Fluorescent Wheel Optimization for Projector Light Source
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional projectors using high-intensity discharge lamps face inefficiencies in light utilization due to increased Etendue values, leading to reduced luminance and increased heat and power consumption when using multiple excitation light sources to enhance light output.
Innovation Solution
A light source unit with a fluorescent material layer, specifically a green fluorescent material layer with a cerium-activated garnet phosphor, is optimized by adjusting the concentration of weight content and thickness to enhance luminescence intensity when excited with blue light, combined with a red light emitting diode and a diffusing area to guide light efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the number of excitation light sources is increased to enhance light output, then light luminance is improved, but heat value and power consumption increase
Solution Approach 1:
The patent changes the parameters of the fluorescent material layer, specifically optimizing the weight content concentration (60-85%) and thickness (50-200 μm) to maximize luminescence intensity. This allows achieving high light output with a single excitation light source, avoiding the need to increase the number of light sources and thereby reducing power consumption and heat generation.
Solution Approach 2:
The patent uses composite fluorescent material layers containing specific combinations of fluorescent materials (such as yellow fluorescent material with 560-580 nm peak, red fluorescent material with 610-650 nm peak, and green fluorescent material with 520-540 nm peak) to achieve high luminance output. This composite approach enhances the efficiency of light conversion, allowing high luminance with lower power consumption compared to using multiple excitation sources.
2Illumination intensity
If the number of excitation light sources is increased to enhance light output, then light luminance is improved, but the size of the projector increases
Solution Approach 1:
By optimizing the thickness and composition parameters of the fluorescent material layer, the patent achieves high luminance output with a compact single excitation light source configuration, avoiding the need for multiple light sources and associated optical components that would increase projector size.
Solution Approach 2:
The fluorescent material layer serves multiple functions: it converts excitation light to multiple wavelengths, acts as a light guide, and provides color mixing. This multi-functionality allows achieving high luminance with a single integrated component rather than multiple separate light sources and optical elements, thereby reducing overall projector size.
3Quantity of substance
If multiple excitation light sources are used to increase light quantity, then light output is improved, but light utilization efficiency decreases
Solution Approach 1:
The patent optimizes the concentration and thickness parameters of the fluorescent material layer to maximize the conversion efficiency of excitation light to visible light. The yellow fluorescent material layer with 60-85% weight content and 50-200 μm thickness achieves high light output with minimal energy loss, improving light utilization efficiency compared to using multiple excitation sources.
Solution Approach 2:
The composite fluorescent material structure enables efficient spectral conversion where the yellow fluorescent material converts blue excitation light to yellow light, and additional red and green fluorescent materials provide color mixing. This composite approach achieves high light quantity with superior energy utilization efficiency by minimizing reabsorption and transmission losses that would occur with multiple excitation sources.
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 enables high-luminance and high-intensity light emission without increasing the quantity of excitation light, improving light utilization efficiency and reducing heat and power consumption, while allowing for a more compact projector design.
Implementation Method 1
a fluorescent plate including at least one or more fluorescent material layers for emitting fluorescent light in a predetermined wavelength band using light emitted from the excitation light source as excitation light
Implementation Method 2
at least a green fluorescent material layer is formed on the fluorescent plate as the fluorescent material layer... when excitation light in a predetermined wavelength band is shone onto the fluorescent material layer
Data Source
AI summary
A light source unit including an excitation light source for emitting light in a blue wavelength band, a fluorescent wheel, a light emitting device for emitting light in a red wavelength band and a light guiding optical system for guiding light emitted from the fluorescent wheel and the light emitting device to a light guiding device. The fluorescent wheel has a fluorescent area where a green fluorescent material layer for emitting fluorescent light in a green wavelength band is disposed and a diffuse area for converting light emitted from the excitation light source into diffuse light of which directivity is weak are disposed end to end in a circumferential direction. A concentration of weight content of the green fluorescent material and a thickness thereof are such that a luminescent intensity of fluorescent light emitted from the green fluorescent material layer is enhanced.