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 includes a discharge vessel with electrodes that project into a discharge space 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 includes at least halides of Sodium and Scandium with a mass ratio of halides of Sodium and Scandium of 0.9-1.5. The lamp further includes an outer enclosure provided around the discharge vessel. The outer enclosure is sealed and filled with a gas at a pressure below 1 bar. The lamp has an efficiency equal to or greater than 90 Im/W in a steady state operation at an electrical power of 25 W.
Claims15
A high pressure gas discharge lamp having an efficiency equal to or greater than 90 Im/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.
A high pressure gas discharge lamp having an efficiency equal to or greater than 90 Im/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,
- wherein said discharge vessel has a maximum inner diameter in the range of 2.0 mm to 2.3 mm.
A high pressure gas discharge lamp having an efficiency equal to or greater than 90 Im/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,
- wherein said discharge vessel has a wall thickness in the range of 1.5 mm to 1.75 mm.
A high pressure gas discharge lamp having an efficiency equal to or greater than 90 lmM/ in a steady state operation at an electrical power of 25W, 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,
- wherein said outer enclosure is arranged at a distance (d2) and filled with a filling gas such that a heat conduction coefficient
- λ
- d
- 2
- is 7.0- 225 W/(m2K, where λ is the thermal conductivity of the filling gas measured at 800° C. and d2 is the distance between said outer enclosure and said discharge vessel.
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 proiecting 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,
- wherein said electrodes are rod-shaped electrodes having a diameter in a range of 215-275 μm.
Dependencies are inferred from the claim text.