Patent ID: 7137859

Claim:
A method of manufacturing a high-pressure discharge lamp, comprising the steps of: combining an electrode metal rod and a heat radiating coil into an electrode assembly to produce a melted tip end from a portion of said heat radiating coil with a protruding end of said metal rod, wherein said melted tip end has a length L 1 and a diameter D 1 ; and machining said end of said metal rod into a nipple, wherein said nipple has a length L 2 and diameter D 2 , and wherein a volume of said electrode assembly and said nipple has volume V 1 and wherein a volume of said end and said nipple has a volume V 2 , and wherein said machining step produces an electrode assembly where at least one of the conditions 0.15≦D 2 /D 1 ≦0.3, 0.2≦L 2 /L 1 ≦0.4, or 0.2≦V 2 /V 1 ≦0.4 are met.