Amber LED Portable Lighting for Smoke Visibility
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Solution Overview
Problem
Current portable lighting devices for emergency and rescue situations face issues with luminous efficacy and visibility due to scattering of short wavelengths of light by airborne particulates, leading to reduced visibility and situational awareness in smoky environments.
Innovation Solution
A portable lighting device utilizing phosphor-converted amber LEDs that emit light primarily within the 550 nm to 700 nm range, minimizing the region of the spectrum reflected by particulates and maximizing penetration, thereby enhancing visibility and depth perception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If full spectrum light sources are used, then visibility and color rendition are improved, but luminous efficacy is reduced due to filtering requirements
Solution Approach 1:
The patent changes the wavelength parameter of the light source from full spectrum (including short wavelengths below 550 nm) to a specific range (550 nm to 700 nm) that avoids scattering while maintaining good color rendition and visibility. This parameter optimization resolves the contradiction by selecting a wavelength range that balances luminous efficacy with acceptable visibility performance in smoke-filled environments.
2Use of energy by moving object
If substantially monochromatic light sources are used, then luminous efficacy is improved, but visibility and color rendition deteriorate due to narrow spectrum
Solution Approach 1:
The patent optimizes the wavelength parameter by selecting a specific range (550 nm to 700 nm) that is broader than monochromatic light but narrower than full spectrum light. This intermediate parameter range maintains high luminous efficacy while providing sufficient color rendition for emergency situations, resolving the contradiction between efficacy and visibility.
3Speed
If short wavelength light is used, then penetration through smoke is improved, but backscattering increases reducing visibility
Solution Approach 1:
The patent changes the wavelength parameter from short wavelengths (which scatter more) to longer wavelengths (550 nm to 700 nm) that experience less Rayleigh scattering and Mie scattering in smoke-filled environments. This parameter change reduces backscattering while maintaining adequate light penetration for visibility.
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 provides improved luminous efficacy and reduced backscattering, allowing for better visibility and situational awareness in smoky environments by minimizing the scattering of light and maximizing penetration through the use of phosphor-converted amber LEDs.
Implementation Method 1
A portable lighting device utilizing phosphor-converted amber LEDs that emit light primarily within the 550 nm to 700 nm range
Implementation Method 2
Rayleigh scattering dictates that light of shorter wavelengths will be scattered to a greater degree than light of longer wavelengths by particles suspended in a medium, such as air
Implementation Method 3
Air molecules are smaller than most smoke particles, and in this regime Raleigh scattering is no longer valid, so Mie theory must be used to understand the interaction between the particles and electromagnetic waves such as visible light
Data Source
AI summary
A portable light may employ a light source positioned adjacent an optical element. The light source may be configured as a light emitting diode generating light with a wavelength primarily within the range of 530 nm to 700 nm with a relative peak intensity of 550 nm to 650 nm. The optical element may be configured to manipulate the emitted light into a beam or other light pattern having specific characteristics such as a certain diameter and/or shape, a certain amount of spill, and/or a certain amount of backscatter. Certain embodiments may be especially useful for emergency and rescue operations performed under conditions such as fire generated smoke.