| 摘要 |
PURPOSE:To prevent sodium from leaking by joining electric conductive members each of which has an electrode on its end to both end portions of a light emitting tube through frit, after processing the outer surface of the electric conductive member with a sand-burst process to form unevenness on the outer surface of the conductive member. CONSTITUTION:An electric conductive member 9, made of niobium, and having an electrode 10 on its end portion is inserted through, enclosed and attached to an end disk 8 made of alumina, which is disposed on the end portion of a light emitting tube 7 of a high pressure sodium vapor lamp. The light emitting tube 7 is made of alumina and encloses sodium, a metal for shock absorbing gas, and rare gas for starting. The outer surface of the conductive member 9 is processed with the sand-burst process by using oxide aluminum powder to form unevennes, and is closely joined to the end disk 8 through frit 11 made of alumina etc. Therefore, the leak of sodium outside the light emitting tube 7 can be inhibited by enlarging the surface area of the conductive member 9, subsequently the joining area, and the strength of the joint. |
