Optical interference filters, and filament tubes and lamps provided therewith

• US 9,115,864 B2
• Filed: 08/21/2013
• Issued: 08/25/2015
• Est. Priority Date: 08/21/2013
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Zhao, Tianji, Brown, Peter William, Ward, Benjamin James
• Primary Examiner(s): Patel, Nimeshkumar
• Assistant Examiner(s): Stern, Jacob R
• Application Number:
  US13/971,930
• Publication Number:
  US 20150055346A1
• Time in Patent Office: 734 Days
• Field of Search: 362/293
• US Class Current: 1/1
• CPC Class Codes: F21V 9/04 for filtering out infrared radiation dichroic reflectors F21V7/22; using liquid-filled chambers F21V9/12
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection
• CPC Class Codes: H01K 1/32 provided with coatings on the walls; Vessels or coatings thereon characterised by the material thereof

Abstract

A multilayer coating systems suitable for use as optical interference filters in lighting systems, for example, halogen lamps. Such an optical interference filter contains alternating layers of a high refractive index material and a low refractive index material. The high refractive index material consists of niobia, titania, and incidental impurities and contains either about 25 to less than 50 mol % titania and the balance niobia and incidental impurities, or contains about 60 to about 80 mol % titania and the balance niobia and incidental impurities.

Claims

1. An optical interference filter comprising alternating layers of a high refractive index material and a low refractive index material, the high refractive index material consisting of niobia, titania, and incidental impurities, the high refractive index material containing either about 25 to less than 50 mol % titania and the balance niobia and incidental impurities, or containing about 60 to about 80 mol % titania and the balance niobia and incidental impurities, the high refractive index material comprising at least one of a 1:

1 titania-niobia complex of TiO₂.Nb₂O₅ and a 1;

3 titania-niobia complex of TiO₂.3Nb₂O₅.

2. The optical interference filter according to claim 1, wherein the high refractive index material contains about 25 to less than 50 mol % titania and the balance niobia and incidental impurities, and the high refractive index material comprises the 1:

1 titania-niobia complex of TiO₂.Nb₂O₅ and the 1;

3 titania-niobia complex of TiO₂.3Nb₂O₅.

3. The optical interference filter according to claim 1, wherein the high refractive index material contains 30 to 40 mol % titania, and the balance niobia and incidental impurities.

4. The optical interference filter according to claim 1, wherein the high refractive index material contains about 60 to about 80 mol % titania and the balance niobia and incidental impurities, and the high refractive index material comprises the 1:

1 titania-niobia complex of TiO₂.Nb₂O₅.

5. The optical interference filter according to claim 1, wherein the high refractive index material contains 73 to 78 mol % titania, and the balance niobia and incidental impurities.

6. The optical interference filter according to claim 1, wherein the low refractive index material contains silica.

7. The optical interference filter according to claim 1, wherein the optical interference filter consists of the alternating layers of the high and low refractive index materials.

8. A filament tube comprising a light-transmissive envelope, a filament adapted as a light source within the envelope, and an optical interference filter comprising a multilayer coating on a surface of the envelope, the optical interference filter transmitting visible light and reflecting infrared radiation back to the filament, the optical interference filter comprising alternating layers of a high refractive index material and a low refractive index material, the high refractive index material consisting of niobia, titania, and incidental impurities, the high refractive index material containing either about 25 to less than 50 mol % titania and the balance niobia and incidental impurities, or containing about 60 to about 80 mol % titania and the balance niobia and incidental impurities, the high refractive index material comprising at least one of a 1:

1 titania-niobia complex of TiO₂.Nb₂O₅ and a 1;

3 titania-niobia complex of TiO₂.3Nb₂O₅.

9. The filament tube according to claim 8, wherein the high refractive index material contains about 25 to less than 50 mol % titania and the balance niobia and incidental impurities, and the high refractive index material comprises the 1:

1 titania-niobia complex of TiO₂.Nb₂O₅ and the 1;

3 titania-niobia complex of TiO₂.3Nb₂O₅.

10. The filament tube according to claim 8, wherein the high refractive index material contains 30 to 40 mol % titania, and the balance niobia and incidental impurities.

11. The filament tube according to claim 8, wherein the high refractive index material contains about 60 to about 80 mol % titania and the balance niobia and incidental impurities, and the high refractive index material comprises the 1:

1 titania-niobia complex of TiO₂.Nb₂O₅.

12. The filament tube according to claim 8, wherein the high refractive index material contains 73 to 78 mol % titania, and the balance niobia and incidental impurities.

13. The filament tube according to claim 8, wherein the low refractive index material contains silica.

14. The filament tube according to claim 8, wherein the optical interference filter consists of the alternating layers of the high and low refractive index materials.

15. A halogen lamp having a filament tube comprising a light-transmissive envelope, a filament adapted as a light source within the envelope, and an optical interference filter comprising a multilayer coating on a surface of the envelope, the optical interference filter transmitting visible light and reflecting infrared radiation back to the filament for re-absorption, the optical interference filter comprising alternating layers of a high refractive index material and a low refractive index material, the high refractive index material consisting of niobia, titania, and incidental impurities, the high refractive index material containing either about 25 to less than 50 mol % titania and the balance niobia and incidental impurities, or containing about 60 to about 80 mol % titania and the balance niobia and incidental impurities, the high refractive index material comprising at least one of a 1:

1 titania-niobia complex of TiO₂.Nb₂O₅ and a 1;

3 titania-niobia complex of TiO₂.3Nb₂O₅.

16. The halogen lamp according to claim 15, wherein the high refractive index material contains about 25 to less than 50 mol % titania and the balance niobia and incidental impurities, and the high refractive index material comprises the 1:

1 titania-niobia complex of TiO₂.Nb₂O₅ and the 1;

3 titania-niobia complex of TiO₂.3Nb₂O₅.

17. The halogen lamp according to claim 15, wherein the high refractive index material contains 30 to 40 mol % titania, and the balance niobia and incidental impurities.

18. The halogen lamp according to claim 15, wherein the high refractive index material contains about 60 to about 80 mol % titania and the balance niobia and incidental impurities, and the high refractive index material comprises the 1:

1 titania-niobia complex of TiO₂.Nb₂O₅.

19. The halogen lamp according to claim 15, wherein the high refractive index material contains 73 to 78 mol % titania, and the balance niobia and incidental impurities.

20. The halogen lamp according to claim 15, wherein the optical interference filter consists of the alternating layers of the high and low refractive index materials.