Patent Treuhand Gesellschaft Fur Elektrische Gluhlampen Mbh

Osram Sylvania Inc.

Osram Gesellschaft MIT Beschraenkter Haftung

Roland Hoffmann

Erolf Weinhardt

Martin Beck

Ernst Panofski

Christian Harzig

Astrid Hoffmann, Legal Representative

Jürgen Dichtl

Kerstin Hoffmann, Legal Representative

Maria Hoffmann, Legal Representative

Sylvia Frenzel

The invention relates to novel gas fillings of low-pressure gas discharge lamps for reducing the starting and arc drop voltages at low Hg vapor pressures. In favor of a mixture consisting of Ne and Kr, the Ar portion of the gas filling is considerably reduced.

Low-pressure gas discharge lamp with a reduced argon proportion in the gas filling

The present invention relates to mercury amalgams in discharge lamps for use at elevated operating temperatures.

Mercury amalgams for elevated temperatures in discharge lamps

The invention relates to electrode coils for discharge lamps having a coiled wire (1) which is wound around by a braiding wire (2). The coiled wire (1) has both turns (II) with an essentially circular cross-section and turns (I, III) with an oval cross-section. In order to produce the bar-shaped coil according to the invention, the unit comprising the coiled wire (1), the first core wire (3) and the braiding wire (2) is wound around a second core wire (4) which is flattened in places. Unrolling of the braiding wire (2) is prevented thereby. Production of the coil is cost-effective, since only two core wires are required and the coil ends are not fused.

Electrode coil for discharge lamps and method for producing such an

The lifetime of cold-start fluorescent lamps is increased, and the ability to withstand repeated ON-OFF switching cycles enhanced by coating the electrodes with an emitter which consists of barium oxide and a small portion of metallic barium and, optionally, up to 20 mol-% of strontium oxide and a small portion of metallic strontium, preferably only up to about 5 mol-% of strontium oxide--metallic strontium. To make the emitter, barium carbonate, optionally mixed with strontium carbonate, is applied in paste form to the electrodes which, when coated, are introduced into an envelope and sealed therein. The envelope is then evacuated, and the electrodes are heated, thus converting the barium carbonate to barium oxide and metallic barium, and the strontium carbonate, if present, to strontium oxide and metallic strontium, so that the electrodes will be coated with barium oxide, optionally strontium oxide, and metallic barium and optionally metallic strontium. The evacuation and activating step can be carried out essentially simultaneously, by evacuating the envelope through a pump tube and heating the electrodes to above about 800.degree. C. by passing a current pulse therethrough.

Discharge lamp, particularly cold-start fluorescent lamp, and method of

An improved low pressure mercury vapor discharge lamp, particularly of the fluorescent type. The inner wall of the glass envelope is coated with a layer of SiO.sub.2 particles which, in turn, is coated with a phosphor layer. The SiO.sub.2 particles have a particle size of below about 100 nm. The SiO.sub.2 particle containing layer containing between 0.5 and 0.7 mg of SiO.sub.2 particles per square centimeter of glass envelope which is coated.

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Augsburg, Germany

Roland Hoffmann