Ceravision Limited

University of Sheffield

Robin Devonshire

Donald M Wilson

Floyd Pothoven

Charles Guthrie

Timothy James Healey

Edwin Charles Odell

Richard Charles Tozer

Eddie Odell

David Andrew Stone

The manufacture of an electrodeless bulb involves one end of a tube closed off, and a first neck is formed in the tube close to the closed end. A second neck is formed in the tube, close to the still open end; a metal halide pellet of known size is dropped into the tube and the tube is evacuated. With the vacuum being maintained heat is applied to the closed end, causing the metal halide pellet to sublime and with it the impurities. The impurities are drawn off, the vacuum being maintained and the metal halide condenses in the tube between the necks. Once the tube is cool, the evacuation is discontinued and the tube is refilled with noble gas and the quartz tube is sealed off at the second neck.

Method of manufacturing an electrode-less incandescent bulb

A method of making an electrodeless incandescent bulb comprises the steps of:

Electrode-less incandescent bulb

An apparatus and method for applying short pulsed waveforms, on the order of 1 &mgr;s pulses at a frequency of about 5 kHz, to a discharge lamp, such as a low-pressure mercury/argon lamp, in order to shift the ratio of the intensities of two of the mercury lines, in particular the 254 nm and 365 nm lines, of which for a sinusoidal excitation signal the 254 nm line is predominant, towards the higher wavelength. This greatly increases the efficiency of a lamp using phosphors excited by these UV emissions, because of the reduced Stokes shift.

Method and apparatus for driving a discharge lamp with pulses that terminate prior to the discharge reaching a steady state

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Sheffield, United Kingdom

Robin Devonshire