Semiconductor light emitting apparatus including elongated hollow wavelength conversion tubes and methods of assembling same

• US 8,004,172 B2
• Filed: 11/18/2008
• Issued: 08/23/2011
• Est. Priority Date: 11/18/2008
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Edmond, John Adam, Hussell, Christopher P.
• Primary Examiner(s): Lee; Eugene
• Assistant Examiner(s): Ho; Anthony
• Application Number:
  US12/273,216
• Publication Number:
  US 20100124243A1
• Time in Patent Office: 1,008 Days
• Field of Search: 257/99, 257/100, 362/178, 313/488, 313/495
• US Class Current: 313/488
• CPC Class Codes: F21K 9/61 using light guides
• 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: F21V 15/01 Housings, e.g. material or assembling of housing parts F21V15/02 takes precedence housings forming signs or letters G09F13/04
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 6/0003 the light guides being doped with fluorescent agents
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/005 provided by one optical element, or plurality thereof, placed on the light output side of the light guide
• CPC Class Codes: G02B 6/0096 the lights guides being of the hollow type

Abstract

A semiconductor light emitting apparatus includes an elongated hollow wavelength conversion tube that includes an elongated wavelength conversion tube wall having wavelength conversion material, such as phosphor, dispersed therein. A semiconductor light emitting device is oriented to emit light inside the elongated hollow wavelength conversion tube to impinge upon the elongated wavelength conversion tube wall and the wavelength conversion material dispersed therein. The elongated hollow wavelength conversion tube may have an open end, a crimped end, a reflective end, and/or other configurations. Multiples tubes and/or multiple semiconductor light emitting devices may also be used in various configurations. Related assembling methods are also described.

Claims

1. A semiconductor light emitting apparatus comprising:

an elongated hollow wavelength conversion tube that comprises an elongated wavelength conversion tube wall having wavelength conversion material dispersed therein; and

a packaged semiconductor light emitting device comprising a mounting substrate, a dome directly on the mounting substrate and a semiconductor light emitting die that is located between the mounting substrate and the dome, the packaged semiconductor light emitting device being oriented such that the dome extends into an end of the elongated hollow wavelength conversion tube, a base of the dome extends adjacent an end of the elongated wavelength conversion tube wall, the mounting substrate provides an end cap for the end of the elongated wavelength conversion tube wall and is wider than the end of the elongated hollow wavelength conversion tube to extend outside the elongated hollow wavelength conversion tube, and the semiconductor light emitting die is oriented to emit light through the dome to inside the elongated hollow wavelength conversion tube to impinge upon the elongated wavelength conversion tube wall and the wavelength conversion material dispersed therein.

2. An apparatus according to claim 1 wherein the packaged semiconductor light emitting device is oriented such that at least about 20% of the emitted light strikes the elongated wavelength conversion tube wall at an oblique angle.

3. An apparatus according to claim 1 wherein the packaged semiconductor light emitting device is oriented such that at least about 90% of the emitted light strikes the elongated wavelength conversion tube wall at an oblique angle.

4. An apparatus according to claim 1 wherein the packaged semiconductor light emitting device is a blue light emitting diode having an area of about 1 mm² and wherein the semiconductor light emitting apparatus produces about 160 lumens per watt at a color temperature of about 4700K.

5. An apparatus according to claim 1 wherein the packaged semiconductor light emitting device is a blue light emitting diode having an area of about 1 mm² and wherein the semiconductor light emitting apparatus produces about 150 lumens per watt at a color temperature of about 5500K.

6. An apparatus according to claim 1 wherein the elongated hollow wavelength conversion tube is oriented relative to the packaged semiconductor light emitting device so as to provide a longer path length through the elongated wavelength conversion tube wall for light that is emitted by the packaged semiconductor light emitting device that does not strike the wavelength conversion material embedded therein without increasing the path length of light that is converted by striking the wavelength conversion material embedded therein.

7. An apparatus according to claim 1 wherein the elongated wavelength conversion tube wall defines a tube axis, wherein the packaged semiconductor light emitting device is configured to emit light symmetrically about an emission axis and wherein the packaged semiconductor light emitting device is oriented such that the emission axis is coincident with the tube axis.

8. An apparatus according to claim 1 wherein the elongated hollow wavelength conversion tube includes first and second opposing ends, and the packaged semiconductor light emitting device is adjacent the first end.

9. An apparatus according to claim 8 wherein the second end is a closed second end.

10. An apparatus according to claim 9 wherein the second end is a crimped second end.

11. An apparatus according to claim 9 further comprising a cap at the second end.

12. An apparatus according to claim 11 wherein the cap comprises wavelength conversion material.

13. An apparatus according to claim 11 wherein the cap comprises reflective material.

14. An apparatus according to claim 8 wherein the packaged semiconductor light emitting device is a first packaged semiconductor light emitting device, the apparatus further comprising a second packaged semiconductor light emitting device adjacent the second end that is oriented to emit light inside the elongated hollow wavelength conversion tube to impinge upon the elongated wavelength conversion tube wall and the wavelength conversion material dispersed therein.

