Tunable White Point Light Source Using Wavelength Converting Element
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Solution Overview
Problem
Existing LED light sources struggle to produce white light with a desired correlated color temperature (CCT) in compact form factors, particularly in applications like accent lamps, where spectral distribution control is challenging, and color tunability is desired.
Innovation Solution
A light source using multiple LED chips with slightly different pump wavelengths and a wavelength converting element, such as a stack or mixture of phosphor or luminescent ceramics, to control the white point by altering the intensity of converted colors, allowing for compact and high-brightness designs with tunable CCT.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional incandescent bulbs are replaced with standard LED light sources, then energy efficiency and longevity are improved, but control over spectral distribution and correlated color temperature (CCT) becomes difficult
Solution Approach 1:
The patent divides the LED light source into multiple segments: multiple LED chips with different pump wavelengths (e.g., 430nm, 450nm, 470nm) and multiple wavelength converting materials (e.g., blue-converting, green-converting, red-converting phosphors). Each segment contributes to specific spectral components, allowing independent control and precise tuning of the overall spectral distribution and CCT.
Solution Approach 2:
The patent employs composite wavelength converting materials comprising multiple phosphor types with different emission characteristics. These composite materials are combined with multiple LED chips to create a unified light source that achieves precise spectral control and tunable white point, resolving the contradiction between energy efficiency and spectral control.
2Manufacturing precision
If LED light sources are designed with multiple components to achieve desired CCT control, then spectral distribution control is improved, but device size and complexity increase
Solution Approach 1:
The patent merges multiple LED chips and multiple wavelength converting materials into a single integrated light source structure. The LED chips are mounted in close proximity and the wavelength converting materials are positioned to receive light from all chips, creating a compact unified device that maintains precise CCT control while minimizing overall size.
Solution Approach 2:
The patent implements a nested arrangement where wavelength converting materials are positioned around or between LED chips, and multiple phosphor layers are stacked or mixed in a compact configuration. This nesting approach allows multiple functional components to occupy overlapping or adjacent spaces, reducing the overall volume while maintaining spectral control capabilities.
3Adaptability or versatility
If multiple different types of LED chips are used to achieve color tunability, then spectral flexibility is improved, but manufacturing complexity and device size increase
Solution Approach 1:
The patent applies local quality by assigning specific pump wavelengths to specific LED chips and specific wavelength conversion functions to specific phosphor materials at different locations within the light source. This spatial differentiation of functional properties enables precise spectral control and color tunability while maintaining a systematic manufacturing approach.
Solution Approach 2:
The patent utilizes parameter changes by varying the pump wavelengths of LED chips (e.g., 430nm, 450nm, 470nm) and the emission characteristics of wavelength converting materials to achieve different color outputs. By adjusting these optical parameters and the intensity ratios of individual LED chips, the light source can be tuned across a range of CCT values and color points.
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
Enables the production of a uniform, high-brightness white light with adjustable CCT, suitable for applications requiring compact and color-tunable lighting, improving upon the limitations of traditional LED implementations by simplifying manufacturing and enhancing luminance and compactness.
Implementation Method 1
a wavelength converting element that includes at least two different wavelength converting materials that convert the light to different colors of light
Implementation Method 2
The wavelength converting element may be, e.g., a stack or mixture of phosphor or luminescent ceramics
Data Source
AI summary
A uniform high brightness light source is provided using a plurality of light emitting diode (LED) chips with slightly different pump wavelengths with a wavelength converting element that includes at least two different wavelength converting materials that convert the light to different colors of light. The intensity of the light produced by the LED chips may be varied to provide a tunable CCT white point. The wavelength converting element may be, e.g., a stack or mixture of phosphor or luminescent ceramics. Moreover, the manufacturing process of the light source is simplified because the LED chips are all manufactured using the same technology eliminating the need to manufacture different types of chips.