Luminaire Light Guide Redirecting End-Face

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Solution Overview

Problem

Existing solid-state luminaires face challenges in efficiently redirecting light to achieve uniform illumination and minimizing material usage, leading to increased manufacturing and distribution costs.

Innovation Solution

A solid-state luminaire module with a light guide featuring a redirecting end-face that reflects guided light back into the guide, allowing it to transmit through side surfaces at specific angles, and an optical coupler system to transform light angles, ensuring efficient light distribution and reduced material requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If light is guided through a light guide to an exit aperture and redirected outward, then light distribution is achieved, but material usage increases and manufacturing costs rise

Engineering Contradiction:
Improvelight distribution uniformityVSAvoidmaterial usage
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

The light guide is divided into functional segments: a first portion that receives light from LEDs and a second portion that redirects light to the exit aperture. This segmentation allows each portion to be optimized for its specific function, improving light distribution while using material efficiently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The light guide transitions from a simple linear structure to a three-dimensional configuration with specific geometric features (exit aperture, reflective surfaces). By utilizing spatial dimensionality, the design achieves effective light redirection without proportionally increasing material volume.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If a light guide with exit aperture is used to redirect light, then illumination is provided, but device complexity increases

Engineering Contradiction:
Improvelight outputVSAvoidlight guide structure
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The light guide integrates multiple functions into a single component: light reception, light guidance, light redirection, and exit aperture formation. By merging these functions, the design reduces overall device complexity compared to using separate components for each function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The light guide structure serves multiple purposes simultaneously: it acts as both a guiding medium and a redirecting element, while the exit aperture configuration provides both light output and structural definition. This multi-functionality simplifies the overall luminaire design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Loss of energy

If light is reflected back into the light guide at the end-face, then light utilization improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improvelight utilization efficiencyVSAvoidend-face alignment
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The design utilizes the critical angle parameter of total internal reflection to achieve light redirection. By carefully selecting the geometric parameters of the light guide and exit aperture, the system achieves efficient light utilization while maintaining manufacturability through standard precision tolerances.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The design replaces complex mechanical alignment systems with an optical solution based on total internal reflection. This substitution reduces the need for high-precision mechanical assembly while achieving effective light redirection and utilization.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 enables more compact, cost-effective luminaire modules with improved light uniformity and reduced material usage, achieving efficient light redirection and propagation while minimizing manufacturing costs.

Implementation Method 1

the light guide is configured to guide the received light in a forward direction through total internal reflection (TIR) off the opposing side surfaces

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

a redirecting end-face located at the opposing end and configured to reflect at least a portion of the guided light - that reaches the opposing end - back into the light guide as return light

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

substantially all the return light impinges on the pair of opposing side surfaces at incident angles smaller than a critical incidence angle and transmits through the pair of opposing side surfaces into the ambient as output light of the luminaire module

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3114397B1Luminaire module having a light guide with a redirecting end-face
Publication Date: 2020.12.16 QUARKSTAR LLC
  • EP3114397B1 patent drawingFigure 1A
  • EP3114397B1 patent drawingFigure 1B~1D
  • EP3114397B1 patent drawingFigure 2

AI summary

A solid-state luminaire module includes one or more light-emitting elements (LEEs) (110) arranged to provide light; and a light guide (130) including a receiving end arranged to receive the light provided by the LEEs and an opposing end, a pair of opposing side surfaces (132a, 132b) extending along a length of the light guide to guide the received light in a forward direction to the opposing end, and a redirecting end-face (140) located at the opposing end and configured to reflect the guided light - that reaches the opposing end - back into the light guide as return light, such that substantially all the return light impinges on the pair of opposing side surfaces (132a, 132b) at incident angles larger than a critical incidence angle and transmits through the pair of opposing side surfaces (132a, 132b) into the ambient as output light of the luminaire module, the output light to propagate in backward directions.