Organic Light Emitting Display Device Color Filter Substrate
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Solution Overview
Problem
Conventional organic light emitting display devices suffer from color inversion and deterioration of color characteristics due to wavelength interference caused by light passing through layers with high refractive indices, such as the gate insulating layer and protective film, which changes color coordinates when viewed from different angles.
Innovation Solution
The solution involves removing the gate insulating layer and protective layer with high refractive indices from the emission regions and forming the color filter layer directly on the substrate, allowing light to be emitted through the overcoat layer and substrate with similar refractive indices, thereby maintaining consistent color coordinates regardless of the viewing angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light passes through layers with high refractive indices (gate insulating layer and protective film), then the device structure is complete and protective, but color inversion and deterioration of color characteristics occur due to wavelength interference
Solution Approach 1:
The patent removes the gate insulating layer and protective film from the light emission path by defining emission regions where these high refractive index layers are absent. Light passes directly from the organic light emitting layer through the substrate, eliminating the wavelength interference caused by high refractive index layers while maintaining the protective function in non-emission areas.
Solution Approach 2:
The patent applies different structural configurations to different regions of the display device. In emission regions, the structure is optimized for light output by removing high refractive index layers, while in non-emission regions, the protective structure is maintained. This local differentiation allows simultaneous achievement of color stability and device protection.
2Manufacturing precision
If the gate insulating layer and protective film are removed from emission regions, then color coordinates remain consistent across viewing angles, but the device structure becomes more complex requiring precise region definition
Solution Approach 1:
The patent combines the emission region definition with the existing pixel structure by using the pixel electrode pattern and organic light emitting layer configuration to naturally define emission areas. The low refractive index regions are formed by the inherent structure of the organic light emitting device components, merging the optical optimization with the existing device architecture.
Solution Approach 2:
The patent addresses the two-dimensional color consistency problem by introducing a spatial dimension solution - creating specific three-dimensional structural configurations in the emission regions where light paths are optimized by removing overhead layers, thus solving the color consistency issue through structural dimensionality rather than material composition changes.
3Productivity
If the color filter layer is formed directly on the substrate in emission regions, then light emission efficiency improves, but the protective function against moisture and oxygen is reduced
Solution Approach 1:
The patent segments the device into emission regions and non-emission regions with different functional optimizations. In emission regions, the color filter layer contacts the substrate directly for optimal light output, while in non-emission regions, the protective structure with encapsulation layers is maintained to provide moisture and oxygen barrier functions. This spatial segmentation allows simultaneous optimization of both light emission and protection.
Solution Approach 2:
The patent introduces an encapsulation layer as an intermediary protective structure that selectively covers non-emission regions while allowing emission regions to maintain direct contact between the color filter layer and substrate. This intermediary layer provides the necessary protection against moisture and oxygen without interfering with the light emission efficiency in the emission areas.
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 prevents deterioration of color characteristics by ensuring light is emitted through layers with matching refractive indices, maintaining consistent color coordinates across different viewing angles and improving color accuracy.
Implementation Method 1
The organic light emitting display device applies an electric field to a first electrode and a second electrode formed at both ends of an organic light emitting layer so as to inject and transport electrons and holes into the organic light emitting layer, thereby utilizing an electroluminescence phenomenon which emits light by binding energy during recombination of the electrons and holes
Implementation Method 2
color inversion is caused by wavelength interference of light according to viewing angle while passing through the protective film 16 and the gate insulating layer 12 having high indexes of refraction
Data Source
AI summary
The organic light emitting display device includes a substrate, a thin film transistor formed on the substrate, a protective film formed to cover the thin film transistor, a color filter layer formed on the substrate exposed by removing a gate insulating layer of the thin film transistor and the protective film, an overcoat layer formed over the entire surface of the substrate to cover the color filter layer and the protective film, a drain contact hole exposing the thin film transistor by selectively removing the protective film and the overcoat layer, and a first electrode connected to the thin film transistor through the drain contact hole on the overcoat layer, a white organic light emitting layer formed on the first electrode, and a second electrode formed to cover the white organic light emitting layer.