Tapered Waveguide Luminaire for Uniform Light Distribution

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Solution Overview

Problem

Low-efficiency light coupling in LED-based luminaires due to the inherent losses when directing light from a lambertian emitting source into a narrow edge of a waveguide plane, leading to suboptimal light distribution and extraction.

Innovation Solution

A luminaire design utilizing a waveguide body with tapered sections and strategically placed extraction features, which control light distribution by refracting and reflecting light through total internal reflection, allowing for efficient light coupling and extraction, thereby enhancing light mixing and uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If light is directed from a lambertian emitting source into a narrow edge of a waveguide plane, then light coupling is achieved, but coupling efficiency is low due to inherent losses

Engineering Contradiction:
Improvelight coupling efficiencyVSAvoidwaveguide structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The waveguide structure is divided into multiple sections with different thicknesses (first section with greater thickness, second section with lesser thickness). This segmentation allows optimized light coupling in each section, reducing overall energy loss while maintaining structural feasibility

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the waveguide are given different local properties (varying thickness) to optimize light coupling at specific locations. The first section has greater thickness for initial light entry, while the second section has lesser thickness for controlled light extraction, addressing coupling efficiency locally rather than uniformly

Inventive Principle:
Principle #3Local quality

2Productivity

If extraction features are strategically placed in the waveguide, then light extraction efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvelight extraction efficiencyVSAvoidwaveguide fabrication difficulty
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The waveguide is segmented into distinct sections (first and second sections) with extraction features strategically placed in specific locations. This segmentation allows optimization of light extraction efficiency in different regions while maintaining a structured approach that facilitates manufacturing

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The thickness parameter of the waveguide is changed between sections (greater in first section, lesser in second section) to optimize light extraction efficiency. This parameter variation is implemented in a controlled manner that balances extraction performance with manufacturing feasibility

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If the waveguide structure is optimized for light distribution, then light uniformity is improved, but the size and weight of the luminaire increase

Engineering Contradiction:
Improvelight distribution uniformityVSAvoidluminaire weight
Core Design Contradiction:
Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

The waveguide is divided into sections of different thicknesses that work together to achieve uniform light distribution. This segmented approach allows light uniformity to be achieved through optimized light paths in each section rather than requiring a uniformly thick, heavier structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections have different local thickness properties optimized for their specific function in the light distribution process. This local optimization achieves overall light uniformity without requiring the entire structure to be uniformly thick, reducing unnecessary material and weight

Inventive Principle:
Principle #3Local quality

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 achieves improved light mixing and extraction efficiency, resulting in a more uniform and controlled light distribution with increased luminaire efficacy and reduced size and weight, while maintaining high optical efficiency.

Implementation Method 1

control light distribution by refracting and reflecting light through total internal reflection

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

The coupling component(s) direct light into the distribution element(s), and condition the light to interact with the subsequent components

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3102873B1Optical waveguide bodies and luminaires utilizing same
Publication Date: 2021.12.22 IDEAL IND LIGHTING LLC
  • EP3102873B1 patent drawingFigure 1
  • EP3102873B1 patent drawingFigure 2~3
  • EP3102873B1 patent drawingFigure 3A~4

AI summary

According to one aspect, a luminaire comprises a waveguide body including a central section and first and second separate side sections extending away from the central section along first and second opposed directions, respectively. The central section includes a coupling portion and the waveguide body has a length and includes a plurality of light extraction features that extract light out of the side sections. At least one LED is disposed adjacent the coupling portion and is operated by a power circuit to produce light that is directed into the waveguide body by the coupling portion. At least one structural member extends along the length of the waveguide body for supporting the waveguide body and encloses at least one of the power circuit and the at least one LED.