High pressure metal vapor discharge lamp
AssigneeTokyo Shibaura Denki Kabushiki Kaisha
InventorsAkihiro Inoue, Tadao Kanoh, Taketo Kamei, Akihiro Kamiya, Toshihiko Ishigami, Akira Kohno, Hirok Sasaki
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Abstract
A high pressure metal vapor discharge lamp including an arc tube having at least a main electrode at each end thereof, a fill sealed in the arc tube, including mercury, metal halide and starting gases selected from the group consisting of Ar, Kr and Xe, a radioactive source material, impregnated with a radioactive substance having a half-life less than 1.times.10.sup.4 years, sealed in the arc tube and a circuit including a conventional low voltage mercury lamp ballast and a glow starter for starting the arc tube.
Claims2
A high pressure metal vapor discharge lamp comprising:
- an arc tube having at least a main electrode at each end thereof and a starting electrode mounted adjacent a selected of said main electrodes;
- a fill, sealed in said arc tube, including mercury, sealed metals and a starting gas selected from the group consisting of Ar, Kr and Xe;
- a radioactive source material, formed of a ceramic material impregnated with a radioactive substance having a half-life less than 1.times.10.sup.4 years, sealed in said arc tube;
- and
- a circuit for starting said arc tube, comprising a glow starter connected across said starting electrode and said selected main electrode for generating a high voltage pulse to start a discharge in said arc tube and a mercury lamp ballast connected to said main electrodes;
- wherein said radioactive source material is mounted on a selected of said main electrodes or said starting electrode.
Dependencies are inferred from the claim text.