15. An apparatus according to claim 14 further comprising a double-sided reflector in the elongated hollow wavelength conversion tube between the first and second packaged semiconductor light emitting devices.

16. An apparatus according to claim 14 wherein the elongated hollow wavelength conversion tube is crimped between the first and second packaged semiconductor light emitting devices.

17. An apparatus according to claim 8 wherein the packaged semiconductor light emitting device is a first packaged semiconductor light emitting device, the apparatus further comprising a second packaged semiconductor light emitting device that extends at least partially into the elongated hollow wavelength conversion tube to emit light towards the second end.

18. An apparatus according to claim 1 wherein the elongated hollow wavelength conversion tube is a first elongated hollow wavelength conversion tube, the apparatus further comprising a second elongated hollow wavelength conversion tube, wherein the first and second elongated hollow wavelength conversion tubes share a common end and wherein the packaged semiconductor light emitting device is adjacent the common end and is oriented to emit light inside the first and second elongated hollow wavelength conversion tubes.

19. An apparatus according to claim 1 wherein the elongated hollow wavelength conversion tube wall includes inner and outer surfaces and wherein the elongated hollow wavelength conversion tube further comprises a supporting layer on the inner surface and/or on the outer surface.

20. An apparatus according to claim 1 wherein the elongated hollow wavelength conversion tube is a first elongated hollow wavelength conversion tube, the apparatus further comprising:

a second elongated hollow wavelength conversion tube that comprises a second elongated wavelength conversion tube wall having wavelength conversion material dispersed therein, the first and second elongated hollow wavelength conversion tubes being coaxial to one another.

21. An apparatus according to claim 1 wherein the elongated tube wall includes inner and outer surfaces and wherein the inner and/or outer surfaces are textured.

22. An apparatus according to claim 21 wherein the inner and/or outer surfaces are non-uniformly textured.

23. An apparatus according to claim 1 wherein the elongated wavelength conversion tube wall has wavelength conversion material non-uniformly dispersed therein.

24. An apparatus according to claim 17 further comprising:

a screw-type base;

a pair of standoffs that maintain the elongated hollow wavelength conversion tube and the first and second packaged semiconductor light emitting devices spaced apart from the base; and

a bulb that is connected to the screw-type base and surrounds the hollow wavelength conversion tube and the first and second semiconductor light emitting devices.

25. An apparatus according to claim 18 further comprising a plurality of elongated hollow wavelength conversion tubes that share the common end and extend around a central axis.

26. An apparatus according to claim 1 wherein the elongated hollow wavelength conversion tube and the packaged semiconductor light emitting device define a light emitting filament, the apparatus further comprising:

at least one additional light emitting filament, each of the at least one additional light emitting filaments comprising an additional elongated hollow wavelength conversion tube that includes an additional elongated wavelength conversion tube wall having wavelength conversion material dispersed therein and an additional packaged semiconductor light emitting device that is oriented to emit light inside the elongated hollow wavelength conversion tube to impinge upon the elongated wavelength conversion tube wall and the wavelength conversion material dispersed therein.

27. An apparatus according to claim 26 wherein the light emitting filament and the at least one additional light emitting filament are oriented end-to-end in a linear array.

28. An apparatus according to claim 26 wherein the light emitting filament and the at least one additional light emitting filament extend about a common origin in a three-dimensional array.

31. An apparatus according to claim 1 wherein the elongated wavelength conversion tube wall is of approximately same diameter as the base of the dome and the end of the elongated wavelength conversion tub wall is directly on the mounting substrate.

29. A method of assembling a semiconductor light emitting apparatus comprising:

inserting a dome that surrounds a semiconductor light emitting device and that is directly on a substrate at least partially into an end of an elongated hollow wavelength conversion tube that comprises an elongated wavelength conversion tube wall having wavelength conversion material dispersed therein, such that a base of the dome extends adjacent an end of the elongated wavelength conversion tube wall, the mounting substrate provides an end cap for the end of the elongated wavelength conversion tube wall and is wider than the end of the elongated hollow wavelength conversion tube to extend outside the elongated hollow wavelength conversion tube, and the semiconductor light emitting die is oriented to emit light through the dome to inside the elongated hollow wavelength conversion tube to impinge upon the elongated wavelength conversion tube wall and the wavelength conversion material dispersed therein.

30. A method according to claim 29 further comprising crimping the elongated hollow wavelength conversion tube remote from the end.