Abstract: To prevent bending of an electrode shaft portion by a method which requires minimum increase in production cost, in an electrode mount for a high pressure discharge lamp. A manufacturing method of an electrode mount for the high pressure discharge lamp includes: a process of subjecting the electrode mount to a heat treatment, the electrode mount including an electrode and a metal foil which are welded to each other; and an oxidation process of producing an oxide on a surface of the electrode shaft portion of the electrode by laser irradiation to form an oxidation portion on the surface, wherein a laser irradiation position is determined such that a whole or part of the oxidation portion is included in a sealing portion of the high pressure discharge lamp when the electrode mount is embedded in the sealing portion.

Abstract: Disclosed is an arrangement for a cut type electrode, wherein the removal of a coil is prevented and the generation of gap between turns of a coil caused by repeatedly turning on and off of the lamp is suppressed. The electrode, which is for a discharge lamp, comprises: a core rod having a leading end portion for discharge formed by a cutting process; and a coil wound around the core rod in n-turns in a state exposing the leading end portion, wherein at least a first portion between a first turn and a turn adjacent to the first turn and a second portion between an n-th turn and a turn adjacent to the n-th turn are welded.

Abstract: To prevent bending of an electrode shaft portion by a method which requires minimum increase in production cost, in an electrode mount for a high pressure discharge lamp. A manufacturing method of an electrode mount for the high pressure discharge lamp includes: a process of subjecting the electrode mount to a heat treatment, the electrode mount including an electrode and a metal foil which are welded to each other; and an oxidation process of producing an oxide on a surface of the electrode shaft portion of the electrode by laser irradiation to form an oxidation portion on the surface, wherein a laser irradiation position is determined such that a whole or part of the oxidation portion is included in a sealing portion of the high pressure discharge lamp when the electrode mount is embedded in the sealing portion.

Abstract: A high pressure discharge lamp electrode of the present invention includes a core rod (10), a head (20), and a coil (30) covering the head. The head includes a smaller-diameter section (21) on the core-rod side and a larger-diameter section (22) on a tip side. The coil covers the smaller-diameter section such that a winding-start end portion (30a) of the lowermost layer is positioned at the tip side of the smaller-diameter section, and covers the smaller-diameter section and the larger-diameter section such that a winding-finish end portion (30b) of the uppermost layer is positioned on the larger-diameter section. At least a portion of the coil is welded to the larger-diameter section.

Abstract: A metal halide lamp of the present invention comprises a luminous tube alone without any outer bulb, the luminous tube containing metal halides such as neodymium halides (NdX.sub.3), dysprosium halides (DyX.sub.3) and cesium halides (CsX) in a total amount by mole of 1.times.10.sup.-6 to 8.times.10.sup.-6 mol/cc and the following molar ratios: ##EQU1## as well as rare gas serving as starting auxiliary gas and mercury serving as buffer gas. This structure permits a predetermined vapor pressure of the metal halides sealed in the luminous tube to be obtained without increasing the wall load, as well as the formation of a metal halide lamp having a long life and good color characteristics.