Patent ID: 7952283

Claim:
A high intensity discharge lamp comprising an arc tube enclosing an arc chamber containing a gas till, the arc tube being terminated by at least one sealed portion; the at least one sealed portion enclosing an electrode assembly comprising at least one electrode extending into the arc chamber; a lead-in wire extending outward from the scaled portion for providing electric contact with a power supply; and an electrically conducting seal foil connecting the lead-in wire and the at least one electrode, the conductor foil providing a sealed electric connection through the sealed portion of the arc tube, and at least one of the at least one electrode being provided with at least one artificial surface irregularity on an external surface thereof only in a region located approximately 1/4 to 3/4 of a distance between the foil and the arc chamber in order to control shape and size of cracks in a seal wall surrounding the at least one electrode, said artificial surface irregularity being provided without additional separate components.