PURPOSE: To shorten substantial distance between electrodes and reduce starting voltage at the time of start by employing an auxiliary electrode connected by high resistance to the electrode in the vicinity of an opening.
CONSTITUTION: A plural number of bulbs 1 are connected in series by bridging through small openings 2 through 4 to form a passage. Electrodes 5 and 6 are provided on both ends of the connected bulbs 1 to form a discharge passage. Auxiliary electrodes 7 and 8 made of metallic wire are provided in the vicinity of the small openings 2 through 4. Resistances 9 and 10 having a resistance value sufficiently higher than the lamp impedance when the lamp is lit are connected between the auxiliary electrodes and the electrodes other than those nearer to the auxiliary electrodes 7 and 8, out of electrode 5, 6 and a inverse voltage is applied between the auxiliary electrodes and the electrodes nearer to the auxiliary electrodes. Namely the substantial electrode distance at the time of start is shortened by activating the auxiliary electrodes 7 and 8. This lowers the starting voltage.
HONMO ISAO
AKEBOSHI MINORU
OKUNO IKUHIRO
