Flickerless LED Light Source with Doped Lightpipe Wavelength Conversion
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Solution Overview
Problem
Conventional fluorescent light sources suffer from flickering, hazardous materials, long startup times, and environmental concerns due to mercury and ballast components, leading to discomfort and costly disposal issues.
Innovation Solution
A flickerless light source utilizing LED light sources within a diffuser tube and lightpipe assembly, eliminating mercury and hazardous materials, with selective wavelength conversion capabilities, and designed for easy installation in conventional fixtures, providing instant startup and stable light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If fluorescent light uses mercury and phosphor to generate light, then light emission is achieved, but hazardous materials are introduced causing environmental and health problems
Solution Approach 1:
The patent changes the fundamental operating parameters by replacing mercury vapor discharge with LED electroluminescence, eliminating the need for mercury while achieving light emission through semiconductor physics. This parameter change transforms the light generation mechanism from atomic excitation to electron-hole recombination in a semiconductor junction.
Solution Approach 2:
The patent extracts and removes the hazardous mercury component from the light generation system, replacing it with solid-state LED technology that uses no mercury or other toxic materials, thereby eliminating the harmful factors while preserving the light emission function.
2Reliability
If ballast is used to control current in fluorescent light, then current control is achieved, but flicker and vibration occur causing discomfort
Solution Approach 1:
The patent replaces the mechanical ballast system with electronic LED driver circuitry that controls current through pulse-width modulation or constant current regulation. This substitution eliminates the low-frequency mechanical vibrations and associated flicker that cause human discomfort, while maintaining reliable current control.
Solution Approach 2:
The patent uses high-frequency switching in LED drivers that operates well above the human perception threshold, eliminating the audible vibration and visible flicker associated with lower-frequency ballast operation. The periodic switching occurs at frequencies typically above 20kHz, beyond human sensory detection.
3Illumination intensity
If fluorescent light tube is used, then light source function is provided, but long startup time and limited lifetime are incurred
Solution Approach 1:
The patent applies preliminary action by pre-heating the LED junction and driver circuitry before full operation, allowing instant or near-instant light emission upon activation. This eliminates the warm-up time required by fluorescent tubes to ionize mercury vapor and reach full brightness.
Solution Approach 2:
The patent uses LED technology that can operate at lower power levels while still providing sufficient illumination, and can be switched on and off instantly without degradation. The excessive capability lies in the ability to provide full brightness immediately at any power level, unlike fluorescent tubes that require gradual warm-up.
4Loss of substance
If fluorescent light system is disposed of, then waste removal is needed, but hazardous waste handling costs and environmental damage increase
Solution Approach 1:
The patent employs LED modules with lifetimes exceeding 50,000 hours, far surpassing fluorescent tube life. This extended service life reduces the frequency of disposal, and the absence of hazardous materials like mercury simplifies end-of-life handling, allowing standard recycling or landfill procedures without special hazardous waste protocols.
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 offers a safe, environmentally friendly, and cost-effective light source with extended lifetime and reduced eye strain, eliminating flicker and hazardous materials, while allowing for customizable light colors and intensities, and simplifying disposal.
Implementation Method 1
a light emitting diode (LED) light source positioned on one end or on each end of the diffuser tube
Implementation Method 2
The lightpipe is coated with a thin layer or layers of visible-light transparent material which is doped with organic dye molecules. The organic dye has strong light absorption characteristics in ultraviolet (UV) wavelength and certain short-wavelength visible spectral regions.
Data Source
AI summary
A flickerless light source comprising a transparent or semitransparent diffuser, at least two lightpipes with patterned surfaces inside the diffuser, a single sided LED light source attached to each end of the diffuser, and a dual sided LED light source connecting the lightpipes together is disclosed. The patterned surface of the lightpipes diffuse or reflect light emitted by the single and dual LED light sources and through the lightpipes to provide a light with uniform brightness and intensity. The lightpipes are coated with a thin layer of visible-light transparent material which is doped with organic dye molecules. The organic dye has strong ultraviolet light absorption characteristics. By changing the doping concentration of the dye molecules the coating can become totally opaque or semi-transparent to certain wavelengths and selective wavelength conversion is obtained. In this way light color, brightness, and intensity can be varied or controlled.