General Electric Company

Welch Allyn, Inc.

Timothy D Russell

James T Dakin

Mark E Duffy

Dean A Bell

Tommie Berry, Jr

Carl H Hess

Charles N Stewart

Curtis E Scott

Mohamed Rahmane

Peter Joel Meschter

Jianmin He

Raghu Ramaiah

Raymond A Heindl

Mary Sue Kaliszewski

Zoltan Toth

Paul G Mathews

Ágoston Böröczki

Ralph M Potter

Gary W Utterback

Ranajit K Datta

Daniel M Cap

Frank I Ewing

Douglas M Rutan

Dale E Brabham

Paul G Hlahol

Edward G Zubler

Natalie Marie Bate

Richard P Gilliard

A lamp includes a discharge vessel with electrodes extending into the discharge vessel and an ionizable fill scaled within the vessel. The fill includes a buffer gas, optionally mercury, and a halide component. The lamp includes available oxygen, sealed within the discharge vessel, at a concentration of at least 0.1 &#x3bc;mol O/cc.

Ceramic metal halide lamp with oxygen content selected for high lumen maintenance

A lamp includes a discharge vessel. Tungsten electrodes extend into the discharge vessel. An ionizable fill is sealed within the vessel. The fill includes a buffer gas and a halide component that includes a rare earth halide. A source of oxygen which includes a lanthanide oxide is present in the discharge vessel. The source of oxygen provides oxygen for a regenerative cycle which reduces blackening of the lamp walls by tungsten from the electrodes.

Lanthanide oxide as an oxygen dispenser in a metal halide lamp

A lamp includes a discharge vessel. Tungsten electrodes extend into the discharge vessel. An ionizable fill is sealed within the vessel. The fill includes a buffer gas, optionally free mercury, a halide component which includes a rare earth halide selected from the group consisting of lanthanum halides, praseodymium halides, neodymium halides, samarium halides, cerium halides, and combinations thereof. A source of available oxygen is present in the discharge vessel. The rare earth halide is present in an amount such that, during lamp operation, in combination with the source of available oxygen, it maintains a difference in vapor phase solubility for tungsten species between a wall of the discharge vessel and at least a portion of at least one of the electrodes.

Metal halide lamp including a source of available oxygen

A method of making a unitized tungsten electrode which exhibits superior mechanical and electrical properties which includes providing a length of cylindrical cut stock having a predetermined diameter and length. The stock is ground to form a rough unfinished electrode having an enlarged tip or nose portion at one end integrally connected to an elongated shank section. The unfinished electrode is treated by exposure to a chemical etchant for a time sufficient to form a finished electrode characterized by a smooth nose and shank surface and rounded undercut and ends. The invention includes the electrode formed by the described process.

Unitized chemically etched tungsten electrode

Stable electrode design and method

An arc lamp assembly which includes in combination a reflector and a light source which is surrounded by said reflector. A dichroic coating on the reflector functions to reflect radiation in the range of about 300 to 600 nm. The light source is an arc lamp which contains a metal halide fill component which includes a mixture of scandium iodide, or other suitable lanthanide, indium iodide, sodium iodide and sodium iodide, whereby the lamp assembly emits effective amounts of WV radiation to cure selected chemical compositions.

Metal halide lamp for curing adhesives

A high intensity metal halide arc discharge lamp, such as an electrodeless lamp wherein RF energy is inductively coupled to the arc discharge, contains a halide of neodymium alone or in combination with other metals such as one or more rare earth metals, Na, Cs and is essentially mercury free (i.e., &lt;1 mg per cc of arc chamber volume).

Low mercury arc discharge lamp containing neodymium

An arc tube of fused silica for a metal halide arc discharge lamp including a fill for the arc tube comprised of a sodium halide, at least one additional metal halide, and an inert starting gas, the arc tube including a tube of fused silica having an inner wall defining an arc chamber, the inner wall of the tube having provided thereon a metal silicate coating which is vitreous and light-transmissive, and which is comprised of a silicate of at least one metal selected from the group consisting essentially of scandium, yttrium, and a rare earth element, and preferably which is the same metal as that of the at least one additional metal halide. Protection of the fused silica arc tube with the metal silicate coating reduces loss of the metallic portion of the fill by diffusion or reaction and corresponding buildup of free halogen in the arc tube.

Protective metal silicate coating for a metal halide arc discharge lamp

A high intensity electrodeless metal halide arc discharge lamp wherein RF energy is coupled to the arc discharge, contains a halide of praseodymium alone or in combination with other metals such as one or more rare earth metals, Na and Cs and is essentially mercury free (i.e., &lt; 1 mg per cc of arc chamber volume).

Low mercury arc discharge lamp containing praseodymium

Sodium metal has been found to be effective in gettering excess halogen present in metal halide lamps containing mercury, an inert starting gas and at least one ionizable metal halide for forming a light-emitting arc.

Metal halide discharge lamp containing a sodium getter

Metal halide vapor arc lamps for reprographic and projection processes emitting in the blue, green and red bands with excellent primary color separation and having long life and lumen maintenance contain mercury, zinc, indium, lithium, thallium, a halogen and a rare earth metal such as lanthanum, scandium or dysporsium in the arc tube.

Reprographic metal halide lamps having long life and maintenance

Metal halide lamps having better lumen maintenance over the life of the lamp contain metal frame parts whose surface is oxidized either prior to lamp assembly or oxidized in-situ during operation of the lamp by oxygen or an oxidizing agent present inside the outer vitreous envelope.

Metal halide lamps with oxidized frame parts

In an arc tube for a high intensity metal halide discharge lamp, a particular composition of metal halide dose is provided to control thorium transport to the electrodes within the arc tube and tungsten transport to the wall to improve arc tube performance.

Growing community of inventors

Cleveland Heights, OH, United States of America

Timothy D Russell