| 摘要 |
PURPOSE:To prevent the reaction between glass solder and sealed luminous metal by sealing a tube end of a luminous tube with a closing member and glass solder and covering the intra-tube exposed section of the glass solder with a sintered body with specific composition. CONSTITUTION:The opening end of a luminous tube 1 consisting of a transparent ceramics tube that encloses alkaline metal such as sodium-mercury amalgam as the luminous metal is sealed with a closing member 2 made of heat resistant metal such as niobium and glass solder 3. The exposed section 3a within the luminous tube made of glass solder 3 is covered with a protective layer 6 consisting of a sintered body with the mixed composition of alumina and rare-earth metal oxide. As a result, since the reaction between the glass solder 3 and the sealed alkaline metal can be prevented without exposing the glass solder 3 even if the solder is melted during lighting, a metal vapor discharge lamp can be provided with its long life. |
