Rippled Light Mixing Rods for Uniform Illuminance
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Solution Overview
Problem
Existing light mixing rods fail to achieve uniform illuminance and color mixing, especially in circular beam patterns, and are sensitive to light source alignment and length, leading to non-uniformity and alignment issues in illumination systems.
Innovation Solution
The use of rippled sidewalls with elongate ridges and valleys in light mixing rods, which redirect light in an azimuthal direction, enhancing mixing and uniformity, and reducing sensitivity to light source alignment and length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional smooth mixing rods are used, then the structure is simple and easy to manufacture, but the illuminance uniformity and color mixing performance are insufficient
Solution Approach 1:
The mixing rod surface is segmented into multiple ridges and valleys, creating a rippled structure that divides the light path into multiple reflection zones. This segmentation enables better light redistribution and mixing, achieving superior illuminance uniformity and color mixing compared to smooth surfaces.
Solution Approach 2:
The mixing rod incorporates localized rippled structures with specific ridge heights, spacing, and profiles in the central region where light mixing is most needed. This local quality enhancement targets the critical mixing zone without complicating the entire structure, balancing performance improvement with manufacturing feasibility.
2Length of moving object
If the mixing rod length is reduced, then the device becomes more compact, but the light mixing performance and uniformity deteriorate
Solution Approach 1:
Instead of relying solely on longitudinal propagation for mixing, the invention introduces azimuthal redirection through rippled sidewalls. Light is redirected in the azimuthal direction, creating mixing paths that utilize the radial dimension. This dimensional change enables effective mixing in shorter rod lengths where traditional longitudinal mixing would be insufficient.
Solution Approach 2:
The rippled structure incorporates curved ridge profiles and rounded vertices that guide light through multiple reflections at controlled angles. This curvature design ensures that even in compact lengths, light undergoes sufficient redirection and mixing to achieve uniform illuminance and color distribution.
3Ease of manufacture
If the mixing rod uses simple geometry, then manufacturing is easier, but the light redirection and mixing capability is limited
Solution Approach 1:
The invention optimizes specific parameters of the rippled structure including ridge height (5-50 micrometers), ridge spacing (50-200 micrometers), and ridge profile curvature. These parameter ranges balance manufacturing ease with optical performance, enabling effective light redirection and color mixing while remaining compatible with conventional fabrication methods like injection molding or precision machining.
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 rippled sidewalls achieve substantially uniform illuminance and color mixing, improving the performance of light mixing rods by increasing uniformity and reducing alignment sensitivity, even in shorter lengths, thus enhancing the quality of illumination systems.
Implementation Method 1
Light from the plurality of light emitting diodes propagating along the optical path reflects from the sloping surfaces and is redirected at a different azimuthal direction toward the output end thereby mixing the light at the output end
Data Source
AI summary
Various embodiments described herein comprise mixers comprising a light pipe having input and output ends and a central region therebetween. An optical path extends in a longitudinal direction from the input end through the central region to the output end. The central region of the light pipe comprises one or more rippled reflective sidewalls having a plurality of elongate ridges and valleys and sloping surfaces therebetween. Light from the input end propagating along the optical path reflects from the sloping surfaces and is redirected at a different azimuthal direction toward the output end thereby mixing the light at the output end. Illuminance and/or color mixing can therefore be provided.