LED Spectral Sorting for Consistent White Light Output
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Solution Overview
Problem
The variability in peak wavelength and radiant power of LEDs leads to inconsistent color temperature and intensity in white LED light sources, increasing manufacturing costs and reducing yield, as existing solutions require multiple recipes and controllers to compensate for these variations.
Innovation Solution
Sorting LED dies into predetermined groups based on spectral measure and output intensity allows for the construction of compound light sources with reduced variability in center wavelength and intensity, enabling the creation of light sources with consistent color and flux without the need for multiple recipes or controllers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If LED chips are measured and sorted into bins according to peak wavelength and output power, then manufacturing precision of individual LEDs is improved, but device complexity and manufacturing cost increase due to requiring multiple recipes for different bins
Solution Approach 1:
The patent divides the LED population into discrete bins based on spectral and intensity characteristics. By segmenting LEDs into groups with similar properties, the system can select combinations that average out variations, achieving consistent output without requiring complex per-LED adjustment mechanisms or multiple manufacturing recipes.
Solution Approach 2:
The patent combines multiple individual LEDs with varying characteristics into a compound light source assembly. By merging several LEDs whose variations are complementary, the aggregate output achieves statistical averaging that reduces overall variation in color temperature and radiant power, eliminating the need for complex control systems.
2Manufacturing precision
If white sources are combined and regulated in intensity to provide predetermined color temperature and intensity, then manufacturing precision is improved, but device complexity increases due to requiring controllers and intensity adjustment mechanisms
Solution Approach 1:
The patent employs passive thermal management where the heat sink structure automatically regulates LED operating temperatures. The thermally conductive housing and heat sink fins dissipate heat passively, maintaining stable LED characteristics without requiring active temperature control systems or complex regulation mechanisms.
3Productivity
If multiple LEDs with varying characteristics are used to increase light output, then productivity is improved, but manufacturing precision worsens due to increased variation in aggregate output
Solution Approach 1:
The patent performs preliminary classification of LEDs into bins based on spectral and intensity measurements before assembly. By pre-sorting LEDs and documenting their characteristics, the system can deliberately select and combine specific bins to achieve target aggregate properties, ensuring consistent output even as total light capacity increases with more LEDs.
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 results in a more cost-effective and efficient manufacturing process by reducing the spread in center wavelength and intensity, improving the consistency and yield of white LED light sources, and enabling the production of light sources with desired spectral and intensity characteristics.
Implementation Method 1
light from a monochromatic LED is typically down converted by a phosphor layer to provide light in additional regions of the visual spectrum. The most common form of white LED utilizes a blue-emitting LED and a layer of phosphor that converts part of the blue light into yellow light.
Data Source
AI summary
A compound light source is characterized by an output spectral measure that lies within a spectral measure design range and an average light intensity per component light source that lies within an output intensity design range. The plurality of component light sources includes light sources whose spectral measure value and output intensity lie outside the corresponding design ranges. The component light sources are chosen from a number of predetermined groups obtained by sorting the component light sources with respect to the spectral measure value and output intensity of each source such that the compound light source has a spectral measure value and output intensity that lies within the corresponding design ranges.