U.S. Philips Corporation

Bart Van Der Leeuw

Cornelis A Jacobs

Jacobus M Claassens

Danny L Hermans

Nicolaas F Van Elderen

The lamp vessel of a high-pressure discharge lamp locally has a coating, which is a smooth, solitary, metallically reflecting graphite film. The graphite film, which increases the temperature of comparatively cold parts of the lamp vessel, can readily be applied and has an excellent adhesion.

High-pressure discharge lamp

A electric gas discharge lamp having a tubular ceramic discharge vessel which is provided at one end with a ceramic end plug which extends axially outside the end of the discharge vessel. The outside diameter of the projecting portion of the end plug being not more than 90% of the outside diameter of the discharge vessel.

Electric gas discharge lamp

The invention relates to a gas-and/or vapor discharge lamp which is provided with a discharge tube and with a heat shield. The heat shield is connected to a bimetal element of the lamp such that, when the temperature of the discharge tube is raised (or lowered) the heat shield is further removed from (or moved towards) the discharge tube. Accordingly the lamp reaches its operating condition rapidly after starting and in the operating condition fluctuations in the temperature are very small.

Discharge lamp with heat shield

The tubular ceramic discharge vessel of electric discharge lamps is sealed according to the invention with a cylindrical and an annular ceramic moulding between which a tubular current leadthrough member is accommodated consisting of tungsten, molybdenum, rhenium or alloys thereof. The current leadthrough member is connected in a vacuum-tight manner to the two ceramic mouldings by means of sealing ceramic.

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Eindhoven, Netherlands

Bart Van Der Leeuw