LED Light-Emitting Device with Segmented Phosphor for Uniform Color
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Solution Overview
Problem
LED light-emitting devices with phosphor wavelength conversion can produce uneven color at different viewing angles due to varying ratios of original and converted light, leading to non-uniform color phenomena.
Innovation Solution
A light-emitting device design featuring a semiconductor stack, electrode, reflective insulating layer, and supporting structure, where the semiconductor stack has a stepped second semiconductor layer and a reflective conductive layer to ensure even light emission and distribution, with a transparent supporting structure and wavelength conversion materials to maintain color consistency across angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If phosphor wavelength conversion is used to convert LED light color, then color conversion capability is improved, but color uniformity at different viewing angles deteriorates
Solution Approach 1:
The phosphor layer is divided into multiple phosphor particles with different particle sizes distributed in specific regions. The first phosphor particles have a first particle size and the second phosphor particles have a second particle size different from the first. This segmentation allows different phosphor regions to emit light at different wavelengths, and by controlling the spatial distribution and size of particles, the patent achieves uniform color output at different viewing angles despite using wavelength conversion
Solution Approach 2:
Different regions of the device are assigned different phosphor characteristics. The patent applies phosphor particles with specific size distributions in specific locations to optimize light emission at different angles. The first phosphor particles and second phosphor particles are distributed differently in space, creating local variations in optical properties that collectively achieve uniform overall color output
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 design ensures consistent color emission across different viewing angles by adjusting the semiconductor stack's composition and structure, enhancing the uniformity and stability of the light output.
Implementation Method 1
The reflective insulating layer surrounds the electrode post and has a second bottom surface being coplanar with the electrode post
Implementation Method 2
The phosphor can absorb the first light from the LED and emit a second light having a color different from the first light
Data Source
AI summary
This disclosure discloses a light-emitting device includes a semiconductor stack, an electrode, an electrode post, a reflective insulating layer, an extending electrode, and a supporting structure. The electrode is disposed on a lower surface of the semiconductor stack, and electrically connected to the semiconductor stack. The electrode post is disposed on the electrode. The reflective insulating layer surrounds the electrode post, and has a bottom surface which is coplanar with the electrode post. The extending electrode is disposed on an upper surface of the semiconductor stack. The supporting structure is located on the extending electrode.