High efficiency glass halogen lamp with interference coating
AssigneeGeneral Electric Company
InventorsAshfaqul Islam Chowdhury, Leonard Edward Hoegler, William Robert Wright
Life of this patent
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Abstract
The disclosure provides a light-transmissive glass halogen filament tube with a filament light source having a coil concentricity ratio of not greater than 20% disposed therein, the filament tube having a multi-layer optical interference coating deposited on the outer surface thereof that transmits visible radiation from about 400-750 nm and reflects infra red radiation from about 800-2500 nm back to the filament for re-absorption, the coated filament tube exhibiting an LPW gain of at least 26%.
Claims23
A glass halogen filament tube comprising a light-transmissive glass filament tube with a filament light source having a coil concentricity ratio of not greater than 20% disposed therein, the filament tube having a multi-layer optical interference coating deposited on the outer surface of the filament tube that transmits visible radiation at greater than 92% from about 400-750 nm and reflects infra-red radiation at greater than 80% from about 800-2500 nm back to the filament for re-absorption, the coated filament tube exhibiting an LPW gain of at least 26%;
- wherein the multi-layer optical interference coating comprises at least 210 layers;
- and
- wherein the multi-layer optical interference coating has a thickness of from about 3μ to about 25μ.
A configuration providing an optical interference multi-layer coating on a glass halogen filament tube, said configuration comprising:
- a) a light-transmissive glass envelope having an outer surface and an inner surface, and including within said envelope at least one light source and a halogen fill gas;
- b) said at least one light source positioned within the envelope such that it has a coil concentricity ratio of not greater than 20%;
- and
- c) a multi-layer optical interference coating provided by PVD or other processing on at least a portion of the outer surface of the envelope that transmits visible radiation at greater than 92% from about 400-750 nm and reflects infra-red radiation at greater than 80% from about 800-2500 nm back to the filament for re-absorption;
- wherein said optical interference coating is compatible with the glass envelope and the coating functions to provide LPW gain of the filament tube of at least about 26%;
- wherein the multi-layer optical interference coating comprises at least 210 layers;
- and
- wherein the multi-layer optical interference coating has a thickness of from about 3μ, to about 25μ.
A filament tube comprising:
- a glass envelope housing a filament positioned therein to achieve a coil concentricity ratio of not greater than 20%,
- a multi-layer optical interference coating on at least a portion of an exterior surface of the envelope that transmits visible radiation at greater than 92% from about 400 nm to about 750 nm and reflects infra-red radiation at greater than 80% from about 800 nm to about 2500 nm;
- wherein the filament tube satisfies the following relationship:
- 1000≦x≦3000;
- 800≦y≦2000;
- and
- 18≦z≦30;
- wherein x corresponds to life in hours, y corresponds to lumens, and z corresponds to lumens per watt (LPW);
- the filament tube exhibits a LPW gain of at least about 26%;
- wherein the multi-layer optical interference coating comprises at least 210 layers;
- and
- wherein the multi-layer optical interference coating has a thickness of from about 3μ to about 25μ.
Dependencies are inferred from the claim text.