IP Library › Granted Patent US 11,257,990
Granted Patent B2
US 11,257,990 · App. 16/143,349 · Granted Feb 22, 2022

Light emitting device

Inventors: Atsushi Bando (Itano-gun, JP); Kazuya Matsuda (Anan, JP)
Assignee: NICHIA CORPORATION
H01L33/504H01L25/0753H01L27/15H01L33/50H01L33/507H01L33/52H01L33/62
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 11,257,990
App. No.
16/143,349
Granted
Feb 22, 2022
Kind
B2
Abstract

A light emitting device includes: a first light emitting element and a second light emitting element, each having a peak emission wavelength in a range of 430 nm to 480 nm; a first light transmissive member disposed on an upper face of the first light emitting element and containing a first phosphor; a second light transmissive member disposed on an upper face of the second light emitting element; and an encapsulant covering the first light transmissive member and the second light transmissive member and containing a second phosphor. The first light emitting element and the second light emitting element are configured to be independently driven. A chromaticity of light exiting from the first light transmissive member differs from a chromaticity of light exiting from the second light transmissive member.

Claims (60)

1. A light emitting device comprising:

a first light emitting element and a second light emitting element, each having a peak emission wavelength in a range of 430 nm to 480 nm, and each comprising a positive electrode and a negative electrode at an upper face thereof;

a first light transmissive member disposed on the upper face of the first light emitting element and containing a first phosphor;

a second light transmissive member disposed on the upper face of the second light emitting element; and

an encapsulant covering the first light transmissive member and the second light transmissive member and disposed between the first light emitting element and the second light emitting element, wherein the encapsulant contains a second phosphor,

wherein the first light emitting element and the second light emitting element are configured to be independently driven,

wherein a chromaticity of light exiting from the first light transmissive member differs from a chromaticity of light exiting from the second light transmissive member,

wherein, in a cross-sectional view, an upper face of the encapsulant includes a first region above the first light emitting element, a second region above the second light emitting element, and a third region between the first region and the second region, and

wherein a maximum height of the first region and a maximum height of the second region are greater than a maximum height of the third region.

2. The light emitting device according to claim 1 , wherein the first phosphor is a red phosphor adapted to emit red light.

3. The light emitting device according to claim 1 , wherein:

the light emitting device comprises a package having a recess, and

the first light emitting element and the second light emitting element are disposed at a bottom of the recess.

4. The light emitting device according claim 1 , wherein the second light transmissive member is substantially free of phosphor.

5. The light emitting device according to claim 1 , wherein:

the first light transmissive member does not cover lateral faces of the first light emitting element, and

the second light transmissive member does not cover lateral faces of the second light emitting element.

6. The light emitting device according to claim 1 , wherein the light emitting device is configured to emit light having a color temperature in a range of 2700 to 3000 K when only the first light emitting element is driven, and is configured to emit light having a color temperature in a range of 5000 to 6500 K when only the second light emitting element is driven.

7. The light emitting device according to claim 1 , wherein the light emitting device is configured to emit light having a color temperature in a range of 2700 to 6500 K.

8. The light emitting device according to claim 1 , wherein the first and second phosphors are adapted such that a wavelength of light emitted from the second phosphor is shorter than a wavelength of light emitted from the first phosphor.

9. The light emitting device according to claim 1 , further comprising:

a first lead, a second lead, and a third lead,

wherein the first light emitting element and the second light emitting element are disposed on an upper face of the first lead.

10. The light emitting device according to claim 1 , further comprising:

a first lead, a second lead, a third lead, and a fourth lead,

wherein the first light emitting element is disposed on an upper face of the first lead,

wherein the second light emitting element is disposed on an upper face of the second lead,

wherein the third lead is electrically connected to one of electrodes of the first light emitting element, and

wherein the fourth lead is electrically connected to one of electrodes of the second light emitting element.

11. The light emitting device according to claim 1 , wherein the first light transmissive member and the second light transmissive member have upper faces that are entirely curved.

12. The light emitting device according to claim 1 , wherein:

the first light transmissive member does not cover lateral faces of the first light emitting element, and the second light transmissive member does not cover lateral faces of the second light emitting element, and

the first and second phosphors are adapted such that a wavelength of light emitted from the second phosphor is shorter than a wavelength of light emitted from the first phosphor.

13. The light emitting device according to claim 1 , wherein:

the first phosphor is a red phosphor adapted to emit red light, and

the first light transmissive member does not cover lateral faces of the first light emitting element, and the second light transmissive member does not cover lateral faces of the second light emitting element.

14. The light emitting device according to claim 1 , wherein:

the second light transmissive member is substantially free of phosphor, and

the first light transmissive member does not cover lateral faces of the first light emitting element, and the second light transmissive member does not cover lateral faces of the second light emitting element.

15. The light emitting device according to claim 1 , wherein:

the first light transmissive member does not cover lateral faces of the first light emitting element, and the second light transmissive member does not cover lateral faces of the second light emitting element, and

the light emitting device is configured to emit light having a color temperature in a range of 2700 to 3000 K when only the first light emitting element is driven, and is configured to emit light having a color temperature in a range of 5000 to 6500 K when only the second light emitting element is driven.

16. The light emitting device according to claim 1 , wherein:

the first light transmissive member does not cover lateral faces of the first light emitting element, and the second light transmissive member does not cover lateral faces of the second light emitting element, and

the first light transmissive member and the second light transmissive member have upper faces that are entirely curved.

17. The light emitting device according to claim 1 , wherein:

the second light transmissive member is substantially free of phosphor,

the first light transmissive member does not cover lateral faces of the first light emitting element, and the second light transmissive member does not cover lateral faces of the second light emitting element, and

the first and second phosphors are adapted such that a wavelength of light emitted from the second phosphor is shorter than a wavelength of light emitted from the first phosphor.

18. The light emitting device according to claim 1 , wherein:

the first phosphor is a red phosphor adapted to emit red light,

the second light transmissive member is substantially free of phosphor,

the first light transmissive member does not cover lateral faces of the first light emitting element, and the second light transmissive member does not cover lateral faces of the second light emitting element, and

the first and second phosphors are adapted such that a wavelength of light emitted from the second phosphor is shorter than a wavelength of light emitted from the first phosphor.

19. The light emitting device according to claim 1 , wherein the encapsulant is in contact with a lateral face of the first light emitting element and a lateral face of the second light emitting element.

20. The light emitting device according to claim 1 , wherein each and every light emitting element included in the light emitting device has a peak emission wavelength in a range of 430 nm to 480 nm.

21. The light emitting device according to any of claims 1 to 3 , wherein the second light transmissive member contains a third phosphor.

22. The light emitting device according to claim 21 , wherein:

a composition of the first phosphor is the same as a composition of the third phosphor, and

an amount of the first phosphor contained in the first light transmissive member differs from an amount of the third phosphor contained in the second light transmissive member.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 26, 2018
From: BANDO, ATSUSHI; MATSUDA, KAZUYA
To: NICHIA CORPORATION
Reel/Frame 046985/0106 →
Priority Claims (5)
JP JP2017-190323 · Sep 29, 2017 · national
JP JP2018-028355 · Feb 21, 2018 · national
JP JP2018-089696 · May 8, 2018 · national
JP JP2018-133153 · Jul 13, 2018 · national
JP JP2018-153832 · Aug 20, 2018 · national
Continuity (1)
Related Publication 20190103525A1 · Apr 4, 2019