High pressure metal vapour discharge lamp - has cylindrical discharge vessel or arc tube of refractory light-transmissive material

摘要

The discharge lamp includes an arc tube (1), an annular member (2) sealed into one end of the arc tube, and a hollow lead (3) hermetically sealed into the annular member and having an enlarged section (10) outside the arc tube. The enlarged section containing a body with capillary interstices which contain a metal or alloy for forming a vapour. The interior of the hollow lead communicates with the interior of the arc tube only by means of a small aperture (9). The hermetic closure of the enlarged section of the hollow lead may be constituted by at least one platelet (14) which is welded or soldered to it over a feed opening in the enlarged section and the body with the capillary interstices may be a filament coil (16).