High-pressure discharge lamp
A high-pressure discharge lamp may include a discharge vessel, which encloses a discharge volume, wherein a filler is housed in the discharge volume, wherein the discharge vessel is equipped with an end which is tubular and in which a two-part feedthrough is sealed by means of glass solder, wherein an electrode is attached to the feedthrough, which protrudes into the discharge volume, wherein the feedthrough is composed of a front part and a rear part, wherein the rear part is manufactured from niobium material and the front part is manufactured from iridium.
1. A high-pressure discharge lamp comprising:
a discharge vessel enclosing a discharge volume and being equipped with an end which is tubular;
a feedthrough comprising a front part and a rear part, the feedthrough being sealed in the end of the discharge vessel by means of glass solder;
an electrode having a shaft attached to the front part of the feedthrough, the electrode protruding at least partially into the discharge volume;
a filler housed in the discharge volume;
wherein the rear part of the feedthrough is coupled to the front part; and
wherein the rear part is manufactured from niobium material and the front part is manufactured from iridium;
wherein the front part is at least partially spherical;
wherein the diameter of the shaft of the electrode is 20-30% smaller than the diameter of the front part.
2. The high-pressure discharge lamp as claimed in claim 1 , wherein the front part is formed to be substantially sphere-like.
3. The high-pressure discharge lamp as claimed in claim 2 , wherein the front part is formed to be a sphere or a concatenation of a plurality of spheres or to be a sphere having pin attachment.
4. The high-pressure discharge lamp as claimed in claim 1 , wherein the glass solder extends from an end of the tubular end up to at least a portion of the front part.
5. The high-pressure discharge lamp as claimed in claim 4 , wherein the glass solder extends at least up to the at least partially spherical portion of the front part.
6. The high-pressure discharge lamp as claimed in claim 1 , wherein the glass solder is a high-temperature solder based on oxides of aluminum and rare earth metals.
7. The high-pressure discharge lamp as claimed in claim 1 , wherein the filler comprises metal halides.
8. The high-pressure discharge lamp as claimed in claim 1 , wherein the filler comprises mercury.
9. The high-pressure discharge lamp as claimed in claim 1 , wherein the diameter of the front part transversely to the lamp axis is in the range from 0.35 mm to 1.2 mm.
10. The high-pressure discharge lamp as claimed in claim 1 , wherein an axial length of a fusion zone is between 0.5 mm and 4 mm.