Abstract: Improved support means are provided to center the filament light source of an incandescent lamp within an open-ended transparent cylinder coated with an infrared reflecting film. Such filament mount construction is adapted for use in a tungsten-halogen lamp. A reflector lamp utilizing the improved tungsten-halogen lamp as a light source is also disclosed.

Abstract: Incandescent lamps having an improved light source are disclosed. The light source contains a halogen compound along with a fill-gas at a pressure above atmospheric. The light source has an oblate ellipsoidal shape so as to obtain a desired temperature gradient which reduces typically experienced "cold spots" that detrimentally contribute to the condensation of halogen compounds within the light source which would otherwise reduce the desired light output of the light source throughout life. Also disclosed is a method of manufacturing the light source.

Abstract: A vitreous arc tube is provided with constricted cylindrical neck portions intermediate the bulb portion proper and the pinched seals. The constricted necks may be formed as an incident in the blowing of the bulb out of quartz tubing. When the seal portions are pressed by the pinching jaws about the foliated inleads, the necks are maintained in substantially their original configuration and merely shrunk slightly about the inleads extending through them. An internal configuration is achieved which is substantially a surface of revolution and fin-effect is avoided.

Abstract: A long life tungsten halogen lamp comprising a fused silica envelope containing a coiled tungsten filament connected across inleads sealed therein which include inner portions of molybdenum wire. The molybdenum wire has been treated to increase its ductility and reduce the concentration of impurities at the surface. The fill gas at a room temperature total pressure of at least 2,000 torr comprises nitrogen, an inert gas and an iodine-bearing component which provides from 3.1 .times. 10.sup..sup.-7 to 9.6 .times. 10.sup..sup.-7 gram atoms of iodine per cubic centimeter of envelope volume.

Abstract: A long life tungsten halogen lamp comprising a fused silica envelope containing a coiled tungsten filament connected across inleads sealed therein which include inner portions of molybdenum wire. The molybdenum wire has been treated to increase its ductility and reduce the concentration of impurities at the surface. The fill gas at a room temperature total pressure of at least 2,000 torr comprises nitrogen, an inert gas and a bromine-bearing component which provides from 1.6 .times. 10.sup.-.sup.8 to 8.0 .times. 10.sup.-.sup.8 gram atoms of bromine per cubic centimeter of envelope volume.