| 摘要 |
PURPOSE:To prevent any adhesion of mercury to the surface of the outer tube bulb of a small fluorescent lamp having a curved discharge path so as to improve the efficiency of the lamp by fusing an exhaust tube, which works as an amalgam formation tube after exhaustion and sealing are completed, to the bottom of the outer bulb. CONSTITUTION:After a light-transmitting outer tube bulb 1 is charged with mercury and a rare gas, two U-shaped inner tubes 4 are installed in the bulb 1, thereby constituting a small fluorescent lamp 10. Each U-shaped inner bulb 4 has an opening at its one end and an electrode 2 installed in the other end. The inner surfaces of the bulbs 4 are coated with phosphor layers. An exhaust tube 6 having an opening located outside the bulb 1 is fused to its bottom 3. Indium 9 which can react with mercury to form an amalgam is inserted in the other opening 7 of the exhaust tube 6 which is located outside the bulb 1 and coated with a porous member 8 made of iron or similar matter. After the process of exhaustion is completed, the externally protruding portion of the exhaust tube 6 is removed before the sealing of the lamp 10 is performed. As a result, it is easily possible to retain the indium 9 in the tube 1 with high reliability, thereby preventing any deterioration of the quality of the lamp 10 which might be caused due to mercury adhesion. |
