DISCHARGE LAMP INCLUDING SECTION OF ELECTRODE WITH COATING CONTAINING HIGH MELTING METAL

摘要

PURPOSE: A discharge lamp is provided to prevent a jump caused due to the different thermal expansion coefficients of a discharge vessel material and an electrode material and adhesion of the discharge vessel material to an electrode. CONSTITUTION: A discharge lamp comprises a discharge tube(1) having an internal space(10) containing an ionizable filler. The discharge tube includes at least one sealed end(11) having a current penetrating portion(2) connected to an electrode(4). The electrode is protruded into the internal space of the discharge tube, and has a section extending into the sealed end. The section of the electrode is provided with a coating containing a high melting metal selected from a group of platinum metals.