LED Module Venting Mechanism for Fog Prevention

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Solution Overview

Problem

LED modules used for outdoor illumination face issues with fogging and distortion of optical materials due to harmful gas formation from manufacturing residues and thermal reactions, which affect light output and distribution.

Innovation Solution

An LED module design featuring a transparent cover with a vent device that allows harmful gases to escape while preventing moisture entry, using a silicone-filled channel within the cover to maintain optical clarity and prevent fogging, and employing materials like Polyurethane or Polymethyl Methacrylate for the cover to provide electrical and thermal protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the LED module uses a hermetic seal to prevent moisture entry, then protection from environmental conditions is improved, but harmful gases from manufacturing residues cannot escape and cause fogging of optical materials

Engineering Contradiction:
Improveprotection from environmental conditionsVSAvoidfogging of optical materials
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies a porous barrier layer that selectively allows harmful gases to pass through while blocking moisture and water vapor. This porous structure resolves the contradiction by enabling gas permeability for harm removal while maintaining hermetic protection against environmental moisture, preventing both fogging and environmental damage.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent uses a composite structure combining a porous barrier layer with the cover assembly. This composite material approach allows the system to simultaneously achieve gas permeability for harmful substances and moisture impermeability for environmental protection, resolving the contradiction between hermetic sealing and gas venting.

Inventive Principle:
Principle #40Composite materials

2Power

If the LED module operates at high temperatures, then light generation efficiency is maintained, but thermal reactions cause formation of harmful gases that fog the optics

Engineering Contradiction:
Improvelight generation efficiencyVSAvoidharmful gases from thermal reactions
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent extracts harmful gases generated during high-temperature LED operation by providing a dedicated egress path through the porous barrier layer. This allows the LED to maintain high operating temperatures for efficient light generation while continuously removing the harmful gases produced by thermal reactions, preventing fogging of the optics.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the harmful effect of thermal reactions into a beneficial outcome by using the temperature-driven gas generation as an indicator to activate the gas removal mechanism. The harmful gases produced at high operating temperatures are channeled through the porous barrier, and their removal prevents fogging while allowing the LED to operate at optimal high temperatures.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If manufacturing flux residues are present on LED components, then assembly is simplified, but these residues outgas during operation and attack silicone materials causing fogging

Engineering Contradiction:
Improveassembly simplicityVSAvoidoutgassing from flux residues
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a porous barrier layer as an intermediary between the LED components with flux residues and the silicone optical materials. This barrier layer allows the harmful outgassing from flux residues to pass through without reaching and attacking the silicone materials, thereby preventing fogging while maintaining the manufacturing simplicity of using flux residues.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively prevents fogging and maintains optical quality by venting out harmful gases, ensuring consistent light output and distribution without compromising the transparency of the optical components.

Implementation Method 1

a vent device (15) adapted to prevent harmful gases from accumulating within said interior space (12) and attacking the silicone or other materials used to manufacture the LED component with a resultant fogging or discoloration of the cover and/or optics

Methodology Applied
Scientific EffectGas permeation: Permeation

Implementation Method 2

an optical silicone adapted to allow light to pass through the silicone unhampered

Methodology Applied
Scientific EffectLight transmission: Refraction

Implementation Method 3

The cover spans an interior space and electrically insulates the LED components

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 4

at least one LED component (2) mounted thereon. The LED component preferably comprises an electronic component used for light generation purposes

Methodology Applied
Scientific EffectLight-emitting diode effect: Light Emitting Diode

Data Source

PatentEP2470831B1LED assembly
Publication Date: 2020.04.08 VOSSLOH SCHWABE OPTOELECTRONICS
  • EP2470831B1 patent drawingFigure 1~4
  • EP2470831B1 patent drawingFigure 5~6

AI summary

An LED module or assembly is disclosed, the assembly having at least one LED component mounted on a support or circuit board and an optical element which encloses the at least one LED component and defines an interior space in which the at least one LED component is housed. A vent device is defined within the optical element for permitting gases generated from operation of the at least one LED component to be vented to atmosphere. The vent device prevents outside moisture from entering the interior space, but permits the gases to pass out to atmosphere for minimizing the likelihood of fogging of the optical elements in the interior space of the assembly.