Ushio Denki Kabushiki Kaisha

Naohisa Ikeda

Masanori Sugihara

Short-arc discharge lamp designed to minimize the phenomenon of foil floating between the metal foil located in the foil sealing area and the sealing quartz component that is in contact with the inside of the metal foil so as to prevent cracks from forming in the foil sealing area, gas leakage from the lamp, and premature breaking of the lamp. The short-arc discharge lamp includes electrodes which are located in an emission space, a metal foil electrically connected to the electrodes, a quartz tube part which surrounds the metal foil, a sealing quartz component in contact with the inside of the metal foil, and a metallic component inserted into the sealing quartz component and electrically connected to the metal foil. The foil sealing area is formed from the metal foil, the quartz tube, and the sealing quartz component, which are sealed against one another. By the sealing action of the foil sealing area, sealing of the emission space is ensured. The short-arc discharge lamp has an electrical input power rating of greater than or equal to 4 kW and an operating pressure during luminous operation of greater than or equal to 2&times;10 Pa, and is operated using direct current. The above-mentioned characteristics are achieved in that the length of the area of a metallic component inserted into the sealing quartz component is greater than or equal to roughly 40% of the total length of the sealing quartz component.

Short-arc discharge lamp

A short-arc discharge lamp ( ) including a light-emitting tube ( ) having at least 15 mg/cc of mercury sealed therein, an anode ( ) and cathode ( ) facing each other and disposed within the light-emitting tube ( ), and a heat-release layer ( ) covering a substantial portion of an outer surface of the cathode ( ) so that when the short-arc discharge lamp ( ) is provided with electricity having a current value of at least 50 A, an inter-electrode power value defined by a ratio Y/X is at least 500 W/mm, X being defined as a distance in millimeters between the anode ( ) and the cathode ( ), and Y being defined as an input power in Watts provided to the short-arc discharge lamp ( ).

Growing community of inventors

Himeji, Japan

Naohisa Ikeda