Patent ID: 6373193
Filing Date: 2002-04-16
Classification: C03C,H01J,H01K,Y02B

Abstract:
A long life, halogen cycle, incandescent lamp for operation in excess of 85 volts comprising: a transparent glass envelope having sealed therewithin a tungsten filament; a pair of electrical lead-ins connecting said filament and extending exteriorly of said envelope for connection to a supply voltage greater than 85 v; and a fill gas within said envelope including a halogen at a pressure of at least three atmospheres, said envelope being constructed of an alkaline earth aluminosilicate glass having a composition consisting essentially of, in weight percent, from >58 to about 64% SiO2, from about 14 to about 17.5% Al2O3; from 0 about 1% B2O3, from 1 to about 7% MgO, from about 5.5 to about 14% CaO, from about 6 to about 17% BaO and from 0 to about 1.5% ZrO2 and wherein the weight ratio of (CaO+SrO+MgO)/BaO is between 1.45 and 1.75.