LED Package Segmented Phosphor Design for Color Gamut
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Solution Overview
Problem
Conventional light emitting diode (LED) packages using mixed phosphors for wavelength conversion suffer from low energy conversion efficiency and light loss due to energy interference and high phosphor density, resulting in poor color index and high color temperature with a lack of red color component.
Innovation Solution
A light emitting diode package is designed with a housing containing a first LED chip emitting blue light, a second LED chip emitting green light, and a wavelength conversion part using phosphors that absorb blue light to emit red light, minimizing energy interference and reducing phosphor density by using a combination of nitride, sulfide, fluoride, and quantum dot phosphors to achieve efficient wavelength conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If mixed phosphors (green phosphors and red phosphors) are employed in the wavelength conversion part to improve color index and reduce color temperature, then the color quality is improved, but luminous efficacy is significantly deteriorated
Solution Approach 1:
The patent segments the wavelength conversion function into two distinct parts: (1) a wavelength conversion part containing only yellow phosphors that converts blue light to yellow light, and (2) a separate red phosphor part containing red phosphors that converts either blue or yellow light to red light. This segmentation prevents energy interference between different phosphors while achieving improved color quality through selective wavelength conversion.
Solution Approach 2:
The patent extracts red phosphors from the mixed phosphor configuration and places them in a separate red phosphor part, taking out only the necessary red wavelength conversion function from the mixed phosphor system. This extraction eliminates the harmful energy interference between green and red phosphors while maintaining the desired red color component in the output light.
2Illumination intensity
If phosphors having different peak wavelengths are mixed in the wavelength conversion part to achieve white light, then color gamut is broadened, but energy conversion efficiency is significantly deteriorated
Solution Approach 1:
The patent divides the wavelength conversion system into segmented parts with specific phosphor types in each part. The wavelength conversion part uses only yellow phosphors for efficient blue-to-yellow conversion, while the red phosphor part uses red phosphors for blue-or-yellow-to-red conversion. This segmentation maintains high energy conversion efficiency by preventing cross-phosphor energy interference while achieving broad color gamut through the combination of yellow and red light components with the remaining blue light.
3Productivity
If high density of phosphors is used in the wavelength conversion part to improve wavelength conversion efficiency, then more light is converted, but light loss arises from phosphor density
Solution Approach 1:
The patent segments the phosphor distribution to create lower density regions. By separating yellow phosphors and red phosphors into different spatial parts, each phosphor type can be distributed at optimized densities without the harmful effects of high overall phosphor density. This segmentation reduces light loss from phosphor aggregation while maintaining effective wavelength conversion in each separate region.
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 improves wavelength conversion efficiency, broadens the color gamut, reduces light loss, and enhances light output, achieving a color gamut of 95% or more and increased light output while reducing power consumption.
Implementation Method 1
a wavelength conversion part including a phosphor absorbing light emitted from the first light emitting diode chip and emitting light having a different wavelength than the light emitted from the first light emitting diode chip
Implementation Method 2
A light emitting diode refers to a compound semiconductor device that has a p-n junction of semiconductors and emits light through recombination of a small number of carriers (electrons and holes)
Data Source
AI summary
A light emitting diode package including a housing, first and second light emitting diode chips disposed in the housing, and a wavelength conversion part including a phosphor to absorb light emitted from the first light emitting diode chip and emit light having a different wavelength than that emitted from the first light emitting diode chip, in which light emitted from the first light emitting diode chip has a shorter wavelength than light emitted from the second light emitting diode chip, the wavelength conversion part is configured to emit red light having a peak wavelength of 580 nm to 700 nm and exhibiting at least three peaks at a wavelength of 600 nm to 660 nm, and the light emitting diode package is configured to emit white light by mixing light emitted from the first light emitting diode chip, the second light emitting diode chip, and the wavelength conversion part.