| 摘要 |
PURPOSE:To obtain a fluorescent character display tube having no exhaust tube by pre-inserting a frit glass into a display tube then evacuating and sealing an exhaust tube thereafter thermally fusing the frit glass and enclosing the exhaust port from inside. CONSTITUTION:A plurality of frit glass 11 burnt temporarily into balls from an opening at the tip of an exhaust tube 5A through said tube 5A are inserted into a display tube 4. Upon completion of evacuation, said tube 5A is sealed to produce a thin projected exhaust tube 5 at the outside of display tube 4. Then said display tube 4 is inclined to collect the frit balls 11 at one position in the inner port of exhaust tube 5 and heat in a high temperature furnace to fuse. Thereafter the projected exhaust tube is cut to produce a fluorescent character display tube having no exhaust tube. |
