Stanley Electric Co., Ltd

Tsuneyoshi Sibasaki

Masanobu Aizawa

Akihiko Tsurumaru

Mitsugu Tayama

Masatomo Yanai

A method for manufacturing a metal halide lamp in which tungsten coils are made to have diameters wider than the outer diameters of electrodes, and to have a coil pitch sufficient to prevent molten quartz glass from entering therebetween; and after the tungsten coils have been fixed around the electrodes, the pitch of the tungsten coils on the sides of the electrodes which are nearest molybdenum foils is extended by dragging a part of the tungsten coils toward the discharge ends of the electrodes to fix it tightly around the electrodes. As a result, when sealing is performed with quartz glass bulb, gaps between the electrodes and the glass bulb are provided on the discharge sides of the electrodes, whereby it can be prevented to occur cracks in the quartz glass bulb due to the thermal expansion of the electrodes; and on the molybdenum foil sides of the electrodes, the quartz glass bulb contacts the electrodes, thereby preventing peeling-off and accumulation of sealed material.

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Iwaki, Japan

Tsuneyoshi Sibasaki