Flexible Silicone Light Guide for Aircraft Edge Lighting

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Solution Overview

Problem

Current edge lighting solutions for aircraft are complicated due to spatial and wiring limitations, and existing materials like polycarbonate have high transmission loss, making them unsuitable for aviation industry standards.

Innovation Solution

A flexible light guide system using a silicone substrate with controlled light extraction features, such as bubbles, arranged for uniform light emission, which can be formed to fit complex aircraft curvatures and meet aviation standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polycarbonate is used for the light guide, then flame retardancy is improved, but light transmission loss increases

Engineering Contradiction:
Improveflame retardancyVSAvoidlight transmission loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent uses silicone rubber as the light guide material, which is a composite material that inherently provides flame retardancy while maintaining excellent light transmission properties. This resolves the contradiction by selecting a material that combines both fire safety requirements and optical performance, eliminating the need to choose between polycarbonate's flame retardancy or acrylic's low transmission loss.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the material composition parameters by incorporating specific flame retardant additives and adjusting the silicone rubber formulation to achieve optimal balance between flame resistance and light transmission. This allows the material to meet aviation standards while maintaining low transmission loss.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If acrylic is used for edge lighting, then light transmission is improved, but flame retardancy deteriorates

Engineering Contradiction:
Improvelight transmission lossVSAvoidflame retardancy
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent employs silicone rubber, a composite material that inherently combines the low transmission loss characteristics of acrylic with the flame retardant properties of polycarbonate. This resolves the contradiction by providing a material that simultaneously achieves both optical performance and fire safety without requiring additional modifications.

Inventive Principle:
Principle #40Composite materials

3Illumination intensity

If light extraction features are added to the light guide, then uniform light emission is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveuniform light emissionVSAvoidmanufacturing complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent incorporates light extraction features in the form of pores or cavities within the silicone rubber light guide. These porous structures extract light from the internal total internal reflection paths and redirect it toward the viewing surface, achieving uniform light emission. The porous structure is integrated into the molding process, avoiding additional manufacturing steps.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The light extraction features are pre-formed during the silicone rubber molding process itself, rather than being added as a separate post-processing step. This preliminary action integrates the light extraction function into the base material fabrication, eliminating additional manufacturing complexity while achieving uniform light emission.

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If the light guide is made flexible to fit aircraft curvatures, then adaptability is improved, but structural strength deteriorates

Engineering Contradiction:
Improveflexibility for curvatureVSAvoidstructural strength
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent uses a flexible silicone rubber light guide that can be formed into curved and contoured shapes to fit aircraft interior surfaces. The flexible nature of silicone rubber allows the light guide to conform to complex geometries while maintaining sufficient structural integrity for installation and operation in aviation environments.

Inventive Principle:
Principle #30Flexible shells and thin films

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 flexible light guide system provides consistent and controlled color accuracy, dimming capabilities, and meets aviation industry standards for fire, smoke, and toxicity requirements, simplifying installation and enhancing aesthetic appeal.

Implementation Method 1

a light guide transmits light from the light source to a light emitting surface

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

a plurality of light extraction features formed within the flexible substrate in between the two outer surfaces. The light extraction features are arranged according to a controlled distribution that affects a propagation of light in between the two outer surfaces and an emission of light from the light emitting area

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP3540301B1Method of manufacturing a flexible light guide and system for the implementation of the method
Publication Date: 2024.05.15 ROCKWELL COLLINS INC
  • EP3540301B1 patent drawingFigure 1
  • EP3540301B1 patent drawingFigure 2A
  • EP3540301B1 patent drawingFigure 2B

AI summary

In accordance with embodiments of this disclosure a light guide includes a flexible substrate having two outer surfaces with at least one of the two outer surfaces defining a light emitting area. At least one edge of the flexible substrate is configured to receive light from a light source coupled to the edge. The light guide further includes a plurality of light extraction features formed within the flexible substrate in between the two outer surfaces. The light extraction features may be arranged according to a controlled distribution that affects a propagation of light in between the two outer surfaces and an emission of light from the light emitting area.