Patent ID: 8339023

Claim:
A discharge lamp, comprising: an airtight tube comprising: a light-emitting unit having a space formed therein, and a seal portion formed on an end of the light-emitting unit; a discharge medium containing a metal halide and a rare gas sealed in the light-emitting unit; a metal foil sealed in the seal portion; an electrode comprising: a first end being overlapped and connected to the metal foil, the metal foil having a concavity at a part overlapped with the electrode on a back surface side of the metal foil in a direction from the metal foil toward the electrode, and a second end being led into the space of the light-emitting unit; and a distorted portion formed on the concavity in the seal portion by a compression distortion caused by formation of the concavity, wherein the concavity is an approximately circular shaped recess, and when its depth is d and length is L 3 , d≧0.01 mm and L 3 ≧0.1 mm are satisfied.