Title:
MANUFACTURE OF DISCHARGE LAMP CATHODE
Document Type and Number:
Japanese Patent JP3246387
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To realize stable arc discharge action for a long time, by finishing the shape of only a portion to be applied by carbonizable treatment to carbonizably treat the whole in the condition; and then cutting the sharpe shape of a cathode tip to finish the tip.
SOLUTION: An arc emission portion 31 in the tip of a tungsten bar 3 (a cathode) is not yet cut as the final form, and a rest portion other than the portion 31 is worked to nearly the final form. In this condition, the rest portion is arranged in a glass-made vessel 20 to heat the bar 3 (the cathode) by a high- frequency heating coil 21, to pass gas, wherein benzene vapor and a hydrogen gas are mixed, through the vessel, thereby forming a desired carbonized layer. For instance, high-frequency heating is made at a heating temperature of 1500°C for 20 min. Then, a desired sharp shape can be finished by cutting a portion, shown by a dot line 31a; that is, a carbonization-untreated portion can be properly manufactured because the portion, shown by the dot line 31a, is cut down after the carbonization-treatment.
Inventors:
Yasuo Ohnishi
Hideyuki Ikegami
Hideyuki Ikegami
Application Number:
JP9793097A
Publication Date:
January 15, 2002
Filing Date:
April 02, 1997
Export Citation:
Assignee:
Ushio, Inc.
International Classes:
H01J61/073; H01J9/04; (IPC1-7): H01J9/04
Domestic Patent References:
| JP4137349A | ||||
| JP586026B2 |
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