Mercury-free metal halide lamp
AssigneeOsram Sylvania Inc.
InventorsDietrich Fromm, Dieter Lang, Klaus Stockwald
Life of this patent
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Abstract
Lighting system, comprising a mercury-free metal halide lamp with a light yield of at least 75 lm/W and a color rendition index of at least 75 and an electronic ballast, the electronic ballast impressing a square-wave power supply on the lamp and keeping the power constant. The filling comprises the following components: a buffer gas which also acts as starting gas to start the lamp, a voltage gradient generator, comprising at least one metal halide which vaporizes readily and which is chiefly (by more than 50%) responsible for generating a voltage gradient which corresponds approximately to that of mercury, and a light generator comprising one metal and/or one metal halide.
Claims25
Lighting system, comprising a mercury-free metal halide lamp with a light yield of at least 75 lm/W and a colour rendition index of at least 75 and an electronic ballast which supplies AC voltage, the lamp comprising a discharge vessel into which electrodes are inserted in a vacuum-tight fashion, characterized in that the electronic ballast provides the lamp with a change in voltage during the polarity reversal at a rate of voltage change of at least 0.3 V/.mu.s, preferably at least 1 V/.mu.s, the filling comprising the following components:
- a buffer gas which also acts as starting gas to start the lamp,
- a voltage gradient generator, comprising at least one metal halide which vaporizes readily and which is responsible for generating a voltage gradient of at least 45 V/cm which preferably corresponds approximately to that of mercury, and
- a light generator comprising at least one metal halide and/or one metal.
Mercury-free metal halide lamp with a light yield of at least 75 lm/W and a colour rendition index of at least 75 for operating on an electronic ballast which supplies an AC voltage and provides a polarity reversal at a rate of voltage change of at least 0.3 V/.mu.s, the lamp comprising a discharge vessel into which electrodes are inserted in a vacuum-tight fashion, characterized in that the filling comprises the following components:
- a buffer gas which also acts as starting gas to start the lamp,
- a voltage gradient generator, comprising at least one metal halide which vaporizes readily and which is responsible for generating a voltage gradient which corresponds approximately to that of mercury, and
- a light generator comprising at least one metal halide and/or one metal.
Mercury-free metal halide lamp, the lamp comprising a discharge vessel into which electrodes are inserted in a vacuum-tight fashion, the discharge vessel being fastened by means of a retaining frame in an outer bulb pinched at one end, characterized in that the retaining frame has a feedback conductor system made from at least three supply leads which are arranged symmetrically.
Dependencies are inferred from the claim text.