High efficiency discharge lamp
AssigneeKoninklijke Philips Electronics N.V.
InventorsMichael Haacke, Ulrich Hechtfischer
Life of this patent
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Abstract
A high pressure gas discharge lamp 10 is described with a discharge vessel 20. Electrodes 24 project into a discharge space 22 of a volume of 12-20 mm3. The discharge space has a filling of rare gas and a metal halide composition which is free of mercury. The metal halide composition comprises at least halides of Sodium and Scandium with a mass ratio of halides of Sodium and Scandium of 0.9-1.5. The lamp 10 further comprises an outer enclosure 18 provided around the discharge vessel 20, which is sealed and filled with a gas at a pressure below 1 bar. The lamp 10 has an efficiency equal to or greater than 90 lm/W in a steady state operation at an electrical power of 25 W.
Claims14
1-15. (canceled)
A high pressure gas discharge lamp having an efficiency equal to or greater than 90 lm/W in a steady state operation at an electrical power of 25 W, the lamp comprising
- a discharge vessel defining a sealed inner discharge space and having at least two electrodes projecting into said discharge space, said discharge space having a volume of 12-20 mm3 and comprising a filling of a rare gas and a metal halide composition, said filling being substantially free of mercury, said metal halide composition comprising at least halides of sodium and scandium, a mass ratio of halides of sodium and scandium being in the range of 0.9-1.5, and
- an outer enclosure disposed around said discharge vessel, said outer enclosure being sealed and filled with a gas at a pressure below 1 bar.
Discharge lamp according to claim 10, wherein said discharge space comprises 10.5-17.5 μg of said metal halide composition per μl of said volume of said discharge space.
Discharge lamp according to claim 1, wherein said rare gas in said discharge space is Xenon, provided at a cold pressure in the range of 10 bar to 18 bar.
Dependencies are inferred from the claim text.