PURPOSE: To shorten an exhaust operation time and to improve lamp characteristics by using glass frits of different softening temperature at an electrode lead wire inserting place and a bulb sealing place of an end plate respectively.
CONSTITUTION: Lead wires 2 are inserted through lead wire inserting parts 22 of an end plate 1 and at the same time the first glass paste 4 of a softening temperature being approximately 440°C is applied to the lead wire inserting parts 22. Subsequently, the second frit paste 5 of a softening temperature being approximately 365°C is applied to an internal tube groove 77 to fix an internal tube 7 and to a groove 32 facing the opening end 31 of a bulb 3. Frit 4, 5 are softened and melted, after passing through a heating furnace to be warmed up by approximately 500°C and when these are cooled, lead wires 2 are sealed to an end plate 1. There after if the internal tube 7 and the bulb 3 are placed on the second frit layer 5, warmed approximately up to 450°C, and the second frit 5 is softened and melted again, and then they are cooled, sealing of a bulb 3 together with an end plate 1 and fixing of an internal tube are completed.
YAMAZAKI HITOSHI
NAKANO SHIZUO
ITOU HIROSHI
YAMAMOTO HIROJI
IMAI JIYUN
