Patent ID: 7598676

Claim:
A discharge lamp comprising a coaxial waveguide for high-frequency electromagnetic wave transmission, wherein the coaxial waveguide comprises an internal conductor, and a pipe-shaped external conductor surrounding said internal conductor, and a discharge tube for emitting light of discharge by plasma generated by electromagnetic waves, wherein the discharge tube is attached to a top of the coaxial waveguide, and is constructed in a double end shape in which both ends of a glass tube are pinched and sealed, wherein the glass tube comprises an ellipse spherical bulged part formed in a middle of a longitudinal direction, wherein an inside of the ellipse spherical bulged part forms discharge space, wherein a conductor assembly is sealed and attached to at least a proximal side pinch seal part, and wherein an electromagnetic wave irradiation part is constructed by the conductor assembly and the external conductor top of the coaxial waveguide surrounding said conductor assembly by inserting and holding the proximal side pinch seal part of the discharge tube in a top opening of the waveguide so that the conductor assembly approaches the internal conductor of the coaxial waveguide.