OLED Micro-Cavity FWHM Optimization for Color Deviation
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Solution Overview
Problem
OLED apparatuses face color deviation issues with viewing angle due to increased color shift caused by micro-cavity effects, leading to degraded display quality when white light is emitted by mixing lights from red, green, and blue light emitting devices.
Innovation Solution
Optimizing the full width at half maximum (FWHM) of the main peak wavelength for each light emitting device to reduce color deviation, achieved by controlling the thickness of the cathode and optimizing the micro-cavity structure between electrodes for each color, thereby minimizing color change rate in color coordinates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the intensity of light is increased by micro-cavity effect, then luminance is improved, but color shift in accordance with viewing angle is increased
Solution Approach 1:
The patent optimizes the full width at half maximum (FWHM) of the main peak wavelength as a key parameter to control color deviation. By adjusting the FWHM values of red, green, and blue light emitting devices and ensuring their sum is 75nm or more, the patent resolves the contradiction between luminance enhancement through micro-cavity effect and color consistency across viewing angles.
2Stability of the object's composition
If the sum of FWHM of main peak wavelengths is increased, then color deviation is reduced, but luminance may be reduced
Solution Approach 1:
The patent establishes an optimal threshold for the sum of FWHM values (75nm or more) that balances color consistency and luminance. This parameter optimization ensures that color deviation is sufficiently reduced while maintaining acceptable luminance levels, resolving the contradiction between these two performance metrics.
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 optimized FWHM of the main peak wavelength reduces color deviation and improves display quality by maintaining color consistency across different viewing angles, with a color change rate of 0.030 or less, even when the sum of FWHM for red, green, and blue lights is 75nm or more, ensuring minimal luminance reduction.
Implementation Method 1
the micro-cavity indicates that a light emission efficiency is improved by amplification and constructive interference of the light emitted from the patterned emission layer through repetitive reflection and re-reflection between the two electrodes
Data Source
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AI summary
Discussed is an organic light emitting display (OLED) apparatus which facilitates to prevent a color deviation for a white color of the OLED apparatus from being increased, and thus improves the properties of color change rate in color coordinates for the white light. The OLED apparatus may include a plurality of light emitting devices for emitting light of different colors, wherein the sum of the full width at half maximum of main peak wavelength of light respectively emitted from each of the plurality of light emitting devices is 75nm or more when the white light is emitted from the OLED apparatus.