Koninklijke Philips Corporation N.v.

Philips Lighting Holding B.v.

Junming Tu

Ray G Gibson

Kevin S Dombrowski

Tom Steere

Ray Gibson

A discharge lamp and a method for forming the lamp, the lamp including a ceramic discharge vessel defining at least part of a cavity containing a metal halide (MH) chemical filling having a power factor of between about 0.75 and 0.85 located within the cavity; and one or more feedthroughs having first and second ends, the first end located in the cavity. The cavity may have an internal length LINT and an internal diameter DINT that are proportional to each other, such that an aspect ratio defined as LINT/DINT is less than or equal to two. The lamp may be started and operated with a probe-start ballast without an internal igniter circuit or without a starting electrode (or internal igniter).

Metal halide lamp with ceramic discharge vessel

A quartz metal halide lamp includes an outer sealed envelope defining an interior space, and an arc tube disposed in the interior space. The arc tube has a fill space. A chemical fill is disposed in the fill space. The chemical fill includes sodium halide and lanthanide halide, with the lanthanide halide selected from the group consisting of europium iodide, europium bromide, praseodymium iodide, praseodymium bromide, ytterbium iodide, ytterbium bromide and combinations thereof. The lanthanide halide is between 2 and 6 weight percent of the chemical fill. Electrodes are partially disposed within the fill space.

Quartz metal halide lamp with improved lumen maintenance

An improved discharge lamp is provided which includes a discharge vessel (arc tube) enclosing a discharge space, the discharge vessel (arc tube) including within the discharge space a metal halide ionizable material; first and second discharge electrode feedthroughs, and first and second current conductors connected to the first and second discharge electrode feedthroughs, respectively. The improvement is through the use of a field wire of a material that includes Ni or Ni alloy, and wherein the field wire material exhibits an electrical resistivity at 25&#xb0; C.&#x3c;10 ohms/mm; a photoelectric emission work function&#x3e;4.0 eV; a thermionic emission work function&#x3e;4.0 eV; and a melting point&#x3e;1200&#xb0; C.

Metal halide lamp with improved field wire

High lumen output quartz metal halide lamps are provided which comprise a vacuum outer fill, and a silicon nitride CVD coating on the outside of the quartz arc tubes (discharge tubes). Instead of nitrogen filled outers, vacuum lamp outers are used to reduce energy loss (since heat conduction loss is reduced) and to increase lumen output. Additionally, only the outside of the arc tubes is coated with silicon nitride, without coating the metal components. This reduces or blocks sodium diffusion through the quartz walls. The silicon nitride coating also retards migration of the trace hydrogen from the lamp outer into the arc tube. At least about a 10% increase, and preferably a 15% increase in lumen output is realized by using a vacuum lamp outer instead of the nitrogen fill outer conventionally used for the traditional quartz fill lamps. The heat conduction loss is reduced and the lamp efficiency is increased significantly.

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Bath, NY, United States of America

Junming Tu