LED assembly

a technology of led assembly and led ring, which is applied in the direction of basic electric elements, electrical apparatus, and semiconductor devices, can solve problems such as yellow ring problems, and achieve the effect of reducing the efficiency of led assembly

Inactive Publication Date: 2015-06-11
LUMILEDS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The solution achieves uniform white light emission across all angles without the yellow ring problem while maintaining LED efficiency by reflecting a controlled amount of blue light at smaller angles, ensuring consistent blue to yellow light ratios and reducing light losses.

Problems solved by technology

Emissions under these angles cause the yellow ring problem.

Method used

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first embodiment

[0028]FIG. 1 shows a light emission diode (LED) assembly according to the invention with a LED die 10, a phosphor layer 12 and a filter layer 14. The led die 10, the phosphor layer 12 and the filter 14 are preferably covered by a semicircle-shaped housing 16 that can have a reflecting coating applied to the interior wall thereof. The LED die 10 that emits blue light with a wavelength of about 400 nm to 500 nm is positioned at the bottom 18 of the LED assembly. On the top of the LED die 10 the phosphor layer 12 is positioned. The phosphor layer 12 emits yellow light with a wavelength of about 570 nm to 590 nm. The phosphor layer 12 may comprise a Lumiramic plate and / or a phosphor powder embedded in a transparent matrix material. The thickness of the phosphor layer 12 is about 100 μm to 120 μm. On the top of the phosphor layer 12 the filter layer 14 is positioned. The filter layer 12 comprises a dielectric layer coating of alternating low and high reflective index materials, like Nb2O...

second embodiment

[0033]FIG. 4 shows a schematic view of a light emitting diode assembly according to the invention. In this embodiment the filter layer 14 is arranged between the LED die 10 and the phosphor layer 12.

third embodiment

[0034]FIG. 5 shows a schematic view of a light emitting diode assembly according to the invention, whereas the LED assembly comprises a first phosphor layer 12 and a second phosphor layer 20. The filter layer 14 is arranged between the first phosphor layer 12 and the second phosphor layer 20, whereas the first phosphor layer 12 is positioned on top of the LED die 10.

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Abstract

A light emission diode (LED) assembly, comprising a LED die (10), a phosphor layer (12), and a filter layer (14), wherein said filter layer (14) is developed in such a manner that light rays with a wavelength of about 400 nm to 500 nm, preferably of about 420 nm to 490 nm, emitted from the LED die (10) are at least partially reflected depending on their emission angle to the normal on the filter layer (14). With the inventive LED assembly it is possible to provide a LED assembly which solves the yellow ring problem without a reduction of the efficiency of the LED assembly.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 13 / 131,384, filed May 26, 2011, to be issued as U.S. Pat. No. 8,957,439 on Feb. 17, 2015, which is a 371(c) national stage entry of PCT / IB09 / 55380 filed on Nov. 27, 2009, which is the international application of EP 08170458.7 filed on Dec. 2, 2008. U.S. Pat. No. 8,957,439 and EP 08170458.7 are incorporated herein by reference.FIELD OF THE INVENTION[0002]The invention relates to the field of light emission diode (LED) assemblies. Particularly the invention relates to enhanced emission phosphor-converting LED light assemblies (pcLED). Such assemblies are often employed to provide white light.BACKGROUND OF THE INVENTION[0003]White light emitting LEDs generally comprise a blue emitting LED combined with a phosphor layer that is stimulated by the blue emission of the LED into emitting yellow light, the combination of the yellow and blue emissions providing a white light. F...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): H01L33/50H01L33/60H01L33/58
CPCH01L33/50H01L33/60H01L33/58H01L33/46H01L24/32H01L2924/12041H01L2924/00
InventorBECHTEL, HANS-HELMUTHEIDEMANN, MATTHIASSCHMIDT, PETER JOSSEFDIEDERICH, THOMAS
OwnerLUMILEDS