Runway Sign LED Lamp with Cylindrical Lens and Reflectors
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Solution Overview
Problem
Existing airport runway signs face challenges in achieving uniform light distribution due to regulatory requirements for reduced 'hot spots' in brightness, which conventional fluorescent lamps struggle to meet efficiently, especially when retrofitting to LED technology.
Innovation Solution
A single LED lamp is used, positioned near the top or bottom edge of the sign, which provides direct illumination to both the front and rear faces without intermediate optical interactions, utilizing a cylindrical lens and diffuse reflecting surfaces to optimize light distribution and minimize waste, ensuring compliance with brightness regulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional fluorescent lamps are used with diffusers to redistribute light, then hot spots are reduced, but energy consumption increases and lamp lifetime decreases
Solution Approach 1:
The patent removes the diffuser component from the lighting system. Instead of using a diffuser to redistribute light, the invention employs LED modules with built-in optical features (reflector and lens) that directly produce uniform light distribution, thereby eliminating the need for energy-consuming diffuser materials and reducing overall energy consumption.
Solution Approach 2:
The patent replaces the mechanical/optical system of fluorescent lamps with diffusers with an LED-based system that uses electronic control and integrated optical elements. The LED modules incorporate reflectors and lenses that optically redirect light without requiring separate diffuser components, achieving both energy efficiency and uniform light distribution.
2Illumination intensity
If fluorescent lamps with diffusers are used to achieve uniform brightness, then hot spots are eliminated, but device complexity increases
Solution Approach 1:
The patent combines the light source, reflector, and lens into a single integrated LED module. This merging of components eliminates the need for separate diffusers and simplifies the overall device structure while maintaining uniform light distribution through the optical features built into the module itself.
Solution Approach 2:
The LED module serves multiple functions simultaneously: it generates light, reflects light in desired directions, and focuses/distributes light uniformly through its integrated lens. This multi-functionality reduces the total number of components needed in the sign assembly.
3Use of energy by moving object
If remote phosphor LED lamps are used to convert blue light to white, then energy efficiency improves, but light distribution uniformity worsens due to isotropic phosphor radiation
Solution Approach 1:
The patent applies different optical properties to different parts of the LED module. The reflector has specific geometric features that redirect light in controlled directions, while the lens has refractive properties that focus and distribute light uniformly. This local optimization of optical quality compensates for the isotropic nature of phosphor radiation and achieves uniform light distribution.
Solution Approach 2:
The patent introduces optical intermediaries (reflector and lens) between the LED chip and the sign surface. These intermediaries mediate the light distribution by redirecting and focusing the isotropic phosphor light into a uniform pattern, solving the uniformity problem while preserving the energy efficiency of LED technology.
4Illumination intensity
If multiple fluorescent lamps are installed in the sign, then sufficient illumination is achieved, but replacement time and labor increase
Solution Approach 1:
The patent combines multiple light sources into a single LED module that contains multiple LED chips or a high-power LED. This consolidation maintains sufficient total light output while reducing the number of replaceable units from multiple lamps to a single module, thereby reducing replacement time and labor.
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 achieves a uniform light distribution across the sign, reducing energy consumption and extending lamp life, while simplifying replacement processes and maintaining regulatory compliance by directing most light to the sign faces and minimizing waste.
Implementation Method 1
utilizing a cylindrical lens and diffuse reflecting surfaces to optimize light distribution
Implementation Method 2
utilizing a cylindrical lens and diffuse reflecting surfaces to optimize light distribution
Implementation Method 3
A single LED lamp is used, positioned near the top or bottom edge of the sign
Data Source
AI summary
A two-sided airfield runway sign with direct illumination by a single LED lamp. Light is produced by a linear array of white-light LEDs. A cylindrical lens is mounted longitudinally adjacent to the LEDs, and collects a central portion of the light emitted from the LEDs. A pair of inclined surfaces extend from the lateral edges of the LEDs to respective lateral edges of the cylindrical lens. The inclined surfaces have a rough surface texture and reflect light diffusely. The inclined surfaces collect a peripheral portion of the light emitted from the LEDs, and direct the reflected light toward the cylindrical lens. The LEDs, cylindrical lens and inclined surfaces are all mechanically supported by a heat sink. The replacement lamp is placed into a runway sign near its top or bottom edge, and illuminates both viewing surfaces of the runway sign simultaneously without a diffuser.