High-power, high-pressure metal halide discharge lamp with improved spectral light distribution

US4647814A · kind A · utility

Assignee

• Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH · DE

Inventors

• Alexander Dobrusskin · Taufkirchen, DE
• Bernd Lewandowski · Feldafing, DE
• Walter Kiele · Munich, DE

Key dates

• Filing date: Jul 15, 1985
• Grant date: Mar 3, 1987
• Expiry date: Jul 15, 2005

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01J61/827
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

To increase the power output of a high-pressure metal halide discharge lamp aving a fill of mercury and at least one noble gas, and rare-earth halides which include at least one of: holmium; dysprosium, preferably present, each, of from 0.01 to 2.4 mg/cm.sup.3 of the discharge vessel, a gadolinium halide, present of from 0.01 to 2.3 mg/cm.sup.3 of the discharge vessel is additionally included in the fill. The discharge vessel is made of quartz, the electrodes of tungsten, and, in an example, a lamp operating at 12 kW, with 380 V power supply at 65 A is obtainable, the light output being comparable to that of daylight based on CIE standard D 60, with a color temperature of 6000.degree. K. so that an overall color temperature of about 5600.degree. K. is obtainable when the lamp is installed in a customary fixture, for example used in theatrical, film or television illumination application. The preferred halogens are bromium and/or iodine, in which the halogen is present in excess over the rare-earth - halide stoichiometric relationship. The specific arc power obtainable is between 1000 to 5000 W/cm, with a wall loading of between 50 to 120 W/cm.sup.2.