High pressure arc lamp assisted start up device and method
AssigneeThe Board of Trustees of the University of Illinois
InventorsJames Gary Eden, Ju Gao, Sung-Jin Park, Clark J. Wagner
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Abstract
Start-up and re-ignition of a high pressure arc lamp are aided by injection of electrons toward a high pressure arc lamp electrode. A microdischarge device directs electrons toward an electrode of the arc lamp and is preferably turned off during normal operation of the arc lamp. The harsh environment of an arc lamp requires the microdischarge to be made from robust materials, such as ceramics, semiconductors or tungsten, for example. In the present invention, the discharge design must allow, preferably through a screen anode, for the escape of electrons from the microdischarge. This invention results in a decrease in the voltage required to start-up or re-ignite a lamp.
Claims15
An arc lamp ignition system, the arc lamp including a high-pressure housing enclosing a gas, and a pair of spaced apart electrodes connected to power feed terminals, the lamp ignition system being within the housing and comprising:
- a microdischarge device disposed to direct electrons toward one of the pair of spaced apart electrodes, wherein
- said microdischarge device comprises a microcavity forming a cathode in a dielectric body and a screen anode formed over the microcavity to permit escape of electrons therefrom;
- and
- said microdischarge is configured and supplied with power from the power feed terminals to turn on at least during a period of higher supply voltage caused by start-up or re-ignition of said lamp.
An arc lamp comprising:
- a high-pressure housing enclosing a discharge gas;
- spaced apart electrodes within said housing;
- power feed terminals forming a circuit with said spaced apart electrodes to induce completion of a circuit by an arc between said spaced apart electrodes under a sufficient voltage condition;
- and
- a microdischarge device disposed to direct electrons toward one of the pair of spaced apart electrodes, wherein
- said microdischarge device comprises a microcavity forming a cathode in a dielectric body and a screen anode formed over the microcavity to permit escape of electrons therefrom;
- and
- said microdischarge is configured and supplied with power from the power feed terminals to at least turn on during a period of higher supply voltage caused by start-up or re-ignition of said lamp.
A method for assisting start-up or re-ignition of an arc lamp, the method comprising:
- with a microdischarge device, directing electrons toward a region between electrodes of the arc lamp by having the microdischarge respond to start-up and re-ignition increased voltage conditions of the arc lamp;
- turning off the microdischarge device during a normal operation of the arc lamp.
Dependencies are inferred from the claim text.