White LED Lamp Deep Red Phosphor Color Rendering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional white LED lamps with BGR phosphors suffer from low color rendering properties due to insufficient red light emission, leading to inaccurate color representation compared to natural sunlight, and require enhancements in luminance and color rendering efficiency.
Innovation Solution
Incorporating a deep red phosphor with a main emission peak in a longer wavelength region than the red phosphor, along with a blue, green, and red phosphor combination, to enhance light emission intensity and color rendering properties by ensuring separate main emission peaks and optimized phosphor compositions, such as europium-activated alkaline-earth chlorophosphate, europium and manganese-activated silicate, and manganese-activated magnesium fluorogermanate phosphors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a blue LED is combined with green and red phosphors (BGR phosphors) to achieve high luminance, then luminance characteristics are improved, but color rendering properties deteriorate due to insufficient red light emission
Solution Approach 1:
The red light emission is segmented into two distinct phosphors: a red phosphor (emission peak 610-630 nm) and a deep red phosphor (emission peak 640-660 nm). This segmentation allows each phosphor to target specific wavelength regions, ensuring both high luminance from the red phosphor and improved color rendering from the deep red phosphor, resolving the contradiction between luminance and color rendering properties
Solution Approach 2:
The patent employs a composite phosphor system comprising blue phosphor, green phosphor, red phosphor, and deep red phosphor in specific combinations. This composite material approach integrates multiple phosphors with complementary emission characteristics to achieve both high luminance (from blue and red phosphors) and excellent color rendering (from green and deep red phosphors), thereby resolving the technical contradiction
2Illumination intensity
If the green phosphor emission peak is shifted to 540-570 nm to enhance brightness, then luminance is improved, but color rendering properties may deteriorate due to spectral distribution changes
Solution Approach 1:
The patent optimizes the green phosphor emission peak wavelength to 540-570 nm, which is a specific parameter change that enhances brightness while maintaining color rendering. This parameter optimization, combined with the addition of deep red phosphor, allows the system to achieve high brightness without sacrificing color rendering properties, as the deep red phosphor compensates for any potential spectral imbalances
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 high luminance and color rendering indices, with average color rendering indices of 96 to 98 and luminance efficiency of 62 Lm/W or more, significantly improving color accuracy and light emission efficiency compared to lamps without deep red phosphors.
Implementation Method 1
an LED chip and a phosphor mixture containing blue, green, red, and deep red phosphors. The phosphors are excited by ultraviolet light or violet light emitted from the LED chip, to thereby emit the white light
Implementation Method 2
Light emitting diodes (LEDs) are semiconductor light emitting elements that convert electrical energy into ultraviolet light and visible light thereby to emit the converted light
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
An object is to provide a white light emitting lamp in which a BGR phosphor containing blue, green and red phosphor is combined with a semiconductor light emitting element such as an LED, a deep red phosphor having a main emission peak in a longer wavelength region than a main emission peak of the red phosphor is further added so as to enhance characteristics, whereby both high luminance and high color rendering properties can be obtained. This invention provides a white light emitting lamp 1 comprising: a semiconductor light emitting element 2 that is placed on a board 3 and emits ultraviolet light or blue light; and a light emitting portion that is formed so as to cover a light emitting surface of the semiconductor light emitting element 2, the light emitting portion containing a blue phosphor B, a green phosphor G, and a red phosphor R that are excited by the light emitted from the semiconductor light emitting element 2 to respectively emit blue light, green light, and red light, the white light emitting lamp 1 emitting white light by mixing light emission colors from the blue phosphor B, the green phosphor G, and the red phosphor R with one another, wherein the light emitting portion further contains a deep red phosphor DR having a main emission peak in a longer wavelength region than a main emission peak of the red phosphor.