Etendue-Preserving Optical Coupling for Uniform LED Illumination
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Solution Overview
Problem
Conventional illumination systems are bulky, inefficient, and unable to provide uniform chromatically controlled lighting, leading to non-uniform brightness and glare issues, as well as low energy efficiency and aesthetic concerns with color variations.
Innovation Solution
The implementation of an etendue-preserving optical coupling system that transforms the light distribution profile of LEDs into a more condensed and uniform output, using a refractive index-matched receiving optical system with a light redirecting element to redirect light efficiently and reduce aperture brightness, thereby enhancing illumination uniformity and reducing glare.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If standard illumination systems are used, then illumination can be provided, but the systems become large, heavy and bulky
Solution Approach 1:
The patent changes the optical parameters by using an etendue-preserving optical coupling system with specific refractive index matching between the coupling system and receiving optical system. This enables compact illumination system design while maintaining illumination performance through optimized light propagation parameters
2Illumination intensity
If standard illumination systems are used, then illumination can be provided, but the systems become bulky
Solution Approach 1:
The patent employs parameter changes through etendue-preserving optical coupling with refractive index matching, which allows the illumination system to achieve compact volume while maintaining effective illumination through optimized optical path parameters
3Illumination intensity
If standard illumination systems are used, then illumination can be provided, but non-uniform brightness occurs with brightest area directly below the system
Solution Approach 1:
The patent introduces an etendue-preserving optical coupling system as an intermediary between the light source and the receiving optical system. This intermediary component with matched refractive index uniformly distributes light across the output aperture, eliminating the non-uniform brightness pattern where the area directly below the system was brightest
4Illumination intensity
If standard illumination systems are used, then illumination can be provided, but glare occurs in areas receiving illumination
Solution Approach 1:
The etendue-preserving optical coupling system acts as a mediator that redistributes light intensity across the output aperture. By maintaining etendue conservation and matching refractive indices, it reduces peak brightness and distributes light more evenly, thereby reducing disability glare for viewers in illuminated areas
5Illumination intensity
If standard illumination systems are used, then illumination can be provided, but net illumination efficiencies are far lower than desired
Solution Approach 1:
The patent optimizes illumination efficiency by changing optical parameters through etendue-preserving coupling with refractive index matching. This minimizes optical losses at interfaces and improves light extraction efficiency, achieving net illumination efficiencies meeting modern energy conservation requirements
6Illumination intensity
If multi-color LED's are used for spectral control, then chromatic illumination can be provided, but color break-up and non-uniformity occur within the aperture
Solution Approach 1:
The etendue-preserving optical coupling system serves as an intermediary that homogenizes multi-color LED light before it enters the receiving optical system. The refractive index matching and etendue conservation properties ensure uniform chromatic distribution across the output aperture, eliminating color break-up and non-uniformity
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 solution results in compact, energy-efficient illumination systems that provide uniform and aesthetically pleasing lighting with reduced glare, achieving improved lumens distribution and maintaining brightness while minimizing aperture brightness and Fresnel reflections.
Implementation Method 1
The optical coupling system is configured to preserve etendue of light propagating from an input aperture to an output aperture
Implementation Method 2
The receiving optical system may have a light redirecting element that is configured to receive light from the light output surface of the optical coupling system along an incident direction and to redirect the light along an output direction that is at an angle with respect to the incident direction
Data Source
AI summary
This disclosure provides systems, methods and apparatus for providing illumination. In one aspect, an etendue preserving optical coupling system configured to: receive incident light through an input aperture; and emit the incident light through an output aperture having an area smaller than an area of the input aperture is provided. The light output from the optical coupling system is coupled into a light receiving system including material having substantially the same refractive index as the refractive index of the material of the optical coupling system. The light receiving system includes a light guide configured to internally propagate the redirected light and to release light to illuminate the ambient environment.