Metal-halide discharge lamp for photooptical purposes
AssigneePatent-Treuhand-Gesellschaft F. Elektrische Gluehlampen mbH
InventorsAnna-Maria Frey, Jurgen Maier, Manfred Pilsak, Ralf Seedorf, Clemens Barthelmes, Thomas Dittrich
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Abstract
A metal-halide discharge lamp for photooptical purposes has a small electe spacing of less than 15 mm, preferably 2-8 mm, to provide an essentially pin-point light source, and a fill which contains AlI.sub.3 in an amount between 0.1 and 4.5 mg/cm.sup.3. Other filling components may in particular be halides of mercury, indium, thallium or cesium; up to 2 mg/cm.sup.3 of AlBr may be added. The lamp is particularly adapted for combination with a, preferably parabolic, reflector.
Claims20
A metal-halide discharge lamp for photooptical purposes having
- a translucent discharge vessel (2);
- two spaced electrodes (4) which face one another within the vessel and which are connected to power leads (8) extending to the outside,
- characterized by
- an arrangement for providing a light source which is close to a pin-point light source and which provides light at a color temperature of at least 5000 K,
- wherein said arrangement comprises
- an electrode spacing of a maximum of 15 mm;
- and
- a filling within the vessel which comprises
- 0.1 to 4.5 mg/cm.sup.3 of Al I.sub.3, as the essential or sole metal-halide component for light generation by said light source;
- and 0 to 2.0 mg/cm.sup.3 of halides (Ha) of indium (InHa) and mercury (HgHa.sub.2), or halides (Ha.sub.2) of mercury (Hg).
Dependencies are inferred from the claim text.