Patent ID: 6242861
Filing Date: 2001-06-05
Classification: H01J

Abstract:
A direct current discharge lamp comprising:a bulb portion containing therein a cathode and an anode which comprises a tungsten pin having a larger diameter than the cathode;a first seal portion outwardly extending from the bulb portion on the anode side;a second seal portion outwardly extending from the bulb portion on the cathode side;a pair of feeder elements respectively inserted through the first and second seal portions for feeding electricity to the anode and cathode; andan extended tube portion interconnecting the bulb portion and the first seal portion,wherein the anode is extended from the bulb portion into the extended tube portion and the extended tube portion has an inner diameter larger than the outer diameter of the anode such that a space exists between the anode and the extended tube portion along a substantial portion of surface area of the anode contained within the extended tube portion.