Tubular light source having overwind

Patent metadata

Field	Value
Publication number	US-9536729-B2
Application number	US-201514832490-A
Country	US
Kind code	B2
Filing date	Aug 21, 2015
Priority date	Mar 15, 2013
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

Embodiments of the present invention generally relate to a tubular lamp with a coiled filament having an overwind wrapped around the coil. In one embodiment, the tubular lamp has a coiled coil filament, and the coiled coil has an overwind wrapped around the coiled coil.

First claim

The invention claimed is:

1. A lamp, comprising:
an envelope having a first end and a second end; and
a filament extending from the first end to the second end of the envelope, wherein the filament includes a primary coil and an overwind wrapped around the primary coil, and wherein the overwind has a pitch ratio between about 1.1 and about 2.0.

2. The lamp of claim 1 , wherein the primary coil comprises potassium doped tungsten.

3. The lamp of claim 2 , wherein the overwind comprises tungsten.

4. The lamp of claim 2 , wherein the overwind comprises potassium doped tungsten.

5. The lamp of claim 1 , wherein the primary coil has a first diameter, the overwind has a second diameter, and a ratio of the first diameter to the second diameter is between about 3:1 and about 15:1.

6. The lamp of claim 5 , wherein the ratio of the first diameter to the second diameter is between about 6:1 and about 12:1.

7. The lamp of claim 1 , wherein the envelope has an arc shape.

8. The lamp of claim 1 , wherein the envelope is circular, and wherein the first end and the second end abut.

9. The lamp of claim 1 , wherein the primary coil comprises a coiled coil.

10. A halogen lamp for a rapid thermal processing (RTP) apparatus, comprising:
a torroidal envelope; and
a continuous filament disposed in the envelope, wherein the filament conforms to the shape of the envelope, and wherein the filament includes a primary coil and an overwind wrapped around the primary coil, and wherein the overwind has a pitch ratio between about 1.1 and about 2.0.

11. The halogen lamp of claim 10 , wherein the primary coil comprises potassium doped tungsten.

12. The halogen lamp of claim 10 , wherein the overwind comprises tungsten.

13. The halogen lamp of claim 10 , wherein the overwind comprises potassium doped tungsten.

14. The halogen lamp of claim 10 , wherein the primary coil has a first diameter, the overwind has a second diameter, and a ratio of the first diameter to the second diameter is between about 3:1 and about 15:1.

15. The halogen lamp of claim 14 , wherein the ratio of the first diameter to the second diameter is between about 6:1 and about 12:1.

16. The halogen lamp of claim 10 , wherein the primary coil comprises a coiled coil.

Assignees

• Applied Materials Inc

Inventors

• Ranish Joseph M

Classifications

• H01K5/02 Primary

  with connections made at opposite ends, e.g. tubular lamp with axially arranged filament · CPC title

• H01K1/14

  characterised by the shape · CPC title

• H01K1/04

  characterised by the material thereof · CPC title

• H01K1/28

  Envelopes; Vessels · CPC title

• H05B3/12

  characterised by the composition or nature of the conductive material · CPC title