Patterned Light-Shielding Layer for OLED Cell Gap
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Solution Overview
Problem
Conventional organic electroluminescent display (OLED) devices face issues with increased overall thickness due to the use of spacers and overcoat layers, leading to color shift and reduced aperture ratio, which complicates the manufacturing process and affects display quality.
Innovation Solution
The implementation of a patterned light-shielding layer between colored filter regions on a second substrate, which maintains a cell gap between the organic electroluminescent unit and the color filter assembly, replacing conventional spacers and omitting the overcoat layer to reduce thickness and simplify fabrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If spacers are disposed beside color filter layers, then the cell gap is maintained, but the width of the black matrix is increased and aperture ratio is reduced
Solution Approach 1:
The patent merges the spacer function into the light-shielding layer itself, specifically using the protruding portion of the light-shielding layer's profile to maintain the cell gap. This eliminates the need for separate spacers that would occupy additional space and reduce the aperture ratio, while still achieving the required cell gap maintenance.
2Stability of the object's composition
If overcoat layer is added to cover color filter layers, then planarization is achieved, but the overall thickness increases
Solution Approach 1:
The patent integrates the overcoat layer function into the light-shielding layer by designing its profile to include a covering portion that extends over the color filter layers. This provides the necessary planarization to enable subsequent photolithography processes while avoiding the addition of a separate overcoat layer that would increase overall device thickness.
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 approach reduces the overall thickness of the OLED device, minimizes color shift, and enhances display quality by maintaining a stable cell gap while simplifying the manufacturing process.
Implementation Method 1
an organic electroluminescent unit (103), interposed between two electrodes
Implementation Method 2
a color filter layer (205) is formed by sequentially forming a red color filter layer CF-R, a green color filter layer CF-G and a blue color filter layer CF-B
Data Source
AI summary
An organic electroluminescent display (OELD) device at least includes a first assembly and a second assembly. The first assembly has a first substrate and an organic electroluminescent unit formed on the first substrate. The second assembly, assembled with the first assembly, includes a second substrate, a color filter layer and a patterned light-shielding layer. The color filter layer is disposed on the second substrate and has plural colored regions with different colors. The patterned light-shielding layer is disposed on the color filter layer and between the colored regions. A part of the patterned light-shielding layer contacts the first assembly to maintain a cell gap between the first assembly and the second assembly.