Ushio Denki Kabushiki Kaisha

Tsuneo Okanuma

Tatsushi Igarashi

Yukio Yasuda

Tatsumi Hiramoto

Hiromitsu Matsuno

Akiyasu Yamaguchi

Yoshio Kagebayashi

A discharge lamp has an electrode comprising a base portion having a base portion side flange portion, and a lid portion having a lid portion side flange portion. In a sealed space of the electrode, heat conductive member is enclosed. At time of lighting, the electrode is not damaged, and the discharge lamp can be stably operated. In the electrode, the diameter direction width of a welding portion of a base portion side flat portion and a lid portion side flat portion is 0.8 to 3.0. Further, an angle formed by the base portion side flat portion and a base side slope portion is 30 degrees or less and an angle formed by the lid portion side flat portion and a lid side slope portion is 30 degrees or less. The sum total of these angle is 160 degrees or less.

Discharge lamp

An emission device which operates a cadmium lamp with a light intensity sufficient for used in industrial applications is achieved by an emission device having a cadmium lamp with a fluorescent tube within which a cathode and an anode are space a small distance apart and a buffer gas for easier initiation of luminous operation and metallic cadmium in an amount per unit volume of the fluorescent tube of 1.times.10.sup.-4 g/cm.sup.3 to 3.times.10.sup.-3 g/cm.sup.3 are encapsulated, and a power source device for supplying an electrical input between the cathode and the anode in an electrical input range from 0.5 kW to 5.0 kW with the condition:

Emission device with a cadmium lamp

An electrically-conductive member is provided on the outer wall of a cathode-sealing portion of a dc discharge lamp such as a super high pressure mercury vapor lamp, and the electrically-conductive member is electrically connected to a sealed cathodic conductor which is contained in the cathode-sealing portion and connected to its cathode rod. The electric potential of the electrically-conductive member is thus kept equal to that of the sealed cathodic conductor while the dc discharge lamp is in operation. As a result, the air-tight connection between the sealed cathodic conductor and the quartz glass of the cathode-sealing portion is maintained stably over a long period of time. Such a dc discharge lamp assures long service life and high reliability.

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Hyogo, Japan

Tsuneo Okanuma