LED Illumination Device with Wavelength Converting Material
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Solution Overview
Problem
Current illumination technologies, such as ultra-high pressure sodium lamps and fluorescent lamps, fail to provide high color saturation efficiently and are limited by heat emission, short lifespan, and color instability, while LED-based solutions face efficiency and complexity issues in achieving desired color outputs.
Innovation Solution
An illumination device combining blue LEDs, red LEDs, and a wavelength converting material that absorbs blue light and emits in the green spectrum, with specific emission ranges and a control system to maintain color stability, achieving high saturation of colors and improved luminous efficacy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If ultra high pressure sodium lamps are used to enhance color saturation, then color rendering is improved, but system efficacy decreases and heat emission increases
Solution Approach 1:
The invention changes the spectral parameters by using specific LED wavelength combinations (blue LED at 440-470nm, red LED at 610-670nm) and matching phosphor materials with specific emission characteristics. This allows achieving high color saturation (R9>90) while maintaining high system efficacy (>100 lm/W) by optimizing the correlation between LED emission and phosphor conversion parameters.
2Illumination intensity
If ultra high pressure sodium lamps are used to enhance color saturation, then color rendering is improved, but heat emission increases reducing shelf life
Solution Approach 1:
The invention replaces the thermal radiation mechanism of HID lamps with electroluminescence in LEDs and photoluminescence in phosphors. This substitution eliminates the need for high-temperature operation, achieving high color saturation without significant heat emission, thereby preserving the shelf life of illuminated articles.
3Illumination intensity
If multiple LEDs of different colors are combined to achieve high color saturation, then color rendering is improved, but device complexity increases
Solution Approach 1:
The invention merges the blue LED light source with a yellow phosphor (Y3Al5O12:Ce) to create an integrated white light emitting element. This combination simplifies the system by reducing the number of separate LED chips and control circuits needed, while still achieving high color saturation through the complementary emission spectra of the blue LED and yellow phosphor.
4Device complexity
If blue LED with green phosphor is used to produce white light, then system simplicity is improved, but color saturation decreases
Solution Approach 1:
The invention uses a composite phosphor system combining yellow phosphor (Y3Al5O12:Ce) with appropriate red phosphor materials to create a multi-component phosphor blend. This composite approach broadens the emission spectrum to include strong red and green components while maintaining yellow, thereby achieving high color saturation (R9>90) without sacrificing system simplicity.
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 device produces white light with high color saturation and stability, enhancing red color rendering and luminous efficacy by optimizing LED emission ranges and using a wavelength converting material like LuAG:Ce, while minimizing thermal effects on the converting material.
Implementation Method 1
a wavelength converting material arranged to receive light of at least said first light wavelength range and having an emission maximum in a third wavelength range which is between said first wavelength range and said second wavelength range
Data Source
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Figure 3
AI summary
The invention relates to an illumination device (1), comprising: at least one LED (3) having an emission maximum in a first wavelength range; at least one LED (2) having an emission maximum in a second wavelength range; and a wavelength converting material (5) arranged to receive light of at least said first light wavelength range and having an emission maximum in a third wavelength range which is between said first wavelength range and said second wavelength range. The illumination device according to the invention may provide white light of acceptable overall color rendering while producing particularly high saturation of selected colors.