PURPOSE: To obtain a light emitting tube having no electrical or optical variations, by a method in which the central portion of a tube stock is heat melted and formed into a U-shape in a mold, an exhaust tube is attached to the central portion of the tube stock and electrodes are sealed to both of the open ends.
CONSTITUTION: A tube stock 1 is heat melted by flames, while rotated, such that the central portion thereof is bent. The tube 1 is placed in a mold 5a while supplied with inactive gas 3 with one of the open ends closed with a cap, so that it is formed into a U-shape. An exhaust tube 6 is welded to the part 1b where the tube is broken by the flow of air so as to communicate with the tube. An intermediate portion of the exhaust tube 6 is held by a holder 11 and a gas introducing tube 10 is attached to the exhaust tube 6. Electrodes 9 held by a holder 8 are inserted into the tube stock 1 from the open ends thereof and then the inactive gas 3 is introduced into the tube through the introducing tube 10 so as to substitute the atmosphere within the tube stock. The outer periphery of the tube stock 1 is heat melted by flames 4 and the electrodes 9 are sealed to the tube stock by a pincher head. Thus, a light emitting tube can be produced.
TAGUCHI SHIYOUICHI
SAITOU MASATO
SUZUKI RIYOU
WATABE KEIJI
Next Patent: METHOD OF MEASURING PRESSURE OF SEALED GAS IN FLUORESCENT LAMP