Volumetric Diffuser for Asymmetric Light Control
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Solution Overview
Problem
Conventional light fixtures with symmetric or surface relief diffusers face challenges in achieving uniform light distribution, efficiency, and cost-effectiveness due to high backscatter, complexity in production, and difficulty in cleaning, particularly when trying to direct light asymmetrically.
Innovation Solution
The use of a thin, low-cost, volumetric diffuser with varying degrees of asymmetry, combined with a waveguide, to efficiently control light spread and reduce speckle contrast, allowing for tailored illumination and power reductions, while being easy to manufacture and clean.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If traditional diffusive elements or symmetric volumetric materials are used to spread light, then light distribution is achieved, but backscatter increases significantly reducing optical efficiency
Solution Approach 1:
The patent applies asymmetry by using asymmetric surface relief diffusers with non-uniform hole or pit distributions, and asymmetric volumetric scattering particles (such as elongated or irregularly shaped particles) instead of symmetric spherical particles. This asymmetric structure directs light preferentially in forward directions while minimizing backscatter, resolving the contradiction between achieving light distribution and reducing energy loss through backscatter.
2Adaptability or versatility
If asymmetric surface relief diffusers are used to direct light asymmetrically, then light direction control is improved, but manufacturing cost increases due to expensive holographic mastering and precision casting
Solution Approach 1:
The patent employs cost-effective manufacturing methods such as injection molding with asymmetric cavity designs, extrusion processes for asymmetric volumetric particles, and replication techniques that avoid expensive holographic mastering. These methods enable mass production of asymmetric diffusers at low cost, resolving the contradiction between achieving asymmetric light direction control and maintaining ease of manufacture.
3Adaptability or versatility
If surface relief diffusers with holes or pits are used for asymmetric scattering, then light scattering control is achieved, but cleaning difficulty increases due to dirt or particles becoming trapped
Solution Approach 1:
The patent extracts the scattering function from surface relief structures with trapped dirt-prone holes and pits, and implements it instead through volumetric scattering particles embedded within a solid matrix. This volumetric approach provides asymmetric scattering functionality without creating surface cavities that trap dirt, thereby resolving the contradiction between achieving asymmetric light scattering and maintaining ease of cleaning.
4Ease of operation
If common commercial symmetric volumetric materials are used, then ease of cleaning is improved, but light scattering control efficiency decreases
Solution Approach 1:
The patent combines asymmetric volumetric scattering particles (with non-spherical shapes or non-uniform refractive indices) within a cleanable volumetric matrix. This asymmetric particle design provides efficient and controllable light scattering while maintaining the ease of cleaning associated with volumetric materials, as the asymmetric particles are embedded within a solid, non-porous matrix that does not trap dirt.
5Adaptability or versatility
If refractive elements with non-planar surfaces are used to control light spread, then light direction control is improved, but fixture volume increases due to greater thickness
Solution Approach 1:
The patent employs thin film diffusers containing volumetric scattering particles distributed throughout their thickness. These thin film structures provide effective light direction control through the scattering action of embedded particles, while maintaining a thin profile that does not significantly increase fixture volume, resolving the contradiction between achieving light direction control and minimizing fixture volume.
6Adaptability or versatility
If LEDs are used as point light sources, then light control potential is improved, but visible speckle contrast on the light fixture increases
Solution Approach 1:
The patent introduces volumetric diffusers containing asymmetric scattering particles as intermediary elements between the LED point light sources and the surrounding environment. These diffusers scatter the coherent LED light in multiple directions, reducing the visibility of speckle patterns while maintaining effective light control through the asymmetric particle distribution, thereby resolving the contradiction between light control and speckle contrast reduction.
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 enhances spatial luminance uniformity, reduces power requirements, and lowers production costs by efficiently directing light, minimizing backscatter, and maintaining high illuminance, thus improving the overall performance and aesthetics of light fixtures.
Implementation Method 1
a volumetric diffuser with asymmetry of varying degree... to efficiently control light spread
Implementation Method 2
When the anisotropic diffuser is used in combination with a waveguide to extract light
Data Source
AI summary
An enhanced light fixture containing a volumetric diffuser to control the spatial luminance uniformity and angular spread of light from the light fixture is disclosed. The volumetric diffuser provides increased spatial luminance uniformity and efficient control over the illuminance such that power reductions, reduced cost or reduced size may be achieved. The volumetric diffuser contains one or more regions of volumetric light scattering particles. The spread of illumination of light from a light emitting source can be efficiently controlled by using a thin, low cost, volumetric, diffuser to direct the light in the desired direction. This allows the reduction in number of light sources, a reduction in power requirements, or a more tailored illumination. When the volumetric diffuser is used in combination with a waveguide to extract light, the light is efficiently coupled out of the waveguide in a thin, planar surface. This transmissive diffuser can be coupled to a reflecting element such that the resulting combination is a light reflecting element with a desired light scattering profile.