Glass-Coated Phosphor Plate for High-Flux White Light
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Solution Overview
Problem
Existing phosphor plates in white light lamps using blue LEDs or LDs do not fully meet the demand for higher luminous flux and whiteness, particularly in applications requiring high heat resistance and durability.
Innovation Solution
A phosphor plate with a specific composition and structure, including (Y1-x-y, Gdx, Cey)3Al5O12 particles and Al2O3 particles, a glass coating layer, and optimized particle sizes and concentrations, enhances luminous flux and whiteness by improving light scattering and conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a blue LED or LD is combined with ceramic phosphors to produce white light, then heat resistance and durability are improved, but luminous flux is insufficient to meet recent demands
Solution Approach 1:
The patent optimizes specific parameters of the YAG:Ce phosphor particles including average particle diameter (4-6 μm), concentration (20-30 vol%), and compositional ratios (x and y parameters) to enhance luminous flux while preserving the ceramic phosphor's heat resistance and durability characteristics
Solution Approach 2:
The patent creates a composite phosphor plate structure combining YAG:Ce phosphor particles with a transparent binder matrix, forming a composite material that integrates the high temperature stability of ceramic phosphors with improved light conversion efficiency and luminous flux output
2Productivity
If phosphor plate structure is optimized to increase luminous flux, then light output is improved, but chromaticity uniformity and whiteness quality may deteriorate
Solution Approach 1:
The patent applies local quality control by specifying precise spatial distributions of phosphor particles including concentration gradients and particle size distributions within the phosphor plate to ensure uniform light conversion across different regions, maintaining chromaticity consistency while maximizing overall luminous flux
Solution Approach 2:
The patent carefully adjusts compositional parameters (x and y in YAG:Ce formula) and physical parameters (particle diameter, concentration) to achieve an optimal balance where increased luminous flux does not compromise the spectral quality, whiteness, and chromaticity uniformity of the emitted light
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 phosphor plate achieves higher luminous flux and improved whiteness with better temperature stability, suitable for applications like car headlights.
Implementation Method 1
the light emitted from the blue LED excites a yellow phosphor in the ceramic phosphor, and white light is emitted by additively mixing blue and yellow
Implementation Method 2
an anti-reflective film that matches a refractive index of the flattened layer can be formed, thereby improving the light extraction efficiency
Implementation Method 3
improving light scattering and conversion efficiency
Data Source
AI summary
A phosphor plate includes a plate-shaped sintered body having a light incident surface and a light exit surface, and a glass coating layer provided at the light exit surface, and the sintered body includes (Y1-x-y, Gdx, Cey)3Al5O12 particles, where x and y fall within ranges 0.018≤x≤0.054 and 0.018≤y≤0.025, and Al2O3 particles, the (Y1-x-y, Gdx, Cey)3Al5O12 particles and the Al2O3 particles have an overall average particle diameter of 3.0 μm to 5.0 μm, the (Y1-x-y, Gdx, Cey)3Al5O12 particles have a concentration of 15 vol % to 25 vol % with respect to a total amount 100 vol % of the (Y1-x-y, Gdx, Cey)3Al5O12 particles and the Al2O3 particles, the sintered body has a thickness of 90 μm to 160 μm.