Method of making a double-ended high-pressure discharge lamp

US5108333A · kind A · utility

Assignee

• Patent Treuhand fur elektrische Gluhlampen m.b.H. · DE

Inventors

• Jurgen Heider · Munich, DE
• Dieter Lang · Kronach, DE
• Hartmuth Bastian · Feuchtwangen, DE
• Stefan Kotter · Augsburg, DE
• Richard Kotschenreuther · Munich, DE

Key dates

• Filing date: Dec 15, 1989
• Grant date: Apr 28, 1992
• Expiry date: Dec 15, 2009

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01J9/247
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

To make a small high-pressure discharge lamp, for example of 50 W rating or less, and suitable, for example, for automotive applications, a quartz glass tube is heated, formed with constrictions, and a gas passed therebetween to expand the portion of the tube between the constrictions into olive shape to form the discharge vessel (6). A preformed first electrode system is introduced through one of the constrictions. The electrode system preferably has a zig-zag lead (9) slightly larger than the internal diameter of the tube to provide for self-centering. The tube is then isolated from atmosphere, for example by being placed in a glove box or coupled to a pumping head (15), for introduction therein of a fill substance, for example in pellet form, of a metal halide and, if desired, mercury; and a fill gas, such as argon or, preferably, xenon, preferably after cleaning and flushing the tube. A second electrode system is then introduced, for example within the glove box, and the end of the tube sealed off, with the fill substance therein. A second pinch seal (18) can then be formed externally of the glove box, or while the tube is still connected to a pumping head, and excess end piece…