TUNGSTEN BAR FOR TUBULAR BULB

• Main Author: KITAMURA MASASHI
• Format: Patent
• Language: English
• Published: 22.08.1995
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY

PURPOSE:To firmly fix an emitter material in a prescribed position by performing polishing finish on an outer peripheral surface of a tungsten bar as a surface which has a large number of recessed parts discontinuous in the circumferential direction and the lengthwise direction and whose average roughness is 3 to 10 microns. CONSTITUTION:Fine recessed parts discontinuous in the circumferential direction and the lengthwise direction are formed at random on an outer peripheral surface of a tungsten bar 1, and surface roughness is set in 3 to 10 microns. These recesses and projections are discontinuous, and polishing finish is performed on the surface, and the recessed parts are uniformized over the full length of the bar 1. In a discharge light emitting bulb using bar 1, a positive electrode member 6 and a negative electrode member 7 are sealed in both end parts of a glass bulb 5 so as to be opposed to each other at prescribed intervals. Here, the member 6 is a tungsten polished bar having a smooth outer peripheral surface, and a nickel bar 8 is welded to the outside of the glass bulb. The member 7 is formed by sealing an emitter material 10 fixed to the vivinity of an inside terminal part of the bar 1 in the glass, and a nickel bar 9 is welded to the outside. Here, the bar 1 is inserted in and fastened to a hollow part of the emitter material 10.