Ceravision Limited

Other

Andrew Simon Neate

Barry Preston

Paul Carpenter

Amjid Sadiq

Floyd Pothoven

Tim Burnitt

Charles Guthrie

Edwin Charles Odell

Edward Charles Odell

John Stocks

Martyn Roscoe

Hussein Sonde

Berry Preston

A light source to be powered by microwave energy, having a dielectric body or fabrication of material lucent for exit of light therefrom, a receptacle within the dielectric body or fabrication, and a lucent microwave-enclosing Faraday cage surrounding the dielectric body or fabrication. The dielectric body or fabrication within the Faraday cage forms at least part of a microwave resonant cavity. A sealed plasma enclosure of lucent material within the receptacle has a means for locating the plasma enclosure within the receptacle with respect to the dielectric body or fabrication.

Light source

A lucent waveguide plasma light source has a quartz waveguide body with a central through bore. The bore has orifices at its opposite ends, opening centrally of flat, end faces of the body. Between these the body has a circular cylindrical periphery. A drawn quartz tube is inserted into the body. The tube has its one end closed and a collar which locates the tube in the bore and is fused to the faces at the orifices of the bore. The tube is evacuated and charged with excitable material and closed as a sealed void. A Faraday cage and an antenna in a bore in the body are provided for feeding microwave energy to the light source. When powered with microwaves, resonance is established in the wave guide and a plasma is established in the void, wherein Light radiates and leaves the waveguide and Faraday cage radially of the periphery.

Lucent waveguide plasma light source

An electrodeless, microwave lamp has a magnetron as a microwave source and an excitable material lucent crucible in whose excitable material a plasma is established. For coupling microwaves from the magnetron into the crucible, an air wave guide coupling circuit is provided, with an output of the magnetron as an input at one quarter lambda from one end and an output at one quarter from the other end as an input to a connection to the crucible.

A Lucent Waveguide Electromagnetic Wave Plasma Light Source has a fabrication () of quartz with an inner closed void enclosure () is formed of 8 mm OD, 4 mm ID drawn tube. It is sealed at its inner and outer ends (). Microwave excitable plasma material is sealed inside the enclosure. Its outer end () protrudes through an end plate () by approximately 10.5 mm and the overall length of the enclosure is approximately 20.5 mm. The tube () from which the void is formed is continued backwards from the inner end of the void enclosure as an antenna sheath (). The 2 mm thick end plate () is circular and has the enclosure () sealed in a central bore in it.

Lucent waveguide electromagnetic wave

An LER LUWPL source luminaire having a magnetron heat conductingly mounted below a finned heat dissipater with a suspension eye. The magnetron is attached to a microwave transition and a lucent crucible. An imperforate cover extends down from the heat dissipater and is closed by a transparent screen, held by a molding. A generally square shaped molding supports a polished-sheet-metal reflector (having four triangular faces, pyramidally arranged, with a square base embodied by a rim supported on the top of the screen above the molding) extending back to the lucent crucible, with its reflective surfaces obliquely facing both the crucible and the screen for reflection of light from the crucible out of the luminaire via the screen. The faces converge to a virtual apex, on the central axis of the lucent crucible. This axis is coincident with the pyramid's normal axis from the apex to the center of the base.

A LUWPL luminaire has a housing with a lower transparent closure and a heat dissipating top of cast aluminum. This has a suspension eye. The housing has an upper flange via which it is bolted with the interposition of a seal to a underside rim of the top. Within the rim, the underside is substantially flat, with a magnetron attachment boss and other attachment points. A magnetron is supported by being clamped by a saddle to the attachment boss at the magnetron's anode. The magnetron is fast with a transition box and a crucible support block. A bracket fixed to certain of the attachment points extends down from the top is screwed to the transition box. Thus the LUWPL parts are securely supported below the top.

Microwave driven electrodeless lamp comprising magnetron without forced convective cooling

A method of applying a Faraday cage to a lucent resonator, the resonator having a void containing microwave-excitable material and being adapted for microwave resonance in the resonator and within the Faraday cage for driving a light emitting plasma in the void, the method consisting in the steps of: deposition of a conductive material onto the lucent resonator; applying, patterning and developing a photoresist material over the conductive material to leave the conductive material exposed where it is not required; removing the conductive material where not required and the photoresist material from the required conductive material, leaving a reticular network of conductive material providing a Faraday cage and depositing a layer of protective material over the cage of conductive material.

Method of applying a faraday cage onto the resonator of a microwave light source

A band pass filter comprises an air filled aluminum chamber, having a lid and a cuboid resonant cavity having a central iris. At opposite end nodes of the cavity, perfect electric conductors (PECs) are provided. One is connected to a feed wire from an input at one end of the cavity. The other PEC is connected via a further feed wire to a radiator in a fabrication of solid-dielectric, lucent material. Threaded tuning projections opposite the PECs and in the iris are provided, whereby the pass band and the transmission characteristics of the filter in the pass band can be tuned to match the input impedance of the band pass filter and the wave guide to the output impedance of a microwave drive circuit (not shown). Typically the impedance will be 50&#x3a9;.

Lamp

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

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 light source is powered by a magnetron and has a quartz crucible having a plasma void with an excitable fill, from which light radiates in use. Two aluminum attachment blocks are attached together and the block is attached to a casing of the magnetron by screws&#x2014;not shown. The quartz crucible is attached to the block by a Faraday cage, in the form of a perforate metal enclosure secured at its rim to the block. An output formation of the magnetron has a conductive, copper cap fitted in electrical contact with it. The cap is extended by a copper rod. The rod extends through the blocks into a bore in the crucible for coupling microwaves from the magnetron into the crucible. An airspace is provided around the cap in the block. From the cap, the rod extends with negligible air gap in an alumina ceramic tube through the airspace and a boss of the block located in an aperture in an end wall of the block.

Luminaire

A lamp comprises a light source in the form of a light emitting resonator, a magnetronand a stub tuner. A reflectoris fitted at the junction of the light source and the stub tuner, for directing the light in a generally collimated beam. The light emitting resonator comprises an enclosureformed of inner and outer envelopesof quartz. These are circular cylindrical tubes, with respective end plates. A tungsten wire mesh, of a mesh size to exhibit a ground plane to microwaves within the resonator, is sandwiched between the tubes and the end plates respectively. Each envelope, comprised of its tube and end plates is hermetic. An earth connection' extends from the mesh to the outside of the envelope. The length axially of the enclosure between the wire mesh sandwiched between the end plates is &#x3bb;/2 for the operating microwave frequency. At one end of the enclosure, a molybdenum drive connectionextends to a tungsten disc. This is arranged transverse the axis A of the enclosure at 1/16&#x3bb; from the mesh at its end of the enclosure. The enclosure is filled with excitable plasma material, such as a dose of metal halide in a rare earth gas. The disc acts as antenna and is driven by the magnetron, via the matching circuit

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.

Growing community of inventors

Aylesbury, United Kingdom

Andrew Simon Neate