Light-emitting device with remote scattering element and total internal reflection extractor element

• US 9,291,763 B2
• Filed: 09/12/2013
• Issued: 03/22/2016
• Est. Priority Date: 09/13/2012
• Status: Active Grant

• Current Assignee: Quarkstar LLC
• Original Assignee: Quarkstar LLC
• Inventors: Stormberg, Hans Peter, Gardner, Robert C., Magel, Gregory A., Schinagl, Ferdinand, Haitz, Roland H.
• Primary Examiner(s): CARIASO, ALAN B
• Application Number:
  US14/427,944
• Publication Number:
  US 20150219820A1
• Time in Patent Office: 922 Days
• US Class Current: 1/1
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21S 8/00 Lighting devices intended for fixed installation F21S9/00, F21S10/00 take precedence; using a string or strip of light sources F21S4/00
• CPC Class Codes: F21V 13/12 Combinations of only three kinds of elements
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0066 specially adapted to cooperate with point like light sources; specially adapted to cooperate with light sources the shape of which is unspecified F21V7/16 - F21V7/30 take precedence
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21V 7/09 with a combination of different curvatures
• CPC Class Codes: F21V 9/32 characterised by the arrangement of the photoluminescent material
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 5/0236 the diffusion taking place within the volume of the element
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: G02B 6/0003 the light guides being doped with fluorescent agents
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0025 Diffusing sheet or layer; Prismatic sheet or layer
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0085 : Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64
• CPC Class Codes: H01L 2933/0091 : Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/507 : the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body

Abstract

A variety of light-emitting devices are disclosed that are configured to output light provided by a light-emitting element (LEE). In general, embodiments of the light-emitting devices feature a light-emitting element, a scattering element that is spaced apart from the light-emitting element and an extractor element coupled to the scattering element, where the extractor element includes, at least in part, a total internal reflection surface. Luminaires incorporating light-emitting devices of this type are also disclosed.

Claims

1. A light-emitting device comprising:

a light-emitting diode (LED) configured to emit pump light during operation;

a phosphor element having a first surface facing the LED, the phosphor element being spaced apart from the LED and positioned to receive at least some pump light from the LED and to emit scattered light; and

an extractor comprising a transparent material, the extractor having an exit surface and a side surface and being arranged to receive a portion of the scattered light through a region adjacent to the phosphor element and to output the scattered light through the exit surface, the side surface being arranged between the region of adjacency and the exit surface, wherein

a medium having a refractive index no is disposed adjacent the first surface of the phosphor element and the phosphor element has a refractive index n₁, where n₀<

n₁, and the transparent material has a refractive index n₂, where n₀<

n₂, and

the side surface comprises a TIR surface, the TIR surface being positioned and shaped such that an angle of incidence on the TIR surface of the scattered light received through the region of adjacency that directly impinges on the TIR surface is incident on the TIR surface at an angle of incidence that is equal to or larger than a critical angle for total internal reflection.

2. The light-emitting device of claim 1, wherein the phosphor element is configured to inelastically scatter at least some of the pump light and to elastically scatter at least some of the pump light.

3. The light-emitting device of claim 1, wherein the TIR surface extends to the exit surface.

4. The light-emitting device of claim 1, wherein the TIR surface extends to the region of adjacency.

5. The light-emitting device of claim 1, wherein the phosphor element is planar.

6. The light-emitting device of claim 1, wherein the phosphor element is a shell.

7. The light-emitting device of claim 6, wherein the shell is convex with respect to the exit surface.

8. The light-emitting device of claim 1, further comprising a reflective layer on a portion of the side surface.

9. The light-emitting device of claim 1, further comprising a reflective element spaced apart from and extending along at least a portion of the side surface, the reflective element configured to redirect a portion of light escaping from the side surface back into the extractor.

10. The light-emitting device of claim 9, wherein the phosphor element is at least partially recessed in the extractor.

11. The light-emitting device of claim 1, wherein the exit surface is non-planar.

12. The light-emitting device of claim 11, wherein the exit surface comprises multiple differently shaped portions.

13. The light-emitting device of claim 1, wherein the exit surface is positioned and shaped such that an angle of incidence on the exit surface of the scattered light passing through the region of adjacency that directly impinges on the exit surface is less than a critical angle for total internal reflection.

14. The light-emitting device of claim 1, wherein the exit surface is positioned and shaped such that an angle of incidence on the exit surface of the scattered light passing through the region of adjacency, that directly impinges on the exit surface or impinges on the exit surface after TIR off the TIR surface, is less than a critical angle for total internal reflection.

15. The light-emitting device of claim 1, wherein where n₁<

n₂.

16. The light-emitting device of claim 1, wherein the phosphor element comprises inelastic and elastic scattering centers.

17. The light-emitting device of claim 16, wherein the scattered light is isotropically scattered light.

18. The light-emitting device of claim 1 further comprising a secondary reflector adjacent the extractor, the secondary reflector configured to redirect light output from the extractor.

19. The light-emitting device of claim 18, wherein the secondary reflector has an input aperture disposed proximate the exit surface.

20. A luminaire, comprising:

a housing; and

a light-emitting device supported by the housing and comprising

a light-emitting diode (LED) configured to emit pump light during operation,

a phosphor element having a first surface facing the LED, the phosphor element being spaced apart from the LED and positioned to receive at least some pump light from the LED and to emit scattered light, and

an extractor comprising a transparent material, the extractor having an exit surface and a side surface and being arranged to receive a portion of the scattered light through a region adjacent to the phosphor element and to output the scattered light through the exit surface, the side surface being arranged between the region of adjacency and the exit surface, wherein

a medium having a refractive index no is disposed adjacent the first surface of the phosphor element and the phosphor element has a refractive index n₁, where n₀<

n₁, and the transparent material has a refractive index n₂, where n₀<

n₂, and

the side surface comprises a TIR surface, the TIR surface being positioned and shaped such that an angle of incidence on the TIR surface of the scattered light received through the region of adjacency that directly impinges on the TIR surface is incident on the TIR surface at an angle of incidence that is equal to or larger than a critical angle for total internal reflection.

21. The luminaire of claim 20, further comprising an optical element supported by the housing and configured to receive light from the light-emitting device, wherein the light emitted from the light-emitting device is further directed and shaped by the optical element.

22. The luminaire of claim 21, wherein the optical element is a reflector.

23. The luminaire of claim 21, wherein the optical element is a lens.

24. A light-emitting device comprising:

a light-emitting element (LEE);

a scattering element having a first surface facing the LEE, the scattering element being spaced apart from the LEE and positioned to receive at least some light from the LEE, and configured to emit scattered light; and

an extractor having a side surface being arranged to receive a portion of the scattered light through a region of adjacency with the scattering element, the extractor configured to emit light through an exit surface, the exit surface arranged distal the region of adjacency with the scattering element, wherein

a medium having a refractive index n₀ is disposed adjacent the first surface of the scattering element and the scattering element has a refractive index n₁, where n₀<

n₁, and the extractor has a refractive index n₂, where n₀<

n₂, and

the side surface being positioned and shaped such that an angle of incidence on the side surface of scattered light received through the region of adjacency that directly impinges on the side surface is equal to or larger than a critical angle for total internal reflection.

25. The light-emitting device of claim 24, wherein the scattering element is shaped as a hemisphere.

26. The light-emitting device of claim 24, wherein the extractor further comprises a light guide, the light guide extending the side surface and comprising the exit surface.