| 摘要 |
An outer tube (2) and a lamp base (5) are sealed to each other with a sealing material (4). A current supply member (3) is inserted through the lamp base (5), and is fixed to the lamp base (5) with the sealing material (4). An air exhaust tube (6) is inserted through the lamp base (5), and is fixed to the lamp base (5) with the sealing material (4). An electrical discharge container is placed inside of the outer tube (2). The sealing material (4) comprises 35 to 75% by volume of a glass powder and 25 to 65% by volume of a fire-resistant filler powder, and has a thermal expansion coefficient of less than 70 x 10-7/°C. The glass powder has a glass composition comprising 55 to 85 mass% of Bi2O3, 5 to 20 mass% of B2O3, 1 to 15 mass% of ZnO, and 0 to 7 mass% of SiO2. |
