Asymmetrical Light Guide for LED Luminaire Glare Reduction

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Solution Overview

Problem

Existing LED-based outdoor luminaires struggle to achieve asymmetric light distribution patterns without expensive secondary optics and often produce glare and aesthetically unappealing pixelated light sources.

Innovation Solution

A luminaire design featuring a light guide assembly with slanted edges and Gaussian dots or prisms that directs light output asymmetrically, allowing for adjustable light distribution patterns without secondary optics, reducing glare and spottiness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If asymmetric light distribution patterns are achieved using traditional methods, then the desired illumination pattern is obtained, but expensive secondary optics and complicated luminaire designs are required

Engineering Contradiction:
Improveasymmetric light distribution patternVSAvoidsecondary optics and luminaire design
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent applies asymmetry by configuring LEDs in an asymmetric arrangement relative to the light guide, with different numbers of LEDs on different sides. The light guide itself has an asymmetric cross-section with different refractive indices on different sides, creating inherent asymmetric light distribution without requiring complex secondary optics

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent extracts the asymmetric light distribution function from separate secondary optical components and integrates it directly into the light guide structure itself. The light guide's asymmetric geometry and refractive index profile inherently provide the asymmetric beam shaping, eliminating the need for additional asymmetric optical elements

Inventive Principle:
Principle #2Taking out (Extraction)

2Illumination intensity

If multiple visible LEDs are used in outdoor luminaires, then the desired light output is achieved, but discomfort glare and pixelated light sources are produced

Engineering Contradiction:
Improvelight outputVSAvoidglare and spottiness
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent merges multiple discrete LED light sources into a unified, uniform light output through the light guide. The light guide acts as an integrating element that combines the light from multiple LEDs and redistributes it uniformly across the exit face, eliminating the pixelated appearance and reducing glare while maintaining high light output

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies local quality by varying the refractive index of the light guide material in different regions. The light guide has different refractive indices on different sides, with gradient variations that control local light extraction and distribution, enabling uniform overall output while managing local light intensity to prevent glare

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 design achieves reduced glare and spottiness while providing customizable, uniform, and efficient asymmetric light distribution, suitable for various lighting applications like street lighting, without the need for expensive secondary optics.

Implementation Method 1

The light guide includes a rear portion including a first edge, a second edge, and a rear edge. The first edge meets the rear edge at a first obtuse angle, and the second edge meets the rear edge at a second obtuse angle

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

The plurality of LEDs disposed on the first edge, the second edge, and the rear edge, and it is arranged to produce an asymmetric light distribution pattern

Methodology Applied
Scientific EffectLight emitting diode: Light Emitting Diode

Data Source

PatentEP3510322B1Luminaire having an asymmetrical light distribution pattern
Publication Date: 2022.05.11 LUMILEDS LLC
  • EP3510322B1 patent drawingFigure 1~3
  • EP3510322B1 patent drawingFigure 4~10
  • EP3510322B1 patent drawingFigure 11~13

AI summary

An apparatus is disclosed including a light guide and a plurality of light emitting diodes (LEDs). The light guide includes a rear portion including a first edge, a second edge, and a rear edge. The first edge meets the rear edge at a first obtuse angle, and the second edge meets the rear edge at a second obtuse angle. The plurality of light emitting diodes (LEDs) disposed on the first edge, the second edge, and the rear edge, and it is arranged to produce an asymmetric light distribution pattern including a rear light emission and a forward light emission having a greater peak intensity than the rear light emission.