lines overlaps with an orthogonal projection of part of the narrow portions and an orthogonal projection of part of the strip-shaped protrusion areas.