Patent-treuhand-gesellschaft F. Elektrische Gluehlampen Mbh

Patent Treuhand Gesellschaft Fur Elektrische Gluhlampen Mbh

Joern Dierks

Juergen Maier

Bernd Lewandowski

Dietmar Ehrlichmann

Walter Kiele

Dieter Franke

Juergen Begemann

The high pressure lamp has a bulb (,) to which a neck (,) is joined. The transition region (,) between the bulb and the neck is conical. A support tube (,) surrounds a holding rod (,) for an electrode (,) within the bulb. The support tube is melt-connected to the neck, and conical with an inner end of the support tube having an outer diameter which is smaller than the outer diameter of the outer end of the support tube. The neck, likewise, is conical, and forms a transition region to the bulb, which is free from the support tube, so that the support tube is recessed within the transition region. This recess is between 3 and 25 mm and corresponds, at the most, to twice the outer diameter of the support tube at its inner end. The ratio of the outer diameter of the outer, or remote, end of the support tube (,) and the outer diameter of the inner, or proximate, end of the support tube is between 1.1 and 2.5.

Electrode support tube for high pressure discharge lamp

To eliminate radiation from the mercury high-pressure discharge lamp of wlengths below 365 nm, the lamp includes a discharge vessel of quartz glass which is doped with vanadium in a quantity of up to about only 250 ppm, by weight, with respect to 1 mm of wall thickness of the quartz glass. This absorbed radiation also heats the quartz glass, so that the outside wall temperature of the vessel can be maintained between about 400.degree. and 950.degree. C. The effect can be enhanced by adding, additionally, titanium and/or tin to provide metal ions to the doping substance, in an overall quantity of up to 500 ppm, by weight. Alternatively, the quartz glass can be coated with TiO.sub.2 or SnO.sub.2. Suitable wall thicknesses for the discharge vessel are between 1 and 5 mm, and the fill therein is preferably mercury in a quantity of between 0.5 and 15 mg/cm.sup.3 and xenon with a cold fill pressure of 0.1 to 2.5 bar. Electrode spacing of the lamp is preferably between 2 and 5 mm. The vanadium portion preferably is less than 200 ppm and may, most desirably, be between 20 and 150 ppm, with respect to 1 mm wall thickness of the quartz glass of the discharge vessel.

Mercury vapor high-pressure discharge lamp and irradiation method,

To essentially eliminate short ultraviolet (UV) radiation from a mercury high-pressure short-arc discharge lamp, that is, wavelengths below the radiation band of 365 nm, the lamp includes a discharge vessel of quartz glass which is coated with a selectively reflective outer coating (2a) and, at the inside, with a selectively absorbing inner coating (2b). The outer coating (2a) is formed by a multi-layer interference reflection filter which preferentially reflects wavelengths between about 240 and 300 nm with a filter cut-off, corresponding to 50% transmission, in the wavelength region between about 290 and 330 nm. The inner coating (2b) is a titanium dioxide coating which, preferentially, absorbs radiation below about 250 nm, with a 50% transmission at about 240 nm. In accordance with a preferred feature of the invention, a radiation absorbing titanium dioxide/silicon dioxide mixed-layer coating (2c) is applied at the outside over the multi-layer interference reflection filter (2a). The outer absorbing coating preferentially absorbs radiation below about 280 nm. Preferably, the multi-layer interference reflection filter is formed by at least 8 alternating ZrO.sub.2 and SiO.sub.2 individual layers; all the coating layers preferably have thicknesses between about 30 and 50 nm.

Mercury-vapor high-pressure short-arc discharge lamp, and method and

Double-ended high-pressure discharge lamp

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Berlin, Germany

Joern Dierks