Patent ID: 7276851
Filing Date: 2007-10-02
Classification: H01J

Abstract:
1. A discharge lamp device, comprising: a cylindrical arc tube containing a discharge medium; an internal electrode provided in the arc tube; and an external electrode unit attached to an outside of the arc tube, wherein the external electrode unit includes: external electrodes arranged intermittently at plural places in a direction of a tube axis, each having a part adjoining an outer wall surface of the arc tube; and an engaging part that integrally links the external electrodes, the external electrode unit formed as an electrode member incorporating the external electrodes and the engaging part so as to be shared to cover half or more of the arc tube in a circumferential direction; a dielectric member interposed between the arc tube and the external electrode unit, the external electrode unit being elastic so as to press the dielectric member against the outer wall surface of the arc tube so as to be held around the arc tube by itself, and a voltage is applied between the internal electrode and the external electrode, thereby lighting the arc tube.