Liquid filament for incandescent lights

Patent metadata

Field	Value
Publication number	US-9305737-B2
Application number	US-201414473518-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Aug 29, 2014
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A filament for a light bulb includes a tube and a filament material within the tube, wherein the filament material is configured to be in a liquid state while the light bulb is in use.

First claim

The invention claimed is:

1. A filament for a light bulb, comprising:
a tube; and
a filament material within the tube, wherein the filament material is configured to be in a liquid state while the light bulb is in use;
wherein the tube is a capillary tube.

2. The filament of claim 1 , wherein the filament material is electrically conductive while in the liquid state.

3. The filament of claim 1 , wherein the liquid filament material wets an inner surface of the tube.

4. The filament of claim 1 , wherein the liquid filament material is configured to spread across at least a portion of an inner surface of the tube via surface tension forces.

5. The filament of claim 1 , wherein the filament material is configured to be a solid or solidify when not receiving energy from an energy source.

6. The filament of claim 1 , wherein the filament material is configured to melt in response to energy received from an energy source.

7. The filament of claim 1 , wherein the filament material is configured to incandesce.

8. The filament of claim 7 , wherein the tube is transparent to at least a portion of the light produced by the filament material.

9. The filament of claim 1 , wherein the tube is thicker at each end than at a location between the two ends.

10. The filament of claim 1 , wherein a first outer surface of the tube and a second outer surface of the tube are configured such that the temperature of the tube is lower at each end of the tube than at a location between the two ends.

11. The filament of claim 1 , wherein a first thickness and outer diameter of the tube and a second thickness and outer diameter of the tube are configured such that a stress of the tube is lower at each end of the tube than at a location between the two ends.

12. The filament of claim 1 , wherein the tube includes a cap with a thickness configured to at least one of (a) reduce a stress of the tube at the ends of the tube, (b) reduce the temperature of the tube at the ends of the tube, or (c) reduce the temperature of a supply wire.

13. The filament of claim 1 , wherein the tube has a higher melting point than the filament material.

14. The filament of claim 1 , wherein the tube is a highly refractory material.

15. The filament of claim 1 , wherein the tube includes at least one of hafnium carbide, hafnium nitride, or tantalum 4 hafnium carbide 5.

16. The filament of claim 1 , wherein the filament material includes at least one of tungsten, hafnium, or rhenium.

17. The filament of claim 1 , wherein the filament has a designed emissivity, and wherein the designed emissivity is relatively high in the visible wavelengths and relatively low in at least one of ultraviolet wavelengths and infrared wavelengths.

18. An incandescent light, comprising:
a tube;
a filament material within the tube;
a supply wire configured to provide energy to the filament material;
a base configured to be in electrical communication with a socket; and
a bulb coupled to the base and configured to enclose the tube and supply wire,
wherein the filament material is configured to enter into a liquid state while the light bulb is in use; and
wherein the bulb contains an inert gas; wherein the opening for the supply wire is configured to allow gas transport between the bulb and an interior space of the tube.

19. The incandescent light of claim 18 , wherein the tube includes an opening for the supply wire.

20. The incandescent light of claim 18 , wherein a first outer surface of the tube and a second outer surface of the tube are configured such that the temperature of the tube is lower at each end of the tube than at a location between the two ends.

21. The incandescent light of claim 18 , wherein a first thickness and outer diameter of the tube and a second thickness and outer diameter of the tube are configured such that a stress of the tube is lower at each end of the tube than at a location between the two ends.

22. The incandescent light of claim 18 , wherein the filament material includes a metal.

23. The incandescent light of claim 22 , wherein the filament material includes at least one of tungsten, hafnium, or rhenium.

24. The incandescent light of claim 18 , wherein the bulb contains a gas configured to counteract evaporation of at least one of the tube and the filament material.

25. The incandescent light of claim 24 , wherein the gas includes at least one of nitrogen gas, a nitrogen donating gas, or a carbon donating gas.

26. The incandescent light of claim 18 , wherein the bulb holds a vacuum in which the tube is supported.

27. An incandescent light, comprising:
a tube;
a filament material within the tube;
a supply wire configured to provide energy to the filament material;
a base configured to be in electrical communication with a socket;
a bulb coupled to the base and configured to enclose the tube and supply wire; and
a control circuit coupled to the supply wire and configured to be in communication with a power source, and further configured to regulate the energy provided to the filament material;
wherein the control circuit is configured to provide energy to the filament material such that the filament material is in a liquid state when the light bulb is in use.

28. The incandescent light of claim 27 , wherein the control circuit is configured to regulate the energy to the filament material such that the filament material does not boil.

29. The incandescent light of claim 27 , wherein a first outer surface of the tube and a second outer surface of the tube are configured such that the temperature of the tube is lower at each end of the tube than at a location between the two ends.

30. The incandescent light of claim 27 , wherein a first thickness and outer diameter of the tube and a second thickness and outer diameter of the tube are configured such that a stress of the tube is lower at each end of the tube than at a location between the two ends.

31. The incandescent light of claim 27 , wherein the tube includes a cap with a thickness configured to at least one of (a) reduce a stress of the tube at the ends of the tube, (b) reduce the temperature of the tube at the ends of the tube, or (c) reduce the temperature of a supply wire.

32. The incandescent light of claim 27 , wherein the filament has a designed emissivity, and wherein the designed emissivity is relatively high in the visible wavelengths and relatively low in at least one of ultraviolet wavelengths and infrared wavelengths.

33. The incandescent light of claim 32 , wherein the designed emissivity is controlled by the control circuit.

Assignees

• Elwha Llc

Inventors

• Hyde Roderick A
• Kare Jordin T
• Tuckerman David B
• Weaver Thomas A
• Wood Jr Lowell L
• Zare Richard N

Classifications

• H01K5/00

  Lamps for general lighting (H01K9/00 - H01K13/00 take precedence) · CPC title

• H01J1/06

  Containers for liquid-pool electrodes; Arrangement or mounting thereof · CPC title

• H01K1/58

  Cooling arrangements · CPC title

• H05B39/04 Primary

  Controlling · CPC title

• H01K1/28

  Envelopes; Vessels · CPC title