LED Light Collector Aperture for Uniform Far-Field Color Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LED packages with multiple LED chips, especially those of different colors, exhibit far field patterns (FFPs) that vary in color intensity with viewing angle, leading to non-uniform color observation, which is detrimental for display applications and other illumination needs.
Innovation Solution
Incorporating a light collector with a reflective surface and a reduced aperture over the LED chips, along with a diffuser material and a lens, to mix the light emissions from multiple point sources into a single or reduced-area source, thereby improving the FFP and maintaining color uniformity across different viewing angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple LED chips of different colors are used in an LED package, then the color variety and illumination capabilities are improved, but the far field pattern exhibits non-uniform color intensity with viewing angle
Solution Approach 1:
The patent merges multiple LED chip light sources into a single effective light source by positioning them within a shared encapsulant structure. The LED chips are arranged in a common package with a single lens and aperture, causing their light emissions to combine and exit through a unified optical path, thereby achieving color uniformity while maintaining multi-color capability
Solution Approach 2:
The encapsulant and lens act as intermediary elements that mediate between the multiple LED chips and the external environment. These components homogenize the light from different colored chips before emission, ensuring uniform color perception across various viewing angles while preserving the diverse color output
2Stability of the object's composition
If a light collector with reflective surface and reduced aperture is used, then the far field pattern and color uniformity are improved, but the device structure becomes more complex
Solution Approach 1:
The encapsulant structure serves multiple functions simultaneously: it provides mechanical support for the LED chips, acts as a light mixing chamber with reflective surfaces, functions as a diffuser, and integrates the lens and aperture assembly. This multi-functionality reduces the need for separate components, thereby limiting the increase in structural complexity while achieving improved color uniformity
3Manufacturing precision
If diffuser material is incorporated in the light collector, then the light mixing efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent employs composite material construction where the encapsulant is formed as an integrated structure combining light-transmissive material with embedded diffuser elements and reflective surfaces. This composite approach achieves effective light mixing within a single manufactured component, avoiding the need for multiple separate elements and thereby limiting the increase in device complexity
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 significantly enhances the color uniformity and reduces color shifts with viewing angle, achieving a figure of merit (FOM) for the far field pattern in the range of 0.7 to 0.995, ensuring consistent and high-quality color emission.
Implementation Method 1
at least one reflective coating on a surface of the light collector wherein the reflective coating forms at least one aperture
Implementation Method 2
the light collector can include diffuser material to facilitate the mixing of the light within the light collector
Implementation Method 3
The LED package can also include a lens to further modify the FFP
Data Source
AI summary
Light-emitting diode (LED) packages and more particularly a light collector for light mixing in LED packages to improve the far field emission pattern (FFP) of the LED packages are disclosed. The LED package can include one or more LED chips with different wavelength ranges, and the light collector placed over the LED chips can have a reflective surface, save for a reduced aperture through which the light from the LED chips can be emitted after mixing in the light collector. The LED package can also include a lens to further improve the FFP. In an embodiment, the light collector can include diffuser material to facilitate the mixing of the light within the light collector. The LED package with the light collector mixes multiple emission point sources into a single point source, or reduced-area source, that considerably improves the FFP of multi-colored LED chips of the LED package.