发明授权
- 专利标题: Electrodeless discharge lamp and apparatus to prevent devitrification
- 专利标题(中): 无电极放电灯和防止失透的装置
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申请号: US09416996申请日: 1999-10-13
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公开(公告)号: US06362565B1公开(公告)日: 2002-03-26
- 发明人: Koichi Katase , Tsuyoshi Ichibakase , Katsushi Seki
- 申请人: Koichi Katase , Tsuyoshi Ichibakase , Katsushi Seki
- 优先权: JP10-299391 19981021
- 主分类号: H01J1720
- IPC分类号: H01J1720
摘要:
An electrodeless discharge lamp and an electrodeless discharge lamp apparatus which prevent the devitrification are provided, where the devitrification occurs due to the use of, as a luminescent substance, a metal halide, particularly a compound made up of a group IIIB metal and a halogen. The inventors recognize the cause of the devitrification as follows: atoms of the metal are dissociated from the luminescent substance and precipitate on the surface of the arc tube wall to melt it as the luminescent substance is excited and emits light. Based on this recognition, a substance is added to the interior of the arc tube to prevent the melting of the arc tube wall and extend the life of the lamp. More specifically, the added substance is another metal halide which contains a halogen, but the valence of the metal of the added metal halide is larger than that of the luminescent-substance metal halide. In addition to this, it is possible to control the ratio of the halogen in the arc tube by controlling the amount of the added metal halide. With this construction, occurrence of the devitrification is prevented while maintaining the discharge stability. The devitrification can also be prevented by adding a simple substance of the metal constituting the luminescent-substance metal halide.