Ceravision Limited

General Electric Company

Barry Preston

Andrew Simon Neate

Edwin Charles Odell

Ashfaqul Islam Chowdhury

Rajasingh Schwartz Israel

Tianji Zhao

Roger Alan Hume

Floyd Pothoven

Amjid Sadiq

Martyn Roscoe

Hussein Sonde

Edwin Charles O'Dell

Floyd R Pothoven

A High Frequency light source has a central body of fused quartz, with a central void, filled with a fill in the void of material excitable by High Frequency energy to form a light emitting plasma. An inner sleeve of perforate metal shim extends along the length of the central body to provide a launching gap. The sleeve has a transverse end portion extending across the other, inner end of the central body. An outer cylinder of fused quartz with an internal bore such as to be a sliding fit with the inner sleeve, itself a sliding fit on the central body. An outer sleeve of perforate metal, enclosing the outer cylinder and having an end portion extending across the flush, void ends of the quartz body and cylinder and having a skirt extending past the flush over an aluminum carrier, clamped and holding the quartz elements against the carrier.

Plasma light source

A Lucent Waveguide Electromagnetic wave Plasma Light Source has a fabrication of fused quartz sheet and drawn tube. An inner closed void enclosure is formed of 8 mm outside diameter, 4 mm inside diameter drawn tube. Electromagnetic wave excitable plasma material is sealed inside the enclosure. The end plate is circular and has the enclosure sealed in a central bore in it, the bore not being numbered as such. A similar plate is positioned to leave a small gap between the inner end of the enclosure and itself. The two tubes are concentric with the two plates extending at right angles to their central axis. The outer tube extends back from the back surface of the inner plate as a skirt.

Lucent waveguide electromagnetic wave plasma light source

A lamp has microwave resonant body () of transparent quartz. The body has a central bore (), having a sealed plasma enclosing bulb () inserted in it. The bulb is of quartz also and has an external diameter which is a close fit in the bore. The bulb itself is of drawn quartz tube () and as such has a smooth internal bore (). End caps () are fused to the tube and encapsulate a charge of a material excitable to form a light emitting plasma in the bulb when microwaves are fed into the body via an antenna () in a bore () in the body. The body is sized to establish resonance within the Faraday cage in the body (), bulb () and fill containing void () within the bulb. There is negligible gap between the bulb and body, whereby they can be regarded as one for resonance purposes. The bulb is fixed in the body by welds ().

Light source

Operation to produce an intermediate product for a crucible for a LUWPL is as follows:

Crucible structure for plasma light source and manufacturing method

A lucent crucible of a Lucent Waveguide Microwave Plasma Light Source (LWMPLS) comprising a Light Emitting Resonator (LER) in form of a crucible () of fused quartz which has a central void () having microwave excitable material () within it. In one example, the void is 4 mm in diameter and has a length (L) of 21 mm. The LWMPLS is operated at a power (P) of 280 W and thus with a plasma loading P/L of 133 w/cm and a wall loading of 106 w/cm2. The lamp is thus operated with a high efficiency&#x2014;in terms of lumens per watt&#x2014;while having a reasonable lifetime.

Microwave driven plasma light source

A plasma crucible has a through bore and two tubes butt scaled on to the end faces of the crucible. One of the tubes is closed prior to the filling of the crucible. The tube is tipped off and worked in a glass lathe to form it to have a flat end. After evacuation, dosing and gas fill, the other tube is tipped off in the similar manner.

Plasma crucible sealing

A discharge tube of glass, filled with a halogen/noble-gas mix, which passes through a &#xbd; lambda wave guide of alumina at an aperture &#xbc; lambda from one end. The wave guide is silver plated to establish resonance between its opposed ends. An antenna/probe is provided in another aperture, driven via a matching circuit from an amplifier. The discharge tube has a length greater than twice the thickness of the wave guide, extending from the wave guide on at least one side thereof.

Lamp

A lampcomprises an oscillator and amplifier sourceof microwave energy, typically operating at 2.45 or 5.8 GHz or other frequencies within an ISM band. The source passes the microwaves via a matching circuitto an antennaextending into a re -entrantin a lucent waveguideThis is of quartz and has a central cavityaccommodating a bulbThe bulb is a sealed tubeof quartz and contains a fill of noble gas and a microwave excitable material, which radiates visible light when excited by microwaves. The bulb has a stemreceived in a stem boreextending from the central cavity. The waveguide is transparent and light from the bulb can leave it in any direction, subject to any reflective surfaces. Microwaves cannot leave the waveguide, which is limited at its surfaces by a Faraday cage. Typically this comprises an ITO coatingon a front face of the waveguide, a light reflective coating, typically of silver with silicon monoxide coatingon a rear face and a wire mesh, which contacts both the ITO and light reflective coatings and is grounded, the wire mesh extending around sides of the waveguide between the front and back surfaces. Light can pass through the wire mesh for collection and use.

Light source for microwave powered lamp

A light source comprising a lucent waveguide of solid dielectric material having: an at least partially light transmitting Faraday cage surrounding the waveguide, a bulb cavity within the waveguide and the Faraday cage and an antenna re-entrant within the waveguide and the Faraday cage and a bulb having a microwave excitable fill, the bulb being received in the bulb cavity.

Microwave light source with solid dielectric waveguide

An electrodeless bulb has a hollow quartz tube, with a solid stem extending from one end and a short hollow tip extending from the other end. The hollow interior of the tube extends into the tip with the same diameter as in the tube, but the wall thickness of the tip is reduced from that of the tube. The bulb is charged with an amount of indium bromide and traces of other metal halides to adjust light spectrum and a filling of xenon gas.

Electrodeless bulb having improved dimensions for light emission

An improved seal for an electric lamp is provided. An oxidation-resistant coating is provided on the current conductor where the outer lead joins the seal foil, preferably at the pinch seal. The coating is preferably a chromium layer covered by a chromium layer or a silver layer covered by a layer of hydrogenated silicon oxy carbon polymer. The coating is preferably applied via sputtering where the coating is subject to high energy electron or ion bombardment during sputtering. Preferably the coating is applied via sputtering at increased deposition pressure.

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Melton Mowbray, United Kingdom

Barry Preston