Short arc type discharge lamp
AssigneeUshio Denki Kabushiki Kaisha
InventorsYoshio KAGEBAYASHI, Takeo MATSUSHIMA
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Abstract
For stably supplying an electron emitting substance and preventing illuminance fluctuations, a cathode is provided made from a tungsten material containing an electron emitting substance and having a taper part a diameter of which becomes smaller towards a tip end, a tip end face formed at the tip end side of said taper part, and a fine hole extending from said tip end face in an interior of said cathode, wherein said fine hole is formed at said tip end face such that it extends over at least two tungsten crystal grains. The invention also relates to a short arc type discharge lamp comprising said cathode.
Claims12
A short arc type discharge lamp, comprising
- a light emission tube,
- a cathode and an anode arranged oppositely to each other in an interior of the light emission tube,
- said cathode being made from a tungsten material containing an electron emitting substance and having a taper part a diameter of which becomes smaller towards a tip end, a tip end face formed at the tip end side of said taper part, and a fine hole extending from said tip end face in an interior of said cathode,
- wherein said fine hole is formed at said tip end face such that it extends over at least two tungsten crystal grains.
A cathode made from a tungsten material containing an electron emitting substance and having a taper part a diameter of which becomes smaller towards a tip end, a tip end face formed at the tip end side of said taper part, and a fine hole extending from said tip end face in an interior of said cathode,
- wherein said fine hole is formed at said tip end face such that it extends over at least two tungsten crystal grains.
Dependencies are inferred from the claim text.