Arc discharge lamp containing mechanism for extinguishing arc at end-of-life

Abstract

An arc discharge lamp having an end-of-life structure and including a light-transmissive envelope having a tubular-shaped main body and a press seal disposed at each end of the main body. An electrode filament having a pair of ends is located in each end of the envelope. Each electrode filament end is in a contiguous relationship with an inside surface of the lamp envelope. When one of the electrode filaments is depleted of electron-emissive material, increased heating of the electrode filament caused by an increase in cathode fall voltage, produces a localized hot spot on the internal surface of the envelope. This localized heating causes a puncture in the lamp envelope and evacuation of the lamp. The introduction of external atmosphere into the lamp extinguishes the arc discharge and renders the lamp inoperable.

Dependencies are inferred from the claim text.