Matsushita Electronics Corporation

Matsushita Electric Industrial Co., Ltd.

Kouichi Sugimoto

Takashi Yamamoto

Yoshiharu Nishiura

Hiroshi Nohara

Kazuo Takeda

Shiki Nakayama

Shunsuke Kakisaka

Shigefumi Oda

Kenji Akiyoshi

A metal vapor discharge lamp having a highly reliable sealed portion. The lamp has an arc tube including a discharge portion of translucent ceramic in which a discharge metal is filled and a pair of electrodes is disposed; small tubular portions coupled to both ends of the discharge portion; feeder bodies inserted into the small tubular portions; and a sealing material sealing the gap between the feeder body and the small tubular portion at the end portion opposite to the discharge portion. The end of the small tubular portions and the inner surface of the discharge portion define a discharge space. The feeder bodies are composed of a conductive cermet and connected to the electrodes. The ends of the feeder bodies extend at least to the ends of the small tubular portions. The temperature of the end of the sealing material on the discharge space side during the lamp operation is not more than 800&deg; C.

Metal vapor discharge lamp having cermet lead-in with improved luminous efficiency and flux rise time

A metal vapor discharge lamp comprises a discharge tube having a ceramic container into which a pair of electrodes and a discharge metal compound are sealed. The container comprises a first cylindrical portion, tapered portions, second cylindrical portions and third cylindrical portions. The third cylindrical portions are shrinkage-fitted to the second cylindrical portions. The electrodes are attached to the third cylindrical portion with a sealing member. An inner wall of the third cylindrical portions and the electrodes define a gap. The inner surface of the tapered portions and a central axis of the electrodes define an angle of 40&deg;-80&deg;. Thus, a metal vapor discharge lamp is provided whose discharge tube does not include disks among its parts, and which can maintain, over a long period of operation, good operating characteristics that depend only little on the lamp orientation.

Metal vapor discharged lamp with specific angle between electrodes and tapered envelope wall

A metal halide lamp comprises a discharge tube of transparent ceramic in which a discharge metal is sealed, the discharge tube having a main cylindrical portion, ring portions provided at both ends of the main cylindrical portion, and tubular cylindrical portions provided at the ring portions; and a pair of electrodes inside the discharge tube; wherein a wall thickness .alpha. (in mm) of the main cylindrical portion satisfies the relation

Metal halide lamp with specific dimension of the discharge tube

A metal halide lamp of the present invention has a ceramic discharge tube and a proximity conductor disposed adjacent to the ceramic discharge tube.

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Osaka, Japan

Kouichi Sugimoto