U.S. Philips Corporation

Peter C Drop

Willy Joseph Endevoets

Alexander Gray Jack

Lambert C Kaldenhoven

Roland Lorenz

Walter J De Rop

Antonie Peter Van Eijl

Robert L Maes

Leonce M Bruninx-Poesen

High-pressure mercury vapor discharge lamp containing rare gas, mercury, sodium halide and at least one halide of at least one of the rare earth metals Ce, Pr, Nd and Lu. The lamp is suitable for a nominal power in the range from 10 to 2000 W. The molar ratio of rare earth metal to sodium, Ln:Na, has a value from 1:20 to 1:1 and the quantity of mercury, A, has a value from 2 to 100 mg/cm.sup.3. Ln:Na and A have in these ranges a low value for lamps having a high value of the power, and higher values according as the nominal power of the lamp has a lower value.

High-pressure mercury vapor discharge lamp

A method for ageing a gas discharge lamp which is provided with a vacuum-tight sealed light-transmissive discharge vessel in which at least two electrodes are disposed and which contains a gas filling. A high-frequency glow discharge is produced in the discharge vessel during a given length of time. The frequency of this discharge preferably has a value between 1 kHz and 100 MHz and the discharge is preferably maintained for 1 to 120 seconds. Ageing results in a considerable reduction in the starting voltage of the lamp.

Method of ageing a gas discharge lamp

A high pressure tin halide discharge lamp having a discharge vessel containing a quantity of rare gas as a starter gas and for each cubic cm of contents of the discharge vessel between 0 and 50 mg of mercury and at least 1 .mu.mol of at least one of the halides of tin. Furthermore the discharge vessel contains at least one of the elements indium, bismuth, lead, gallium and zinc or halides thereof to correct the color point of the radiation emitted by the lamp.

High pressure tin halide discharge lamp

Growing community of inventors

Eindhoven, Netherlands

Peter C Drop