LED Package Tunable Chromaticity via Segmented Binning
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Solution Overview
Problem
Current lighting technologies face challenges in achieving uniform color and luminance in solid state lighting devices, particularly in LED packages, where existing binning methods result in inefficient use of LEDs and limited color consistency due to restrictive chromaticity bins.
Innovation Solution
The development of a light emitting device package assembly with multiple white LEDs, each emitting light within non-overlapping chromaticity regions spaced apart by significant MacAdam ellipses, allowing for tunable combined light output and improved color consistency by selecting LEDs from subregions within a chromaticity region, enabling the use of LEDs outside standard bins while maintaining desired color characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If LED chips are grouped and binned according to chromaticity values using conventional binning methods, then color consistency is improved, but LED utilization efficiency deteriorates due to restrictive chromaticity bins
Solution Approach 1:
The patent changes the chromaticity parameters by selecting LED chips from non-overlapping chromaticity regions spaced apart by MacAdam ellipses, rather than using conventional tight binning. This allows a broader range of LED chips to be utilized while maintaining acceptable color consistency through the combination of multiple regions.
Solution Approach 2:
The patent segments the chromaticity space into multiple non-overlapping regions (first, second, third chromaticity regions) spaced apart by MacAdam ellipses. By distributing LED chips across these segmented regions and combining their output, the system achieves both broader utilization and maintained color consistency.
2Productivity
If multiple LED chips with different chromaticity values are combined in a package, then LED utilization efficiency is improved, but color uniformity deteriorates
Solution Approach 1:
The patent changes the approach by selecting LED chips from specifically spaced chromaticity regions (separated by MacAdam ellipses) rather than random or conventional binning. This parameter selection ensures that when multiple chips are combined, their chromaticities complement each other to maintain uniformity while expanding utilization.
Solution Approach 2:
The patent uses phosphor as an intermediary element that receives light from LED chips with different chromaticities and converts it to a more uniform output. The phosphor acts as a mediator that harmonizes the chromaticity differences among multiple LED chips.
3Manufacturing precision
If restrictive chromaticity bins are used for LED binning, then color consistency is improved, but the range of usable LEDs deteriorates
Solution Approach 1:
The patent changes the chromaticity selection parameters by using non-overlapping regions spaced apart by MacAdam ellipses instead of conventional tight bins. This parameter change expands the range of usable LEDs while maintaining color consistency through the structured selection approach.
Solution Approach 2:
The patent introduces a new dimension to chromaticity selection by considering MacAdam ellipse spacing as a critical parameter. This adds a spatial dimension to the binning process, allowing expansion into broader chromaticity spaces while maintaining quality through the ellipse-spacing criterion.
4Productivity
If a broader range of LEDs is used in packages, then LED utilization efficiency is improved, but color distribution tightness deteriorates
Solution Approach 1:
The patent changes the selection parameters by using chromaticity regions spaced apart by MacAdam ellipses, which provides a structured approach to expanding the LED range. This parameter change maintains color distribution tightness through the geometric spacing criterion while improving utilization efficiency.
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 enhances color consistency and reduces waste by allowing the use of a broader range of LEDs, achieving a tighter color distribution and improved luminous flux, with the ability to tune the chromaticity of the combined light output to various points within a defined region, surpassing the limitations of conventional binning methods.
Implementation Method 1
The light engine may include a single optical waveguide into which multiple wavelengths of light are coupled
Implementation Method 2
The light engine may include a tunable laser diode, which may be tuned to a wavelength corresponding to a peak emission wavelength of a downconverter
Implementation Method 3
downconverter material in a second portion of the waveguide to a second wavelength
Data Source
Figure 1A~1B
Figure 1C
Figure 2
AI summary
A light emitting device package assembly includes a light emitting device package body, and first, second and third white light emitting devices on the package body, each of the first, second and third white light emitting devices emits light when energized having a chromaticity that falls within a respective one of first, second and third non-overlapping chromaticity regions in a two dimensional chromaticity space. The first, second and third chromaticity regions are spaced apart in the two dimensional chromaticity space by respective regions having at least the size of a seven step MacAdam ellipse. Related solid state luminaires and methods are also disclosed.