Spectral Converter for LED Color Consistency
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Solution Overview
Problem
White light solid-state lighting sources made from LEDs are susceptible to process variations, leading to inconsistent color points and brightness, which complicates manufacturing and increases inventory costs due to the need for binning to achieve desired color temperatures and brightness levels.
Innovation Solution
The use of spectral converters, composed of different phosphorescent and fluorescent materials, are applied to adjust the spectral output of LEDs to achieve consistent assembly spectral outputs, allowing for the production of lighting assemblies with similar predetermined spectral outputs, even when source spectral outputs vary due to manufacturing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If binning is used to control color temperature and brightness consistency, then product quality consistency is improved, but production yield is reduced and inventory costs increase
Solution Approach 1:
The patent uses spectral converters with different characteristics (conversion efficiency, peak wavelength, bandwidth) to adjust the output spectrum of LEDs. By selecting and combining different spectral converters, the system can transform LEDs with varying initial parameters into consistent output specifications, eliminating the need for binning while maintaining quality consistency.
Solution Approach 2:
Spectral converters act as intermediary components between the LED light source and the final light output. These converters mediate the transformation of light wavelengths, allowing the system to compensate for LED variations and achieve consistent color temperature and brightness without requiring precise sorting of individual LEDs.
2Manufacturing precision
If binning is used to control color temperature and brightness consistency, then product quality consistency is improved, but inventory costs increase
Solution Approach 1:
By using spectral converters to dynamically adjust LED output parameters, the system can produce consistent quality products from a broader range of LED inputs. This eliminates the need to maintain separate inventories for different color bins, as a single inventory of LEDs can be transformed into various color temperature outputs as needed.
Solution Approach 2:
The spectral converter system provides multi-functionality by enabling a single LED inventory to serve multiple color temperature requirements. Instead of needing separate inventories for warm white, cool white, and other color bins, the same LED stock can be adapted to produce various color temperatures through appropriate spectral converter selection.
3Manufacturing precision
If spectral converters are used to adjust LED output, then color temperature consistency is improved, but device complexity increases
Solution Approach 1:
The patent applies spectral converters locally at specific positions around the LED, such as on the reflective cup or in close proximity to the LED chip. This localized approach allows for spectral adjustment without requiring complex system-level modifications, keeping the overall device structure relatively simple while achieving the desired spectral consistency.
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 ensures color temperature consistency across lighting assemblies, reducing production yield loss and inventory costs by enabling the manufacture of lighting fixtures with uniform spectral outputs, suitable for a wide range of applications, including camera flash devices and general illumination.
Implementation Method 1
a spectral converter formed on a portion of the reflective surface adjacent to, but distanced from, the light source die. The spectral converter is configured to convert light from the light source die having a spectral output varying about a peak wavelength into light having a converted spectral output varying about a converted peak wavelength
Implementation Method 2
spectral converters, composed of different phosphorescent and fluorescent materials
Implementation Method 3
spectral converters, composed of different phosphorescent and fluorescent materials
Data Source
AI summary
In one embodiment, a light-emitting device having a body, a reflector, a light source die, and a spectral converter is disclosed. The spectral converter may be formed adjacent to, but distanced away from, the light source die. The spectral converter may be configured to spectrally adjust a portion of the light output having a predetermined spectral content. In another embodiment, a system for illumination having a plurality of lighting assemblies is disclosed. Each of the lighting assemblies comprises a spectral converter configured to spectrally adjust a portion of the light output so that the plurality of lighting assemblies are configured to emit substantially similar spectral output. In yet another embodiment, a lighting apparatus having the spectral converter is disclosed.