Light emitting device with improved warm-white color point

Patent metadata

Field	Value
Publication number	US-10837607-B2
Application number	US-201816140012-A
Country	US
Kind code	B2
Filing date	Sep 24, 2018
Priority date	Sep 26, 2017
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A light emitting device is disclosed and includes an emission source configured to emit a primary blue light and a wavelength-converting element configured to convert the primary blue light to a secondary light having a correlated color temperature (CCT) in the range of 1600K-2500K and color rendering index (CRI) in the range of 40-60, the wavelength-converting element including a red phosphor material having a peak emission wavelength that is less than 620 nm and a green phosphor material having a peak emission wavelength that is greater than 530 nm. The device may exhibit a melanopic/photopic ratio of less than 0.25 and/or may exhibit a radiometric power fraction of light having a wavelength below 530 nm below 0.1.

First claim

What is being claimed is:

1. A light emitting device, comprising:
an emission source configured to emit a primary blue light; and
a wavelength-converting element configured to convert the primary blue light to a secondary light having a correlated color temperature (CCT) in a range of 1600K-2500K, a melanopic/photopic ratio of less than 0.25, and a color rendering index (CRI) in a range of 40-60, the wavelength-converting element including a red phosphor material having a peak emission wavelength that is less than 620 nm and a green phosphor material having a peak emission wavelength that is greater than 530 nm.

2. The light emitting device of claim 1 , wherein the red phosphor has a peak emission wavelength of approximately 604 nm, and the green phosphor has a peak emission wavelength of approximately 543 nm.

3. The light emitting device of claim 1 , wherein the emission source includes at least one light emitting diode.

4. The light emitting device of claim 1 , wherein the peak emission wavelength of the green phosphor material is approximately in a range 530-560 nm and the peak emission wavelength of the red phosphor material is approximately in a range of 580-620 nm.

5. The light emitting device of claim 1 , wherein the wavelength-converting element has a green-to-red phosphor weight ratio of approximately 1.6.

6. The light emitting device of claim 1 , wherein the wavelength-converting element has a green-to-red phosphor weight ratio of approximately 1.01.

7. The light emitting device of claim 1 , wherein the wavelength-converting element has a green-to-red phosphor weight ratio of approximately 0.64.

8. The light emitting device of claim 1 , wherein the green phosphor material includes a YAG phosphor.

9. The light emitting device of claim 1 , wherein the red phosphor material includes a BSSNE phosphor.

10. The light emitting device of claim 1 , wherein the red phosphor material and the green phosphor material are suspended in a silicone matrix, and the wavelength-converting element has a phosphor-to-silicon mass ratio in the range of 0.62-0.68.

11. A light emitting device, comprising: an emission source configured to emit a primary blue light; and a wavelength-converting element configured to convert the primary blue light to a secondary light having a correlated color temperature (CCT) in a range of 1600K-2500K, a radiometric power fraction of light having a wavelength below 530 nm is below 0.1, and color rendering index (CRT) in a range of 40-60, the wavelength-converting element including a red phosphor material having a peak emission wavelength that is less than 620 nm and a green phosphor material having a peak emission wavelength that is greater than 530 nm.

12. The light emitting device of claim 11 , wherein the red phosphor has a peak emission wavelength of approximately 604 nm, and the green phosphor has a peak emission wavelength of approximately 543 nm.

13. The light emitting device of claim 11 , wherein the emission source includes at least one light emitting diode.

14. The light emitting device of claim 11 , wherein the peak emission wavelength of the green phosphor material is approximately in a range 530-560 nm and the peak emission wavelength of the red phosphor material is approximately in a range of 580-620 nm.

15. The light emitting device of claim 11 , wherein the wavelength-converting element has a green-to-red phosphor weight ratio of approximately 1.6.

16. The light emitting device of claim 11 , wherein the wavelength-converting element has a green-to-red phosphor weight ratio of approximately 1.01.

17. The light emitting device of claim 11 , wherein the wavelength-converting element has a green-to-red phosphor weight ratio of approximately 0.64.

18. The light emitting device of claim 11 , wherein the green phosphor material includes a YAG phosphor.

19. The light emitting device of claim 11 , wherein the red phosphor material includes a BSSNE phosphor.

20. The light emitting device of claim 11 , wherein the red phosphor material and the green phosphor material are suspended in a silicone matrix, and the wavelength-converting element has a phosphor-to-silicon mass ratio in the range of 0.62-0.68.

Assignees

• Lumileds Llc

Inventors

• Soer Wouter
• Bechtel Hans-Helmut

Classifications

• H10W90/00

  Package configurations · CPC title

• C09K11/77348

  Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides · CPC title

• C09K11/77347

  Silicon Nitrides or Silicon Oxynitrides · CPC title

• C09K11/7734

  Aluminates · CPC title

• H10H20/8515

  not being in contact with the bodies · CPC title