Incandescent lamp source utilizing an integral cylindrical transparent heat mirror

摘要

An improved incandescent lamp comprising an inner envelope disposed within an outer envelope is disclosed. The inner envelope contains a halogen gas along with a relatively high pressure efficient fill gas. The inner envelope houses a tungsten filament which is partly surrounded by a separate light-transmissive cylinder. The separate cylinder has on one of its surfaces a selective infrared reflective filter capable of efficiently operating at a temperature range of up to and including about 950 DEG to about 1050 DEG C.