| 摘要 |
PURPOSE:To increase efficiency and strengthen structure by forming a translucent cylindrical heat insulator which extends to a seal and discharge space surroundings adjacent to the seal and is made of the same material as a luminescent tube by melt-bonding its end to the seal. CONSTITUTION:An electrode constituent 2b is sealed to the lower end of a tube 18, and a heat insulating short tube 19 which was fixed in the upper part by a short tube holder 25 is lowered to a specified position with the short tube holder 25. The lower end of the heat insulating tube 19 is heated from the outside by a fire 26 and melted and melt-bonded to the sealing end part of the luminescent tube 7 by a pincher. Since a heat insulator 6 is made of the same translucent material as the luminescent tube 1, efficiency drop caused by the heat insulator is decreased and structure is strengthened, efficiency and color are stabilized, and generation of crack is eliminated. |
