US 5,043,634 AGranted

Pulsed light source

AssigneeGTE Products Corporation

InventorsHarold L. Rothwell, Jr., Peter J. Van Peenen, George J. English

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Abstract

A pulsed light source includes a sealed, ultraviolet-transmissive lamp tube defining a discharge region containing a rare gas or a mixture of rare gases, anode and cathode electrodes sealed into the lamp tube at opposite ends, leads for connecting the electrodes to a pulsed source of electrical energy and a phosphor material located on a surface external to the discharge region. The lamp tube contains mercury in sufficient quantity to cover the cathode electrode when the lamp tube is oriented with the cathode electrode at the bottom. The cathode electrode is protected by the mercury from sputtering that results from ion bombardment. The mercury emits pulsed ultraviolet radiation which stimulates emission of visible light by the phosphor material. Lamp tube pressure is below 200 torr. The light source is operable over a range of pulse widths and duty cycles. The color of light emission is determined by the phosphor. The phosphor can be located on the outer surface of the lamp tube or on a separate glass sleeve.

Claims23

Dependent claims

A pulsed visible light source comprising:

a sealed, ultraviolet-transmissive lamp tube defining a discharge region containing a rare gas or a mixture of rare gases;
an anode electrode and a cathode electrode sealed into said lamp tube at spaced-apart locations, and means for connecting said electrodes to an external pulsed source of electrical energy;
mercury in the liquid state without the application of auxiliary heat within said lamp tube in sufficient quantity to form a pool that covers said cathode electrode when said lamp tube is oriented in a normal operating position with said cathode electrode at the bottom;
a first quantity of mercury vapor within said discharge region, said first quantity of mercury vapor being responsive to pulsed excitation from said source of electrical energy to emit pulsed ultraviolet radiation;
during said pulsed excitation, a second quantity of mercury vapor within said discharge region, said second quantity of mercury vapor originating from liquid mercury splashed from said mercury pool above said cathode electrode by ion bombardment of said mercury pool, said second quantity of mercury vapor being responsive to pulsed excitation from said source of electrical energy to emit pulsed ultraviolet radiation;
and
a phosphor material located on a surface external to said discharge region, said phosphor material being responsive to said pulsed ultraviolet radiation from said mercury to emit visible light.

4 more elements

A pulsed visible light source comprising:

a sealed, ultraviolet-transmissive lamp tube defining a discharge region containing a rare gas or a mixture of rare gases;
an anode electrode and a cathode electrode sealed into said lamp tube at opposite ends thereof;
source means for providing pulsed excitation and means for coupling said pulsed excitation to said electrodes;
said lamp tube containing mercury in the liquid state without the application of auxiliary heat in sufficient quantity to cover said cathode electrode when said lamp tube is oriented in a normal operating position with said cathode electrode at the bottom, said mercury being responsive to said pulsed excitation to emit pulsed ultraviolet radiation;
a first quantity of mercury vapor within said discharge region, said first quantity of mercury vapor being responsive to pulsed excitation from said source means to emit pulsed ultraviolet radiation;
during said pulsed excitation, a second quantity of mercury vapor within said discharge region, said second quantity of mercury vapor originating from liquid mercury splashed from said mercury pool above said cathode electrode by ion bombardment of said mercury pool, said second quantity of mercury vapor being responsive to pulsed excitation from said source means to emit pulsed ultraviolet radiation;
and
a phosphor material located on a surface external to said discharge region, said phosphor material being responsive to said pulsed ultraviolet radiation to emit visible light.

5 more elements

Dependencies are inferred from the claim text.