| 摘要 |
PURPOSE:To obtain a captioned lamp with no decrease in a luminous flux while having an improved light distribution property by providing a getter holding material inside an outer tube so as to surround the luminous tube end part far from the sealing part of the outer tube and a getter coating on the inside surface of the outer tube. CONSTITUTION:A ring-shaped getter holding material 13 is provided on the luminous tube end part far from the sealing part of an outer tube 9, namely on the periphery of the tube end part, where an electrode conductor 2 is sealed in, so as to surround the tube end part while said getter holding material 13 is held by a lead wire 7 through a getter support 14. Barium getter is in advance filled inside the getter holding material 13 while flushing the getter material 13 from outside, for instance, by heating with a high frequency heating device after forming the tip 12 by vacuum-exhausting the outer tube 9. As a result, a getter coating 15 is formed made of barium on the end part inside surface in the opposite direction to the sealing part of the outer tube 9, namely on the end part inside surface centering about the tip 12 while maintaining the inside of the outer tube high vacuum throughout lamp life. |
