OLED Microlens Refractive Index Equalization
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Solution Overview
Problem
Optical display devices like OLEDs experience color shifts at oblique viewing angles due to differences in light divergence angles and microcavity resonance, leading to variations in luminance and color temperature.
Innovation Solution
The implementation of lenses with specific refractive indices on OLED subpixel elements to refract light beams, ensuring equivalent light divergence angles across different colors, thereby reducing color shifts. These lenses can be convex, concave, or gradient refractive index lenses, either as single units or laminated layers, and may incorporate materials like polycarbonate or liquid crystals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If lenses with different refractive indices are added to subpixel elements, then color shift is reduced and viewing angle consistency is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent applies different refractive indices to different lens positions corresponding to different subpixel colors. Specifically, the green subpixel has a lens with refractive index of 1.7, the blue subpixel has a lens with refractive index of 1.9, and the red subpixel has a lens with refractive index of 1.5. This local differentiation of optical properties compensates for the different light emission characteristics of each color, achieving consistent viewing angles without requiring complex overall system redesign
Solution Approach 2:
The patent employs lenses made from different materials with specific refractive indices to address color-dependent light divergence. By selecting materials with appropriate optical properties (polycarbonate for green, high-index material for blue, lower-index material for red), the system achieves uniform angular distribution across all colors while maintaining manufacturing feasibility through material selection rather than complex structural design
2Manufacturing precision
If multiple lenses with different refractive indices are implemented, then light divergence angles are equalized across colors, but manufacturing precision requirements increase
Solution Approach 1:
The patent controls the light divergence angle by adjusting the refractive index parameter of each lens rather than precisely controlling lens geometry. By selecting materials with specific refractive indices (1.7 for green, 1.9 for blue, 1.5 for red), the system achieves the desired angular distribution with standard manufacturing tolerances, avoiding the need for ultra-precise lens shaping and positioning
3Stability of the object's composition
If lenses are added to correct light divergence, then color consistency is improved, but device cost and structural complexity increase
Solution Approach 1:
The patent implements a simple yet effective solution by placing individual lenses directly over each subpixel element. Each lens is tailored to its specific color with an appropriate refractive index, creating a localized correction that maintains overall system simplicity. The lens structure follows the subpixel arrangement without adding complex optical paths or multiple lens layers
Solution Approach 2:
The patent achieves color consistency by changing the refractive index parameter of simple spherical lenses rather than using complex optical systems. This parameter-based approach allows standard lens fabrication methods to be used while achieving the desired optical effect, thereby minimizing both structural complexity and manufacturing cost
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 reduces color shifts and extends the service life of OLED displays by maintaining consistent luminance and color across various viewing angles, improving the angular distribution of light emission.
Implementation Method 1
A first lens is disposed on the second subpixel element, and is formed to have a first refractive index that is configured to refract the second light beam of the second subpixel element to a second refracted light divergence angle that is equivalent to the first light divergence angle
Data Source
AI summary
An organic light-emitting diode (OLED) pixel is composed of a plurality of subpixel elements and one or more lenses, including first, second and third subpixel elements that emit light beams having first, second and third colors, respectively. The first subpixel element exhibits a first light divergence angle, the second subpixel element exhibits a second light divergence angle, and the third subpixel element exhibits a third light divergence angle. A first lens is disposed on the second subpixel element, with a first refractive index to refract the light beam of the second subpixel element to a light divergence angle that is equivalent to the first light divergence angle. A second lens is disposed on the third subpixel element, with a refractive index to refract the light beam of the third subpixel element to a divergence angle that is equivalent to the first light divergence angle.