DISCHARGE TUBE FOR HIGH-PRESSURE DISCHARGE LAMP AND HIGH-PRESSURE DISCHARGE LAMP

摘要

A ceramic discharge tube (1A) for a high−pressure discharge lamp having ionized luminous substance and starting gas filled in the inside space thereof, comprising a tubular center luminous part (2A) and a pair of tubular end parts (3) projected from both sides of the center luminous part (2A), wherein the maximum wall thickness (1) of the end parts (3) is 0.5 to 0.9 times the maximum wall thickness (t) of the center luminous part (2A), whereby the luminous efficiency of the high−pressure discharge lamp can be increased.