Hybrid Waveguide Down-Converter Diffuser for White Light
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Solution Overview
Problem
Current solid-state lighting technologies, such as LEDs and OLEDs, face challenges in being cost- and energy-competitive with traditional lighting solutions, with issues including high manufacturing costs, low light outcoupling efficiency, poor color rendering index, and short operational lifetimes, limiting their widespread adoption.
Innovation Solution
A solid-state light source system incorporating a light pump coupled with a hybrid waveguide-down-converter-diffuser system, where a waveguide with a higher refractive index core and cladding is coated with wavelength conversion materials, allowing for efficient conversion of blue light into white light, with adjustable shapes and surface treatments to enhance light outcoupling and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If blue LEDs are coated with yellow phosphors to create white LEDs, then manufacturing is simplified, but color rendering index deteriorates to approximately 70
Solution Approach 1:
The patent segments the wavelength conversion function into multiple independent phosphor layers, each converting blue light to different spectral regions. This allows separate optimization of each phosphor layer for both manufacturing ease and color rendering performance, resolving the contradiction between simple manufacturing and high CRI.
Solution Approach 2:
The patent uses composite phosphor materials including yellow phosphors, red phosphors, and green phosphors in specific combinations. This composite approach enables simultaneous achievement of manufacturability (using proven yellow phosphor technology) and superior color rendering (adding red and green phosphors to fill spectral gaps).
2Illumination intensity
If external lenses and diffusers are added to LED dies, then light distribution is improved, but manufacturing and assembly costs increase
Solution Approach 1:
The patent merges the diffuser function into the waveguide structure itself by creating a hybrid waveguide-down-converter-diffuser assembly. The waveguide integrates light guiding, wavelength conversion, and diffusion functions in a single component, eliminating the need for separate external lenses and diffusers while maintaining light distribution performance.
Solution Approach 2:
The waveguide structure serves multiple functions simultaneously: it guides light from the LED die, converts wavelengths through integrated phosphor layers, and diffuses light for uniform distribution. This multi-functionality reduces the number of components and simplifies manufacturing while achieving the desired illumination uniformity.
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
This approach significantly increases light outcoupling efficiency, reduces manufacturing costs, and allows for precise tuning of color rendering index, making the technology more competitive and viable for commercial use while extending the operational lifetime of the down-converter materials.
Implementation Method 1
a waveguide with a higher refractive index core and cladding
Implementation Method 2
a down-converter for converting the light energy from the waveguide to a lesser light energy
Data Source
AI summary
A solid state light source comprising a light pump outputting light energy; a waveguide optically coupled to the light pump source for receiving the light energy; and a down-converter for converting the light energy from the waveguide to a lesser light energy.