U.S. Philips Corporation

Franciscus M Oostvogels

Adrianus P Severijns

Petrus J Severin

Wiggert Kroontje

Rein W Van Der Wolf

Louis E Vrenken

Charles C Meulemans

Aime P Van Laarhoven

Gustaaf Melis

The irradiation device comprises a short arc discharge lamp, in which a pair of electrodes are arranged, between which a discharge path extends. An optical conductor is sealed with its first end into the wall of the lamp vessel in such a manner that its light entrance window is arranged laterally of the discharge path and is directed to the discharge path.

Irradiation device comprising a short arc discharge lamp

A low-pressure alkali metal vapor discharge lamp has a getter for bi- and triatomic gases and a getter holder in the arc tube near at least one electrode. The electrodes need be heated less strongly during evacuation of the prior to final dosing, as a result of which no emitter material of the electrodes is lost. The ignition voltage is considerably lower than that of conventional lamps without a getter.

Low-pressure alkali metal vapor discharge lamp with arc tube gettering

High-pressure discharge lamps, having a sealed discharge vessel surrounded by a sealed glass envelope, are known in which an oxidizable metal foil (e.g. of molybdenum) is located, in the space between the vessel and the envelope substantial on the axis of the vessel and is electrically in series with the discharge path. If the envelope is fractured for any reason and the lamp is subsequently ignited, the temperature of the foil is increased due to the discharge current passing through it. The foil is oxidized, and hence fractured, by the air which has permeated said space and the lamp is, extinguished. Such oxidation and fracture normally takes about ten minutes. In accordance with the invention, the foil (14) in the space between the envelope (1) and vessel (2) is arranged close to the wall of the vessel adjacent to an electrode (6) so as to be heated mainly by heat generated in the vessel. This reduces the fracturing time to about one minute.

High-pressure discharge lamp

A low-pressure mercury vapor discharge lamp having an internal transmissive starting strip with two separate parts. The separation between the parts is bridged by a narrow straight or helix-shaped conductive connecting strip to bring the total resistance of the starting strip to a value between 50,000 and 150,000 ohms.

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Eindhoven, Netherlands

Franciscus M Oostvogels