Metal vapor discharge lamp

Abstract

Abstract PURPOSE:To obtain a metal vapor discharge lamp with the low starting voltage and excellent light output life performance by providing a translucent film to prevent the reaction between metal halogenide and a quartz tube wall on the inner surface of a luminous tube except one portion. CONSTITUTION:Luminous metal halogenide, e.g., scandium, sodium, is sealed in a luminous tube 1 made of quartz together with a proper quantity of mercury and rare gas. In addition, a translucent film 3 mainly composed of aluminum phosphate, titanium oxide, aluminum oxide, etc. is formed on the inner surface of the luminous tube 1 made of quartz. A notch 4 to pass impure gas is provided at one portion of this translucent film 3. Accordingly, the reaction between the metal halogenide and quartz tube wall is suppressed by the translucent protective film 3 formed on the inner surface of the luminous tube, on the other hand, the impure gas entering during production, etc. permeates and diffuses outside the luminous tube through the notch 4 to be adsorbed by a getter material 7, thereby the impure gas concentration in the luminous tube is reduced, the starting voltage is lowered, and the light output life performance is improved.

Inventors

• 👤 Katsumi Takatsu
• 👤 勝美 高津
• 👤 Hisao Yoshiike
• 👤 久夫 吉池

Bibliographic Details