Low pressure metal vapor discharge lamp with tubular member and magnetic means
AssigneeHitachi, Ltd.
InventorsMikiya Yamane, Teruichi Tomura, Yoshio Watanabe
Life of this patent
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Abstract
A low pressure metal vapor discharge lamp has a discharge envelope of a double tube structure filled with an inert gas and a small quantity of metal. The discharge envelope comprises a sealed outer glass bulb, and an inner glass tube disposed within the outer glass bulb substantially concentrically therewith and having one open end and the other closed end. The lamp further has a single cathode inside the inner glass tube, a plurality of anodes disposed exteriorly of the inner glass tube and interiorly of the outer glass bulb, and a permanent magnet disposed near the open end of the inner glass tube for applying a magnetic field of a fixed intensity near the open end.
Claims24
A low pressure metal vapor discharge lamp comprising:
- a discharge envelope including an outer bulb made of light-transmissive material and an inner tube disposed within said outer bulb, said inner tube having one open end and the other closed end;
- an inert gas and metal filled in said envelope;
- a cathode disposed interiorly of said inner tube;
- an anode disposed exteriorly of said inner tube and interiorly of said outer bulb;
- and
- magnetic field applying means disposed near the open end of said inner tube for applying a magnetic field near the open end.
A low pressure metal vapor discharge lamp comprising:
- a discharge envelope including an outer bulb made of light-transmissive material and an inner tube disposed within said outer bulb, said inner tube having one open end and the other closed end;
- an inert gas and metal filled in said envelope;
- a cathode disposed interiorly of said inner tube;
- a plurality of anodes disposed exteriorly of said inner tube and interiorly of said outer bulb;
- and
- magnetic field applying means disposed near the open end of said inner tube for applying a magnetic field near the open end.
A low pressure mercury vapor discharge lamp comprising:
- a discharge envelope including an outer glass bulb and an inner glass tube disposed concentrically therewith, said inner glass tube having one open end and the other closed end;
- an inert gas and a small quantity of mercury filled in said envelope;
- a cathode disposed interiorly of said inner glass tube and near the closed end of said inner glass tube;
- a plurality of anodes disposed, near the closed end of said inner glass tube, exteriorly of said inner glass tube and interiorly of said outer glass bulb;
- and
- a permanent magnet disposed near the open end of said inner glass tube for applying a magnetic field of a fixed intensity near the open end.
Dependencies are inferred from the claim text.