PURPOSE: To provide a one side sealed type metal vapor discharge lamp for regulating the positions of insulating sleeves laid on electrodes so as to prevent the damage of the insulating sleeves and discharge on the electrode axis.
CONSTITUTION: A crushed sealing part 2 is formed at one end of a light emitting tube 1 and at the same time a pair of metal foil conductors 6 are sealed to the crushed sealing part and electrode axes 4 are connected to the metal foil conductors. Regarding a one side sealed type metal vapor discharge lamp wherein these tip parts of the electrode axes are set face to face in a discharge space and the base parts of the electrode axes are covered with insulating sleeves 8, coil springs 9 to push the insulating sleeves in the sealing part direction are installed between the insulating sleeves and the tip parts of electrode axises. Consequently, since the coil springs push the insulating sleeves even if the insulating sleeves are pushed by quartz when the light emitting tube is crushed and sealed, the positions of the insulating sleeves can be regulated.
INUKAI SHINJI
NISHIZAWA MAKOTO
SANO HISANORI
