LED Light-Mixing Optics for Uniform White Projection at Close Range
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Solution Overview
Problem
Conventional LED lighting systems face issues with incomplete color mixing and non-uniformity when the distance between the LED lighting module and the projection surface is insufficient, leading to color fringing and scalloping, which affects applications such as automotive and aeronautical lighting.
Innovation Solution
The use of an optical device with specular and diffuse layers to enhance light mixing, allowing for uniform white light emission even when the LED lighting module is positioned close to the projection surface, achieved by reflecting and scattering light within the optical device before exiting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the LED lighting module is positioned close to the projection surface, then the device can be used in applications with limited space (e.g., automotive, aeronautical), but the light mixing becomes incomplete and non-uniform, resulting in color fringing and scalloping
Solution Approach 1:
The patent introduces an optical device as an intermediary component between the LED lighting module and the projection surface. This optical device includes a light guide with internal reflecting surfaces that mediate the light mixing process, enabling uniform color mixing even at close distances where direct projection would fail.
Solution Approach 2:
The patent transforms the light mixing problem from a spatial distance issue into a dimensional issue by using internal reflecting surfaces within the light guide. Instead of relying on long projection distances for mixing, the light is redirected through multiple internal paths and dimensions, achieving uniform mixing within a compact structure.
2Device complexity
If conventional light mixing techniques are used, then the system structure remains simple, but the light mixing requires a minimum distance of 1 to 3 feet away from the LED lighting module
Solution Approach 1:
The patent uses internal reflecting surfaces within the light guide to create multiple light paths in different dimensions. This allows light mixing to occur within the volume of the light guide itself rather than requiring long linear distance, effectively compressing the mixing space.
Solution Approach 2:
The optical device is nested within or integrated with the LED lighting module structure. The light guide contains and directs the light within its internal structure, embedding the mixing function within the existing system rather than requiring separate external mixing components.
3Length of stationary object
If the light is projected onto a surface closer than the minimum distance, then space is saved, but color mixing becomes incomplete resulting in color fringing and scalloping
Solution Approach 1:
The optical device serves as a mediator that ensures uniform color mixing before light reaches the projection surface. By introducing this intermediary with controlled internal reflection paths, the system achieves consistent illumination quality regardless of the reduced distance to the surface.
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
Ensures superior light mixing and color uniformity, enabling uniform white light projection regardless of the distance from the LED lighting module to the surface, applicable to various lighting applications including aeronautical, automotive, residential, and commercial lighting.
Implementation Method 1
The optical device includes a light guide with internal reflecting surfaces that redirect light from the LED assembly, causing the light to reflect and mix within the light guide before exiting
Implementation Method 2
The optical device includes diffuse layers that scatter light within the optical device before exiting, enhancing light mixing
Data Source
Figure 1A~1B
Figure 1C
Figure 2A
AI summary
An optical device includes a lower surface that is substantially transparent. The optical device further includes an upper surface disposed opposite the lower surface and having a first specular layer disposed thereon. The optical device further includes a first lateral surface extending between the lower surface and the upper surface and having a second specular layer disposed on at least a portion thereof.