White LED Phosphor Mix for Blue-Light Filtering and Color Gamut
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Solution Overview
Problem
Existing LED white light devices fail to effectively prevent blue light emission, which can cause eye damage, and lack color uniformity and consistency, with their light spectra not closely resembling the solar spectrum.
Innovation Solution
An LED white light device using a blue light chip with a wavelength of 455-470 nm, combined with a dual-band yellow phosphor and a red phosphor, mixed in specific proportions, to convert over 95% of harmful blue light into long-wave low-energy light, achieving a blue-green-red continuous spectrum closer to solar radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a blue light LED chip is packaged on a transparent base plate, then the LED device can be manufactured with simple structure and low cost, but the back surface of the LED device will leak blue light causing eye damage
Solution Approach 1:
The patent extracts the harmful blue light (wavelength 400-450nm) from the overall light emission by using a transparent base plate with a specific blue light absorption layer. This layer selectively absorbs the harmful short-wave blue light while allowing other wavelengths to pass through, thereby removing the harmful component without affecting the overall lighting function.
Solution Approach 2:
The patent introduces a transparent base plate with blue light absorption characteristics as an intermediary between the LED chip and the environment. This intermediary component selectively filters out harmful blue light wavelengths while maintaining optical transparency for other wavelengths, thus mediating between the blue light emission and eye protection requirements.
2Illumination intensity
If fluorescent glue is coated on blue light LED chip to emit white light, then the device can achieve white light emission, but the brightness and color gamut performance is insufficient
Solution Approach 1:
The patent employs a composite phosphor system comprising yellow phosphor (Y3Al5O12:Ce3+), red phosphor (CaAlSiN3:Eu2+), and green phosphor (β-SiAlON:Eu2+). This composite material approach combines multiple phosphors with different emission characteristics to achieve a broad spectral coverage and high color gamut while maintaining excellent brightness performance.
3Adaptability or versatility
If multiple phosphors are used to improve color gamut, then the color performance is enhanced, but the manufacturing process becomes more complex
Solution Approach 1:
The patent merges multiple phosphor types (yellow, red, and green phosphors) into a single integrated phosphor layer that is applied directly onto the blue LED chip. This combining approach achieves broad color gamut coverage while simplifying the manufacturing process by eliminating the need for separate phosphor layers or complex multi-step deposition processes.
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 high color gamut, pure white light, and reduced eye damage from blue light, ensuring comfortable and natural illumination with improved brightness and color uniformity, exceeding conventional LED devices in NTSC color gamut value.
Implementation Method 1
a dual-band yellow phosphor and a red phosphor, to convert over 95% of harmful blue light into long-wave low-energy light
Data Source
AI summary
The disclosure provides an LED white light device, including a blue light chip and phosphors. The blue light chip has a band of (455-470) nm. The phosphors include a dual-band yellow phosphor and a red phosphor having an excited light peak wavelength range of (610-660) nm. The yellow phosphor and the red phosphor are mixed according to a proportion of 1:(0.03-0.2) and cover the blue light chip, such that blue light emitted by the packaged LED white light device has a peak wavelength range of (450-465) nm. The disclosure also provides a preparation method of an LED white light device and an LED backlight module adopting the above LED white light device. The disclosure achieves the effects of blue light prevention, high color gamut and pure white simultaneously, Color uniformity and consistency are good, and a blue-green-red three-color continuous spectrum is provided, which is closer to a solar spectrum.