General Electric Company

The United States of America As Represented by the United States

Peter D Johnson

John M Anderson

James T Dakin

Seth D Silverstein

Roger Neal Johnson

Bruce F Griffing

Willard T Grubb

Carl Lawrence Chalek

Charles E Jones

Improved efficacy and color rendition at white color temperatures is achieved in an electrodeless metal halide arc discharge lamp with a novel combination of arc tube fill materials, including sodium halide, cerium halide, and xenon. A preferred lamp structural configuration imparts further efficacy improvement at higher lamp operating temperatures and isothermal lamp operation.

High efficacy electrodeless high intensity discharge lamp

High pressure xenon is used as a buffer gas in place of mercury in a high pressure sodium iodide arc discharge lamp. Xenon buffer gas has a more favorable influence than mercury on the sodium D-line spectrum and does not react with halides in the lamp fill. The use of xenon buffer gas increases the efficacy of the high pressure sodium iodide arc lamp.

High pressure metal halide arc lamp with xenon buffer gas

An electrodeless arc lamp comprises an outer jacket hermetically sealing and thermally protecting an arc tube inside which has an upwardly convex bottom center section. The absence of chemically reactive electrode material makes it possible to use metal halides other than iodides. The tube contains chlorides, bromides or a mixture thereof of scandium and sodium in a nearly equimolar relationship in addition to mercury and an inert gas. Good color balance can be obtained at reduced reservoir temperature and with less power loss. Reduction in wall temperature makes it possible to attain longer lamp life.

Very high efficacy electrodeless high intensity discharge lamps

Halides of aluminum or tin, or other metals, in combination with sodium chloride in the presence of mercury and excess aluminum or tin metal are used as a fill material in a solenoidal metal halide arc lamp. This fill results in very good color and a high efficacy.

Ingredients for solenoidal metal halide arc lamps

An amalgam is disposed within the arc tube of a high intensity arc discharge lamp so as to stabilize the electrical power being supplied to the lamp against variations in line voltage. The vapor pressure of mercury in the arc tube varies as a function of the lamp temperature which depends in turn on applied lamp voltage. The resulting change in arc voltage due to corresponding changes in mercury pressure operates to restore the power input to its approximate original value.

Stabilized high intensity discharge lamp

A lead-tin-bismuth alloy is disposed within a solenoidal electric field lamp to control the mercury vapor pressure. In accordance with one embodiment of the present invention, the alloy is placed within the tip-off region of the lamp envelope. The alloy is fixed within the tip-off region by a means of wetting the alloy to a metal wire structure such as a helix or a cylindrical screen. Alternatively, the alloy may be placed on an interior surface of the envelope by first wetting the glass with a layer of indium or other metallic wetting agent. Additionally, methods for wetting the lead-tin-bismuth alloy to the metal wire include firing the alloy in contact with the wire in a hydrogen atmosphere at a sufficiently high temperature to wet the alloy to the wire. The present invention permits the control of mercury vapor pressure in solenoidal electric field discharge lamps.

Use of amalgams in solenoidal electric field lamps

A high voltage fuse comprises one or more fusible strips or wires (fusible elements) electrically connected between nonfusible external electrical connection means with at least one portion of the fusible element ('a rapid melting portion') being designed to melt open when the current exceeds a given value for a given period of time. The fuse further comprises exothermic material, disposed on electrically-conductive wire, which is placed adjacent to portions of the fusible element. Electric circuit connection means connect the electrically-conductive wire to electrically opposite sides of the rapid melting portion. The electrical circuit connection means provides for either parallel or series connection of the wire surrounded by the exothermic material. In operation, during the passage of a sufficiently high current, an arc develops in the immediate vicinity of the rapid melting portions and the voltage drop occurring across this arc supplies power to the electrically-conductive wire which ignites the exothermic material so as to either blast or melt away specific remaining portions of the fuse. As a result, a plurality of series connected arcs are formed so that the sum of the voltages across the arcs increases to a level sufficient to bring the current through the fuse to a zero value in a short time.

High voltage, high current fuse with combustion assisted operation

A fluorescent lamp comprises a source of near ultraviolet radiation together with an outer shell at least partially surrounding the ultraviolet source and comprising an ultraviolet transmissive material, the shell having embedded or dissolved therein a phosphor material having an indexed refraction approximately, but not quite equal, to the index of refraction of the shell.

Fluorescent lamp with non-scattering phosphor

A high intensity discharge lamp is provided with means for reflecting infrared radiation from the hot central portion of the arc tube onto the cooler end portions of the tube. The infrared reflective means may be provided by one or more infrared reflecting shields surrounding a portion of the arc tube or by an indentation in the outer glass envelope of the lamp.

High intensity discharge lamp with infrared reflecting means for

Apparatus is disclosed for uniform exposure of a plurality of objects such as semiconductor wafers to radiation utilizing sources of radiation of linear configuration. The apparatus includes a baffle assembly of particular construction and constitution situated between the linear sources and the region to be irradiated.

Irradiation apparatus utilizing linear radiation sources

A lead-tin-bismuth alloy is disposed within a solenoidal electric field lamp to control the mercury vapor pressure. In accordance with one embodiment of the present invention, the alloy is placed within the tip-off region of the lamp envelope. The alloy is fixed within the tip-off region by a means of wetting the alloy to a metal wire structure such as a helix or a cylindrical screen. Alternatively, the alloy may be placed on an interior surface of the envelope by first wetting the glass with a layer of indium. Additionally, methods for wetting the lead-tin-bismuth alloy to the metal wire include firing the alloy in contact with the wire in a hydrogen atmosphere at a sufficiently high temperature to wet the alloy to the wire. The present invention permits the control of mercury vapor pressure in solenoidal electric field discharge lamps.

A relative humidity sensitive material comprises a mixture of at least one hygroscopic salt and an at least partially electrically conductive metal based powder. Each salt in the relative humidity sensitive material has a cationic constituent selected from the group consisting of the alkali and alkaline earth metals and an anionic constituent selected from the group consisting of a chlorate, perchlorate, and chloro aluminate. The metal based powder preferably comprises a metal or metal oxide powder or powder mixture including such constituents as Zr, CO.sub.3 O.sub.4, and MnO.sub.2. Additionally, the material may include a binding agent and a slurry mixture may be formed for placement of the resultant material between electrodes on a substrate so as to form a relative humidity sensor. These sensors are employed either individually or configured in a system used to either indicate or control the relative humidity.

Relative humidity sensitive material

The amount of mercury used in a metal halide-mercury arc discharge lamp is controllably selected to produce a voltage gradient along the arc discharge of between approximately 2 v/cm and approximately 10 v/cm. When such a lamp is operated vertically, the usually observed color separation does not occur. Even though this voltage gradient is substantially less than the conventional gradient employed in such lamps, no significant loss of efficacy occurs.

High intensity discharge lamps with uniform color

In high intensity discharge lamps, particularly those that are configured to operate in a particular orientation, end coatings are provided which increase the efficacy of the lamp. In one embodiment of the present invention, reflective end coatings are provided exteriorly and at the ends of the discharge tube except for an approximately semicircularly shaped portion through which the optical output of the lamp radiates. The particular coating pattern provided in the present invention reduces the number of internal reflections occurring within the discharge tube and accordingly increases the efficacy of the lamp.

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Schenectady, NY, United States of America

Peter D Johnson